forked from louischatriot/nedb
-
Notifications
You must be signed in to change notification settings - Fork 0
/
model.js
executable file
·835 lines (670 loc) · 25.1 KB
/
model.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
/**
* Handle models (i.e. docs)
* Serialization/deserialization
* Copying
* Querying, update
*/
var util = require('util')
, _ = require('underscore')
, modifierFunctions = {}
, lastStepModifierFunctions = {}
, comparisonFunctions = {}
, logicalOperators = {}
, arrayComparisonFunctions = {}
;
/**
* Check a key, throw an error if the key is non valid
* @param {String} k key
* @param {Model} v value, needed to treat the Date edge case
* Non-treatable edge cases here: if part of the object if of the form { $$date: number } or { $$deleted: true }
* Its serialized-then-deserialized version it will transformed into a Date object
* But you really need to want it to trigger such behaviour, even when warned not to use '$' at the beginning of the field names...
*/
function checkKey (k, v) {
if (typeof k === 'number') {
k = k.toString();
}
if (k[0] === '$' && !(k === '$$date' && typeof v === 'number') && !(k === '$$deleted' && v === true) && !(k === '$$indexCreated') && !(k === '$$indexRemoved')) {
throw new Error('Field names cannot begin with the $ character');
}
if (k.indexOf('.') !== -1) {
throw new Error('Field names cannot contain a .');
}
}
/**
* Check a DB object and throw an error if it's not valid
* Works by applying the above checkKey function to all fields recursively
*/
function checkObject (obj) {
if (util.isArray(obj)) {
obj.forEach(function (o) {
checkObject(o);
});
}
if (typeof obj === 'object' && obj !== null) {
Object.keys(obj).forEach(function (k) {
checkKey(k, obj[k]);
checkObject(obj[k]);
});
}
}
/**
* Serialize an object to be persisted to a one-line string
* For serialization/deserialization, we use the native JSON parser and not eval or Function
* That gives us less freedom but data entered in the database may come from users
* so eval and the like are not safe
* Accepted primitive types: Number, String, Boolean, Date, null
* Accepted secondary types: Objects, Arrays
*/
function serialize (obj) {
var res;
res = JSON.stringify(obj, function (k, v) {
checkKey(k, v);
if (v === undefined) { return undefined; }
if (v === null) { return null; }
// Hackish way of checking if object is Date (this way it works between execution contexts in node-webkit).
// We can't use value directly because for dates it is already string in this function (date.toJSON was already called), so we use this
if (typeof this[k].getTime === 'function') { return { $$date: this[k].getTime() }; }
return v;
});
return res;
}
/**
* From a one-line representation of an object generate by the serialize function
* Return the object itself
*/
function deserialize (rawData) {
return JSON.parse(rawData, function (k, v) {
if (k === '$$date') { return new Date(v); }
if (typeof v === 'string' || typeof v === 'number' || typeof v === 'boolean' || v === null) { return v; }
if (v && v.$$date) { return v.$$date; }
return v;
});
}
/**
* Deep copy a DB object
* The optional strictKeys flag (defaulting to false) indicates whether to copy everything or only fields
* where the keys are valid, i.e. don't begin with $ and don't contain a .
