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| /**
* Module Dependencies
*/
var _ = require('lodash');
var async = require('async');
var hop = require('../helpers').object.hasOwnProperty;
/**
* Update nested associations. Will take a values object and perform updating and
* creating of all the nested associations. It's the same as syncing so it will first
* remove any associations related to the parent and then "sync" the new associations.
*
* @param {Array} parents
* @param {Object} values
* @param {Object} associations
* @param {Function} cb
*/
module.exports = function(parents, associations, cb) {
var self = this;
// Combine model and collection associations
associations = _.extend(associations.collections, associations.models);
// Build up .add and .update operations for each association
var operations = buildOperations.call(self, parents, associations);
// Now that our operations are built, lets go through and run any updates.
// Then for each parent, find all the current associations and remove them then add
// all the new associations in using .add()
sync.call(self, parents, operations, cb);
};
/**
* Build Up Operations (add and update)
*
* @param {Array} associations
* @param {Object} values
* @return {Object}
*/
function buildOperations(parents, associations) {
var self = this;
var operations = {};
// For each association, grab the primary key value and normalize into model.add methods
_.keys(associations).forEach(function(association) {
var optValues = associations[association];
// If values are being nulled out just return. This is used when removing foreign
// keys on the parent model.
Iif (optValues === null) return;
// Pull out any association values that have primary keys, these will need to be updated. All
// values can be added for each parent however.
operations[association] = {
add: [],
update: []
};
// Normalize optValues to an array
if (!Array.isArray(optValues)) optValues = [optValues];
queueOperations.call(self, parents, association, operations[association], optValues);
});
return operations;
}
/**
* Queue Up Operations.
*
* Takes the array normalized association values and queues up
* operations for the specific association.
*
* @param {String} association
* @param {Object} operation
* @param {Array} values
*/
function queueOperations(parents, association, operation, values) {
var self = this;
var attribute = self.offshore.schema[self.identity].attributes[association];
var modelName;
if (hop(attribute, 'collection')) modelName = attribute.collection;
if (hop(attribute, 'foreignKey')) modelName = attribute.references;
Iif (!modelName) return;
var collection = self.offshore.collections[modelName];
// Grab the relation's PK
var relatedPK = _.find(collection.attributes, { primaryKey: true });
var relatedPkName = collection.primaryKey;
// If this is a join table, we can just queue up operations on the parent
// for this association.
if (collection.junctionTable) {
// For each parent, queue up any .add() operations
parents.forEach(function(parent) {
values.forEach(function(val) {
Iif (!hop(parent, association)) return;
Iif (typeof parent[association].add !== 'function') return;
parent[association].add(val);
});
});
return;
}
values.forEach(function(val) {
// Check the values and see if the model's primary key is given. If so look into
// the schema attribute and check if this is a collection or model attribute. If it's
// a collection attribute lets update the child record and if it's a model attribute,
// update the child and set the parent's foreign key value to the new primary key.
//
// If a custom PK was used and it's not autoIncrementing add the record. This
// allows nested creates to work when custom PK's are used.
if (!relatedPK.autoIncrement && !collection.autoPK) {
operation.add.push(val);
return;
}
// If it's missing a PK queue up an add
if (!hop(val, relatedPkName)) {
operation.add.push(val);
return;
}
// Build up the criteria that will be used to update the child record
var criteria = {};
criteria[relatedPkName] = val[relatedPkName];
// Queue up the update operation
operation.update.push({ model: modelName, criteria: criteria, values: val });
// Check if the parents foreign key needs to be updated
if (!hop(attribute, 'foreignKey')) {
operation.add.push(val[relatedPkName]);
return;
}
// Set the new foreign key value for each parent
parents.forEach(function(parent) {
parent[association] = val[relatedPkName];
});
});
}
/**
* Sync Associated Data
*
* Using the operations, lets go through and run any updates on any nested object with
* primary keys. This ensures that all the data passed up is persisted. Then for each parent,
* find all the current associations and unlink them and then add all the new associations
* in using .add(). This ensures that whatever is passed in to an update is what the value will
* be when queried again.
*
* @param {Object} operations
* @param {Function} cb
*/
function sync(parents, operations, cb) {
var self = this;
async.auto({
// Update any nested associations
update: function(next) {
updateRunner.call(self, parents, operations, next);
},
// For each parent, unlink all the associations currently set
unlink: ['update', function(next) {
unlinkRunner.call(self, parents, operations, next);
}],
// For each parent found, link any associations passed in by either creating
// the new record or linking an existing record
link: ['unlink', function(next) {
linkRunner.call(self, parents, operations, next);
}]
}, cb);
}
////////////////////////////////////////////////////////////////////////////////////////
// .sync() - Async Auto Runners
////////////////////////////////////////////////////////////////////////////////////////
/**
* Run Update Operations.
