Custom model logic

[SINCE Orbeon Forms 4.4]

NOTE: This is an advanced feature which requires XForms knowledge.

It can be useful to be able to define custom model logic, either for a particular form or shared among a number of forms. The oxf.fr.detail.model.custom property allows you to do just that:

<property
  as="xs:anyURI"
  name="oxf.fr.detail.model.custom.*.*"
  value="oxf:/forms/acme/whizz.xml"/>

The value of the property is a URL which points to a file containing the custom logic. The format of the file is that of an XForms model. The custom content is included in your form's main model, which is identified by fr-form-model. This means that you have access to your form data in instance fr-form-instance, for example.

Here is a very simple example:

<xf:model xmlns:xf="http://www.w3.org/2002/xforms">
    <xf:message event="foobar">Your email is: <xf:output value="instance()//email"/>.</xf:message>
</xf:model>

Here we define custom XForms that reacts to an event called foobar and displays a message to the user.

We can create a custom button that dispatches that event with the following properties:

<!-- Place custom button on all `acme` forms -->
<property
  as="xs:string"
  name="oxf.fr.detail.buttons.acme.*"
  value="whizz"/>

<!-- Label for the button -->
<property
  as="xs:string"
  name="oxf.fr.resource.acme.*.en.detail.buttons.whizz"
  value="Whizz"/>

<!-- React to button activation by dispatching the event -->
<property
  as="xs:string"
  name="oxf.fr.detail.process.whizz.acme.*"
  value='xf:dispatch("foobar")'/>

<!-- Specify the custom model content -->
<property
  as="xs:anyURI"
  name="oxf.fr.detail.model.custom.acme.*"
  value='oxf:/forms/acme/whizz.xml'/>

The result: