tdpeuter/2025SELab2-project-Dwengo
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chore(backend): Aanpassingen Dwengo Learning-Object-Repository

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Processing uit Dwengo Learning-Object-Repository geconverteerd naar TypeScript en aangepast aan onze app.

Functionaliteit van Dwengo Learning-Object-Repository in ons project gekopiëerd en deels aanBestanden die enkel types of interfaces exporteren hernoemd naar *.d.tsgepast aan TypeScript en ons project.
This commit is contained in:
Gerald Schmittinger 2025-03-07 23:20:57 +01:00
parent ba3da01d2d
commit 463c8c9fc0
45 changed files with 1258 additions and 3747 deletions
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13
backend/src/controllers/learning-objects.ts
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@ -5,6 +5,8 @@ import learningObjectService from "../services/learning-objects/learning-object-
import {EnvVars, getEnvVar} from "../util/envvars";
import {Language} from "../entities/content/language";
import {BadRequestException} from "../exceptions";
import attachmentService from "../services/learning-objects/attachment-service";
import {NotFoundError} from "@mikro-orm/core";
function getLearningObjectIdentifierFromRequest(req: Request): LearningObjectIdentifier {
if (!req.params.hruid) {
@ -60,3 +62,14 @@ export async function getLearningObjectHTML(req: Request, res: Response): Promis
const learningObject = await learningObjectService.getLearningObjectHTML(learningObjectId);
res.send(learningObject);
}
export async function getAttachment(req: Request, res: Response): Promise<void> {
const learningObjectId = getLearningObjectIdentifierFromRequest(req);
const name = req.params.attachmentName;
const attachment = await attachmentService.getAttachment(learningObjectId, name);
if (!attachment) {
throw new NotFoundError(`Attachment ${name} not found`);
}
res.setHeader("Content-Type", attachment.mimeType).send(attachment.content)
}

39
backend/src/data/content/attachment-repository.ts
View file

@ -1,15 +1,40 @@
import { DwengoEntityRepository } from '../dwengo-entity-repository.js';
import { Attachment } from '../../entities/content/attachment.entity.js';
import { LearningObject } from '../../entities/content/learning-object.entity.js';
import {Language} from "../../entities/content/language";
import {LearningObjectIdentifier} from "../../entities/content/learning-object-identifier";
export class AttachmentRepository extends DwengoEntityRepository<Attachment> {
public findByLearningObjectAndNumber(
learningObject: LearningObject,
sequenceNumber: number
) {
public findByLearningObjectIdAndName(
learningObjectId: LearningObjectIdentifier,
name: string
): Promise<Attachment | null> {
return this.findOne({
learningObject: learningObject,
sequenceNumber: sequenceNumber,
learningObject: {
hruid: learningObjectId.hruid,
language: learningObjectId.language,
version: learningObjectId.version,
},
name: name,
});
}
public findByMostRecentVersionOfLearningObjectAndName(
hruid: string,
language: Language,
attachmentName: string
): Promise<Attachment | null> {
return this.findOne({
learningObject: {
hruid: hruid,
language: language
},
name: attachmentName
}, {
orderBy: {
learningObject: {
version: 'DESC'
}
}
});
}
// This repository is read-only for now since creating own learning object is an extension feature.

12
backend/src/data/content/learning-object-repository.ts
View file

@ -1,6 +1,7 @@
import { DwengoEntityRepository } from '../dwengo-entity-repository.js';
import { LearningObject } from '../../entities/content/learning-object.entity.js';
import { LearningObjectIdentifier } from '../../entities/content/learning-object-identifier.js';
import {Language} from "../../entities/content/language";
export class LearningObjectRepository extends DwengoEntityRepository<LearningObject> {
public findByIdentifier(
@ -12,5 +13,16 @@ export class LearningObjectRepository extends DwengoEntityRepository<LearningObj
version: identifier.version,
});
}
public findLatestByHruidAndLanguage(hruid: string, language: Language) {
return this.findOne({
hruid: hruid,
language: language
}, {
orderBy: {
version: "DESC"
}
});
}
// This repository is read-only for now since creating own learning object is an extension feature.
}

7
backend/src/entities/content/attachment.entity.ts
View file

@ -1,13 +1,14 @@
import { Entity, ManyToOne, PrimaryKey, Property } from '@mikro-orm/core';
import { LearningObject } from './learning-object.entity.js';
import {AttachmentRepository} from "../../data/content/attachment-repository";
@Entity()
@Entity({repository: () => AttachmentRepository})
export class Attachment {
@ManyToOne({ entity: () => LearningObject, primary: true })
learningObject!: LearningObject;
@PrimaryKey({ type: 'integer' })
sequenceNumber!: number;
@PrimaryKey({ type: 'string' })
name!: string;
@Property({ type: 'string' })
mimeType!: string;

184
backend/src/entities/content/language.ts
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@ -1,6 +1,186 @@
export enum Language {
Afar = 'aa',
Abkhazian = 'ab',
Afrikaans = 'af',
Akan = 'ak',
Albanian = 'sq',
Amharic = 'am',
Arabic = 'ar',
Aragonese = 'an',
Armenian = 'hy',
Assamese = 'as',
Avaric = 'av',
Avestan = 'ae',
Aymara = 'ay',
Azerbaijani = 'az',
Bashkir = 'ba',
Bambara = 'bm',
Basque = 'eu',
Belarusian = 'be',
Bengali = 'bn',
Bihari = 'bh',
Bislama = 'bi',
Bosnian = 'bs',
Breton = 'br',
Bulgarian = 'bg',
Burmese = 'my',
Catalan = 'ca',
Chamorro = 'ch',
Chechen = 'ce',
Chinese = 'zh',
ChurchSlavic = 'cu',
Chuvash = 'cv',
Cornish = 'kw',
Corsican = 'co',
Cree = 'cr',
Czech = 'cs',
Danish = 'da',
Divehi = 'dv',
Dutch = 'nl',
French = 'fr',
Dzongkha = 'dz',
English = 'en',
Germany = 'de',
Esperanto = 'eo',
Estonian = 'et',
Ewe = 'ee',
Faroese = 'fo',
Fijian = 'fj',
Finnish = 'fi',
French = 'fr',
Frisian = 'fy',
Fulah = 'ff',
Georgian = 'ka',
German = 'de',
Gaelic = 'gd',
Irish = 'ga',
Galician = 'gl',
Manx = 'gv',
Greek = 'el',
Guarani = 'gn',
Gujarati = 'gu',
Haitian = 'ht',
Hausa = 'ha',
Hebrew = 'he',
Herero = 'hz',
Hindi = 'hi',
HiriMotu = 'ho',
Croatian = 'hr',
Hungarian = 'hu',
Igbo = 'ig',
Icelandic = 'is',
Ido = 'io',
SichuanYi = 'ii',
Inuktitut = 'iu',
Interlingue = 'ie',
Interlingua = 'ia',
Indonesian = 'id',
Inupiaq = 'ik',
Italian = 'it',
Javanese = 'jv',
Japanese = 'ja',
Kalaallisut = 'kl',
Kannada = 'kn',
Kashmiri = 'ks',
Kanuri = 'kr',
Kazakh = 'kk',
Khmer = 'km',
Kikuyu = 'ki',
Kinyarwanda = 'rw',
Kirghiz = 'ky',
Komi = 'kv',
Kongo = 'kg',
Korean = 'ko',
Kuanyama = 'kj',
Kurdish = 'ku',
Lao = 'lo',
Latin = 'la',
Latvian = 'lv',
Limburgan = 'li',
Lingala = 'ln',
Lithuanian = 'lt',
Luxembourgish = 'lb',
LubaKatanga = 'lu',
Ganda = 'lg',
Macedonian = 'mk',
Marshallese = 'mh',
Malayalam = 'ml',
Maori = 'mi',
Marathi = 'mr',
Malay = 'ms',
Malagasy = 'mg',
Maltese = 'mt',
Mongolian = 'mn',
Nauru = 'na',
Navajo = 'nv',
SouthNdebele = 'nr',
NorthNdebele = 'nd',
Ndonga = 'ng',
Nepali = 'ne',
NorwegianNynorsk = 'nn',
NorwegianBokmal = 'nb',
Norwegian = 'no',
Chichewa = 'ny',
Occitan = 'oc',
Ojibwa = 'oj',
Oriya = 'or',
Oromo = 'om',
Ossetian = 'os',
Punjabi = 'pa',
Persian = 'fa',
Pali = 'pi',
Polish = 'pl',
Portuguese = 'pt',
Pashto = 'ps',
Quechua = 'qu',
Romansh = 'rm',
Romanian = 'ro',
Rundi = 'rn',
Russian = 'ru',
Sango = 'sg',
Sanskrit = 'sa',
Sinhala = 'si',
Slovak = 'sk',
Slovenian = 'sl',
NorthernSami = 'se',
Samoan = 'sm',
Shona = 'sn',
Sindhi = 'sd',
Somali = 'so',
Sotho = 'st',
Spanish = 'es',
Sardinian = 'sc',
Serbian = 'sr',
Swati = 'ss',
Sundanese = 'su',
Swahili = 'sw',
Swedish = 'sv',
Tahitian = 'ty',
Tamil = 'ta',
Tatar = 'tt',
Telugu = 'te',
Tajik = 'tg',
Tagalog = 'tl',
Thai = 'th',
Tibetan = 'bo',
Tigrinya = 'ti',
Tonga = 'to',
Tswana = 'tn',
Tsonga = 'ts',
Turkmen = 'tk',
Turkish = 'tr',
Twi = 'tw',
Uighur = 'ug',
Ukrainian = 'uk',
Urdu = 'ur',
Uzbek = 'uz',
Venda = 've',
Vietnamese = 'vi',
Volapuk = 'vo',
Welsh = 'cy',
Walloon = 'wa',
Wolof = 'wo',
Xhosa = 'xh',
Yiddish = 'yi',
Yoruba = 'yo',
Zhuang = 'za',
Zulu = 'zu'
}

