Availability

This feature is available since Orbeon Forms 2018.2.

Rationale

Orbeon Forms supports services and actions. With Orbeon Forms 2018.2, a first step towards more powerful actions is introduced. There is no interface for it yet, but instead an XML configuration which you can paste into the form definition via the "Edit Source" dialog.

Enhancements

In addition to the features available through the "Actions" dialog, the following enhancements are available:

• Call an action in response to multiple events.

• Support more event types.

• Call an arbitrary number of services.

• Run actions without calling services.

• Iterate over service responses.

• Clear repeated grid or repeated section iterations.

• Add repeated grid or repeated section iterations.

Updating the form definition

You place listeners and actions within the source code, preferably before the end of the main <xf:model> content. For example:

    <!-- other Form Builder code here -->
​
    <fr:listener
        version="2018.2"
        .../>
​
    <fr:action name="my-action" version="2018.2">
        ...
    </fr:action>
​
    <!-- Put `<fr:listener>` and `<fr:action>` just above this. -->
</xf:model>

Error handling

With Orbeon Forms 2018.2, errors when running services are silently ignored and the action continues.

With Orbeon Forms 2019.1, errors:

1. cause the entire action to stop.

2. run the oxf.fr.detail.process.action-service-error process

The default implementation of the service error process is as follows:

<property as="xs:string"  name="oxf.fr.detail.process.action-service-error.*.*">
    error-message("service-error")
</property>

You can provide your own service error process in properties-local.xml.

Evaluation context of XPath expressions

The context item used for XPath evaluations is set as follows:

• At the beginning of an action, it is the root element of the form data.

• Within an <fr:data-iterate>, and until a service response is available, it is the current iteration item.

• After a service call, whether at the top-level or within an <fr:data-iterate>, it is the root element of the preceding action response.

[SINCE Orbeon Forms 2019.1]

You can explicitly set the XPath evaluation context to the current iteration item within a <fr:data-iterate> with the expression-context attribute set to current-iteration.

In the following example, without the expression-context="current-iteration" attribute, the second <fr:value> would evaluate within the context of the first service call's response.

<fr:data-iterate ref="/response/row">
    <fr:service-call service="my-first-service">
        <fr:value
            value="foo"
            ref="/some/path"/>
    </fr:service-call>
    <fr:service-call service="my-second-service">
        <fr:value
            expression-context="current-iteration"
            value="bar"
            ref="/some/other/path"/>
    </fr:service-call>
</fr:data-iterate>

To be more explicit, the attribute can also be set on the first <fr:value>:

<fr:data-iterate ref="/response/row">
    <fr:service-call service="my-first-service">
        <fr:value
            expression-context="current-iteration"
            value="foo"
            ref="/some/path"/>
    </fr:service-call>
    <fr:service-call service="my-second-service">
        <fr:value
            expression-context="current-iteration"
            value="bar"
            ref="/some/other/path"/>
    </fr:service-call>
</fr:data-iterate>

Repeated calls to services

[SINCE Orbeon Forms 2019.1]

You can iterate over data and call a given service multiple times. Consider a service returning a list of images ids, and a service returning the content of an image by id, for example. Here is an example that does just that:

<fr:action name="populate-attachments" version="2018.2">
​
    <fr:service-call service="get-attachments-list"/>
​
    <fr:repeat-clear repeat="attachments-grid"/>
​
    <fr:data-iterate ref="/response/text">
​
        <fr:service-call service="get-attachment">
            <fr:url-param name="text" value="."/>
        </fr:service-call>
​
        <fr:repeat-add-iteration  repeat="attachments-grid"  at="end"/>
        <fr:control-setattachment control="image-attachment" at="end"/>
    </fr:data-iterate>
​
</fr:action>

Currently, this is only supported with one level of nesting within <fr:data-iterate>.

