/**
@module ember-data
*/
import { inspect } from '@ember/debug';
import EmberError from '@ember/error';
import { get } from '@ember/object';
import { assign } from '@ember/polyfills';
/**
@class Snapshot
@namespace DS
@private
@constructor
@param {DS.Model} internalModel The model to create a snapshot from
*/
export default class Snapshot {
constructor(internalModel, options = {}) {
this._attributes = Object.create(null);
this._belongsToRelationships = Object.create(null);
this._belongsToIds = Object.create(null);
this._hasManyRelationships = Object.create(null);
this._hasManyIds = Object.create(null);
this._internalModel = internalModel;
let record = internalModel.getRecord();
/**
The underlying record for this snapshot. Can be used to access methods and
properties defined on the record.
Example
```javascript
let json = snapshot.record.toJSON();
```
@property record
@type {DS.Model}
*/
this.record = record;
record.eachAttribute((keyName) => this._attributes[keyName] = get(record, keyName));
/**
The id of the snapshot's underlying record
Example
```javascript
// store.push('post', { id: 1, author: 'Tomster', title: 'Ember.js rocks' });
postSnapshot.id; // => '1'
```
@property id
@type {String}
*/
this.id = internalModel.id;
/**
A hash of adapter options
@property adapterOptions
@type {Object}
*/
this.adapterOptions = options.adapterOptions;
this.include = options.include;
/**
The name of the type of the underlying record for this snapshot, as a string.
@property modelName
@type {String}
*/
this.modelName = internalModel.modelName;
this._changedAttributes = record.changedAttributes();
}
/**
The type of the underlying record for this snapshot, as a DS.Model.
@property type
@type {DS.Model}
*/
get type() {
// TODO @runspired we should deprecate this in favor of modelClass but only once
// we've cleaned up the internals enough that a public change to follow suite is
// uncontroversial.
return this._internalModel.modelClass;
}
/**
Returns the value of an attribute.
Example
```javascript
// store.push('post', { id: 1, author: 'Tomster', title: 'Ember.js rocks' });
postSnapshot.attr('author'); // => 'Tomster'
postSnapshot.attr('title'); // => 'Ember.js rocks'
```
Note: Values are loaded eagerly and cached when the snapshot is created.
@method attr
@param {String} keyName
@return {Object} The attribute value or undefined
*/
attr(keyName) {
if (keyName in this._attributes) {
return this._attributes[keyName];
}
throw new EmberError("Model '" + inspect(this.record) + "' has no attribute named '" + keyName + "' defined.");
}
/**
Returns all attributes and their corresponding values.
Example
```javascript
// store.push('post', { id: 1, author: 'Tomster', title: 'Ember.js rocks' });
postSnapshot.attributes(); // => { author: 'Tomster', title: 'Ember.js rocks' }
```
@method attributes
@return {Object} All attributes of the current snapshot
*/
attributes() {
return assign({}, this._attributes);
}
/**
Returns all changed attributes and their old and new values.
Example
```javascript
// store.push('post', { id: 1, author: 'Tomster', title: 'Ember.js rocks' });
postModel.set('title', 'Ember.js rocks!');
postSnapshot.changedAttributes(); // => { title: ['Ember.js rocks', 'Ember.js rocks!'] }
```
@method changedAttributes
@return {Object} All changed attributes of the current snapshot
*/
changedAttributes() {
let changedAttributes = Object.create(null);
let changedAttributeKeys = Object.keys(this._changedAttributes);
for (let i=0, length = changedAttributeKeys.length; i < length; i++) {
let key = changedAttributeKeys[i];
changedAttributes[key] = this._changedAttributes[key].slice();
}
return changedAttributes;
}
/**
Returns the current value of a belongsTo relationship.
`belongsTo` takes an optional hash of options as a second parameter,
currently supported options are:
- `id`: set to `true` if you only want the ID of the related record to be
returned.
Example
```javascript
// store.push('post', { id: 1, title: 'Hello World' });
// store.createRecord('comment', { body: 'Lorem ipsum', post: post });
commentSnapshot.belongsTo('post'); // => DS.Snapshot
commentSnapshot.belongsTo('post', { id: true }); // => '1'
// store.push('comment', { id: 1, body: 'Lorem ipsum' });
commentSnapshot.belongsTo('post'); // => undefined
```
Calling `belongsTo` will return a new Snapshot as long as there's any known
data for the relationship available, such as an ID. If the relationship is
known but unset, `belongsTo` will return `null`. If the contents of the
relationship is unknown `belongsTo` will return `undefined`.
Note: Relationships are loaded lazily and cached upon first access.
