About Mashup Expression Language

The configuration of the Mashup UI through the Mashup Builder makes an extensive use of expressions such as ${feeds["cloudview"].metas["name"]} that allows you to construct text that contains dynamic content from your feeds.

These expressions, known as the Mashup Expression Language (MEL), actually provide much more than just dynamic variables and support common operations that would usually require editing JSP files.

See Also
Syntax
Handling Categories, Facets and entries

MEL Functions appear in a contextual menu on the left when you click in widget and property fields. The elements displayed in this contextual menu correspond to Mashup API elements in Atom format, for example:

  • ${feed.*} corresponds to <feed>

  • ${entry.*} corresponds to <entry>

  • etc.

    For more information about the Mashup API and its Atom elements, see Using the Mashup API in the Exalead CloudView Mashup Programmer's Guide.

Tip: When you add MEL expressions, you can verify their syntax by selecting the Debug tab and clicking Validate. You can also use the autocomplete function by pressing Ctrl+space.
Important: MEL is always computed server-side whereas JS is computed client-side. JS cannot be used inside MEL, but you can use MEL inside JS. For example, you can use MEL to iterate over a list and save values as an array/object init in JS, and then use this array/object in your JS.