*/
function deepCopy (obj, strictKeys) {
var res;
if ( typeof obj === 'boolean' ||
typeof obj === 'number' ||
typeof obj === 'string' ||
obj === null ||
(util.isDate(obj)) ) {
return obj;
}
if (util.isArray(obj)) {
res = [];
obj.forEach(function (o) { res.push(deepCopy(o, strictKeys)); });
return res;
}
if (typeof obj === 'object') {
res = {};
Object.keys(obj).forEach(function (k) {
if (!strictKeys || (k[0] !== '$' && k.indexOf('.') === -1)) {
res[k] = deepCopy(obj[k], strictKeys);
}
});
return res;
}
return undefined; // For now everything else is undefined. We should probably throw an error instead
}
/**
* Tells if an object is a primitive type or a "real" object
* Arrays are considered primitive
*/
function isPrimitiveType (obj) {
return ( typeof obj === 'boolean' ||
typeof obj === 'number' ||
typeof obj === 'string' ||
obj === null ||
util.isDate(obj) ||
util.isArray(obj));
}
/**
* Utility functions for comparing things
* Assumes type checking was already done (a and b already have the same type)
* compareNSB works for numbers, strings and booleans
*/
function compareNSB (a, b) {
if (a < b) { return -1; }
if (a > b) { return 1; }
return 0;
}
function compareArrays (a, b) {
var i, comp;
for (i = 0; i < Math.min(a.length, b.length); i += 1) {
comp = compareThings(a[i], b[i]);
if (comp !== 0) { return comp; }
}
// Common section was identical, longest one wins
return compareNSB(a.length, b.length);
}
/**
* Compare { things U undefined }
* Things are defined as any native types (string, number, boolean, null, date) and objects
* We need to compare with undefined as it will be used in indexes
* In the case of objects and arrays, we deep-compare
* If two objects dont have the same type, the (arbitrary) type hierarchy is: undefined, null, number, strings, boolean, dates, arrays, objects
* Return -1 if a < b, 1 if a > b and 0 if a = b (note that equality here is NOT the same as defined in areThingsEqual!)
*
* @param {Function} _compareStrings String comparing function, returning -1, 0 or 1, overriding default string comparison (useful for languages with accented letters)
*/
function compareThings (a, b, _compareStrings) {
var aKeys, bKeys, comp, i
, compareStrings = _compareStrings || compareNSB;
// undefined
if (a === undefined) { return b === undefined ? 0 : -1; }
if (b === undefined) { return a === undefined ? 0 : 1; }
// null
if (a === null) { return b === null ? 0 : -1; }
if (b === null) { return a === null ? 0 : 1; }
// Numbers
if (typeof a === 'number') { return typeof b === 'number' ? compareNSB(a, b) : -1; }
if (typeof b === 'number') { return typeof a === 'number' ? compareNSB(a, b) : 1; }
// Strings
if (typeof a === 'string') { return typeof b === 'string' ? compareStrings(a, b) : -1; }
if (typeof b === 'string') { return typeof a === 'string' ? compareStrings(a, b) : 1; }
// Booleans
if (typeof a === 'boolean') { return typeof b === 'boolean' ? compareNSB(a, b) : -1; }
if (typeof b === 'boolean') { return typeof a === 'boolean' ? compareNSB(a, b) : 1; }
// Dates
if (util.isDate(a)) { return util.isDate(b) ? compareNSB(a.getTime(), b.getTime()) : -1; }
if (util.isDate(b)) { return util.isDate(a) ? compareNSB(a.getTime(), b.getTime()) : 1; }
// Arrays (first element is most significant and so on)
if (util.isArray(a)) { return util.isArray(b) ? compareArrays(a, b) : -1; }
if (util.isArray(b)) { return util.isArray(a) ? compareArrays(a, b) : 1; }
// Objects
aKeys = Object.keys(a).sort();
bKeys = Object.keys(b).sort();
for (i = 0; i < Math.min(aKeys.length, bKeys.length); i += 1) {
comp = compareThings(a[aKeys[i]], b[bKeys[i]]);
if (comp !== 0) { return comp; }
}
return compareNSB(aKeys.length, bKeys.length);
}
// ==============================================================
// Updating documents
// ==============================================================
/**
* The signature of modifier functions is as follows
* Their structure is always the same: recursively follow the dot notation while creating
* the nested documents if needed, then apply the "last step modifier"
* @param {Object} obj The model to modify
* @param {String} field Can contain dots, in that case that means we will set a subfield recursively
