Engine API Reference - v2.6.1
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    Class Component

    Components are used to attach functionality on a Entity. Components can receive update events each frame, and expose properties to the PlayCanvas Editor.

    Hierarchy (View Summary)

    Index

    Properties

    Accessors

    Methods

    Properties

    entity: Entity

    The Entity that this Component is attached to.

    The ComponentSystem used to create this Component.

    Accessors

    Methods

    • Fire an event, all additional arguments are passed on to the event listener.

      Parameters

      • name: string

        Name of event to fire.

      • Optionalarg1: any

        First argument that is passed to the event handler.

      • Optionalarg2: any

        Second argument that is passed to the event handler.

      • Optionalarg3: any

        Third argument that is passed to the event handler.

      • Optionalarg4: any

        Fourth argument that is passed to the event handler.

      • Optionalarg5: any

        Fifth argument that is passed to the event handler.

      • Optionalarg6: any

        Sixth argument that is passed to the event handler.

      • Optionalarg7: any

        Seventh argument that is passed to the event handler.

      • Optionalarg8: any

        Eighth argument that is passed to the event handler.

      Returns EventHandler

      Self for chaining.

      obj.fire('test', 'This is the message');
      
    • Test if there are any handlers bound to an event name.

      Parameters

      • name: string

        The name of the event to test.

      Returns boolean

      True if the object has handlers bound to the specified event name.

      obj.on('test', () => {}); // bind an event to 'test'
      obj.hasEvent('test'); // returns true
      obj.hasEvent('hello'); // returns false
    • Detach an event handler from an event. If callback is not provided then all callbacks are unbound from the event, if scope is not provided then all events with the callback will be unbound.

      Parameters

      • Optionalname: string

        Name of the event to unbind.

      • Optionalcallback: HandleEventCallback

        Function to be unbound.

      • Optionalscope: any

        Scope that was used as the this when the event is fired.

      Returns EventHandler

      Self for chaining.

      const handler = () => {};
      obj.on('test', handler);

      obj.off(); // Removes all events
      obj.off('test'); // Removes all events called 'test'
      obj.off('test', handler); // Removes all handler functions, called 'test'
      obj.off('test', handler, this); // Removes all handler functions, called 'test' with scope this
    • Attach an event handler to an event.

      Parameters

      • name: string

        Name of the event to bind the callback to.

      • callback: HandleEventCallback

        Function that is called when event is fired. Note the callback is limited to 8 arguments.

      • Optionalscope: any = ...

        Object to use as 'this' when the event is fired, defaults to current this.

      Returns EventHandle

      Can be used for removing event in the future.

      obj.on('test', (a, b) => {
      console.log(a + b);
      });
      obj.fire('test', 1, 2); // prints 3 to the console
      const evt = obj.on('test', (a, b) => {
      console.log(a + b);
      });
      // some time later
      evt.off();
    • Attach an event handler to an event. This handler will be removed after being fired once.

      Parameters

      • name: string

        Name of the event to bind the callback to.

      • callback: HandleEventCallback

        Function that is called when event is fired. Note the callback is limited to 8 arguments.

      • Optionalscope: any = ...

        Object to use as 'this' when the event is fired, defaults to current this.

      Returns EventHandle

      • can be used for removing event in the future.
      obj.once('test', (a, b) => {
      console.log(a + b);
      });
      obj.fire('test', 1, 2); // prints 3 to the console
      obj.fire('test', 1, 2); // not going to get handled