2
backend/src/entities/content/learning-object.entity.ts
View file

@ -11,7 +11,7 @@ import {
import { Language } from './language.js';
import { Attachment } from './attachment.entity.js';
import { Teacher } from '../users/teacher.entity.js';
import {DwengoContentType} from "../../services/learning-objects/processing/content_type";
import {DwengoContentType} from "../../services/learning-objects/processing/content-type";
@Entity()
export class LearningObject {

8
backend/src/routes/learning-objects.ts
View file

@ -1,6 +1,6 @@
import express from 'express';
import {
getAllLearningObjects,
getAllLearningObjects, getAttachment,
getLearningObject, getLearningObjectHTML,
} from '../controllers/learning-objects.js';
@ -30,4 +30,10 @@ router.get('/:hruid', getLearningObject);
// Example: http://localhost:3000/learningObject/un_ai7/html
router.get('/:hruid/html', getLearningObjectHTML);
// Parameter: hruid of learning object, name of attachment.
// Query: language, version (optional).
// Route to get the raw data of the attachment for one learning object based on its hruid.
// Example: http://localhost:3000/learningObject/u_test/attachment/testimage.png
router.get('/:hruid/html/:attachmentName', getAttachment);
export default router;

21
backend/src/services/learning-objects/attachment-service.ts Normal file
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@ -0,0 +1,21 @@
import {getAttachmentRepository} from "../../data/repositories";
import {Attachment} from "../../entities/content/attachment.entity";
import {LearningObjectIdentifier} from "../../interfaces/learning-content";
const attachmentRepo = getAttachmentRepository();
const attachmentService = {
getAttachment(learningObjectId: LearningObjectIdentifier, attachmentName: string): Promise<Attachment | null> {
if (learningObjectId.version) {
return attachmentRepo.findByLearningObjectIdAndName({
hruid: learningObjectId.hruid,
language: learningObjectId.language,
version: learningObjectId.version,
}, attachmentName);
} else {
return attachmentRepo.findByMostRecentVersionOfLearningObjectAndName(learningObjectId.hruid, learningObjectId.language, attachmentName);
}
}
}
export default attachmentService;

23
backend/src/services/learning-objects/processing/audio/audio-processor.ts Normal file
View file

@ -0,0 +1,23 @@
/**
* Based on https://github.com/dwengovzw/Learning-Object-Repository/blob/main/app/processors/audio/audio_processor.js
*/
import Processor from "../processor.js";
import DOMPurify from 'isomorphic-dompurify';
import {type} from "node:os";
import {DwengoContentType} from "../content-type";
class AudioProcessor extends Processor<string> {
constructor() {
super(DwengoContentType.AUDIO_MPEG);
}
protected renderFn(audioUrl: string): string {
return DOMPurify.sanitize(`<audio controls>
<source src="${audioUrl}" type=${type}>
Your browser does not support the audio element.
</audio>`);
}
}
export default AudioProcessor;

82
backend/src/services/learning-objects/processing/audio/audio_processor.js
View file

@ -1,82 +0,0 @@
/**
* Based on
*/
import Processor from "../processor.ts";
import { isValidHttpUrl } from '../../utils/utils.js'
import { findFile } from '../../utils/file_io.js'
import InvalidArgumentError from '../../utils/invalid_argument_error.js'
import DOMPurify from 'isomorphic-dompurify';
import ProcessingHistory from "../../models/processing_history.js";
import path from "path"
import fs from "fs"
class AudioProcessor extends Processor {
constructor() {
super();
this.types = ["audio/mpeg"] // TODO add functionality to accept other audio types (ogg, wav)
}
/**
*
* @param {string} audioUrl
* @param {object} args Optional arguments specific to the render function of the AudioProcessor
* @returns
*/
render(audioUrl, args = { files: [], metadata: {} }) {
if ((!args.files || args.files.length <= 0 || !findFile(audioUrl, args.files)) && !isValidHttpUrl(audioUrl)) {
if (args.metadata && args.metadata.hruid && args.metadata.version && args.metadata.language){
ProcessingHistory.error(args.metadata.hruid, args.metadata.version, args.metadata.language, "The audio file cannot be found. Please check if the url is spelled correctly.")
}else{
ProcessingHistory.error("generalError", "99999999", "en", "The audio file cannot be found. Please check if the url is spelled correctly.")
}
throw new InvalidArgumentError("The audio file cannot be found. Please check if the url is spelled correctly.");
}
let type;
if (!args.metadata || !args.metadata.content_type || !this.types.includes(args.metadata.content_type)) {
type = this.types[0];
} else {
type = args.metadata.content_type;
}
if (isValidHttpUrl(audioUrl)) {
return DOMPurify.sanitize(`<audio controls>
<source src="${audioUrl}" type=${type}>
Your browser does not support the audio element.
</audio>`);
}
if (!args.metadata._id) {
throw new InvalidArgumentError("The metadata for for the object which uses the file '" + audioUrl + "' is not loaded in the processor.");
}
return DOMPurify.sanitize(`<audio controls>
<source src="@@URL_REPLACE@@/${process.env.LEARNING_OBJECT_STORAGE_NAME}/${args.metadata._id}/${audioUrl}" type=${type}>
Your browser does not support the audio element.
</audio>`);
}
processFiles(files, metadata){
let args = {}
let inputString = "";
let file = files.find((f) => {
let ext = path.extname(f.originalname);
if (ext == ".mp3") {
inputString = f["originalname"]
// add files to args to check if file exists
args.files = files;
args.metadata = metadata
return true;
}else{
return false;
}
});
return [this.render(inputString, args), files]
}
}
export default AudioProcessor;