* @param {Model} value
*/
/**
* Set a field to a new value
*/
lastStepModifierFunctions.$set = function (obj, field, value) {
obj[field] = value;
};
/**
* Unset a field
*/
lastStepModifierFunctions.$unset = function (obj, field, value) {
delete obj[field];
};
/**
* Push an element to the end of an array field
* Optional modifier $each instead of value to push several values
* Optional modifier $slice to slice the resulting array, see https://docs.mongodb.org/manual/reference/operator/update/slice/
* Différeence with MongoDB: if $slice is specified and not $each, we act as if value is an empty array
*/
lastStepModifierFunctions.$push = function (obj, field, value) {
// Create the array if it doesn't exist
if (!obj.hasOwnProperty(field)) { obj[field] = []; }
if (!util.isArray(obj[field])) { throw new Error("Can't $push an element on non-array values"); }
if (value !== null && typeof value === 'object' && value.$slice && value.$each === undefined) {
value.$each = [];
}
if (value !== null && typeof value === 'object' && value.$each) {
if (Object.keys(value).length >= 3 || (Object.keys(value).length === 2 && value.$slice === undefined)) { throw new Error("Can only use $slice in cunjunction with $each when $push to array"); }
if (!util.isArray(value.$each)) { throw new Error("$each requires an array value"); }
value.$each.forEach(function (v) {
obj[field].push(v);
});
if (value.$slice === undefined || typeof value.$slice !== 'number') { return; }
if (value.$slice === 0) {
obj[field] = [];
} else {
var start, end, n = obj[field].length;
if (value.$slice < 0) {
start = Math.max(0, n + value.$slice);
end = n;
} else if (value.$slice > 0) {
start = 0;
end = Math.min(n, value.$slice);
}
obj[field] = obj[field].slice(start, end);
}
} else {
obj[field].push(value);
}
};
/**
* Add an element to an array field only if it is not already in it
* No modification if the element is already in the array
* Note that it doesn't check whether the original array contains duplicates
*/
lastStepModifierFunctions.$addToSet = function (obj, field, value) {
var addToSet = true;
// Create the array if it doesn't exist
if (!obj.hasOwnProperty(field)) { obj[field] = []; }
if (!util.isArray(obj[field])) { throw new Error("Can't $addToSet an element on non-array values"); }
if (value !== null && typeof value === 'object' && value.$each) {
if (Object.keys(value).length > 1) { throw new Error("Can't use another field in conjunction with $each"); }
if (!util.isArray(value.$each)) { throw new Error("$each requires an array value"); }
value.$each.forEach(function (v) {
lastStepModifierFunctions.$addToSet(obj, field, v);
});
} else {
obj[field].forEach(function (v) {
if (compareThings(v, value) === 0) { addToSet = false; }
});
if (addToSet) { obj[field].push(value); }
}
};
/**
* Remove the first or last element of an array
*/
lastStepModifierFunctions.$pop = function (obj, field, value) {
if (!util.isArray(obj[field])) { throw new Error("Can't $pop an element from non-array values"); }
if (typeof value !== 'number') { throw new Error(value + " isn't an integer, can't use it with $pop"); }
if (value === 0) { return; }
if (value > 0) {
obj[field] = obj[field].slice(0, obj[field].length - 1);
} else {
obj[field] = obj[field].slice(1);
}
};
/**
* Removes all instances of a value from an existing array
*/
lastStepModifierFunctions.$pull = function (obj, field, value) {
var arr, i;
if (!util.isArray(obj[field])) { throw new Error("Can't $pull an element from non-array values"); }
arr = obj[field];
for (i = arr.length - 1; i >= 0; i -= 1) {
if (match(arr[i], value)) {
arr.splice(i, 1);
}
}
};
/**
* Increment a numeric field's value
*/
lastStepModifierFunctions.$inc = function (obj, field, value) {
if (typeof value !== 'number') { throw new Error(value + " must be a number"); }
if (typeof obj[field] !== 'number') {
if (!_.has(obj, field)) {
obj[field] = value;
} else {
throw new Error("Don't use the $inc modifier on non-number fields");
}
} else {
obj[field] += value;
}
};
/**
* Updates the value of the field, only if specified field is greater than the current value of the field
*/
lastStepModifierFunctions.$max = function (obj, field, value) {
