Action Syntax
Last updated
Last updated
This feature is available since Orbeon Forms 2018.2.
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 dialog.
In addition to the features available through the , 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.
Clear repeated grid or repeated section repetitions.
Add repeated grid or repeated section repetitions.
Repeatedly run parts of an action. [SINCE Orbeon Forms 2019.1]
Conditionally run parts of an action. [SINCE Orbeon Forms 2019.1]
You place listeners and actions within the source code, preferably before the end of the main <xf:model> content. For example:
A listener looks like this:
version
Yes
format version
always 2018.2
modes
No
space-separated list of modes
The listener is enabled for each mode listed only. If absent, the listener is enabled for all modes.
events
Yes
space-separated list of event names
When more than one event name is present, the listener reacts if any of the listed events is present.
controls
Yes for events which relate to a particular control, like enabled or value-changed
space-separated list of control names
When more than one control name is present, the listener reacts if an event is dispatched to any of the listed controls.
actions
No, but nothing will happen if there is not at least one action referenced
space-separated list of action names
When more than one action name is present, all the specified actions are called when the listener reacts to an event.
NOTE: It is disallowed 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.
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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
An action looks like this:
version
Yes
format version
always 2018.2
name
Yes
action name
must be unique in the form definition
[SINCE Orbeon Forms 2019.1]
<fr:data-iterate> allows you to iterate over data. The contained actions are executed once for each value returned by the expression.
Containing actions can include one or more calls to services.
ref
Yes
sequence XPath expression
runs in the current XPath evaluation context
In the following example, each repetition adds a row to the grid, calls a service, passing the attachment id, and sets the attachment value on the last row.
[SINCE Orbeon Forms 2019.2]
Calls to <fr:data-iterate> can be nested. This allows, for example, filling nested repeated sections and/or grids with the result of a service call that returns hierarchical data.
Example:
[SINCE Orbeon Forms 2019.1]
<fr:if> allows you to conditionally run a block of actions.
condition
Yes
boolean XPath expression
runs in the current XPath evaluation context
In the following example, with the repetition performed by <fr:data-iterate>, the call to the service that retrieves an attachment depends on whether there is a non-blank attachment id provided.
Previously, actions were run synchronously. That is, they were blocking any other form processing until completed. It is now possible to run actions asynchronously. This means that the form processing can continue while the actions are running in the background. This is particularly useful when the actions call services.
You can enable asynchronous actions:
at the action level, using the async="true attribute
at the form level, using the oxf.fr.detail.actions.async.*.* property
Example of configuration property:
It is currently not possible to mix and match synchronous and asynchronous service calls within a given action.
An asynchronous action, by default, causes a response to the client (web browser) to wait forever for its completion. This is done to enhance the backward-compatibility of asynchronous actions. This can be disabled:
at the action level, using the response-must-await="0ms" attribute (or 0 followed by any other unit allowed as shown below)
at the form level, using the oxf.fr.detail.actions.response-must-await.*.* property
Example of configuration property:
If response-must-await is set to 0ms, a response to the client doesn't wait for the completion of asynchronous actions. Instead, the response is sent immediately, and the pending action's service calls continue to wait in the background. The client polls the server at regular intervals to check for the completion of such pending services, and then resumes the processing of the actions. This is useful when an action calls long-running services, and you don't want to keep the client waiting for its completion.
Possible values for this property and attribute are:
forever
"$length$unit" (whitespace allowed around and between tokens)
$length is a positive long integer value
$unit is as described below
h
hours
m
minutes
s
seconds
ms
milliseconds
Practically, units in the ms and s ranges are the most useful.
Examples:
response-must-await="0ms": don't wait
response-must-await="200ms": wait up to 200 milliseconds
response-must-await="5s": wait up to 5 seconds
response-must-await="forever"`: wait indefinitely
For example, the Form Runner Landing page runs multiple background services to load lists of published forms. The page waits a few hundreds of milliseconds for the completion of those services, and if they take longer, for example due to a slow database, the page is shown to the user, and the services continue to run in the background.
In the future, asynchronous actions will likely be enabled by default.
Many individual actions refer to form controls. When form controls are present in a repeated section or repeated grid, there can be ambiguity as to which control is being referred to.
For this reason, an optional at attribute can be specified. That attribute is a space-separated list of tokens, one for each repetition level.
A token can take the following values:
start: the first repetition
end: the last repetition
a strictly positive integer: the repetition at that specific position
When the at attribute is not present, it defaults to being relative to the action source. This usually means targeting the first repetition.