83
backend/src/services/learning-objects/processing/blockly/blockly_processor.js
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@ -1,83 +0,0 @@
import Processor from "../processor.ts";
import { isValidHttpUrl } from '../../utils/utils.js'
import InvalidArgumentError from '../../utils/invalid_argument_error.js'
import DOMPurify from 'isomorphic-dompurify';
import Logger from "../../logger.js";
import path from "path"
let logger = Logger.getLogger()
class BlocklyProcessor extends Processor {
constructor() {
super();
this.blockly_base_url = process.env.SIMULATOR_READONLY_BASE_PATH;
}
/**
*
* @param {string} blocklyXml
* @param {object} args Optional arguments specific to the render function of the BlocklyProcessor
* @returns
*/
render(blocklyXml, args = { language: "nl", id: "" }, {height = 315, aspect_ratio = 'iframe-16-9'} = {}) {
if (!args.language || args.language.trim() == "") {
args.language = "nl";
}
if (!args.id || args.id.trim() == "") {
throw new InvalidArgumentError("The unique object id must be passed to the blockly processor.");
}
let languages = ["aa", "ab", "af", "ak", "sq", "am", "ar", "an", "hy", "as", "av", "ae", "ay", "az", "ba", "bm", "eu", "be", "bn", "bh", "bi", "bs", "br", "bg", "my", "ca", "ch", "ce", "zh", "cu", "cv", "kw", "co", "cr", "cs", "da", "dv", "nl", "dz", "en", "eo", "et", "ee", "fo", "fj", "fi", "fr", "fy", "ff", "ka", "de", "gd", "ga", "gl", "gv", "el", "gn", "gu", "ht", "ha", "he", "hz", "hi", "ho", "hr", "hu", "ig", "is", "io", "ii", "iu", "ie", "ia", "id", "ik", "it", "jv", "ja", "kl", "kn", "ks", "kr", "kk", "km", "ki", "rw", "ky", "kv", "kg", "ko", "kj", "ku", "lo", "la", "lv", "li", "ln", "lt", "lb", "lu", "lg", "mk", "mh", "ml", "mi", "mr", "ms", "mg", "mt", "mn", "na", "nv", "nr", "nd", "ng", "ne", "nn", "nb", "no", "ny", "oc", "oj", "or", "om", "os", "pa", "fa", "pi", "pl", "pt", "ps", "qu", "rm", "ro", "rn", "ru", "sg", "sa", "si", "sk", "sl", "se", "sm", "sn", "sd", "so", "st", "es", "sc", "sr", "ss", "su", "sw", "sv", "ty", "ta", "tt", "te", "tg", "tl", "th", "bo", "ti", "to", "tn", "ts", "tk", "tr", "tw", "ug", "uk", "ur", "uz", "ve", "vi", "vo", "cy", "wa", "wo", "xh", "yi", "yo", "za", "zu"];
if (!languages.includes(args.language)) {
throw new InvalidArgumentError("The language must be valid. " + args.language + " is not a supported language.")
}
if (typeof blocklyXml == 'undefined') {
throw new InvalidArgumentError("The blockly XML is undefined. Please provide correct XML code.")
}
let simulatorUrl = `${this.blockly_base_url}`
let form = `
<form action="${simulatorUrl}" method="post" id="blockly_form_${args.id}" target="blockly_iframe_${args.id}">
<input name="xml" type="hidden" value='${blocklyXml}'>
</form>
`
let iframe = `
<div class="iframe-container ${aspect_ratio}"><iframe name="blockly_iframe_${args.id}" height="530px" width="420px" allowfullscreen></iframe></div>
`
let code = `(function(){
var auto = setTimeout(function(){ submitform(); }, 50);
function submitform(){
document.forms["blockly_form_${args.id}"].submit();
}
})()
`
let script = `<script>${code}</script>`
let html = form + iframe // DOMPurify.sanitize(form + iframe, {ALLOW_UNKNOWN_PROTOCOLS: true, ADD_TAGS: ["iframe", "xml"], ADD_ATTR: ['allow', 'allowfullscreen', 'frameborder', 'scrolling', 'target']});
html = html + script;
return html; //TODO is not sanitized using DOMPurify.sanitize (problems with script tags)
}
processFiles(files, metadata){
let args = {}
let inputString = "";
let file = files.find((f) => {
let ext = path.extname(f.originalname);
if (ext == ".xml") {
inputString = f.buffer.toString('utf8');
args.language = metadata.language;
args.id = metadata._id;
return true;
}else{
return false;
}
});
return [this.render(inputString, args), files]
}
}
export default BlocklyProcessor;

0
backend/src/services/learning-objects/processing/content_type.ts → backend/src/services/learning-objects/processing/content-type.ts
View file

67
backend/src/services/learning-objects/processing/ct_schema/ct_schema_processor.js
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@ -1,67 +0,0 @@
import Logger from '../../logger.js';
import InvalidArgumentError from "../../utils/invalid_argument_error.js";
import { MarkdownProcessor } from '../markdown/markdown_processor.js';
class CTSchemaProcessor extends MarkdownProcessor{
logger = Logger.getLogger();
constructor(args = { files: [], metadata: {} }) {
super();
this.staticPath = `${process.env.DOMAIN_URL}${process.env.STATIC_BASE_PATH}/img/ct_schema/`;
}
/**
*
* @param {string} mdText a string containing the content for the four ct schema in markdown
* @returns The sanitized version of the generated html.
*/
render(text, args = {}) {
let html = "";
// 1. Split text into markdown parts for each CT aspect
// 2. Call super.render on the individual parts
// 3. Group the parts together with specific html structure
const regexObject = {
context: /<context>([\s\S]*?)<\/context>/,
decomp: /<decomposition>([\s\S]*?)<\/decomposition>/,
abstr: /<abstraction>([\s\S]*?)<\/abstraction>/,
pattern: /<patternRecognition>([\s\S]*?)<\/patternRecognition>/,
algo: /<algorithms>([\s\S]*?)<\/algorithms>/,
impl: /<implementation>([\s\S]*?)<\/implementation>/,
}
let htmlObject = {}
let htmlStructure = (valueObject) => `
<div class="ct_schema_container">
<div class="ct_context_container">${valueObject.context}</div>
<div class="ct_row1_container">
<div class="ct_decomposition_container">${valueObject.decomp}<div class="ct_logo"><img src="${this.staticPath + "decompositie.png"}"/></div></div>
<div class="ct_pattern_recognition_container">${valueObject.pattern}<div class="ct_logo"><img src="${this.staticPath + "patroonherkenning.png"}"/></div></div>
</div>
<div class="ct_row2_container">
<div class="ct_abstraction_container">${valueObject.abstr}<div class="ct_logo"><img src="${this.staticPath + "abstractie.png"}"/></div></div>
<div class="ct_algorithm_container">${valueObject.algo}<div class="ct_logo"><img src="${this.staticPath + "algoritme.png"}"/></div></div>
</div>
<div class="ct_implementation_container">${valueObject.impl}<div class="ct_logo"><img src="${this.staticPath + "decompositie.png"}"/></div></div>
</div>`
try {
for (let key in regexObject) {
let match = text.match(regexObject[key]);
if (match && match.length >= 1){
htmlObject[key] = super.render(match[1]);
}else{
htmlObject[key] = "";
}
}
} catch (e) {
throw new InvalidArgumentError(e.message);
return ""
}
return htmlStructure(htmlObject);
}
}
export { CTSchemaProcessor };