if (typeof obj[field] === 'undefined') {
obj[field] = value;
} else if (value > obj[field]) {
obj[field] = value;
}
};
/**
* Updates the value of the field, only if specified field is smaller than the current value of the field
*/
lastStepModifierFunctions.$min = function (obj, field, value) {
if (typeof obj[field] === 'undefined') {
obj[field] = value;
} else if (value < obj[field]) {
obj[field] = value;
}
};
// Given its name, create the complete modifier function
function createModifierFunction (modifier) {
return function (obj, field, value) {
var fieldParts = typeof field === 'string' ? field.split('.') : field;
if (fieldParts.length === 1) {
lastStepModifierFunctions[modifier](obj, field, value);
} else {
if (obj[fieldParts[0]] === undefined) {
if (modifier === '$unset') { return; } // Bad looking specific fix, needs to be generalized modifiers that behave like $unset are implemented
obj[fieldParts[0]] = {};
}
modifierFunctions[modifier](obj[fieldParts[0]], fieldParts.slice(1), value);
}
};
}
// Actually create all modifier functions
Object.keys(lastStepModifierFunctions).forEach(function (modifier) {
modifierFunctions[modifier] = createModifierFunction(modifier);
});
/**
* Modify a DB object according to an update query
*/
function modify (obj, updateQuery) {
var keys = Object.keys(updateQuery)
, firstChars = _.map(keys, function (item) { return item[0]; })
, dollarFirstChars = _.filter(firstChars, function (c) { return c === '$'; })
, newDoc, modifiers
;
if (keys.indexOf('_id') !== -1 && updateQuery._id !== obj._id) { throw new Error("You cannot change a document's _id"); }
if (dollarFirstChars.length !== 0 && dollarFirstChars.length !== firstChars.length) {
throw new Error("You cannot mix modifiers and normal fields");
}
if (dollarFirstChars.length === 0) {
// Simply replace the object with the update query contents
newDoc = deepCopy(updateQuery);
newDoc._id = obj._id;
} else {
// Apply modifiers
modifiers = _.uniq(keys);
newDoc = deepCopy(obj);
modifiers.forEach(function (m) {
var keys;
if (!modifierFunctions[m]) { throw new Error("Unknown modifier " + m); }
// Can't rely on Object.keys throwing on non objects since ES6
// Not 100% satisfying as non objects can be interpreted as objects but no false negatives so we can live with it
if (typeof updateQuery[m] !== 'object') {
throw new Error("Modifier " + m + "'s argument must be an object");
}
keys = Object.keys(updateQuery[m]);
keys.forEach(function (k) {
modifierFunctions[m](newDoc, k, updateQuery[m][k]);
});
});
}
// Check result is valid and return it
checkObject(newDoc);
if (obj._id !== newDoc._id) { throw new Error("You can't change a document's _id"); }
return newDoc;
};
// ==============================================================
// Finding documents
// ==============================================================
/**
* Get a value from object with dot notation
* @param {Object} obj
* @param {String} field
*/
function getDotValue (obj, field) {
var fieldParts = typeof field === 'string' ? field.split('.') : field
, i, objs;
if (!obj) { return undefined; } // field cannot be empty so that means we should return undefined so that nothing can match
if (fieldParts.length === 0) { return obj; }
if (fieldParts.length === 1) { return obj[fieldParts[0]]; }
if (util.isArray(obj[fieldParts[0]])) {
// If the next field is an integer, return only this item of the array
i = parseInt(fieldParts[1], 10);
if (typeof i === 'number' && !isNaN(i)) {
return getDotValue(obj[fieldParts[0]][i], fieldParts.slice(2))
}
// Return the array of values
objs = new Array();
for (i = 0; i < obj[fieldParts[0]].length; i += 1) {
objs.push(getDotValue(obj[fieldParts[0]][i], fieldParts.slice(1)));
}
return objs;
} else {
return getDotValue(obj[fieldParts[0]], fieldParts.slice(1));
}
}
/**
* Check whether 'things' are equal
* Things are defined as any native types (string, number, boolean, null, date) and objects
* In the case of object, we check deep equality
* Returns true if they are, false otherwise
*/
function areThingsEqual (a, b) {
var aKeys , bKeys , i;
// Strings, booleans, numbers, null
if (a === null || typeof a === 'string' || typeof a === 'boolean' || typeof a === 'number' ||
