loopback-datasource-juggler/lib/include.js

1001 lines
33 KiB
JavaScript
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

var async = require('async');
var utils = require('./utils');
var List = require('./list');
var includeUtils = require('./include_utils');
var isPlainObject = utils.isPlainObject;
var defineCachedRelations = utils.defineCachedRelations;
var uniq = utils.uniq;
/*!
* Normalize the include to be an array
* @param include
* @returns {*}
*/
function normalizeInclude(include) {
var newInclude;
if (typeof include === 'string') {
return [include];
} else if (isPlainObject(include)) {
// Build an array of key/value pairs
newInclude = [];
var rel = include.rel || include.relation;
var obj = {};
if (typeof rel === 'string') {
obj[rel] = new IncludeScope(include.scope);
newInclude.push(obj);
} else {
for (var key in include) {
obj[key] = include[key];
newInclude.push(obj);
}
}
return newInclude;
} else if (Array.isArray(include)) {
newInclude = [];
for (var i = 0, n = include.length; i < n; i++) {
var subIncludes = normalizeInclude(include[i]);
newInclude = newInclude.concat(subIncludes);
}
return newInclude;
} else {
return include;
}
}
function IncludeScope(scope) {
this._scope = utils.deepMerge({}, scope || {});
if (this._scope.include) {
this._include = normalizeInclude(this._scope.include);
delete this._scope.include;
} else {
this._include = null;
}
};
IncludeScope.prototype.conditions = function() {
return utils.deepMerge({}, this._scope);
};
IncludeScope.prototype.include = function() {
return this._include;
};
/**
* Find the idKey of a Model.
* @param {ModelConstructor} m - Model Constructor
* @returns {String}
*/
function idName(m) {
return m.definition.idName() || 'id';
}
/*!
* Look up a model by name from the list of given models
* @param {Object} models Models keyed by name
* @param {String} modelName The model name
* @returns {*} The matching model class
*/
function lookupModel(models, modelName) {
if (models[modelName]) {
return models[modelName];
}
var lookupClassName = modelName.toLowerCase();
for (var name in models) {
if (name.toLowerCase() === lookupClassName) {
return models[name];
}
}
}
/**
* Utility Function to allow interleave before and after high computation tasks
* @param tasks
* @param callback
*/
function execTasksWithInterLeave(tasks, callback) {
//let's give others some time to process.
//Context Switch BEFORE Heavy Computation
process.nextTick(function () {
//Heavy Computation
async.parallel(tasks, function (err, info) {
//Context Switch AFTER Heavy Computation
process.nextTick(function () {
callback(err, info);
});
});
});
}
/*!
* Include mixin for ./model.js
*/
module.exports = Inclusion;
/**
* Inclusion - Model mixin.
*
* @class
*/
function Inclusion() {
}
/**
* Normalize includes - used in DataAccessObject
*
*/
Inclusion.normalizeInclude = normalizeInclude;
/**
* Enables you to load relations of several objects and optimize numbers of requests.
*
* Examples:
*
* Load all users' posts with only one additional request:
* `User.include(users, 'posts', function() {});`
* Or
* `User.include(users, ['posts'], function() {});`
*
* Load all users posts and passports with two additional requests:
* `User.include(users, ['posts', 'passports'], function() {});`
*
* Load all passports owner (users), and all posts of each owner loaded:
*```Passport.include(passports, {owner: 'posts'}, function() {});
*``` Passport.include(passports, {owner: ['posts', 'passports']});
*``` Passport.include(passports, {owner: [{posts: 'images'}, 'passports']});
*
* @param {Array} objects Array of instances
* @param {String|Object|Array} include Which relations to load.
