Table of Contents
Description
The <script> element allows the definition of functions to initialize the component, and to respond to events (including key events) and field value changes. The BrightScript interfaces for the SceneGraph nodes used by BrightScript are the same interfaces defined for roSGNode objects.
You can include any type of BrightScript object declarations, definitions, and creation, and the related functions to operate on the BrightScript objects, in a <script> element, except for certain objects and functions that must be used asynchronously in a Task node (see BrightScript Support). In addition, there are two functions that are declared specifically for use in SceneGraph component <script> elements:
Relative URIs
Available since firmware version 7.6
BrightScript files can be imported using relative URIs. If the uri does not specify a complete pkg: file path, the uri will be interpreted as a file path relative to the XML file.
For example, given an XML file called MainScene.xml located at:
pkg:/components/framework/MainScene.xml
A .brs file can have the following uri:
<script type="text/brightscript" uri="Task.brs" />
and resolve to:
pkg:/components/framework/Task.brs
Attributes
The <script> element has two attributes.
| Attribute | Required | Description |
|---|---|---|
| type | required | A string defining the type of the script. This should be set to "text/brightscript" for BrightScript code. |
| uri | optional | A string specifying an external file that contains script code associated with the component. This file must be located in the pkg:/components directory of the application, and have the .brs extension for BrightScript code. |
Examples
Here's an example of a BrightScript function that creates a component named StopWatch parented to the root node of the component, and sets its translation field to x=100, y=200:
function createStopwatch(parent as object) as object
stopWatch = m.top.createChild("StopWatch")
stopWatch.translation = [100, 200]
return stopWatch
end function
The <script> element contains zero or more BrightScript functions. Because BrightScript can contain special characters reserved for XML, the body of the <script> element must be enclosed in an XML CDATA section. For example:
<script type = "text/brightscript" >
<![CDATA[
function createStopwatch(parent as object) as object
stopWatch = m.top.createChild("StopWatch")
stopWatch.translation = [100, 200]
return stopwatch
end function
]]>
</script>
The CDATA section can contain any valid BrightScript code, including any BrightScript library.
BrightScript code can also be included from an external file using the uri attribute of the <script> element:
<script type = "text/brightscript" uri = "pkg:/components/VideoTheater.brs" />
XML component files may include more than one <script> element. This allows for the dividing the BrightScript code into logical groupings, as well as including BrightScript source from more than one external file.