Example

The following example:

• listens to an activation event on the button my-button

• in response, calls the my-action action, which

  • sets values from controls into the my-service service request

  • calls the my-service service

• when the service call completes

  • the my-repeated-grid repeated grid is cleared

  • iterating over the XML response, for each iteration

    • adds an iteration at the end of the my-repeated-grid repeated grid

    • sets the value of controls on the new iteration

  • finally, all the result-dropdown dropdown control items are updated

    <!-- other Form Builder code here -->
​
    <fr:listener
        version="2018.2"
        events="activated"
        controls="my-button"
        actions="my-action"/>
​
    <fr:action name="my-action" version="2018.2">
​
        <fr:service-call service="my-service">
            <fr:value control="foo" ref="/*/request/foo"/>
            <fr:value control="bar" ref="/*/request/bar"/>
        </fr:service-call>
​
        <fr:repeat-clear repeat="my-repeated-grid"/>
​
        <fr:data-iterate ref="/*/response/row">
            <fr:repeat-add-iteration repeat="my-repeated-grid" at="end"/>
            <fr:control-setvalue value="@field" control="result-field" at="end"/>
            <fr:control-setvalue value="@dropdown" control="result-dropdown" at="end"/>
        </fr:data-iterate>
​
        <fr:control-setitems
            items="/*/response/item"
            label="@label"
            value="@value"
            control="result-dropdown"/>
​
    </fr:action>
​
    <!-- Put `<fr:listener>` and `<fr:action>` just above this. -->
</xf:model>

Syntax

Listeners

Basic syntax

A listener looks like this:

<fr:listener
    version="2018.2"
    modes="..."
    events="..."
    controls="..."
    actions="..."
>

NOTE: It is not recommended to mix and match, in a single listener, events for which a control name is required and events for which a control name is not required. Instead, use multiple listeners.

Modes supported

• new

• edit

• view

• pdf

Events supported

Controls:

• enabled: the control has become enabled

• disabled: the control has become disabled

• visible: the control has become visible (for example in a wizard page)

• hidden: the control has become hidden (for example in a wizard page)

• value-changed: the value of an enabled control has changed

• activated: the control has been activated (clicked, or enter in text field)

• item-selected: an item of an enabled control has been selected

• item-deselected: an item of an enabled control has been deselected

Form load:

• form-load-before-data: run before the data's initial values are calculated

• form-load-after-data: run when the data is ready

• form-load-after-controls: run after the controls are ready

See also Running processes upon page load for the detail of the form load events.

Actions

Basic syntax

An action looks like this:

<fr:action version="2018.2">

• version

  • mandatory action format version

  • must always be 2018.2

Calling a service

<fr:service-call>

Iterating over data

<fr:data-iterate>

Removing all iterations of a repeat

<fr:repeat-clear>

Adding iterations to a repeat

<fr:repeat-add-iteration>

Removing iterations from a repeat

<fr:repeat-remove-iteration>

Setting the value of a control

<fr:control-setvalue/>

Setting the choices of a selection control

<fr:control-setitems>

Writing to a dataset

<fr:dataset-write
    name="dataset-name"/>

This action takes the latest service result and saves it to the dataset specified by name.

Calling a process

[SINCE Orbeon Forms 2019.1]

<fr:process-call
    scope="oxf.fr.detail.process"
    name="send"/>

Navigating to a page or URL

[SINCE Orbeon Forms 2019.1]

<fr:navigate
    location="https://www.bbc.com/news"/>

Setting the value of an attachment control

[SINCE Orbeon Forms 2019.1]

When the response of a service is binary, this action allows setting the value of an attachment control to the content of the service response:

<fr:control-setattachment
    control="my-attachment"/>

This supports the following controls:

• <fr:attachment>

• <fr:image-attachment>

The mediatype and received by the service and the actual size of the attachment are automatically set. However, the filename is not set automatically.

See also the following actions:

• <fr:control-setfilename>

• <fr:control-setmediatype>

Setting the filename of an attachment control

[SINCE Orbeon Forms 2019.1]

This action allows setting the filename of an attachment control:

<fr:control-setfilename
    control="my-attachment"
    value="'My Image.png'"/>

This supports the following controls:

• <fr:attachment>

• <fr:image-attachment>

Setting the mediatype of an attachment control

[SINCE Orbeon Forms 2019.1]

This action allows setting the mediatype of an attachment control:

<fr:control-setmediatype
    control="my-attachment"
    value="'image/png'"/>

This supports the following controls:

• <fr:attachment>

• <fr:image-attachment>

Note that the <fr:control-setattachment> action automatically sets a mediatype.

See also

• ​Actions​

• ​HTTP services​

• ​Database services​