b === null || typeof b === 'string' || typeof b === 'boolean' || typeof b === 'number') { return a === b; }
// Dates
if (util.isDate(a) || util.isDate(b)) { return util.isDate(a) && util.isDate(b) && a.getTime() === b.getTime(); }
// Arrays (no match since arrays are used as a $in)
// undefined (no match since they mean field doesn't exist and can't be serialized)
if ((!(util.isArray(a) && util.isArray(b)) && (util.isArray(a) || util.isArray(b))) || a === undefined || b === undefined) { return false; }
// General objects (check for deep equality)
// a and b should be objects at this point
try {
aKeys = Object.keys(a);
bKeys = Object.keys(b);
} catch (e) {
return false;
}
if (aKeys.length !== bKeys.length) { return false; }
for (i = 0; i < aKeys.length; i += 1) {
if (bKeys.indexOf(aKeys[i]) === -1) { return false; }
if (!areThingsEqual(a[aKeys[i]], b[aKeys[i]])) { return false; }
}
return true;
}
/**
* Check that two values are comparable
*/
function areComparable (a, b) {
if (typeof a !== 'string' && typeof a !== 'number' && !util.isDate(a) &&
typeof b !== 'string' && typeof b !== 'number' && !util.isDate(b)) {
return false;
}
if (typeof a !== typeof b) { return false; }
return true;
}
/**
* Arithmetic and comparison operators
* @param {Native value} a Value in the object
* @param {Native value} b Value in the query
*/
comparisonFunctions.$lt = function (a, b) {
return areComparable(a, b) && a < b;
};
comparisonFunctions.$lte = function (a, b) {
return areComparable(a, b) && a <= b;
};
comparisonFunctions.$gt = function (a, b) {
return areComparable(a, b) && a > b;
};
comparisonFunctions.$gte = function (a, b) {
return areComparable(a, b) && a >= b;
};
comparisonFunctions.$ne = function (a, b) {
if (a === undefined) { return true; }
return !areThingsEqual(a, b);
};
comparisonFunctions.$in = function (a, b) {
var i;
if (!util.isArray(b)) { throw new Error("$in operator called with a non-array"); }
for (i = 0; i < b.length; i += 1) {
if (areThingsEqual(a, b[i])) { return true; }
}
return false;
};
comparisonFunctions.$nin = function (a, b) {
if (!util.isArray(b)) { throw new Error("$nin operator called with a non-array"); }
return !comparisonFunctions.$in(a, b);
};
comparisonFunctions.$regex = function (a, b) {
if (!util.isRegExp(b)) { throw new Error("$regex operator called with non regular expression"); }
if (typeof a !== 'string') {
return false
} else {
return b.test(a);
}
};
comparisonFunctions.$exists = function (value, exists) {
if (exists || exists === '') { // This will be true for all values of exists except false, null, undefined and 0
exists = true; // That's strange behaviour (we should only use true/false) but that's the way Mongo does it...
} else {
exists = false;
}
if (value === undefined) {
return !exists
} else {
return exists;
}
};
// Specific to arrays
comparisonFunctions.$size = function (obj, value) {
if (!util.isArray(obj)) { return false; }
if (value % 1 !== 0) { throw new Error("$size operator called without an integer"); }
return (obj.length == value);
};
comparisonFunctions.$elemMatch = function (obj, value) {
if (!util.isArray(obj)) { return false; }
var i = obj.length;
var result = false; // Initialize result
while (i--) {
if (match(obj[i], value)) { // If match for array element, return true
result = true;
break;
}
}
return result;
};
arrayComparisonFunctions.$size = true;
arrayComparisonFunctions.$elemMatch = true;
/**
* Match any of the subqueries
* @param {Model} obj
* @param {Array of Queries} query
*/
logicalOperators.$or = function (obj, query) {
var i;
if (!util.isArray(query)) { throw new Error("$or operator used without an array"); }
for (i = 0; i < query.length; i += 1) {
if (match(obj, query[i])) { return true; }
}
return false;
};
/**
* Match all of the subqueries
* @param {Model} obj
* @param {Array of Queries} query
*/
logicalOperators.$and = function (obj, query) {
var i;
if (!util.isArray(query)) { throw new Error("$and operator used without an array"); }
for (i = 0; i < query.length; i += 1) {
if (!match(obj, query[i])) { return false; }
}
return true;
};
/**
* Inverted match of the query
* @param {Model} obj
* @param {Query} query
*/
logicalOperators.$not = function (obj, query) {