*
* Uses the information stored in an operation to perform a .update() on the
* associated model using the new values.
*
* @param {Object} operation
* @param {Function} cb
*/
function updateRunner(parents, operations, cb) {
var self = this;
// There will be an array of update operations inside of a namespace. Use this to run
// an update on the model instance of the association.
function associationLoop(association, next) {
async.each(operations[association].update, update, next);
}
function update(operation, next) {
var model = self.offshore.collections[operation.model]._loadQuery(self._query);
model.update(operation.criteria, operation.values).exec(next);
}
// Operations are namespaced under an association key. So run each association's updates
// in parallel for now. May need to be limited in the future but all adapters should
// support connection pooling.
async.each(Object.keys(operations), associationLoop, cb);
}
/**
* Unlink Associated Records.
*
* For each association passed in to the update we are essentially replacing the
* association's value. In order to do this we first need to clear out any associations
* that currently exist.
*
* @param {Object} operations
* @param {Function} cb
*/
function unlinkRunner(parents, operations, cb) {
var self = this;
// Given a parent, build up remove operations and run them.
function unlinkParentAssociations(parent, next) {
var opts = buildParentRemoveOperations.call(self, parent, operations);
removeOperationRunner.call(self, opts, next);
}
async.each(parents, unlinkParentAssociations, cb);
}
/**
* Link Associated Records
*
* Given a set of operations, associate the records with the parent records. This
* can be done by either creating join table records or by setting foreign keys.
* It defaults to a parent.add() method for most situations.
*
* @param {Object} operations
* @param {Function} cb
*/
function linkRunner(parents, operations, cb) {
var self = this;
function linkChildRecords(parent, next) {
// Queue up `.add()` operations on the parent model and figure out
// which records need to be created.
//
// If an .add() method is available always use it. If this is a nested model an .add()
// method won't be available so queue up a create operation.
var recordsToCreate = buildParentLinkOperations.call(self, parent, operations);
// Create the new records and update the parent with the new foreign key
// values that may have been set when creating child records.
createNewRecords.call(self, parent, recordsToCreate, function(err) {
Iif (err) return next(err);
updateParentRecord(parent, cb);
});
}
// Update the parent record one last time. This ensures a model attribute (single object)
// on the parent can create a new record and then set the parent's foreign key value to
// the newly created child record's primary key.
//
// Example:
// Parent.update({
// name: 'foo',
// nestedModel: {
// name: 'bar'
// }
// })
//
// The above query would create the new nested model and then set the parent's nestedModel
// value to the newly created model's primary key.
//
// We then run a .save() to persist any .add() records that may have been used. The update and
// .save() are used instead of a find and then save because it's the same amount of queries
// and it's easier to take advantage of all that the .add() method gives us.
//
//
// TO-DO:
// Make this much smarter to reduce the amount of queries that need to be run. We should probably
// be able to at least cut this in half!
//
function updateParentRecord(parent, next) {
var criteria = {};
var model = self.offshore.collections[self.identity]._loadQuery(self._query);
criteria[self.primaryKey] = parent[self.primaryKey];
var pValues = parent.toObject();
model.update(criteria, pValues).exec(function(err) {
Iif (err) return next(err);
// Call .save() to persist any .add() functions that may have been used.
parent._loadQuery(self._query).save(next);
});
}
async.each(parents, linkChildRecords, cb);
}
////////////////////////////////////////////////////////////////////////////////////////
// .sync() - Helper Functions
////////////////////////////////////////////////////////////////////////////////////////
/**
* Build up operations for performing unlinks.
*
* Given a parent and a set of operations, queue up operations to either
* remove join table records or null out any foreign keys on an child model.
*
* @param {Object} parent
* @param {Object} operations
* @return {Array}
*/
function buildParentRemoveOperations(parent, operations) {
var self = this;
var opts = [];
// Inspect the association and see if this relationship has a joinTable.
// If so create an operation criteria that clears all matching records from the
// table. If it doesn't have a join table, build an operation criteria that
// nulls out the foreign key on matching records.