@method belongsTo
@param {String} keyName
@param {Object} [options]
@return {(DS.Snapshot|String|null|undefined)} A snapshot or ID of a known
relationship or null if the relationship is known but unset. undefined
will be returned if the contents of the relationship is unknown.
*/
belongsTo(keyName, options) {
let id = options && options.id;
let relationship, inverseInternalModel, hasData;
let result;
if (id && keyName in this._belongsToIds) {
return this._belongsToIds[keyName];
}
if (!id && keyName in this._belongsToRelationships) {
return this._belongsToRelationships[keyName];
}
relationship = this._internalModel._relationships.get(keyName);
if (!(relationship && relationship.relationshipMeta.kind === 'belongsTo')) {
throw new EmberError("Model '" + inspect(this.record) + "' has no belongsTo relationship named '" + keyName + "' defined.");
}
hasData = get(relationship, 'hasData');
inverseInternalModel = get(relationship, 'inverseInternalModel');
if (hasData) {
if (inverseInternalModel && !inverseInternalModel.isDeleted()) {
if (id) {
result = get(inverseInternalModel, 'id');
} else {
result = inverseInternalModel.createSnapshot();
}
} else {
result = null;
}
}
if (id) {
this._belongsToIds[keyName] = result;
} else {
this._belongsToRelationships[keyName] = result;
}
return result;
}
/**
Returns the current value of a hasMany relationship.
`hasMany` takes an optional hash of options as a second parameter,
currently supported options are:
- `ids`: set to `true` if you only want the IDs of the related records to be
returned.
Example
```javascript
// store.push('post', { id: 1, title: 'Hello World', comments: [2, 3] });
postSnapshot.hasMany('comments'); // => [DS.Snapshot, DS.Snapshot]
postSnapshot.hasMany('comments', { ids: true }); // => ['2', '3']
// store.push('post', { id: 1, title: 'Hello World' });
postSnapshot.hasMany('comments'); // => undefined
```
Note: Relationships are loaded lazily and cached upon first access.
@method hasMany
@param {String} keyName
@param {Object} [options]
@return {(Array|undefined)} An array of snapshots or IDs of a known
relationship or an empty array if the relationship is known but unset.
undefined will be returned if the contents of the relationship is unknown.
*/
hasMany(keyName, options) {
let ids = options && options.ids;
let relationship, members, hasData;
let results;
if (ids && keyName in this._hasManyIds) {
return this._hasManyIds[keyName];
}
if (!ids && keyName in this._hasManyRelationships) {
return this._hasManyRelationships[keyName];
}
relationship = this._internalModel._relationships.get(keyName);
if (!(relationship && relationship.relationshipMeta.kind === 'hasMany')) {
throw new EmberError("Model '" + inspect(this.record) + "' has no hasMany relationship named '" + keyName + "' defined.");
}
hasData = get(relationship, 'hasData');
members = get(relationship, 'members');
if (hasData) {
results = [];
members.forEach((member) => {
if (!member.isDeleted()) {
if (ids) {
results.push(member.id);
} else {
results.push(member.createSnapshot());
}
}
});
}
if (ids) {
this._hasManyIds[keyName] = results;
} else {
this._hasManyRelationships[keyName] = results;
}
return results;
}
/**
Iterates through all the attributes of the model, calling the passed
function on each attribute.
Example
```javascript
snapshot.eachAttribute(function(name, meta) {
// ...
});
```
@method eachAttribute
@param {Function} callback the callback to execute
@param {Object} [binding] the value to which the callback's `this` should be bound
*/
eachAttribute(callback, binding) {
this.record.eachAttribute(callback, binding);
}
/**
Iterates through all the relationships of the model, calling the passed
function on each relationship.
Example
```javascript
snapshot.eachRelationship(function(name, relationship) {
// ...
});
```
@method eachRelationship
@param {Function} callback the callback to execute
@param {Object} [binding] the value to which the callback's `this` should be bound
*/
eachRelationship(callback, binding) {
this.record.eachRelationship(callback, binding);
}
/**
Serializes the snapshot using the serializer for the model.
Example
```app/adapters/application.js
import DS from 'ember-data';
export default DS.Adapter.extend({
createRecord(store, type, snapshot) {
var data = snapshot.serialize({ includeId: true });
var url = `/${type.modelName}`;
return fetch(url, {
method: 'POST',
body: data,
}).then((response) => response.json())
}
});
```
@method serialize
@param {Object} options
@return {Object} an object whose values are primitive JSON values only
*/
serialize(options) {
return this.record.store.serializerFor(this.modelName).serialize(this, options);
}
}