models/assessment.js

   1 const CourseModel = require("../models/course");
   2 const UserModel = require("../models/user");
   3 const ObjectId = require("bson-objectid");
   4 const TokenGen = require("../utils/tokenGenerator");
   5 const db = require("../utils/database");
   6
   7 const AssessmentModel =
   8 {
   9     /*
  10      * Structure:
  11      *   _id: BSON id
  12      *   cid: course ID
  13      *   name: varchar
  14      *   active: boolean true/false
  15      *   mode: secure | exam | open (decreasing security)
  16      *   fixed: bool (questions in fixed order; default: false)
  17      *   display: "one" or "all" (generally "all" for open questions, but...)
  18      *   time: 0, //<=0 means "untimed"; otherwise, time in seconds
  19      *   introduction: "",
  20      *   coefficient: number, default 1
  21      *   questions: array of
  22      *     index: for paper test, like 2.1.a (?!); and quiz: 0, 1, 2, 3...
  23      *     wording: varchar (HTML)
  24      *     options: array of varchar --> if present, question type == quiz!
  25      *     fixed: bool, options in fixed order (default: false)
  26      *     answer: array of integers (for quiz) or html text (for paper); striped in exam mode
  27      *     active: boolean, is question in current assessment?
  28      *     points: points for this question (default 1)
  29      *     time: 0 (<=0: untimed)
  30      *   papers : array of
  31      *     number: student number
  32      *     inputs: array of {index,answer[array of integers or html text],startTime}
  33      *     current: index of current question (if relevant: display="one")
  34      *     startTime
  35      *     discoTime, totalDisco: last disconnect timestamp (if relevant) + total time
  36      *     discoCount: number of disconnections
  37      *     password: random string identifying student for exam session TEMPORARY
  38      */
  39
  40     //////////////////
  41     // BASIC FUNCTIONS
  42
  43     getById: function(aid, callback)
  44     {
  45         db.assessments.findOne(
  46             { _id: aid },
  47             callback
  48         );
  49     },
  50
  51     getByPath: function(cid, name, callback)
  52     {
  53         db.assessments.findOne(
  54             {
  55                 cid: cid,
  56                 name: name,
  57             },
  58             callback
  59         );
  60     },
  61
  62     insert: function(cid, name, callback)
  63     {
  64         db.assessments.insert(
  65             {
  66                 name: name,
  67                 cid: cid,
  68                 active: false,
  69                 mode: "exam",
  70                 fixed: false,
  71                 display: "one",
  72                 time: 0,
  73                 introduction: "",
  74                 coefficient: 1,
  75                 questions: [ ],
  76                 papers: [ ],
  77             },
  78             callback
  79         );
  80     },
  81
  82     getByCourse: function(cid, callback)
  83     {
  84         db.assessments.find(
  85             { cid: cid },
  86             callback
  87         );
  88     },
  89
  90     // arg: full assessment without _id field
  91     replace: function(aid, assessment, cb)
  92     {
  93         // Should be: (but unsupported by mongojs)
  94 //      db.assessments.replaceOne(
  95 //          { _id: aid },
  96 //          assessment,
  97 //          cb
  98 //      );
  99         // Temporary workaround:
 100         db.assessments.update(
 101             { _id: aid },
 102             { $set: assessment },
 103             cb
 104         );
 105     },
 106
 107     getQuestions: function(aid, callback)
 108     {
 109         db.assessments.findOne(
 110             {
 111                 _id: aid,
 112                 display: "all",
 113             },
 114             { questions: 1},
 115             (err,res) => {
 116                 callback(err, !!res ? res.questions : null);
 117             }
 118         );
 119     },
 120
 121     getQuestion: function(aid, index, callback)
 122     {
 123         db.assessments.findOne(
 124             {
 125                 _id: aid,
 126                 display: "one",
 127             },
 128             { questions: 1},
 129             (err,res) => {
 130                 if (!!err || !res)
 131                     return callback(err, res);
 132                 const qIdx = res.questions.findIndex( item => { return item.index == index; });
 133                 if (qIdx === -1)
 134                     return callback({errmsg: "Question not found"}, null);
 135                 callback(null, res.questions[qIdx]);
 136             }
 137         );
 138     },
 139
 140     getPaperByNumber: function(aid, number, callback)
 141     {
 142         db.assessments.findOne(
 143             {
 144                 _id: aid,