Object.keys(operations).forEach(function(association) {
var criteria = {};
var searchCriteria = {};
var attribute = self.offshore.schema[self.identity].attributes[association];
/////////////////////////////////////////////////////////////////////////
// Parent Record:
// If the foreign key is stored on the parent side, null it out
/////////////////////////////////////////////////////////////////////////
if (hop(attribute, 'foreignKey')) {
// Set search criteria where primary key is equal to the parents primary key
searchCriteria[self.primaryKey] = parent[self.primaryKey];
// Store any information we may need to build up an operation.
// Use the `nullify` key to show we want to perform an update and not a destroy.
criteria = {
model: self.identity,
criteria: searchCriteria,
keyName: association,
nullify: true
};
opts.push(criteria);
return;
}
/////////////////////////////////////////////////////////////////////////
// Child Record:
// Lookup the attribute on the other side of the association on in the
// case of a m:m association the child table will be the join table.
/////////////////////////////////////////////////////////////////////////
var child = self.offshore.schema[attribute.collection];
var childAttribute = child.attributes[attribute.onKey];
// Set the search criteria to use the collection's `via` key and the parent's primary key.
searchCriteria[attribute.on] = parent[self.primaryKey];
// If the childAttribute stores the foreign key, find all children with the
// foreignKey equal to the parent's primary key and null them out or in the case of
// a `junctionTable` flag destroy them.
Eif (hop(childAttribute, 'foreignKey')) {
// Store any information needed to perform the query. Set nullify to false if
// a `junctionTable` property is found.
criteria = {
model: child.identity,
criteria: searchCriteria,
keyName: attribute.on,
nullify: !hop(child, 'junctionTable')
};
opts.push(criteria);
return;
}
});
return opts;
}
/**
* Remove Operation Runner
*
* Given a criteria object matching a remove operation, perform the
* operation using offshore collection instances.
*
* @param {Array} operations
* @param {Function} callback
*/
function removeOperationRunner(operations, cb) {
var self = this;
function runner(operation, next) {
var values = {};
// If nullify is false, run a destroy method using the criteria to destroy
// the join table records.
if (!operation.nullify) {
self.offshore.collections[operation.model]._loadQuery(self._query).destroy(operation.criteria).exec(next);
return;
}
// Run an update operation to set the foreign key to null on all the
// associated child records.
values[operation.keyName] = null;
self.offshore.collections[operation.model]._loadQuery(self._query).update(operation.criteria, values).exec(next);
}
// Run the operations
async.each(operations, runner, cb);
}
/**
* Build up operations for performing links.
*
* Given a parent and a set of operations, queue up operations to associate two
* records together. This could be using the parent's `.add()` method which handles
* the logic for us or building up a `create` operation that we can run to create the
* associated record with the correct foreign key set.
*
* @param {Object} parent
* @param {Object} operations
* @return {Object}
*/
function buildParentLinkOperations(parent, operations) {
var recordsToCreate = {};
// Determine whether to use the parent association's `.add()` function
// or whether to queue up a create operation.
function determineOperation(association, opt) {
// Check if the association has an `add` method, if so use it.
Eif (hop(parent[association], 'add')) {
parent[association].add(opt);
return;
}
recordsToCreate[association] = recordsToCreate[association] || [];
recordsToCreate[association].push(opt);
}
// For each operation look at all the .add operations and determine
// what to do with them.
Object.keys(operations).forEach(function(association) {
operations[association].add.forEach(function(opt) {
determineOperation(association, opt);
});
});
return recordsToCreate;
}
/**
* Create New Records.
*
* Given an object of association records to create, perform a create
* on the child model and set the parent's foreign key to the newly
* created record's primary key.
*
* @param {Object} parent
* @param {Object} recordsToCreate
* @param {Function} cb
*/
function createNewRecords(parent, recordsToCreate, cb) {
var self = this;
// For each association, run the createRecords function
// in the model context.
function mapAssociations(association, next) {
// First, pull the model attribute's referenced (foreign) collection
var attribute = self.offshore.schema[self.identity].attributes[association];
var referencedCollection = attribute.references;
var model = self.offshore.collections[referencedCollection]._loadQuery(self._query);
var records = recordsToCreate[association];
function createRunner(record, nextRecord) {
var args = [parent, association, record, nextRecord];
createRecord.apply(model, args);
}
async.each(records, createRunner, next);
}
// Create a record and set the parent's foreign key to the
// newly created record's primary key.
function createRecord(parent, association, record, next) {
var self = this;
this.create(record).exec(function(err, val) {
if (err) return next(err);
parent[association] = val[self.primaryKey];
next();
});
}
async.each(Object.keys(recordsToCreate), mapAssociations, cb);
}
|