* @param {Object} [options] Options for CRUD
* @param {Function} cb Callback called when relations are loaded
*
*/
Inclusion.include = function (objects, include, options, cb) {
if (typeof options === 'function' && cb === undefined) {
cb = options;
options = {};
}
var self = this;
if (!include || (Array.isArray(include) && include.length === 0) ||
(isPlainObject(include) && Object.keys(include).length === 0)) {
// The objects are empty
return process.nextTick(function() {
cb && cb(null, objects);
});
}
include = normalizeInclude(include);
async.each(include, function(item, callback) {
processIncludeItem(objects, item, options, callback);
}, function(err) {
cb && cb(err, objects);
});
function processIncludeItem(objs, include, options, cb) {
var relations = self.relations;
var relationName;
var subInclude = null, scope = null;
if (isPlainObject(include)) {
relationName = Object.keys(include)[0];
if (include[relationName] instanceof IncludeScope) {
scope = include[relationName];
subInclude = scope.include();
} else {
subInclude = include[relationName];
//when include = {user:true}, it does not have subInclude
if (subInclude === true) {
subInclude = null;
}
}
}
else {
relationName = include;
subInclude = null;
}
var relation = relations[relationName];
if (!relation) {
cb(new Error('Relation "' + relationName + '" is not defined for '
+ self.modelName + ' model'));
return;
}
var polymorphic = relation.polymorphic;
//if (polymorphic && !polymorphic.discriminator) {
// cb(new Error('Relation "' + relationName + '" is polymorphic but ' +
// 'discriminator is not present'));
// return;
//}
if (!relation.modelTo) {
if (!relation.polymorphic) {
cb(new Error('Relation.modelTo is not defined for relation' +
relationName + ' and is no polymorphic'));
return;
}
}
// Just skip if inclusion is disabled
if (relation.options.disableInclude) {
return cb();
}
//prepare filter and fields for making DB Call
var filter = (scope && scope.conditions()) || {};
if ((relation.multiple || relation.type === 'belongsTo') && scope) {
var includeScope = {};
// make sure not to miss any fields for sub includes
if (filter.fields && Array.isArray(subInclude) &&
relation.modelTo.relations) {
includeScope.fields = [];
subInclude.forEach(function (name) {
var rel = relation.modelTo.relations[name];
if (rel && rel.type === 'belongsTo') {
includeScope.fields.push(rel.keyFrom);
}
});
}
utils.mergeQuery(filter, includeScope, {fields: false});
}
//Let's add a placeholder where query
filter.where = filter.where || {};
//if fields are specified, make sure target foreign key is present
var fields = filter.fields;
if (Array.isArray(fields) && fields.indexOf(relation.keyTo) === -1) {
fields.push(relation.keyTo);
}
else if (isPlainObject(fields) && !fields[relation.keyTo]) {
fields[relation.keyTo] = true;
}
/**
* call relation specific include functions
*/
if (relation.multiple) {
if (relation.modelThrough) {
//hasManyThrough needs separate handling
return includeHasManyThrough(cb);
}
//This will also include embedsMany with belongsTo.
//Might need to optimize db calls for this.
if (relation.type === 'embedsMany') {
//embedded docs are part of the objects, no need to make db call.
//proceed as implemented earlier.
return includeEmbeds(cb);
}
if (relation.type === 'referencesMany') {
return includeReferencesMany(cb);
}
//This handles exactly hasMany. Fast and straightforward. Without parallel, each and other boilerplate.
if(relation.type === 'hasMany' && relation.multiple && !subInclude) {
return includeHasManySimple(cb);
}
//assuming all other relations with multiple=true as hasMany
return includeHasMany(cb);
}
else {
if (polymorphic) {
if (relation.type === 'hasOne') {
return includePolymorphicHasOne(cb);
}
return includePolymorphicBelongsTo(cb);
}
if (relation.type === 'embedsOne') {
return includeEmbeds(cb);
}
//hasOne or belongsTo
return includeOneToOne(cb);
}
/**
* Handle inclusion of HasManyThrough/HasAndBelongsToMany/Polymorphic
* HasManyThrough relations
* @param callback
*/
function includeHasManyThrough(callback) {
var sourceIds = [];
//Map for Indexing objects by their id for faster retrieval
var objIdMap = {};
for (var i = 0; i < objs.length; i++) {
var obj = objs[i];
// one-to-many: foreign key reference is modelTo -> modelFrom.