 145                 "papers.number": number,
 146             },
 147             (err,a) => {
 148                 if (!!err || !a)
 149                     return callback(err,a);
 150                 for (let p of a.papers)
 151                 {
 152                     if (p.number == number)
 153                         return callback(null,p); //reached for sure
 154                 }
 155             }
 156         );
 157     },
 158
 159     // NOTE: no callbacks for 2 next functions, failures are not so important
 160     // (because monitored: teachers can see what's going on)
 161
 162     addDisco: function(aid, number, deltaTime)
 163     {
 164         db.assessments.update(
 165             {
 166                 _id: aid,
 167                 "papers.number": number,
 168             },
 169             { $inc: {
 170                 "papers.$.discoCount": 1,
 171                 "papers.$.totalDisco": deltaTime,
 172             } },
 173             { $set: { "papers.$.discoTime": null } }
 174         );
 175     },
 176
 177     setDiscoTime: function(aid, number)
 178     {
 179         db.assessments.update(
 180             {
 181                 _id: aid,
 182                 "papers.number": number,
 183             },
 184             { $set: { "papers.$.discoTime": Date.now() } }
 185         );
 186     },
 187
 188     getDiscoTime: function(aid, number, cb)
 189     {
 190         db.assessments.findOne(
 191             { _id: aid },
 192             (err,a) => {
 193                 if (!!err)
 194                     return cb(err, null);
 195                 const idx = a.papers.findIndex( item => { return item.number == number; });
 196                 cb(null, a.papers[idx].discoTime);
 197             }
 198         );
 199     },
 200
 201     hasInput: function(aid, number, password, idx, cb)
 202     {
 203         db.assessments.findOne(
 204             {
 205                 _id: aid,
 206                 "papers.number": number,
 207                 "papers.password": password,
 208             },
 209             (err,a) => {
 210                 if (!!err || !a)
 211                     return cb(err,a);
 212                 let papIdx = a.papers.findIndex( item => { return item.number == number; });
 213                 for (let i of a.papers[papIdx].inputs)
 214                 {
 215                     if (i.index == idx)
 216                         return cb(null,true);
 217                 }
 218                 cb(null,false);
 219             }
 220         );
 221     },
 222
 223     // https://stackoverflow.com/questions/27874469/mongodb-push-in-nested-array
 224     setInput: function(aid, number, password, input, callback) //input: index + arrayOfInt (or txt)
 225     {
 226         db.assessments.update(
 227             {
 228                 _id: aid,
 229                 "papers.number": number,
 230                 "papers.password": password,
 231             },
 232             { $push: { "papers.$.inputs": input } },
 233             callback
 234         );
 235     },
 236
 237     endAssessment: function(aid, number, password, callback)
 238     {
 239         db.assessments.update(
 240             {
 241                 _id: aid,
 242                 "papers.number": number,
 243                 "papers.password": password,
 244             },
 245             { $set: {
 246                 "papers.$.endTime": Date.now(),
 247                 "papers.$.password": "",
 248             } },
 249             callback
 250         );
 251     },
 252
 253     remove: function(aid, cb)
 254     {
 255         db.assessments.remove(
 256             { _id: aid },
 257             cb
 258         );
 259     },
 260
 261     removeGroup: function(cid, cb)
 262     {
 263         db.assessments.remove(
 264             { cid: cid },
 265             cb
 266         );
 267     },
 268
 269     /////////////////////
 270     // ADVANCED FUNCTIONS
 271
 272     getByRefs: function(initials, code, name, cb)
 273     {
 274         UserModel.getByInitials(initials, (err,user) => {
 275             if (!!err || !user)
 276                 return cb(err || {errmsg: "User not found"});
 277             CourseModel.getByPath(user._id, code, (err2,course) => {
 278                 if (!!err2 || !course)
 279                     return cb(err2 || {errmsg: "Course not found"});
 280                 AssessmentModel.getByPath(course._id, name, (err3,assessment) => {
 281                     if (!!err3 || !assessment)
 282                         return cb(err3 || {errmsg: "Assessment not found"});
 283                     cb(null,assessment);
 284                 });
 285             });
 286         });
 287     },
 288
 289     checkPassword: function(aid, number, password, cb)
 290     {
 291         AssessmentModel.getById(aid, (err,assessment) => {
 292             if (!!err || !assessment)