38
backend/src/services/learning-objects/processing/extern/extern-processor.ts vendored Normal file
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@ -0,0 +1,38 @@
/**
* Based on https://github.com/dwengovzw/Learning-Object-Repository/blob/main/app/processors/extern/extern_processor.js
*/
import Processor from "../processor.js";
import DOMPurify from 'isomorphic-dompurify';
import {ProcessingError} from "../processing-error";
import {isValidHttpUrl} from "../../../../util/links";
import {DwengoContentType} from "../content-type";
class ExternProcessor extends Processor<string> {
constructor() {
super(DwengoContentType.EXTERN);
}
override renderFn(externURL: string) {
if (!isValidHttpUrl(externURL)) {
throw new ProcessingError("The url is not valid: " + externURL);
}
// If a seperate youtube-processor would be added, this code would need to move to that processor
// Converts youtube urls to youtube-embed urls
let match = /(.*youtube.com\/)watch\?v=(.*)/.exec(externURL)
if (match) {
externURL = match[1] + "embed/" + match[2];
}
return DOMPurify.sanitize(`
<div class="iframe-container">
<iframe src="${externURL}" allowfullscreen></iframe>
</div>`,
{ ADD_TAGS: ["iframe"], ADD_ATTR: ['allow', 'allowfullscreen', 'frameborder', 'scrolling']}
);
}
}
export default ExternProcessor;

37
backend/src/services/learning-objects/processing/extern/extern_processor.js vendored
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@ -1,37 +0,0 @@
import Processor from "../processor.ts";
import { isValidHttpUrl } from '../../utils/utils.js'
import InvalidArgumentError from '../../utils/invalid_argument_error.js'
import DOMPurify from 'isomorphic-dompurify';
import Logger from "../../logger.js";
let logger = Logger.getLogger()
class ExternProcessor extends Processor {
constructor() {
super();
}
/**
*
* @param {string} externURL
* @param {object} args Optional arguments specific to the render function of the ExternProcessor
* @returns
*/
render(externURL, {height = 315, aspect_ratio = 'iframe-16-9'} = {}) {
if (!isValidHttpUrl(externURL)) {
throw new InvalidArgumentError("The url is not valid: " + externURL);
}
// If a seperate youtube-processor would be added, this code would need to move to that processor
// Converts youtube urls to youtube-embed urls
let match = /(.*youtube.com\/)watch\?v=(.*)/.exec(externURL)
if (match) {
externURL = match[1] + "embed/" + match[2];
}
return DOMPurify.sanitize(`<div class="iframe-container ${aspect_ratio}"><iframe width="420px" height="${height}px" src="${externURL}" allowfullscreen></iframe></div>`, { ADD_TAGS: ["iframe"], ADD_ATTR: ['allow', 'allowfullscreen', 'frameborder', 'scrolling']});
}
}
export default ExternProcessor;

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/**
* Based on https://github.com/dwengovzw/Learning-Object-Repository/blob/main/app/processors/gift/gift_processor.js
*/
import Processor from "../processor.js";
import DOMPurify from 'isomorphic-dompurify';
import {GIFTQuestion, parse} from "gift-pegjs"
import {DwengoContentType} from "../content-type";
import {GIFTQuestionRenderer} from "./question-renderers/gift-question-renderer";
import {MultipleChoiceQuestionRenderer} from "./question-renderers/multiple-choice-question-renderer";
import {CategoryQuestionRenderer} from "./question-renderers/category-question-renderer";
import {DescriptionQuestionRenderer} from "./question-renderers/description-question-renderer";
import {EssayQuestionRenderer} from "./question-renderers/essay-question-renderer";
import {MatchingQuestionRenderer} from "./question-renderers/matching-question-renderer";
import {NumericalQuestionRenderer} from "./question-renderers/numerical-question-renderer";
import {ShortQuestionRenderer} from "./question-renderers/short-question-renderer";
import {TrueFalseQuestionRenderer} from "./question-renderers/true-false-question-renderer";
class GiftProcessor extends Processor<string> {
private renderers: RendererMap = {
Category: new CategoryQuestionRenderer(),
Description: new DescriptionQuestionRenderer(),
Essay: new EssayQuestionRenderer(),
Matching: new MatchingQuestionRenderer(),
Numerical: new NumericalQuestionRenderer(),
Short: new ShortQuestionRenderer(),
TF: new TrueFalseQuestionRenderer(),
MC: new MultipleChoiceQuestionRenderer()
}
constructor() {
super(DwengoContentType.GIFT);
}
override renderFn(giftString: string) {
const quizQuestions: GIFTQuestion[] = parse(giftString);
let html = "<div class='gift'>";
for (let question of quizQuestions) {
html += this.renderQuestion(question);
}
html += "</div>"
return DOMPurify.sanitize(html);
}
private renderQuestion<T extends GIFTQuestion>(question: T): string {
const renderer = this.renderers[question.type] as GIFTQuestionRenderer<T>;
return renderer.render(question);
}
}
type RendererMap = {
[K in GIFTQuestion["type"]]: GIFTQuestionRenderer<Extract<GIFTQuestion, { type: K }>>
};
export default GiftProcessor;

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import Processor from "../processor.ts";
import { isValidHttpUrl } from '../../utils/utils.js'
import { findFile } from '../../utils/file_io.js'
import InvalidArgumentError from '../../utils/invalid_argument_error.js'
import DOMPurify from 'isomorphic-dompurify';
import ProcessingHistory from "../../models/processing_history.js";
import path from "path"
import fs from "fs"
import { parse } from "gift-pegjs"
class GiftProcessor extends Processor {
constructor() {
super();
this.types = ["text/gift"]
}
/**
*
* @param {string} audioUrl
* @param {object} args Optional arguments specific to the render function of the GiftProcessor
* @returns
*/
render(giftString, args = { }) {
const quizQuestions = parse(giftString);
console.log(quizQuestions);
return DOMPurify.sanitize(`<audio controls>
<source src="@@URL_REPLACE@@/>
Your browser does not support the audio element.
</audio>`);
}
processFiles(files, metadata){
let inputString = "";
let file = files.find((f) => {
let ext = path.extname(f.originalname);
if (ext == ".txt") {
inputString = f.buffer.toString('utf8');
return true;
}else{
return false;
}
});
return [this.render(inputString), files]
}
}
export default GiftProcessor;

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import {GIFTQuestionRenderer} from "./gift-question-renderer";
import {Category} from "gift-pegjs";
import {ProcessingError} from "../../processing-error";
export class CategoryQuestionRenderer extends GIFTQuestionRenderer<Category> {
render(question: Category): string {
throw new ProcessingError("The question type 'Category' is not supported yet!");
}
}

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import {GIFTQuestionRenderer} from "./gift-question-renderer";
import {Description} from "gift-pegjs";
import {ProcessingError} from "../../processing-error";
export class DescriptionQuestionRenderer extends GIFTQuestionRenderer<Description> {
render(question: Description): string {
throw new ProcessingError("The question type 'Description' is not supported yet!");
}
}

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import {GIFTQuestionRenderer} from "./gift-question-renderer";
import {Essay} from "gift-pegjs";
export class EssayQuestionRenderer extends GIFTQuestionRenderer<Essay> {
render(question: Essay): string {
return "";
}
}

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import {GIFTQuestion} from "gift-pegjs";
/**
* Subclasses of this class are renderers which can render a specific type of GIFT questions to HTML.
*/
export abstract class GIFTQuestionRenderer<T extends GIFTQuestion> {
/**
* Render the given question to HTML.
* @param question The question.
* @returns The question rendered as HTML.
*/
abstract render(question: T): string;
}

