Class DataAdapter
publicimport DataAdapter from '@ember/debug/data-adapter';
The DataAdapter
helps a data persistence library
interface with tools that debug Ember such
as the Ember Inspector
for Chrome and Firefox.
This class will be extended by a persistence library which will override some of the methods with library-specific code.
The methods likely to be overridden are:
getFilters
detect
columnsForType
getRecords
getRecordColumnValues
getRecordKeywords
getRecordFilterValues
getRecordColor
The adapter will need to be registered
in the application's container as dataAdapter:main
.
Example:
Application.initializer({
name: "data-adapter",
initialize: function(application) {
application.register('data-adapter:main', DS.DataAdapter);
}
});
addObserver (key, target, method, sync) Observable public
Inherited from Observable packages/@ember/object/observable.ts:364
- key
- String
The key to observe
- target
- Object
The target object to invoke
- method
- String|Function
The method to invoke
- sync
- Boolean
Whether the observer is sync or not
- returns
- Observable
Adds an observer on a property.
This is the core method used to register an observer for a property.
Once you call this method, any time the key's value is set, your observer will be notified. Note that the observers are triggered any time the value is set, regardless of whether it has actually changed. Your observer should be prepared to handle that.
There are two common invocation patterns for .addObserver()
:
- Passing two arguments:
- the name of the property to observe (as a string)
- the function to invoke (an actual function)
- Passing three arguments:
- the name of the property to observe (as a string)
- the target object (will be used to look up and invoke a function on)
- the name of the function to invoke on the target object (as a string).
import Component from '@ember/component';
export default Component.extend({
init() {
this._super(...arguments);
// the following are equivalent:
// using three arguments
this.addObserver('foo', this, 'fooDidChange');
// using two arguments
this.addObserver('foo', (...args) => {
this.fooDidChange(...args);
});
},
fooDidChange() {
// your custom logic code
}
});
Observer Methods
Observer methods have the following signature:
import Component from '@ember/component';
export default Component.extend({
init() {
this._super(...arguments);
this.addObserver('foo', this, 'fooDidChange');
},
fooDidChange(sender, key, value, rev) {
// your code
}
});
The sender
is the object that changed. The key
is the property that
changes. The value
property is currently reserved and unused. The rev
is the last property revision of the object when it changed, which you can
use to detect if the key value has really changed or not.
Usually you will not need the value or revision parameters at the end. In this case, it is common to write observer methods that take only a sender and key value as parameters or, if you aren't interested in any of these values, to write an observer that has no parameters at all.
cacheFor (keyName) Object public
Inherited from Observable packages/@ember/object/observable.ts:556
- keyName
- String
- returns
- Object
The cached value of the computed property, if any
Returns the cached value of a computed property, if it exists. This allows you to inspect the value of a computed property without accidentally invoking it if it is intended to be generated lazily.
columnsForType Array public
Defined in packages/@ember/debug/data-adapter.ts:451
- returns
- Array
An array of columns of the following format: name: {String} The name of the column. desc: {String} Humanized description (what would show in a table column name).
Get the columns for a given model type.
decrementProperty (keyName, decrement) Number public
Inherited from Observable packages/@ember/object/observable.ts:517
- keyName
- String
The name of the property to decrement
- decrement
- Number
The amount to decrement by. Defaults to 1
- returns
- Number
The new property value
Set the value of a property to the current value minus some amount.
player.decrementProperty('lives');
orc.decrementProperty('health', 5);
destroy EmberObject public
Inherited from CoreObject packages/@ember/object/core.ts:537
- returns
- EmberObject
receiver
Destroys an object by setting the isDestroyed
flag and removing its
metadata, which effectively destroys observers and bindings.
If you try to set a property on a destroyed object, an exception will be raised.
Note that destruction is scheduled for the end of the run loop and does not happen immediately. It will set an isDestroying flag immediately.
detect public
Defined in packages/@ember/debug/data-adapter.ts:437
- returns
boolean Whether the class is a model class or not.
Detect whether a class is a model.
Test that against the model class of your persistence library.
get (keyName) Object public
Inherited from Observable packages/@ember/object/observable.ts:171
- keyName
- String
The property to retrieve
- returns
- Object
The property value or undefined.
Retrieves the value of a property from the object.