// use modelFrom.keyFrom in where filter later
var sourceId = obj[relation.keyFrom];
if (sourceId) {
sourceIds.push(sourceId);
objIdMap[sourceId.toString()] = obj;
}
// sourceId can be null. but cache empty data as result
defineCachedRelations(obj);
obj.__cachedRelations[relationName] = [];
}
//default filters are not applicable on through model. should be applied
//on modelTo later in 2nd DB call.
var throughFilter = {
where: {}
};
throughFilter.where[relation.keyTo] = {
inq: uniq(sourceIds)
};
if (polymorphic) {
//handle polymorphic hasMany (reverse) in which case we need to filter
//by discriminator to filter other types
throughFilter.where[polymorphic.discriminator] =
relation.modelFrom.definition.name;
}
/**
* 1st DB Call of 2 step process. Get through model objects first
*/
relation.modelThrough.find(throughFilter, options, throughFetchHandler);
/**
* Handle the results of Through model objects and fetch the modelTo items
* @param err
* @param {Array<Model>} throughObjs
* @returns {*}
*/
function throughFetchHandler(err, throughObjs) {
if (err) {
return callback(err);
}
// start preparing for 2nd DB call.
var targetIds = [];
var targetObjsMap = {};
for (var i = 0; i < throughObjs.length; i++) {
var throughObj = throughObjs[i];
var targetId = throughObj[relation.keyThrough];
if (targetId) {
//save targetIds for 2nd DB Call
targetIds.push(targetId);
var sourceObj = objIdMap[throughObj[relation.keyTo]];
var targetIdStr = targetId.toString();
//Since targetId can be duplicates, multiple source objs are put
//into buckets.
var objList = targetObjsMap[targetIdStr] =
targetObjsMap[targetIdStr] || [];
objList.push(sourceObj);
}
}
//Polymorphic relation does not have idKey of modelTo. Find it manually
var modelToIdName = idName(relation.modelTo);
filter.where[modelToIdName] = {
inq: uniq(targetIds)
};
//make sure that the modelToIdName is included if fields are specified
if (Array.isArray(fields) && fields.indexOf(modelToIdName) === -1) {
fields.push(modelToIdName);
}
else if (isPlainObject(fields) && !fields[modelToIdName]) {
fields[modelToIdName] = true;
}
/**
* 2nd DB Call of 2 step process. Get modelTo (target) objects
*/
relation.modelTo.find(filter, options, targetsFetchHandler);
function targetsFetchHandler(err, targets) {
if (err) {
return callback(err);
}
var tasks = [];
//simultaneously process subIncludes. Call it first as it is an async
//process.
if (subInclude && targets) {
tasks.push(function subIncludesTask(next) {
relation.modelTo.include(targets, subInclude, options, next);
});
}
//process & link each target with object
tasks.push(targetLinkingTask);
function targetLinkingTask(next) {
async.each(targets, linkManyToMany, next);
function linkManyToMany(target, next) {
var targetId = target[modelToIdName];
var objList = targetObjsMap[targetId.toString()];
async.each(objList, function (obj, next) {
if (!obj) return next();
obj.__cachedRelations[relationName].push(target);
processTargetObj(obj, next);
}, next);
}
}
execTasksWithInterLeave(tasks, callback);
}
}
}
/**
* Handle inclusion of ReferencesMany relation
* @param callback
*/
function includeReferencesMany(callback) {
var modelToIdName = idName(relation.modelTo);
var allTargetIds = [];
//Map for Indexing objects by their id for faster retrieval
var targetObjsMap = {};
for (var i = 0; i < objs.length; i++) {
var obj = objs[i];
// one-to-many: foreign key reference is modelTo -> modelFrom.