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import {GIFTQuestionRenderer} from "./gift-question-renderer";
import {Matching} from "gift-pegjs";
import {ProcessingError} from "../../processing-error";
export class MatchingQuestionRenderer extends GIFTQuestionRenderer<Matching> {
render(question: Matching): string {
throw new ProcessingError("The question type 'Matching' is not supported yet!");
}
}

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import {GIFTQuestionRenderer} from "./gift-question-renderer";
import {MultipleChoice} from "gift-pegjs";
export class MultipleChoiceQuestionRenderer extends GIFTQuestionRenderer<MultipleChoice> {
render(question: MultipleChoice): string {
return "";
}
}

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import {GIFTQuestionRenderer} from "./gift-question-renderer";
import {Numerical} from "gift-pegjs";
import {ProcessingError} from "../../processing-error";
export class NumericalQuestionRenderer extends GIFTQuestionRenderer<Numerical> {
render(question: Numerical): string {
throw new ProcessingError("The question type 'Numerical' is not supported yet!");
}
}

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import {GIFTQuestionRenderer} from "./gift-question-renderer";
import {ShortAnswer} from "gift-pegjs";
import {ProcessingError} from "../../processing-error";
export class ShortQuestionRenderer extends GIFTQuestionRenderer<ShortAnswer> {
render(question: ShortAnswer): string {
throw new ProcessingError("The question type 'ShortAnswer' is not supported yet!");
}
}

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import {GIFTQuestionRenderer} from "./gift-question-renderer";
import {TrueFalse} from "gift-pegjs";
import {ProcessingError} from "../../processing-error";
export class TrueFalseQuestionRenderer extends GIFTQuestionRenderer<TrueFalse> {
render(question: TrueFalse): string {
throw new ProcessingError("The question type 'TrueFalse' is not supported yet!");
}
}

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/**
* Based on https://github.com/dwengovzw/Learning-Object-Repository/blob/main/app/processors/image/block_image_processor.js
*/
import InlineImageProcessor from "./inline-image-processor.js"
import DOMPurify from 'isomorphic-dompurify';
class BlockImageProcessor extends InlineImageProcessor {
constructor(){
super();
}
override renderFn(imageUrl: string){
let inlineHtml = super.render(imageUrl);
return DOMPurify.sanitize(`<div>${inlineHtml}</div>`);
}
}
export default BlockImageProcessor;

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import InlineImageProcessor from "./inline_image_processor.js"
import DOMPurify from 'isomorphic-dompurify';
import path from 'path'
class BlockImageProcessor extends InlineImageProcessor{
constructor(){
super();
}
/**
*
* @param {string} imageUrl
* @param {object} args Optional arguments specific to the render function of the BlockImageProcessor
* @returns
*/
render(imageUrl, args = { altText: ""}){
let inlineHtml = super.render(imageUrl, args);
return DOMPurify.sanitize(`<div>${inlineHtml}</div>`);
}
}
export default BlockImageProcessor;

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/**
* Based on https://github.com/dwengovzw/Learning-Object-Repository/blob/main/app/processors/image/inline_image_processor.js
*/
import Processor from "../processor.js";
import DOMPurify from 'isomorphic-dompurify';
import {DwengoContentType} from "../content-type.js";
import {ProcessingError} from "../processing-error.js";
import {isValidHttpUrl} from "../../../../util/links";
class InlineImageProcessor extends Processor<string> {
constructor(contentType: DwengoContentType = DwengoContentType.IMAGE_INLINE) {
super(contentType);
}
override renderFn(imageUrl: string) {
if (!isValidHttpUrl(imageUrl)) {
throw new ProcessingError(`Image URL is invalid: ${imageUrl}`);
}
return DOMPurify.sanitize(`<img src="${imageUrl}" alt="">`);
}
}
export default InlineImageProcessor;

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import Processor from "../processor.ts";
import { isValidHttpUrl } from '../../utils/utils.js'
import InvalidArgumentError from '../../utils/invalid_argument_error.js'
import DOMPurify from 'isomorphic-dompurify';
import ProcessingHistory from "../../models/processing_history.js";
import path from "path"
class InlineImageProcessor extends Processor {
constructor() {
super();
}
/**
*
* @param {string} imageUrl
* @param {object} args Optional arguments specific to the render function of the InlineImageProcessor
* @returns
*/
render(imageUrl, args = { altText: "", metadata: {} }) {
if (!isValidHttpUrl(imageUrl) && (!imageUrl || !imageUrl.toLowerCase().match(/^(?!http.*$)[^.].*\.(jpe?g|png|svg|gif)/))) {
if (args.metadata && args.metadata.hruid && args.metadata.version && args.metadata.language){
ProcessingHistory.error(args.metadata.hruid, args.metadata.version, args.metadata.language, "The image cannot be found. Please check if the url is spelled correctly.")
}else{
ProcessingHistory.error("generalError", "99999999", "en", "The image cannot be found. Please check if the url is spelled correctly.")
}
throw new InvalidArgumentError("The image cannot be found. Please check if the url is spelled correctly.");
}
if (typeof args.altText == 'undefined') {
args.altText = "";
}
if (isValidHttpUrl(imageUrl)) {
return DOMPurify.sanitize(`<img src="${imageUrl}" alt="${args.altText}">`);
}
if (!args.metadata._id) {
throw new InvalidArgumentError("The metadata for for the object which uses the file '" + imageUrl + "' is not loaded in the processor.");
}
return DOMPurify.sanitize(`<img src="@@URL_REPLACE@@/${process.env.LEARNING_OBJECT_STORAGE_NAME}/${args.metadata._id}/${imageUrl}" alt="${args.altText}">`);
}
processFiles(files, metadata){
let args = {};
let inputString = "";
let file = files.find((f) => {
let ext = path.extname(f.originalname);
if (ext.match(/\.(jpe?g)|(png)|(svg)$/)){
inputString = f["originalname"];
args.metadata = metadata
return true;
}else{
return false;
}
});
return [this.render(inputString, args), files]
}
}
export default InlineImageProcessor;

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import Processor from "../processor.ts";
class LearningObjectProcessor extends Processor {
constructor() {
super();
}
/**
*
* @param {string} learningObjectId
* @param {object} args Optional arguments
* @returns
*/
render(objectString, args = {}) {
return `@@OBJECT_REPLACE/${objectString}@@`;
}
}
export default LearningObjectProcessor;