This method is usually similar to using object[keyName]
or object.keyName
,
however it supports both computed properties and the unknownProperty
handler.
Because get
unifies the syntax for accessing all these kinds
of properties, it can make many refactorings easier, such as replacing a
simple property with a computed property, or vice versa.
Computed Properties
Computed properties are methods defined with the property
modifier
declared at the end, such as:
import { computed } from '@ember/object';
fullName: computed('firstName', 'lastName', function() {
return this.get('firstName') + ' ' + this.get('lastName');
})
When you call get
on a computed property, the function will be
called and the return value will be returned instead of the function
itself.
Unknown Properties
Likewise, if you try to call get
on a property whose value is
undefined
, the unknownProperty()
method will be called on the object.
If this method returns any value other than undefined
, it will be returned
instead. This allows you to implement "virtual" properties that are
not defined upfront.
getFilters Array public
Defined in packages/@ember/debug/data-adapter.ts:285
- returns
- Array
List of objects defining filters. The object should have a
name
anddesc
property.
Specifies how records can be filtered.
Records returned will need to have a filterValues
property with a key for every name in the returned array.
getProperties (list) Object public
Inherited from Observable packages/@ember/object/observable.ts:216
- list
- String...|Array
of keys to get
- returns
- Object
To get the values of multiple properties at once, call getProperties
with a list of strings or an array:
record.getProperties('firstName', 'lastName', 'zipCode');
// { firstName: 'John', lastName: 'Doe', zipCode: '10011' }
is equivalent to:
record.getProperties(['firstName', 'lastName', 'zipCode']);
// { firstName: 'John', lastName: 'Doe', zipCode: '10011' }
getRecordColor (record) String public
Defined in packages/@ember/debug/data-adapter.ts:647
- record
- Object
The record instance
- returns
- String
The records color. Possible options: black, red, blue, green.
Each record can have a color that represents its state.
getRecordColumnValues Object public
Defined in packages/@ember/debug/data-adapter.ts:612
- returns
- Object
Keys should match column names defined by the model type.
Gets the values for each column.
getRecordFilterValues (record) Object public
Defined in packages/@ember/debug/data-adapter.ts:635
- record
- Object
The record instance.
- returns
- Object
The filter values.
Returns the values of filters defined by getFilters
.
getRecordKeywords Array public
Defined in packages/@ember/debug/data-adapter.ts:624
- returns
- Array
Relevant keywords for search.
Returns keywords to match when searching records.
getRecords Array public
Defined in packages/@ember/debug/data-adapter.ts:579
- returns
- Array
An array of records. This array will be observed for changes, so it should update when new records are added/removed.
Fetches all loaded records for a given type.
incrementProperty (keyName, increment) Number public
Inherited from Observable packages/@ember/object/observable.ts:495
- keyName
- String
The name of the property to increment
- increment
- Number
The amount to increment by. Defaults to 1
- returns
- Number
The new property value
Set the value of a property to the current value plus some amount.
person.incrementProperty('age');
team.incrementProperty('score', 2);
init public
Inherited from CoreObject packages/@ember/object/core.ts:318
An overridable method called when objects are instantiated. By default, does nothing unless it is overridden during class definition.
Example:
import EmberObject from '@ember/object';
const Person = EmberObject.extend({
init() {
alert(`Name is ${this.get('name')}`);
}
});
let steve = Person.create({
name: 'Steve'
});
// alerts 'Name is Steve'.
NOTE: If you do override init
for a framework class like Component
from @ember/component
, be sure to call this._super(...arguments)
in your init
declaration!
If you don't, Ember may not have an opportunity to
do important setup work, and you'll see strange behavior in your
application.
notifyPropertyChange (keyName) Observable public
Inherited from Observable packages/@ember/object/observable.ts:346
- keyName
- String
The property key to be notified about.
- returns
- Observable
Notify the observer system that a property has just changed.