The following example sets the value of the control my-repeated-value in all repetitions of the my-repeated-value repeated grid to 42
Assume now that the control my-repeated-value is within a repeated grid, itself nested within two levels of repeated sections. The following example sets the value of the control my-repeated-value in the third repetition of the last repetition of the first repetition to 42:
<fr:service-call> calls a service by name.
service
Yes
name of the service to call
must be an existing service
or:
control
No
control name
either this or value must be specified
value
No
value expression
either this or control must be specified
ref
Yes
destination expression
points to an element or attribute in the request XML
control
No
control name
either this or value must be specified
value
No
value expression
either this or control must be specified
name
Yes
parameter name
URL parameter name
control
No
control name
either this or value must be specified
value
No
value expression
either this or control must be specified
index
Yes
positive integer
SQL query parameter index
repeat
Yes
repeated grid or repeated section name
at
No
space-delimited position tokens: start, end, or a positive integer
missing leading tokens default to end
This action starts by identifying a single repeated grid or section with the repeat attribute. See <fr:repeat-add-iteration> for details. The only difference is that with this action, at is only used to identify the ancestor repeated sections if any.
With my-repeated-grid nested within my-repeated-section:
Remove all repetitions of my-repeated-section:
Remove all repetitions of the last my-repeated-grid:
Remove all repetitions of the first my-repeated-grid:
Remove all repetitions of the second my-repeated-grid:
repeat
Yes
repeated grid or repeated section name
at
No
space-delimited position tokens: start, end, or a positive integer
missing leading tokens default to end
This action starts by identifying a single repeated grid or section with the repeat attribute. If the repeated grid or section is at the top-level, there is only one possible match. If the repeated grid or section is nested within one or more repeated sections, then a single repetition of the ancestor repeated sections is determined using the optional at attribute.
With my-repeated-grid nested within my-repeated-section:
Insert a new repetition at the end of the last my-repeated-grid:
or:
or:
Insert a new repetition at the end of the first my-repeated-grid:
Insert a new repetition at the start of the first my-repeated-grid:
Insert a new repetition after repetition 2 of the third my-repeated-grid:
Insert a new repetition at the end of my-repeated-section:
or:
repeat
Yes
repeated grid or repeated section name
at
No
space-delimited position tokens: start, end, or a positive integer
missing leading tokens default to end
This action starts by identifying a single repeated grid or section with the repeat attribute. See <fr:repeat-add-iteration> for details.
With my-repeated-grid nested within my-repeated-section:
Remove the last repetition of the last my-repeated-grid:
or:
or:
Remove the last repetition of the first my-repeated-grid:
Remove repetition 2 of the third my-repeated-grid:
<fr:control-setvalue/> sets the value of a form control.
control
Yes
control name
value
Yes
value expression
value to set
at
No
space-delimited position tokens: start, end, or a positive integer
missing leading tokens default to end
[SINCE Orbeon Forms 2020.1]
<fr:control-clear/> clears the value of a control. For attachment controls, this clears the file but also the file metadata (filename, mediatype, and size).
control
Yes
control name
at
No
space-delimited position tokens: start, end, or a positive integer
missing leading tokens default to end
Example:
<fr:control-setitems/> sets the choices (or "itemset") of a selection control such as a dropdown or radio buttons.
control
Yes
control name
items
Yes
XPath expression returning one XPath item for each choice
label
Yes
relative XPath expression returning the label for the current choice
hint
No
relative XPath expression returning the hint for the current choice
[SINCE Orbeon Forms 2020.1]
value
Yes
relative XPath expression returning the value for the current choice
at
No
space-delimited position tokens: start, end, or a positive integer
missing leading tokens default to end
NOTE: Hints are only supported for checkboxes and radio buttons as of Orbeon Forms 2020.1.
name
Yes
dataset name
This action takes the latest service result and saves it to the dataset specified by name. Example:
[SINCE Orbeon Forms 2022.1.2]
name
Yes
dataset name
This action clears the content of the dataset with the given name. Specifically, it replaces it with a single anonymous root element (<_/>). Example:
[SINCE Orbeon Forms 2019.1]
scope
Yes
property scope
name
Yes
process name
[SINCE Orbeon Forms 2019.1]
location
Yes
path or URL
2024.1.1
target
No
_self or _blank or name of the browsing context
where to display the location
[SINCE Orbeon Forms 2019.1]
control
Yes
control name
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:
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>
<fr:control-setsize>
[SINCE Orbeon Forms 2019.1]
control
Yes
control name
value
Yes
value expression
value of the filename to set
This action allows setting the filename of an attachment control. Example:
This supports the following controls:
<fr:attachment>
<fr:image-attachment>
[SINCE Orbeon Forms 2019.1]
control
Yes
control name
value
Yes
value expression
value of the mediatype to set
This action allows setting the mediatype of an attachment control. Example:
This supports the following controls:
<fr:attachment>
<fr:image-attachment>
Note that the <fr:control-setattachment> action automatically sets a mediatype.
control
Yes
control name
value
Yes
value expression
value of the size to set
This action allows setting the mediatype of an attachment control. Example:
This supports the following controls:
<fr:attachment>
<fr:image-attachment>
Note that the <fr:control-setattachment> action automatically sets a size.
[SINCE Orbeon Forms 2022.1.2]
control
Yes
control name
This action allows setting the focus on a form control. Example:
[SINCE Orbeon Forms 2022.1.2]
control
Yes
control name
visited
No
true or false
defaults to true
This action allows setting whether a form control is visited or not. Example:
When working with actions, some form controls can benefit from having their "visited" status reset so that the user doesn't see extra errors appear. The <fr:control-setvisited> action allows doing that.
[SINCE Orbeon Forms 2022.1, 2021.1.2, 2020.1.7] The <fr:alert> action is intended to be used for debugging, allowing you to get some visibility on the value of intermediary results, or more generally the value of any expression is at a given point.
message
Yes
path or URL
Yes
The <fr:copy-content> action allows you to copy form content:
from non-repeated form controls to other non-repeated form controls
from non-repeated form controls to repeated form controls
from repeated form controls to other repeated form controls
Assuming that:
control-1, control-2, control-3, and control-4 are all within repeated grids or repeated sections
non-repeated-control is non-repeated, and control-5 is repeated
Then, in the following example, each <fr:map> expresses that all repeated controls denoted by the left attribute (source) are copied to the corresponding repeated controls denoted by the right attribute (destination).
When both the source and destination are repeated, the destination repeat's iterations are enforced, which means:
Extra iterations in the destination are removed from the end if needed, to match the number of iterations in the source.
New iterations in the destination are added at the end if needed, to match the number of iterations in the source.
For each iteration, the values of controls specified with <fr:map> are copied over.
Each <fr:map> element can individually refer to separate repeated grids and sections. In other words, not all left need to be in the same repeated grid or section, and not all right need to be in the same repeated grid or section.
When the source is non-repeated and the destination is also non-repeated, the value of the control is simply copied.
When the source is non-repeated and the destination is repeated, the value of the control is copied to one or more of the destination controls. The right-at attribute can be used to control this behavior:
start: first control only
end: last control only
strictly positive integer: specific position
all: all controls
This scenario is not supported yet.
When the warn attribute is set to true, the action will show a warning dialog if the action will overwrite existing content in the destination. An overwrite is considered when:
The destination has more iterations than the source.
The destination has the same number of iterations as the source or less, but the action would overwrite a non-blank destination value.
The default is false.
With Orbeon Forms 2018.2, errors when running services are silently ignored and the action continues.
With Orbeon Forms 2019.1, errors:
cause the entire action to stop.
run the oxf.fr.detail.process.action-service-error process
The default implementation of the service error process is as follows:
You can provide your own service error process in properties-local.xml.
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.
To be more explicit, the attribute can also be set on the first <fr:value>:
For concrete examples of Action Syntax use, see .
See also for the detail of the form load events.
all: all controls
When calling an , you can set XML request body values using nested <fr:value> elements.
When calling an , you can pass URL parameters using nested <fr:url-param> elements.
When calling a , you can pass parameters using nested <fr:sql-param> elements.
In Orbeon Forms, a form control can be visited or not. Visited controls have been visited by the user, which means that the user navigated through the form control, possibly without changing its value. One way to visit form controls is to navigate using the "Tab" key, or to click on the form control and then click outside of it. Another way is to use the default "Save" or "Send" buttons, which by default visit all the form controls before proceeding. The notion is used to determine whether to show validation errors associated with that form control. Form controls can also be visited when they are calculated, visible, and their value changes.
The value of the message attribute uses the , so the example below would show a dialog with the message "The answer is 42".
See also .
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