XUL Scripts MIME types

The following script languages are supported:

• XUL Javascript scripts
• XUL Groovy scripts
• XUL Python scripts

Several MIME types are supported for each scripting language. The MIME is defined through the type attribute of the script element. For example:

      <script type="application/groovy">
      public int getValue(){
        return 10;
      }
      </script>

Languages MIME types

Javascript MIME types

The MIME types supported for Javascript scripts are:

• "text/javascript"
• "text/ecmascript"
• "application/javascript"
• "application/ecmascript"
• "application/x-javascript"

Groovy MIME types

The MIME types supported for Groovy scripts are:

• "text/groovy"
• "application/javascript"
• "application/groovy"
• "application/x-groovy"

Python MIME types

The MIME types supported for Python scripts are:

• "text/python"
• "application/python"
• "application/x-python"

Inferring script types

The algorithm to infer the language of a script is the following:

• If the script element has a type attribute, the framework will use this MIME type to get the language of the script
• If the script element has no type attribute but it is an external script, the framework will use the extension of the script file to infer the language of a script
• If the script is external but the file has no extension, or embedded without a type attribute, the framework will assume that it is a XUL Javascript script

For example:

• This script is detected as a XUL Groovy script because of the type attribute:

             <script type="text/groovy"> 
              public int clicked() {
                context.echo("Clicked!");
              }
             </script>
  

• This script is assumed by default to be a XUL Javascript script:

             <script> 
              function clicked() {
                print("Clicked!");
              }
             </script>
  

• This script is detected as a XUL Groovy script because of the file extension:

             <script src="myScript.groovy" />
  

Understanding Script parsing exceptions

You can have strange exceptions when parsing you script if you defined the wrong MIME type. For example if you have the following embedded script:

      <script>
      public int checked() {
        context.echo("checked!");
      }      
      </script>

The framework will show the following exception:

The reason here is that:

• You did not define a MIME type for your script
• As this is an embedded script, the framework assumed it was a XUL Javascript script
• Obviously it is a XUL Groovy script, so the framework tried to compile the script as Javascript but failed