Sometimes you need to change a value directly or indirectly without
actually calling get()
or set()
on it. In this case, you can use this
method instead. Calling this method will notify all observers that the
property has potentially changed value.
removeObserver (key, target, method, sync) Observable public
Inherited from Observable packages/@ember/object/observable.ts:457
- key
- String
The key to observe
- target
- Object
The target object to invoke
- method
- String|Function
The method to invoke
- sync
- Boolean
Whether the observer is async or not
- returns
- Observable
Remove an observer you have previously registered on this object. Pass
the same key, target, and method you passed to addObserver()
and your
target will no longer receive notifications.
set (keyName, value) Object public
Inherited from Observable packages/@ember/object/observable.ts:241
- keyName
- String
The property to set
- value
- Object
The value to set or
null
.- returns
- Object
The passed value
Sets the provided key or path to the value.
record.set("key", value);
This method is generally very similar to calling object["key"] = value
or
object.key = value
, except that it provides support for computed
properties, the setUnknownProperty()
method and property observers.
Computed Properties
If you try to set a value on a key that has a computed property handler
defined (see the get()
method for an example), then set()
will call
that method, passing both the value and key instead of simply changing
the value itself. This is useful for those times when you need to
implement a property that is composed of one or more member
properties.
Unknown Properties
If you try to set a value on a key that is undefined in the target
object, then the setUnknownProperty()
handler will be called instead. This
gives you an opportunity to implement complex "virtual" properties that
are not predefined on the object. If setUnknownProperty()
returns
undefined, then set()
will simply set the value on the object.
Property Observers
In addition to changing the property, set()
will also register a property
change with the object. Unless you have placed this call inside of a
beginPropertyChanges()
and endPropertyChanges(),
any "local" observers
(i.e. observer methods declared on the same object), will be called
immediately. Any "remote" observers (i.e. observer methods declared on
another object) will be placed in a queue and called at a later time in a
coalesced manner.
setProperties (hash) Object public
Inherited from Observable packages/@ember/object/observable.ts:289
- hash
- Object
the hash of keys and values to set
- returns
- Object
The passed in hash
Sets a list of properties at once. These properties are set inside
a single beginPropertyChanges
and endPropertyChanges
batch, so
observers will be buffered.
record.setProperties({ firstName: 'Charles', lastName: 'Jolley' });
toString String public
Inherited from CoreObject packages/@ember/object/core.ts:572
- returns
- String
string representation
Returns a string representation which attempts to provide more information
than Javascript's toString
typically does, in a generic way for all Ember
objects.
import EmberObject from '@ember/object';
const Person = EmberObject.extend();
person = Person.create();
person.toString(); //=> "<Person:ember1024>"
If the object's class is not defined on an Ember namespace, it will indicate it is a subclass of the registered superclass:
const Student = Person.extend();
let student = Student.create();
student.toString(); //=> "<(subclass of Person):ember1025>"
If the method toStringExtension
is defined, its return value will be
included in the output.
const Teacher = Person.extend({
toStringExtension() {
return this.get('fullName');
}
});
teacher = Teacher.create();
teacher.toString(); //=> "<Teacher:ember1026:Tom Dale>"
toggleProperty (keyName) Boolean public
Inherited from Observable packages/@ember/object/observable.ts:539
- keyName
- String
The name of the property to toggle
- returns
- Boolean
The new property value
Set the value of a boolean property to the opposite of its current value.
starship.toggleProperty('warpDriveEngaged');
watchModelTypes (typesAdded, typesUpdated) Function public
Defined in packages/@ember/debug/data-adapter.ts:299
- typesAdded
- Function
Callback to call to add types. Takes an array of objects containing wrapped types (returned from
wrapModelType
).- typesUpdated
- Function
Callback to call when a type has changed. Takes an array of objects containing wrapped types.
- returns
- Function
Method to call to remove all observers
Fetch the model types and observe them for changes.
watchRecords (modelName, recordsAdded, recordsUpdated, recordsRemoved) Function public
Defined in packages/@ember/debug/data-adapter.ts:347
- modelName
- String
The model name.
- recordsAdded
- Function
Callback to call to add records. Takes an array of objects containing wrapped records. The object should have the following properties: columnValues: {Object} The key and value of a table cell. object: {Object} The actual record object.
- recordsUpdated
- Function
Callback to call when a record has changed. Takes an array of objects containing wrapped records.
- recordsRemoved
- Function
Callback to call when a record has removed. Takes an array of objects containing wrapped records.
- returns
- Function
Method to call to remove all observers.
Fetch the records of a given type and observe them for changes.
willDestroy public
Inherited from CoreObject packages/@ember/object/core.ts:564
Override to implement teardown.