// use modelFrom.keyFrom in where filter later
var targetIds = obj[relation.keyFrom];
if (targetIds) {
if (typeof targetIds === 'string') {
// For relational DBs, the array is stored as stringified json
// Please note obj is a plain object at this point
targetIds = JSON.parse(targetIds);
}
//referencesMany has multiple targetIds per obj. We need to concat
// them into allTargetIds before DB Call
allTargetIds = allTargetIds.concat(targetIds);
for (var j = 0; j < targetIds.length; j++) {
var targetId = targetIds[j];
var targetIdStr = targetId.toString();
var objList = targetObjsMap[targetIdStr] =
targetObjsMap[targetIdStr] || [];
objList.push(obj);
}
}
// sourceId can be null. but cache empty data as result
defineCachedRelations(obj);
obj.__cachedRelations[relationName] = [];
}
filter.where[relation.keyTo] = {
inq: uniq(allTargetIds)
};
relation.applyScope(null, filter);
/**
* Make the DB Call, fetch all target objects
*/
relation.modelTo.find(filter, options, targetFetchHandler);
/**
* Handle the fetched target objects
* @param err
* @param {Array<Model>}targets
* @returns {*}
*/
function targetFetchHandler(err, targets) {
if (err) {
return callback(err);
}
var tasks = [];
//simultaneously process subIncludes
if (subInclude && targets) {
tasks.push(function subIncludesTask(next) {
relation.modelTo.include(targets, subInclude, options, next);
});
}
targets = utils.sortObjectsByIds(modelToIdName, allTargetIds, targets);
//process each target object
tasks.push(targetLinkingTask);
function targetLinkingTask(next) {
async.each(targets, linkManyToMany, next);
function linkManyToMany(target, next) {
var objList = targetObjsMap[target[relation.keyTo].toString()];
async.each(objList, function (obj, next) {
if (!obj) return next();
obj.__cachedRelations[relationName].push(target);
processTargetObj(obj, next);
}, next);
}
}
execTasksWithInterLeave(tasks, callback);
}
}
/**
* Handle inclusion of HasMany relation
* @param callback
*/
function includeHasManySimple(callback) {
//Map for Indexing objects by their id for faster retrieval
var objIdMap = includeUtils.buildOneToOneIdentityMap(objs, relation.keyFrom);
// all ids of primary objects to use in query
var sourceIds = Object.keys(objIdMap);
filter.where[relation.keyTo] = {
inq: uniq(sourceIds)
};
relation.applyScope(null, filter);
relation.modelTo.find(filter, options, targetFetchHandler2);
function targetFetchHandler2(err, targets) {
if(err) {
return callback(err);
}
var targetsIdMap = includeUtils.buildOneToManyIdentityMap(targets, relation.keyTo);
includeUtils.join(objIdMap, targetsIdMap, function(obj1, valueToMergeIn){
obj1[relation.name] = valueToMergeIn;
});
callback(err, objs);
}
/**
* Process fetched related objects
* @param err
* @param {Array<Model>} targets
* @returns {*}
*/
function targetFetchHandler(err, targets) {
console.log("### query done. I'm in targetFetchHandler");
console.log("### obtained: \ntargets(permission) count: " + targets.length + "\nobjs(users) count: " + objs.length);
if (err) {
return callback(err);
}
var modelToFKIdMap = includeUtils.buildOneToManyIdentityMap(targets, relation.keyTo);
var tasks = [];
//simultaneously process subIncludes
if (subInclude && targets) {
tasks.push(function subIncludesTask(next) {
relation.modelTo.include(targets, subInclude, options, next);
});
}
//process each target object
tasks.push(targetLinkingTask);
function targetLinkingTask(next) {
if (targets.length === 0) {
return async.each(objs, function(obj, next) {
processTargetObj(obj, next);
}, next);
}
// TODO: show targets length
// почему так сложно???? Не очень понимаю.