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import LearningObjectProcessor from "../learning_object/learing_object_processor.js";
import PdfProcessor from "../pdf/pdf_processor.js";
import AudioProcessor from "../audio/audio_processor.js";
import ExternProcessor from "../extern/extern_processor.js";
import BlocklyProcessor from "../blockly/blockly_processor.js";
import { findFile } from "../../utils/file_io.js";
import InlineImageProcessor from "../image/inline_image_processor.js";
import { isValidHttpUrl } from "../../utils/utils.js";
import ProcessingHistory from "../../models/processing_history.js";
class LearningObjectMarkdownRenderer {
learingObjectPrefix = '@learning-object';
pdfPrefix = '@pdf';
audioPrefix = '@audio';
externPrefix = '@extern';
videoPrefix = '@youtube';
notebookPrefix = '@notebook';
blocklyPrefix = '@blockly';
constructor(args = { files: [], metadata: {} }) {
this.args = args;
}
heading(text, level) {
const escapedText = text.toLowerCase().replace(/[^\w]+/g, '-');
return `
<h${level}>
<a name="${escapedText}" class="anchor" href="#${escapedText}">
<span class="header-link"></span>
</a>
${text}
</h${level}>`;
};
// When the syntax for a link is used => [text](href "title")
// render a custom link when the prefix for a learning object is used.
link(href, title, text) {
if (href.startsWith(this.learingObjectPrefix)) {
// link to learning-object
let query = href.split(/\/(.+)/, 2)[1].split("/")
return `<a href="@@URL_REPLACE@@/api/learningObject/getRaw?hruid=${query[0]}&language=${query[1]}&version=${query[2]}&redirect=true" target="_blank" title="${title}">${text}</a>`
} else if (href.startsWith(this.blocklyPrefix)) {
// link to blockly (downloads)
if (title) {
return `<a href="@@URL_REPLACE@@/api/learningObject/downloadFile/${process.env.LEARNING_OBJECT_STORAGE_NAME}/${this.args.metadata._id}/${href.split(/\/(.+)/, 2)[1]}" target="_blank" title="${title}">${text}</a>`
}
return `<a href="@@URL_REPLACE@@/api/learningObject/downloadFile/${process.env.LEARNING_OBJECT_STORAGE_NAME}/${this.args.metadata._id}/${href.split(/\/(.+)/, 2)[1]}" target="_blank">${text}</a>`
} else {
// any other link
if (isValidHttpUrl(href)) {
return `<a href="${href}" target="_blank" title="${title}">${text}</a>`;
} else {
if (title) {
return `<a href="@@URL_REPLACE@@/${process.env.LEARNING_OBJECT_STORAGE_NAME}/${this.args.metadata._id}/${href}" target="_blank" title="${title}">${text}</a>`
}
return `<a href="@@URL_REPLACE@@/${process.env.LEARNING_OBJECT_STORAGE_NAME}/${this.args.metadata._id}/${href}" target="_blank" >${text}</a>`
}
}
};
// When the syntax for an image is used => ![text](href "title")
// render a learning object, pdf, audio or video if a prefix is used.
image(href, title, text) {
if (href.startsWith(this.learingObjectPrefix)) {
// embedded learning-object
let proc = new LearningObjectProcessor();
return proc.render(href.split(/\/(.+)/, 2)[1]);
} else if (href.startsWith(this.pdfPrefix)) {
// embedded pdf
let proc = new PdfProcessor();
return proc.render(href.split(/\/(.+)/, 2)[1], { files: this.args.files, metadata: this.args.metadata });
} else if (href.startsWith(this.audioPrefix)) {
// embedded audio
let proc = new AudioProcessor();
return proc.render(href.split(/\/(.+)/, 2)[1], { files: this.args.files, metadata: this.args.metadata });
} else if (href.startsWith(this.externPrefix) || href.startsWith(this.videoPrefix) || href.startsWith(this.notebookPrefix)) {
// embedded youtube video or notebook (or other extern content)
let proc = new ExternProcessor();
return proc.render(href.split(/\/(.+)/, 2)[1]);
} else if (href.startsWith(this.blocklyPrefix)) {
// embedded blockly program
let proc = new BlocklyProcessor();
if (this.args.files) {
let file = findFile(href.split(/\/(.+)/, 2)[1], this.args.files)
if (file) {
return proc.render(file.buffer, { language: this.args.metadata.language ? this.args.metadata.language : "nl", id: this.args.metadata._id });
}
}
ProcessingHistory.error("generalError", "99999999", "en", `"The blockly preview with reference ${href} could not be loaded. Are you sure the correct xml file was passed?`)
return "";
}/*else if (href.startsWith(this.learingObjectPrefix)){
let [hruid, version, language] = href.split(/\/(.+)/, 2)[1].split("/")
return learningObjectApiController.getHtmlObject({hruid: hruid, version: version, language: language})
}*/ else {
// embedded image
let proc = new InlineImageProcessor();
return proc.render(href, { metadata: this.args.metadata })
}
};
}
export default LearningObjectMarkdownRenderer

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import PdfProcessor from "../pdf/pdf-processor.js";
import AudioProcessor from "../audio/audio-processor.js";
import ExternProcessor from "../extern/extern-processor.js";
import InlineImageProcessor from "../image/inline-image-processor.js";
import {RendererObject, Tokens} from "marked";
import {getUrlStringForLearningObject, isValidHttpUrl} from "../../../../util/links";
import {ProcessingError} from "../processing-error";
import {LearningObjectIdentifier} from "../../../../interfaces/learning-content";
import {Language} from "../../../../entities/content/language";
import Image = Tokens.Image;
import Heading = Tokens.Heading;
import Link = Tokens.Link;
const prefixes = {
learningObject: '@learning-object',
pdf: '@pdf',
audio: '@audio',
extern: '@extern',
video: '@youtube',
notebook: '@notebook',
blockly: '@blockly',
};
function extractLearningObjectIdFromHref(href: string): LearningObjectIdentifier {
const [hruid, language, version] = href.split(/\/(.+)/, 2)[1].split("/");
return {hruid, language: language as Language, version};
}
/**
* An extension for the renderer of the Marked Markdown renderer which adds support for
* - a custom heading,
* - links to other learning objects,
* - embeddings of other learning objects.
*/
const dwengoMarkedRenderer: RendererObject = {
heading(heading: Heading) {
const text = heading.text;
const level = heading.depth;
const escapedText = text.toLowerCase().replace(/[^\w]+/g, '-');
return `
<h${level}>
<a name="${escapedText}" class="anchor" href="#${escapedText}">
<span class="header-link"></span>
</a>
${text}
</h${level}>`;
},
// When the syntax for a link is used => [text](href "title")
// render a custom link when the prefix for a learning object is used.
link(link: Link) {
const href = link.href;
const title = link.title || "";
const text = link.text;
if (href.startsWith(prefixes.learningObject)) {
// link to learning-object
const learningObjectId = extractLearningObjectIdFromHref(href);
return `
<a href="${getUrlStringForLearningObject(learningObjectId)}]" target="_blank" title="${title}">${text}</a>
`;
} else {
// any other link
if (!isValidHttpUrl(href)) {
throw new ProcessingError("Link is not a valid HTTP URL!");
}
return `<a href="${href}" target="_blank" title="${title}">${text}</a>`;
}
},
// When the syntax for an image is used => ![text](href "title")
// render a learning object, pdf, audio or video if a prefix is used.
image(img: Image) {
const href = img.href;
if (href.startsWith(prefixes.learningObject)) {
// embedded learning-object
const learningObjectId = extractLearningObjectIdFromHref(href);
return `
<learning-object hruid="${learningObjectId.hruid}" language="${learningObjectId.language}" version="${learningObjectId.version}"/>
`; // Placeholder for the learning object since we cannot fetch its HTML here (this has to be a sync function!)
} else if (href.startsWith(prefixes.pdf)) {
// embedded pdf
let proc = new PdfProcessor();
return proc.render(href.split(/\/(.+)/, 2)[1]);
} else if (href.startsWith(prefixes.audio)) {
// embedded audio
let proc = new AudioProcessor();
return proc.render(href.split(/\/(.+)/, 2)[1]);
} else if (href.startsWith(prefixes.extern) || href.startsWith(prefixes.video) || href.startsWith(prefixes.notebook)) {
// embedded youtube video or notebook (or other extern content)
let proc = new ExternProcessor();
return proc.render(href.split(/\/(.+)/, 2)[1]);
} else {
// embedded image
let proc = new InlineImageProcessor();
return proc.render(href)
}
},
}
export default dwengoMarkedRenderer;

