Completed overview about prototype-Methods

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Oliver Sartun 2013-05-28 14:57:27 +02:00
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README.md
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@ -71,15 +71,108 @@ In order to set up you UndoManager you have to do the following steps:
// 3. Start tracking the changes
myUndoManager.startTracking(); // Everything that happens from now on, can be undone
## Undo or Redo Actions
## Backbone.Undo.js methods
To undo the last set of actions, just call `undo()`
Methods you can call on an instance of Backbone.Undo:
myUndoManager.undo();
### Constructor
To redo undone actions, call `redo()`
new Backbone.Undo([object]);
myUndoManager.redo();
The constructor can be called with an optional argument. The argument is an object of attributes. So far only the
attribute `maximumStackLength` is supported.
var undoManager = new Backbone.Undo; // possible, because arguments are optional
var undoManager = new Backbone.Undo({
maximumStackLength: 30
});
The attribute `maximumStackLength` defines how many undo-actions should be in the undo-stack at the utmost, which means
how many actions are undoable. The default value is `Infinity` so there's no limit at all.
### register
undoManager.register(obj, [obj, ...]);
Your undo-instance must know the object on which actions should be undone/redone. Therefore you have to register these
objects:
var model = new Backbone.Model;
var collection = new Backbone.Collection;
undoManager.register(model, collection);
The register-method doesn't check whether the object is an instance of Backbone.Model or Backbone.Collection. That makes
it possible to bind other objects which don't derive from Backbone constructors and yet have `on()` and `off()` methods
and trigger an `"all"` event.
### unregister
undoManager.unregister(obj, [obj, ...]);
Previously registered objects can be unregistered using the `unregister()` method. Changes to those objects can't be
undone after they have been unregsitered.
var myModel = new Backbone.Model;
undoManager.register(myModel);
undoManager.startTracking();
myModel.set("foo", "bar"); // Can be undone
undoManager.unregister(myModel);
myModel.set("foo", "baz"); // Can't be undone
### startTracking
undoManager.startTracking();
Your undo-manager won't store any changes that happen to registered objects until you called `startTracking()`.
var myModel = new Backbone.Model;
undoManager.register(myModel);
myModel.set("foo", "bar"); // Can't be undone because tracking changes didn't start yet
undoManager.startTracking();
myModel.set("foo", "baz"); // Can be undone
### stopTracking
undoManager.stopTracking();
If you want to stop tracking changes for whatever reason, you can do that by calling `stopTracking()`
myModel.set("foo", 1);
undoManager.startTracking();
myModel.set("foo", 2);
undoManager.stopTracking();
myModel.set("foo", 3);
undoManager.undo(); // "foo" is 1 instead of 2, because the last change wasn't tracked
// btw: You shouldn't call `undo` within your code. See 'Problems that may occur'
### undo
undoManager.undo();
The method to undo the last set of actions is `undo()`. It undoes all actions that happened within one call cycle. That's
why you shouldn't and can't call `undo()` within your code to undo actions. See 'Problems that may occur' for more
information.
### redo
undoManager.redo();
The method to redo an undone set of actions is `redo()`. Like `undo()` it redoes all actions that happened within
one call cycle. See 'Problems that may occur' for more information.
## Supported Events
Backbone.Undo.js uses Backbone-Events to generate the undo-actions. It has built-in support for the following events
* `add` When a model is added to a collection
* `remove` When a model is removed from a collection
* `reset` When a collection is reset and all models are replaced by new models (or no models) at once
* `change` When an attribute of a model was changed
### Supporting other events
If you want to generate undo-actions when other Backbone- or custom events are triggered, you can do so by extending
Backbone.Undo.
### Problems that may occur
@ -139,26 +232,3 @@ changes to the model asynchronously.
Obviously noone would ever do that. In fact you also shouldn't do that: Your webapp shouldn't have any reference to the
undo-manager within your code. Try to develop it independently from the undo-manager and then add an
undo-manager-controller which for example binds the undo/redo-calls to Shortcuts like ctrl+Z.
## Backbone.Undo.js methods
Methods you can call on an instance of Backbone.Undo:
### Constructor
The constructor can be called with an optional argument. The argument is an object of attributes. So far only the
attribute `maximumStackLength` is supported.
var undoManager = new Backbone.Undo; // possible, because arguments are optional
undoManager = new Backbone.Undo({
maximumStackLength: 30
});
The attribute `maximumStackLength` defines how many undo-actions should be in the undo-stack at the utmost, which means
how many actions are undoable. The default value is `Infinity` so there's no limit at all.
### startTracking
Your undo-manager won't store any changes that happen to registered objects until you called startTracking:
undoManager.startTracking()