async.each(targets, linkManyToOne, next);
function linkManyToOne(target, next) {
console.log("### processing target: " + JSON.stringify(target));
//fix for bug in hasMany with referencesMany
var targetIds = [].concat(target[relation.keyTo]);
console.log("### targetIds: " + JSON.stringify(targetIds));
async.each(targetIds, function (targetId, next) {
var obj = objIdMap[targetId.toString()];
if (!obj) return next();
obj.__cachedRelations[relationName].push(target);
//console.time("@@@Prepare1");
processTargetObj(obj, next);
//console.timeEnd("@@@Prepare1");
}, function(err, processedTargets) {
if (err) {
return next(err);
}
console.time("finding object with empty ids");
var objsWithEmptyRelation = objs.filter(function(obj) {
return obj.__cachedRelations[relationName].length === 0;
});
console.timeEnd("finding object with empty ids"); // 0-1 ms
console.log("### objs with empty relations count: " + objsWithEmptyRelation.length);
//next(processedTargets);
console.time("Prepare empty");
async.each(objsWithEmptyRelation, function(obj, next) {
console.time("Prepare one");
processTargetObj(obj, next);
console.timeEnd("Prepare one");
}, function(err) {
console.timeEnd("Prepare empty");
next(err, processedTargets);
});
});
}
}
console.log("### tasks count: " + tasks.length);
execTasksWithInterLeave(tasks, callback);
}
}
/**
* Handle inclusion of HasMany relation
* @param callback
*/
function includeHasMany(callback) {
var sourceIds = [];
//Map for Indexing objects by their id for faster retrieval
var objIdMap = {};
for (var i = 0; i < objs.length; i++) {
var obj = objs[i];
// one-to-many: foreign key reference is modelTo -> modelFrom.
// use modelFrom.keyFrom in where filter later
var sourceId = obj[relation.keyFrom];
if (sourceId) {
sourceIds.push(sourceId);
objIdMap[sourceId.toString()] = obj;
}
// sourceId can be null. but cache empty data as result
defineCachedRelations(obj);
obj.__cachedRelations[relationName] = [];
}
filter.where[relation.keyTo] = {
inq: uniq(sourceIds)
};
relation.applyScope(null, filter);
relation.modelTo.find(filter, options, targetFetchHandler);
/**
* Process fetched related objects
* @param err
* @param {Array<Model>} targets
* @returns {*}
*/
function targetFetchHandler(err, targets) {
if (err) {
return callback(err);
}
var tasks = [];
//simultaneously process subIncludes
if (subInclude && targets) {
tasks.push(function subIncludesTask(next) {
relation.modelTo.include(targets, subInclude, options, next);
});
}
//process each target object
tasks.push(targetLinkingTask);
function targetLinkingTask(next) {
if (targets.length === 0) {
return async.each(objs, function(obj, next) {
processTargetObj(obj, next);
}, next);
}
async.each(targets, linkManyToOne, next);
function linkManyToOne(target, next) {
//fix for bug in hasMany with referencesMany
var targetIds = [].concat(target[relation.keyTo]);
async.each(targetIds, function (targetId, next) {
var obj = objIdMap[targetId.toString()];
if (!obj) return next();
obj.__cachedRelations[relationName].push(target);
processTargetObj(obj, next);
}, function(err, processedTargets) {
if (err) {
return next(err);
}
var objsWithEmptyRelation = objs.filter(function(obj) {
return obj.__cachedRelations[relationName].length === 0;
});
async.each(objsWithEmptyRelation, function(obj, next) {
processTargetObj(obj, next);
}, function(err) {
next(err, processedTargets);
});
});
}
}
execTasksWithInterLeave(tasks, callback);
}
}
/**
* Handle Inclusion of Polymorphic BelongsTo relation
* @param callback
*/
function includePolymorphicBelongsTo(callback) {
var targetIdsByType = {};
//Map for Indexing objects by their type and targetId for faster retrieval
var targetObjMapByType = {};
for (var i = 0; i < objs.length; i++) {
var obj = objs[i];
var discriminator = polymorphic.discriminator;
var modelType = obj[discriminator];
if (modelType) {
targetIdsByType[modelType] = targetIdsByType[modelType] || [];
targetObjMapByType[modelType] = targetObjMapByType[modelType] || {};
var targetIds = targetIdsByType[modelType];
var targetObjsMap = targetObjMapByType[modelType];
var targetId = obj[relation.keyFrom];
if (targetId) {
targetIds.push(targetId);
var targetIdStr = targetId.toString();
targetObjsMap[targetIdStr] = targetObjsMap[targetIdStr] || [];
//Is belongsTo. Multiple objects can have the same
//targetId and therefore map value is an array
targetObjsMap[targetIdStr].push(obj);
}
}
defineCachedRelations(obj);
obj.__cachedRelations[relationName] = null;
}
async.each(Object.keys(targetIdsByType), processPolymorphicType,
callback);
/**
* Process Polymorphic objects of each type (modelType)
* @param {String} modelType
* @param callback
*/
function processPolymorphicType(modelType, callback) {
var typeFilter = {where: {}};
utils.mergeQuery(typeFilter, filter);
var targetIds = targetIdsByType[modelType];
typeFilter.where[relation.keyTo] = {
inq: uniq(targetIds)
};
var Model = lookupModel(relation.modelFrom.dataSource.modelBuilder.
