Extending Jcrop

Due to its elegant object-oriented design, it's easy to extend Jcrop in your application without modifying the Jcrop source code.

Proceed with caution!

Any customizations or changes you make can cause errors or future incompatibilities. It is not recommended to extend Jcrop unless you are very sure of what you're doing!

Why extend Jcrop?

  • Experiment with bug fixes or modifications
  • Create customized behavior or interfaces

Extensible Classes

Option Name Jcrop Class Description
widgetConstructor Jcrop.Widget Cropping Widget
stageConstructor Jcrop.Stage Default DOM stage

Extending Jcrop classes

Here's a class extended from Jcrop.Widget that logs Rect coordinates to the console each time the widget is redrawn/rendered. It augments the default behavior by calling a super method.

class MyWidget extends Jcrop.Widget {
  render(pos) {

See the following sections for how to use this extended class with Jcrop, as well as a list of classes that can be extended through Jcrop options.

Replacing global default

The global defaults for Jcrop can be modified before Jcrop.attach() or similar method is called. This will affect all subsequent invocations.

Jcrop.defaults.widgetConstructor = MyWidget;

With a single instance

Pass the configuration key when attaching an instance. This setting will affect all objects constructed by the instance as long as the options are in effect.

Jcrop.attach('target',{ widgetConstructor: MyWidget });

Update existing instance

Use setOptions() method to update an existing instance.

jcrop.setOptions({ widgetConstructor: MyWidget });

Don't be late to the party

As most classes are used to build parts of the interface, updating classes/constructors on an existing instance only affects objects constructed after your change.