 293                 return cb(err, assessment);
 294             const paperIdx = assessment.papers.findIndex( item => { return item.number == number; });
 295             if (paperIdx === -1)
 296                 return cb({errmsg: "Paper not found"}, false);
 297             cb(null, assessment.papers[paperIdx].password == password);
 298         });
 299     },
 300
 301     add: function(uid, cid, name, cb)
 302     {
 303         // 1) Check that course is owned by user of ID uid
 304         CourseModel.getById(cid, (err,course) => {
 305             if (!!err || !course)
 306                 return cb({errmsg: "Course retrieval failure"});
 307             if (!course.uid.equals(uid))
 308                 return cb({errmsg:"Not your course"},undefined);
 309             // 2) Insert new blank assessment
 310             AssessmentModel.insert(cid, name, cb);
 311         });
 312     },
 313
 314     update: function(uid, assessment, cb)
 315     {
 316         const aid = ObjectId(assessment._id);
 317         // 1) Check that assessment is owned by user of ID uid
 318         AssessmentModel.getById(aid, (err,assessmentOld) => {
 319             if (!!err || !assessmentOld)
 320                 return cb({errmsg: "Assessment retrieval failure"});
 321             CourseModel.getById(ObjectId(assessmentOld.cid), (err2,course) => {
 322                 if (!!err2 || !course)
 323                     return cb({errmsg: "Course retrieval failure"});
 324                 if (!course.uid.equals(uid))
 325                     return cb({errmsg:"Not your course"},undefined);
 326                 // 2) Replace assessment
 327                 delete assessment["_id"];
 328                 assessment.cid = ObjectId(assessment.cid);
 329                 AssessmentModel.replace(aid, assessment, cb);
 330             });
 331         });
 332     },
 333
 334     // Set password in responses collection
 335     startSession: function(aid, number, password, cb)
 336     {
 337         AssessmentModel.getPaperByNumber(aid, number, (err,paper) => {
 338             if (!!err)
 339                 return cb(err,null);
 340             if (!paper && !!password)
 341                 return cb({errmsg: "Cannot start a new exam before finishing current"},null);
 342             if (!!paper)
 343             {
 344                 if (!password)
 345                     return cb({errmsg: "Missing password"});
 346                 if (paper.password != password)
 347                     return cb({errmsg: "Wrong password"});
 348             }
 349             AssessmentModel.getQuestions(aid, (err2,questions) => {
 350                 if (!!err2)
 351                     return cb(err2,null);
 352                 if (!!paper)
 353                     return cb(null,{paper:paper});
 354                 const pwd = TokenGen.generate(12); //arbitrary number, 12 seems enough...
 355                 db.assessments.update(
 356                     { _id: aid },
 357                     { $push: { papers: {
 358                         number: number,
 359                         startTime: Date.now(),
 360                         endTime: undefined,
 361                         password: password,
 362                         totalDisco: 0,
 363                         discoCount: 0,
 364                         inputs: [ ], //TODO: this is stage 1, stack indexed answers.
 365                         // then build JSON tree for easier access / correct
 366                     }}},
 367                     (err3,ret) => { cb(err3,{password:password}); }
 368                 );
 369             });
 370         });
 371     },
 372
 373     newAnswer: function(aid, number, password, input, cb)
 374     {
 375         // Check that student hasn't already answered
 376         AssessmentModel.hasInput(aid, number, password, input.index, (err,ret) => {
 377             if (!!err)
 378                 return cb(err,null);
 379             if (!!ret)
 380                 return cb({errmsg:"Question already answered"},null);
 381             AssessmentModel.setInput(aid, number, password, input, (err2,ret2) => {
 382                 if (!!err2 || !ret2)
 383                     return cb(err2,ret2);
 384                 return cb(null,ret2);
 385             });
 386         });
 387     },
 388
 389     // NOTE: no callbacks for next function, failures are not so important
 390     // (because monitored: teachers can see what's going on)
 391     newConnection: function(aid, number)
 392     {
 393         //increment discoCount, reset discoTime to NULL, update totalDisco
 394         AssessmentModel.getDiscoTime(aid, number, (err,discoTime) => {
 395             if (!!discoTime)
 396                 AssessmentModel.addDisco(aid, number, Date.now() - discoTime);
 397         });
 398     },
 399 }
 400
 401 module.exports = AssessmentModel;