Class DataAdapter

public

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:

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Application.initializer({
  name: "data-adapter",

  initialize: function(application) {
    application.register('data-adapter:main', DS.DataAdapter);
  }
});

Show:

Module: @ember/debug
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).
component.js
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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:

component.js
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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.

Module: @ember/debug
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.

Module: @ember/debug
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.

Module: @ember/debug
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.

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player.decrementProperty('lives');
orc.decrementProperty('health', 5);
Module: @ember/debug
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.

Module: @ember/debug
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.

Module: @ember/debug
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:

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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.

Module: @ember/debug
returns
Array
List of objects defining filters. The object should have a `name` and `desc` 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.

Module: @ember/debug
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:

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record.getProperties('firstName', 'lastName', 'zipCode');
// { firstName: 'John', lastName: 'Doe', zipCode: '10011' }

is equivalent to:

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record.getProperties(['firstName', 'lastName', 'zipCode']);
// { firstName: 'John', lastName: 'Doe', zipCode: '10011' }
Module: @ember/debug
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.

Module: @ember/debug
returns
Object
Keys should match column names defined by the model type.

Gets the values for each column.

Module: @ember/debug
record
Object
The record instance.
returns
Object
The filter values.

Returns the values of filters defined by getFilters.

Module: @ember/debug
returns
Array
Relevant keywords for search.

Returns keywords to match when searching records.

Module: @ember/debug
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.

Module: @ember/debug
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.

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person.incrementProperty('age');
team.incrementProperty('score', 2);
Module: @ember/debug

An overridable method called when objects are instantiated. By default, does nothing unless it is overridden during class definition.

Example:

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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.

Module: @ember/debug
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.

Module: @ember/debug
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.

Module: @ember/debug
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.

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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.

Module: @ember/debug
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.

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record.setProperties({ firstName: 'Charles', lastName: 'Jolley' });
Module: @ember/debug
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.

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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:

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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.

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const Teacher = Person.extend({
  toStringExtension() {
    return this.get('fullName');
  }
});
teacher = Teacher.create();
teacher.toString(); //=> "<Teacher:ember1026:Tom Dale>"
Module: @ember/debug
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.

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starship.toggleProperty('warpDriveEngaged');
Module: @ember/debug
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.

Module: @ember/debug
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.

Module: @ember/debug

Override to implement teardown.