models, modelType);
if (!Model) {
callback(new Error('Discriminator type "' + modelType +
' specified but no model exists with such name'));
return;
}
relation.applyScope(null, typeFilter);
Model.find(typeFilter, options, targetFetchHandler);
/**
* Process fetched related objects
* @param err
* @param {Array<Model>} targets
* @returns {*}
*/
function targetFetchHandler(err, targets) {
if (err) {
return callback(err);
}
var tasks = [];
//simultaneously process subIncludes
if (subInclude && targets) {
tasks.push(function subIncludesTask(next) {
Model.include(targets, subInclude, options, next);
});
}
//process each target object
tasks.push(targetLinkingTask);
function targetLinkingTask(next) {
var targetObjsMap = targetObjMapByType[modelType];
async.each(targets, linkOneToMany, next);
function linkOneToMany(target, next) {
var objList = targetObjsMap[target[relation.keyTo].toString()];
async.each(objList, function (obj, next) {
if (!obj) return next();
obj.__cachedRelations[relationName] = target;
processTargetObj(obj, next);
}, next);
}
}
execTasksWithInterLeave(tasks, callback);
}
}
}
/**
* Handle Inclusion of Polymorphic HasOne relation
* @param callback
*/
function includePolymorphicHasOne(callback) {
var sourceIds = [];
//Map for Indexing objects by their id for faster retrieval
var objIdMap = {};
for (var i = 0; i < objs.length; i++) {
var obj = objs[i];
// one-to-one: foreign key reference is modelTo -> modelFrom.
// use modelFrom.keyFrom in where filter later
var sourceId = obj[relation.keyFrom];
if (sourceId) {
sourceIds.push(sourceId);
objIdMap[sourceId.toString()] = obj;
}
// sourceId can be null. but cache empty data as result
defineCachedRelations(obj);
obj.__cachedRelations[relationName] = null;
}
filter.where[relation.keyTo] = {
inq: uniq(sourceIds)
};
relation.applyScope(null, filter);
relation.modelTo.find(filter, options, targetFetchHandler);
/**
* Process fetched related objects
* @param err
* @param {Array<Model>} targets
* @returns {*}
*/
function targetFetchHandler(err, targets) {
if (err) {
return callback(err);
}
var tasks = [];
//simultaneously process subIncludes
if (subInclude && targets) {
tasks.push(function subIncludesTask(next) {
relation.modelTo.include(targets, subInclude, options, next);
});
}
//process each target object
tasks.push(targetLinkingTask);
function targetLinkingTask(next) {
async.each(targets, linkOneToOne, next);
function linkOneToOne(target, next) {
var sourceId = target[relation.keyTo];
if (!sourceId) return next();
var obj = objIdMap[sourceId.toString()];
if (!obj) return next();
obj.__cachedRelations[relationName] = target;
processTargetObj(obj, next);
}
}
execTasksWithInterLeave(tasks, callback);
}
}
/**
* Handle Inclusion of BelongsTo/HasOne relation
* @param callback
*/
function includeOneToOne(callback) {
var targetIds = [];
var objTargetIdMap = {};
for (var i = 0; i < objs.length; i++) {
var obj = objs[i];
if (relation.type === 'belongsTo') {
if (obj[relation.keyFrom] === null ||
obj[relation.keyFrom] === undefined) {
defineCachedRelations(obj);
obj.__cachedRelations[relationName] = null;
continue;
}
}
var targetId = obj[relation.keyFrom];
if (targetId) {
targetIds.push(targetId);
var targetIdStr = targetId.toString();
objTargetIdMap[targetIdStr] = objTargetIdMap[targetIdStr] || [];
objTargetIdMap[targetIdStr].push(obj);
}
defineCachedRelations(obj);
obj.__cachedRelations[relationName] = null;
}
filter.where[relation.keyTo] = {
inq: uniq(targetIds)
};
relation.applyScope(null, filter);
relation.modelTo.find(filter, options, targetFetchHandler);
/**
* Process fetched related objects
* @param err