return !match(obj, query);
};
/**
* Use a function to match
* @param {Model} obj
* @param {Query} query
*/
logicalOperators.$where = function (obj, fn) {
var result;
if (!_.isFunction(fn)) { throw new Error("$where operator used without a function"); }
result = fn.call(obj);
if (!_.isBoolean(result)) { throw new Error("$where function must return boolean"); }
return result;
};
/**
* Tell if a given document matches a query
* @param {Object} obj Document to check
* @param {Object} query
*/
function match (obj, query) {
var queryKeys, queryKey, queryValue, i;
// Primitive query against a primitive type
// This is a bit of a hack since we construct an object with an arbitrary key only to dereference it later
// But I don't have time for a cleaner implementation now
if (isPrimitiveType(obj) || isPrimitiveType(query)) {
return matchQueryPart({ needAKey: obj }, 'needAKey', query);
}
// Normal query
queryKeys = Object.keys(query);
for (i = 0; i < queryKeys.length; i += 1) {
queryKey = queryKeys[i];
queryValue = query[queryKey];
if (queryKey[0] === '$') {
if (!logicalOperators[queryKey]) { throw new Error("Unknown logical operator " + queryKey); }
if (!logicalOperators[queryKey](obj, queryValue)) { return false; }
} else {
if (!matchQueryPart(obj, queryKey, queryValue)) { return false; }
}
}
return true;
};
/**
* Match an object against a specific { key: value } part of a query
* if the treatObjAsValue flag is set, don't try to match every part separately, but the array as a whole
*/
function matchQueryPart (obj, queryKey, queryValue, treatObjAsValue) {
var objValue = getDotValue(obj, queryKey)
, i, keys, firstChars, dollarFirstChars;
// Check if the value is an array if we don't force a treatment as value
if (util.isArray(objValue) && !treatObjAsValue) {
// If the queryValue is an array, try to perform an exact match
if (util.isArray(queryValue)) {
return matchQueryPart(obj, queryKey, queryValue, true);
}
// Check if we are using an array-specific comparison function
if (queryValue !== null && typeof queryValue === 'object' && !util.isRegExp(queryValue)) {
keys = Object.keys(queryValue);
for (i = 0; i < keys.length; i += 1) {
if (arrayComparisonFunctions[keys[i]]) { return matchQueryPart(obj, queryKey, queryValue, true); }
}
}
// If not, treat it as an array of { obj, query } where there needs to be at least one match
for (i = 0; i < objValue.length; i += 1) {
if (matchQueryPart({ k: objValue[i] }, 'k', queryValue)) { return true; } // k here could be any string
}
return false;
}
// queryValue is an actual object. Determine whether it contains comparison operators
// or only normal fields. Mixed objects are not allowed
if (queryValue !== null && typeof queryValue === 'object' && !util.isRegExp(queryValue) && !util.isArray(queryValue)) {
keys = Object.keys(queryValue);
firstChars = _.map(keys, function (item) { return item[0]; });
dollarFirstChars = _.filter(firstChars, function (c) { return c === '$'; });
if (dollarFirstChars.length !== 0 && dollarFirstChars.length !== firstChars.length) {
throw new Error("You cannot mix operators and normal fields");
}
// queryValue is an object of this form: { $comparisonOperator1: value1, ... }
if (dollarFirstChars.length > 0) {
for (i = 0; i < keys.length; i += 1) {
if (!comparisonFunctions[keys[i]]) { throw new Error("Unknown comparison function " + keys[i]); }
if (!comparisonFunctions[keys[i]](objValue, queryValue[keys[i]])) { return false; }
}
return true;
}
}
// Using regular expressions with basic querying
if (util.isRegExp(queryValue)) { return comparisonFunctions.$regex(objValue, queryValue); }
// queryValue is either a native value or a normal object
// Basic matching is possible
if (!areThingsEqual(objValue, queryValue)) { return false; }
return true;
}
// Interface
module.exports.serialize = serialize;
module.exports.deserialize = deserialize;
module.exports.deepCopy = deepCopy;
module.exports.checkObject = checkObject;
module.exports.isPrimitiveType = isPrimitiveType;
module.exports.modify = modify;
module.exports.getDotValue = getDotValue;
module.exports.match = match;
module.exports.areThingsEqual = areThingsEqual;
module.exports.compareThings = compareThings;