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/**
* Based on https://github.com/dwengovzw/Learning-Object-Repository/blob/main/app/processors/markdown/markdown_processor.js
* and https://github.com/dwengovzw/Learning-Object-Repository/blob/main/app/processors/markdown/learing_object_markdown_renderer.js [sic!]
*/
import {marked} from 'marked'
import Processor from '../processor.js';
import InlineImageProcessor from '../image/inline-image-processor.js';
import {DwengoContentType} from "../content-type";
import {ProcessingError} from "../processing-error";
import dwengoMarkedRenderer from "./learning-object-markdown-renderer";
class MarkdownProcessor extends Processor<string> {
constructor() {
super(DwengoContentType.TEXT_MARKDOWN);
}
override renderFn(mdText: string) {
let html = "";
try {
mdText = this.replaceLinks(mdText); // Replace html image links with path based on metadata
marked.use({renderer: dwengoMarkedRenderer});
html = marked(mdText, {async: false});
} catch (e: any) {
throw new ProcessingError(e.message);
}
return html;
}
replaceLinks(html: string) {
let proc = new InlineImageProcessor();
html = html.replace(/<img.*?src="(.*?)".*?(alt="(.*?)")?.*?(title="(.*?)")?.*?>/g, (
match: string,
src: string,
alt: string,
altText: string,
title: string,
titleText: string
) => {
return proc.render(src);
});
return html;
}
}
export { MarkdownProcessor };

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import { marked } from 'marked'
import DOMPurify from 'isomorphic-dompurify';
import LearningObjectMarkdownRenderer from './learing_object_markdown_renderer.js';
import ObjectConverter from '../../utils/object_converter.js';
import yaml from "js-yaml"
import Logger from '../../logger.js';
import Processor from '../processor.ts';
import InvalidArgumentError from "../../utils/invalid_argument_error.js";
import ProcessingHistory from '../../models/processing_history.js';
import path from "path";
import InlineImageProcessor from '../image/inline_image_processor.js';
class MarkdownProcessor extends Processor {
logger = Logger.getLogger();
constructor(args = { files: [], metadata: {} }) {
super();
}
/**
*
* @param {string} mdText Plain markdown string to be converted to html. May contain links to learning objects which results in recursive processing.
* @returns The sanitized version of the generated html.
*/
render(mdText, args = {metadata: {}}) {
let html = "";
try {
mdText = this.replaceLinks(mdText, args.metadata); // Replace html image links with path based on metadata
html = marked(mdText); //DOMPurify.sanitize(marked(mdText), { ADD_TAGS: ["embed", "iframe", "script"] });
} catch (e) {
throw new InvalidArgumentError(e.message);
}
return html;
}
replaceLinks(html, metadata) {
let proc = new InlineImageProcessor();
html = html.replace(/<img.*?src="(.*?)".*?(alt="(.*?)")?.*?(title="(.*?)")?.*?>/g, (match, src, alt, altText, title, titleText) => {
return proc.render(src, { metadata: metadata, altText: altText || "No alt text", title: titleText || "No title" });
});
return html;
}
/**
*
* @param {string} mdTextWithYAMLMeta Markdown string with metadata. Compatible with jekyll (https://jekyllrb.com/docs/front-matter/)
* @returns {object} {original input, metadata string, }
*/
static stripYAMLMetaData(mdTextWithYAMLMeta) {
let trimmedInput = mdTextWithYAMLMeta.trim();
const metadataregex = /(?<=^---).+?(?=---)/s
const mdregex = /(?<=---.*---).+?$/s
let metadataText = trimmedInput.match(metadataregex);
let mdText = "";
if (metadataText) {
// Yes, metadata
metadataText = metadataText[0].trim();
mdText = trimmedInput.match(mdregex);
mdText = mdText ? mdText[0].trim() : "";
} else {
// No metadata
metadataText = "";
mdText = trimmedInput;
}
let metadata = {};
try {
metadata = yaml.load(metadataText);
} catch (e) {
ProcessingHistory.error("generalError", "99999999", "en", `Unable to convert metadata to YAML: ${e}`)
}
return {
original: mdTextWithYAMLMeta,
metadata: metadata,
markdown: mdText
}
}
processFiles(files, metadata){
let resfiles = [];
let inputString = "";
let file = files.find((f) => {
let ext = path.extname(f.originalname);
if (ext == ".md"){
inputString = f.buffer.toString('utf8');
resfiles = files;
return true;
}else{
return false;
}
});
// Remove index.md file to create a list of files for checking during rendering process
let filtered = files.filter((f) => {
let ignoreregex = /(.*index\.md)|(^\..*)$/;
return !f["originalname"].match(ignoreregex);
})
// Strip metadata from content
let splitdata = MarkdownProcessor.stripYAMLMetaData(inputString)
// A bit stupid but marked does not work with an instance of a class only with plain object
const renderer = new ObjectConverter().toJSON(new LearningObjectMarkdownRenderer({ files: filtered, metadata: metadata }));
marked.use({ renderer });
return [this.render(splitdata.markdown, {metadata: metadata}), resfiles]
}
}
export { MarkdownProcessor };

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@ -0,0 +1,28 @@
/**
* Based on https://github.com/dwengovzw/Learning-Object-Repository/blob/main/app/processors/pdf/pdf_processor.js
*/
import Processor from "../processor.js";
import DOMPurify from 'isomorphic-dompurify';
import {DwengoContentType} from "../content-type.js";
import {isValidHttpUrl} from "../../../../util/links.js";
import {ProcessingError} from "../processing-error.js";
class PdfProcessor extends Processor<string> {
constructor() {
super(DwengoContentType.APPLICATION_PDF);
}
override renderFn(pdfUrl: string) {
if (!isValidHttpUrl(pdfUrl)) {
throw new ProcessingError(`PDF URL is invalid: ${pdfUrl}`);
}
return DOMPurify.sanitize(`
<embed src="${pdfUrl}" type="application/pdf" width="100%" height="800px"/>
`, { ADD_TAGS: ["embed"] }
);
}
}
export default PdfProcessor;

63
backend/src/services/learning-objects/processing/pdf/pdf_processor.js
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@ -1,63 +0,0 @@
import Processor from "../processor.ts";
import { isValidHttpUrl } from '../../utils/utils.js'
import { findFile } from '../../utils/file_io.js'
import InvalidArgumentError from '../../utils/invalid_argument_error.js'
import DOMPurify from 'isomorphic-dompurify';
import ProcessingHistory from "../../models/processing_history.js";
import path from "path"
class PdfProcessor extends Processor {
constructor() {
super();
}
/**
*
* @param {string} pdfUrl
* @param {object} args Optional arguments specific to the render function of the PdfProcessor
* @returns
*/
render(pdfUrl, args = { files: [], metadata: {} }) {
if ((!args.files || args.files.length <= 0 || !findFile(pdfUrl, args.files)) && !isValidHttpUrl(pdfUrl)) {
let errormessage = `The pdf file ${pdfUrl} cannot be found. Please check if the url is spelled correctly.`
if (args.metadata && args.metadata.hruid && args.metadata.version && args.metadata.language){
ProcessingHistory.error(args.metadata.hruid, args.metadata.version, args.metadata.language, errormessage)
}else{
ProcessingHistory.error("generalError", "99999999", "en", errormessage)
}
throw new InvalidArgumentError("The pdf file cannot be found. Please check if the url is spelled correctly.");
}
if (isValidHttpUrl(pdfUrl)) {
return DOMPurify.sanitize(`<embed src="${pdfUrl}" type="application/pdf" width="100%" height="800px"/>`, { ADD_TAGS: ["embed"] })
}
if (!args.metadata || !args.metadata._id) {
throw new InvalidArgumentError("The metadata for for the object which uses the file '" + pdfUrl + "' is not loaded in the processor.");
}
return DOMPurify.sanitize(`<embed src="@@URL_REPLACE@@/${process.env.LEARNING_OBJECT_STORAGE_NAME}/${args.metadata._id}/${pdfUrl}" type="application/pdf" width="100%" height="800px"/>`, { ADD_TAGS: ["embed"] })
}
processFiles(files, metadata){
let args = {}
let inputString = "";
let file = files.find((f) => {
let ext = path.extname(f.originalname);
if (ext == ".pdf") {
inputString = f["originalname"]
// add files to args to check if file exists
args.files = files;
args.metadata = metadata
return true;
}else{
return false;
}
});
return [this.render(inputString, args), files]
}
}
export default PdfProcessor;