* @param {Array<Model>} targets
* @returns {*}
*/
function targetFetchHandler(err, targets) {
if (err) {
return callback(err);
}
var tasks = [];
//simultaneously process subIncludes
if (subInclude && targets) {
tasks.push(function subIncludesTask(next) {
relation.modelTo.include(targets, subInclude, options, next);
});
}
//process each target object
tasks.push(targetLinkingTask);
function targetLinkingTask(next) {
async.each(targets, linkOneToMany, next);
function linkOneToMany(target, next) {
var targetId = target[relation.keyTo];
var objList = objTargetIdMap[targetId.toString()];
async.each(objList, function (obj, next) {
if (!obj) return next();
obj.__cachedRelations[relationName] = target;
processTargetObj(obj, next);
}, next);
}
}
execTasksWithInterLeave(tasks, callback);
}
}
/**
* Handle Inclusion of EmbedsMany/EmbedsManyWithBelongsTo/EmbedsOne
* Relations. Since Embedded docs are part of parents, no need to make
* db calls. Let the related function be called for each object to fetch
* the results from cache.
*
* TODO: Optimize EmbedsManyWithBelongsTo relation DB Calls
* @param callback
*/
function includeEmbeds(callback) {
async.each(objs, function (obj, next) {
processTargetObj(obj, next);
}, callback);
}
/**
* Process Each Model Object and make sure specified relations are included
* @param {Model} obj - Single Mode object for which inclusion is needed
* @param callback
* @returns {*}
*/
function processTargetObj(obj, callback) {
var inst = (obj instanceof self) ? obj : new self(obj);
// Calling the relation method on the instance
if (relation.type === 'belongsTo') {
// If the belongsTo relation doesn't have an owner
if (obj[relation.keyFrom] === null || obj[relation.keyFrom] === undefined) {
defineCachedRelations(obj);
// Set to null if the owner doesn't exist
obj.__cachedRelations[relationName] = null;
if (obj === inst) {
obj.__data[relationName] = null;
} else {
obj[relationName] = null;
}
return callback();
}
}
/**
* Sets the related objects as a property of Parent Object
* @param {Array<Model>|Model|null} result - Related Object/Objects
* @param cb
*/
function setIncludeData(result, cb) {
if (obj === inst) {
if (Array.isArray(result) && !(result instanceof List)) {
result = new List(result, relation.modelTo);
}
obj.__data[relationName] = result;
obj.setStrict(false);
} else {
obj[relationName] = result;
}
cb(null, result);
}
//obj.__cachedRelations[relationName] can be null if no data was returned
if (obj.__cachedRelations &&
obj.__cachedRelations[relationName] !== undefined) {
return setIncludeData(obj.__cachedRelations[relationName],
callback);
}
//If related objects are not cached by include Handlers, directly call
//related accessor function even though it is not very efficient
var related; // relation accessor function
if ((relation.multiple || relation.type === 'belongsTo') && scope) {
var includeScope = {};
var filter = scope.conditions();
// make sure not to miss any fields for sub includes
if (filter.fields && Array.isArray(subInclude) && relation.modelTo.relations) {
includeScope.fields = [];
subInclude.forEach(function(name) {
var rel = relation.modelTo.relations[name];
if (rel && rel.type === 'belongsTo') {
includeScope.fields.push(rel.keyFrom);
}
});
}
utils.mergeQuery(filter, includeScope, {fields: false});
related = inst[relationName].bind(inst, filter);
} else {
related = inst[relationName].bind(inst, undefined);
}
related(options, function (err, result) {
if (err) {
return callback(err);
} else {
defineCachedRelations(obj);
obj.__cachedRelations[relationName] = result;
return setIncludeData(result, callback);
}
});
}
}
};