XBL library
Introduction
The XForms engine finds XBL bindings in the following ways:
Inline bindings, that is bindings under the form's
xh:head, are always processed.Bindings by name are searched in the Orbeon Forms resources.
Other bindings (such as bindings by attribute) are searched based on the
oxf.xforms.xbl.libraryproperty.
Inline bindings
You can place inline xbl:xbl elements within the xh:head element, at the same level as xf:model elements. For example:
By name bindings
Orbeon Forms allows for automatic inclusion of XBL bindings when matching by name only. This avoids including the XBL for those components in all the forms that use them. In addition, the bindings can be shared among forms, which saves memory and makes loading them faster.
Say element <acme:button> is found by the XForms engine, in your own http://www.acme.com/xbl namespace:
The resource, if found, is automatically included in the page for XBL processing.
Such bindings are checked for freshness every time a form is loaded. If a binding is out of date, it is reloaded and the form is recompiled.
Other bindings
Bindings which are not inline and which are not by name only need to be explicitly listed so that the XForms engine is able to process them. You do this with the oxf.xforms.xbl.library property.
With Orbeon Forms 4.9, this property is empty as no built-in XBL component binds by attribute in that version:
XBL components with bindings by attribute can be added using the same format used by oxf.xforms.resources.baseline. Component references are separated by whitespace. With Orbeon Forms 4.10, the property is as follows:
With Orbeon Forms 2016.1, the property is as follows:
The fr prefix must be in scope, and there must be a mapping (via oxf.xforms.xbl.mapping) for the URI associated with that prefix (this is the case by default for fr and http://orbeon.org/oxf/xml/form-runner).