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/**
* Based on https://github.com/dwengovzw/Learning-Object-Repository/blob/main/app/processors/processing_proxy.js
*/
import BlockImageProcessor from "./image/block-image-processor.js";
import InlineImageProcessor from "./image/inline-image-processor.js";
import { MarkdownProcessor } from "./markdown/markdown-processor.js";
import TextProcessor from "./text/text-processor.js";
import AudioProcessor from "./audio/audio-processor.js";
import PdfProcessor from "./pdf/pdf-processor.js";
import ExternProcessor from "./extern/extern-processor.js";
import GiftProcessor from "./gift/gift-processor.js";
import {LearningObject} from "../../../entities/content/learning-object.entity";
import Processor from "./processor";
import {DwengoContentType} from "./content-type";
import {LearningObjectIdentifier} from "../../../interfaces/learning-content";
import {Language} from "../../../entities/content/language";
const EMBEDDED_LEARNING_OBJECT_PLACEHOLDER = /<learning-object hruid="([^"]+)" language="([^"]+)" version="([^"]+)"\/>/g;
class ProcessingService {
private processors!: Map<DwengoContentType, Processor<any>>;
constructor() {
const processors = [
new InlineImageProcessor(),
new BlockImageProcessor(),
new MarkdownProcessor(),
new TextProcessor(),
new AudioProcessor(),
new PdfProcessor(),
new ExternProcessor(),
new GiftProcessor()
];
processors.forEach(processor => {
this.processors.set(processor.contentType, processor);
});
}
/**
* Render the given learning object.
* @param learningObject The learning object to render
* @param fetchEmbeddedLearningObjects A function which takes a learning object identifier as an argument and
* returns the corresponding learning object. This is used to fetch learning
* objects embedded into this one.
* If this argument is omitted, embedded learning objects will be represented
* by placeholders.
* @returns Rendered HTML for this LearningObject as a string.
*/
render(learningObject: LearningObject, fetchEmbeddedLearningObjects?: (loId: LearningObjectIdentifier) => LearningObject): string {
let html = this.processors.get(learningObject.contentType)!.renderLearningObject(learningObject);
if (fetchEmbeddedLearningObjects) {
// Replace all embedded learning objects.
return html.replace(
EMBEDDED_LEARNING_OBJECT_PLACEHOLDER,
(_, hruid: string, language: string, version: string): string => {
// Fetch the embedded learning object...
const learningObject = fetchEmbeddedLearningObjects({hruid, language: language as Language, version})
// ... and render it.
return this.render(learningObject);
}
);
}
return html;
}
}
export default ProcessingService;

50
backend/src/services/learning-objects/processing/processing_service.ts
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@ -1,50 +0,0 @@
/**
* Based on https://github.com/dwengovzw/Learning-Object-Repository/blob/main/app/processors/processing_proxy.js
*/
import BlockImageProcessor from "./image/block_image_processor.js";
import InlineImageProcessor from "./image/inline_image_processor.js";
import { CTSchemaProcessor } from "./ct_schema/ct_schema_processor.js";
import { MarkdownProcessor } from "./markdown/markdown_processor.js";
import TextProcessor from "./text/text_processor.js";
import AudioProcessor from "./audio/audio_processor.js";
import PdfProcessor from "./pdf/pdf_processor.js";
import ExternProcessor from "./extern/extern_processor.js";
import BlocklyProcessor from "./blockly/blockly_processor.js";
import GiftProcessor from "./gift/gift_processor.js";
import {LearningObject} from "../../../entities/content/learning-object.entity";
import Processor from "./processor";
import {DwengoContentType} from "./content_type";
class ProcessingService {
private processors!: Map<DwengoContentType, Processor<any>>;
constructor() {
const processors = [
new InlineImageProcessor(),
new BlockImageProcessor(),
new MarkdownProcessor(),
new TextProcessor(),
new AudioProcessor(),
new PdfProcessor(),
new ExternProcessor(),
new BlocklyProcessor(),
new GiftProcessor(),
new CTSchemaProcessor()
];
processors.forEach(processor => {
this.processors.set(processor.contentType, processor);
});
}
/**
* Render the given learning object.
* @param learningObject
*/
render(learningObject: LearningObject): string {
return this.processors.get(learningObject.contentType)!.renderLearningObject(learningObject);
}
}
export default ProcessingService;

15
backend/src/services/learning-objects/processing/processor.ts
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@ -1,6 +1,6 @@
import {LearningObject} from "../../../entities/content/learning-object.entity";
import {ProcessingError} from "./processing-error";
import {DwengoContentType} from "./content_type";
import {DwengoContentType} from "./content-type";
/**
* Abstract base class for all processors.
@ -19,7 +19,9 @@ abstract class Processor<T> {
* @return Rendered HTML-string
* @throws ProcessingError if the rendering fails.
*/
abstract render(toRender: T): string;
render(toRender: T): string {
return this.renderFn(toRender);
}
/**
* Render a learning object with the content type for which this processor is responsible.
@ -35,6 +37,15 @@ abstract class Processor<T> {
return this.renderLearningObjectFn(toRender);
}
/**
* Function which actually renders the content.
*
* @param toRender Content to be rendered
* @return Rendered HTML as a string
* @protected
*/
protected abstract renderFn(toRender: T): string;
/**
* Function which actually executes the rendering of a learning object.
* By default, this just means rendering the content in the content property of the learning object.

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/**
* Based on https://github.com/dwengovzw/Learning-Object-Repository/blob/main/app/processors/text/text_processor.js
*/
import DOMPurify from 'isomorphic-dompurify'
import Processor from "../processor.js"
import {DwengoContentType} from "../content-type.js";
class TextProcessor extends Processor<string> {
constructor() {
super(DwengoContentType.TEXT_PLAIN);
}
override renderFn(text: string) {
// Sanitize plain text to prevent xss.
return DOMPurify.sanitize(text);
}
}
export default TextProcessor;

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backend/src/services/learning-objects/processing/text/text_processor.js
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@ -1,36 +0,0 @@
import DOMPurify from 'isomorphic-dompurify'
import Processor from "../processor.ts"
import path from "path"
class TextProcessor extends Processor {
constructor() {
super();
}
/**
*
* @param {string} plain text
* @param {object} args Optional arguments
* @returns
*/
render(text, args = {}) {
// Sanitize plain text to prevent xss.
return DOMPurify.sanitize(text);
}
processFiles(files, metadata){
let inputString = "";
let file = files.find((f) => {
let ext = path.extname(f.originalname);
if (ext == ".txt") {
inputString = f.buffer.toString('utf8');
return true;
}else{
return false;
}
});
return [this.render(inputString), files]
}
}
export default TextProcessor;

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import {LearningObjectIdentifier} from "../interfaces/learning-content";
export function isValidHttpUrl(url: string): boolean {
try {
const parsedUrl = new URL(url);
return parsedUrl.protocol === "http:" || parsedUrl.protocol === "https:";
} catch (e) {
return false;
}
}
export function getUrlStringForLearningObject(learningObjectIdentifier: LearningObjectIdentifier): string {
let url = `/learningObject/${learningObjectIdentifier.hruid}/html?language=${learningObjectIdentifier.language}`;
if (learningObjectIdentifier.version) {
url += `&version=${learningObjectIdentifier.version}`;
}
return url;
}