Package org.apache.tapestry5.corelib.components

Class Trigger

  • public class Trigger
extends Object
    Triggers an arbitrary event during rendering. This is often useful to add JavaScript to a page or a component (via calls to the JavaScriptSupport environmental).
    Since:
    5.2.0
    Component Parameters 
    NameTypeFlagsDefaultDefault Prefix
    eventString  literal

    Examples

    In this example, we are showing how to trigger an event from the template of a page. When the following page is rendered the both instances of the component Trigger publish an arbitrary event.

    TriggerDemo.tml

    <html xmlns:t="http://tapestry.apache.org/schema/tapestry_5_1_0.xsd">
    <body>
        <h1>Trigger Demo</h1>
        
        <p> ... </p>

        <t:trigger event="addAdditionalScriptLinks"/>

        <p> ... </p>
        
        <t:trigger event="provideAdditionalMarkup"/>
    </body>
</html>

    Inside the handler method for the event addAdditionalScriptLinks we add a link to a JavaScript file. The handler method for the event provideAdditionalMarkup provides some additional markup. The MarkupWriter is passed as the event context.

    TriggerDemo.java

    public class TriggerDemo
{
    
    @Environmental
    private JavaScriptSupport jsSupport;
    
    @Inject @Path("context:js/scripts.js")
    private Asset scripts;
    
    public void onAddAdditionalScriptLinks()
    {
       jsSupport.importJavaScriptLibrary(scripts);
    }
    
    public void onProvideAdditionalMarkup(MarkupWriter writer)
    {   
        writer.writeRaw("Hello.");
    }
}

    • Constructor Detail