Syntax

Abstract

Actions are written in two ways, depending on whether you want to use a group of action or a single action.

When using a group of actions, you place them in an <xforms:action> tag. This groups the actions together, so that the actions all respond to the same trigger event. Once triggered, each action is processed in turn. The following syntax applies:

   <xforms:action ev:event="event"

								context="context"

								if="condition"

								while="while-condition"

								iterate="for-each" >

      <action1 action_settings>

...

      <actionn action_settings>

   </xforms:action>

Table 1. xforms actions parameters

Parameter	Type	Description
action	string	The specific type of action you want to use.
action_setting	string	One or more attributes that sets any values required for the specific action, as well as attributes for any of the parameters below.
context	XPath	Optional. Resets the in-scope evaluation context node for other attributes on the xforms:action and other actions within the xforms:action.
event	string	This sets the event that will trigger the actions. For more information about events, refer to XForms event handlers.
condition	XPath	Optional. An XPath expression that evaluates to either true or false. If false, the actions within the xforms:action tag are not processed. This expression is evaluated relative to the context set by its nearest ancestor with a single node or nodeset binding. This allows for conditional logic within actions.
for-each	XPath	Optional. The actions in the xforms:action are performed once for each node in the nodeset obtained by this expression. The actions are performed in the context of each of the nodes.
while-condition	string	Optional. An XPath expression that provides a looping condition for the action This works like a standard while loop expression. While the condition is true, the loop will run. Useful to delete all table rows or copy any number of elements from one parent to another.

Optionally, you can use only a single action. In this case, no <xforms:action> tag is required, as the triggering event is included on the action's tag. This is written as shown:

   <action ev:event="event"

											 context="context"

											 if="condition"

											 while="while-condition"

											 iterate="for-each" specific_action_settings>

Table 2. xform action parameter

Parameter	Type	Description
action	string	The specific type of action you want to use.
context	XPath	Optional. Resets the in-scope evaluation context node for certain other attributes on the action.
event	string	This sets the event that will trigger the action. For more information about events, refer to XForms event handlers.
condition	XPath	Optional. An XPath expression that evaluates to either true or false. If false, the action is not processed. This expression is evaluated relative to the context set by its nearest ancestor with a single node or nodeset binding, or by the context set by the context attribute. This allows for conditional logic within actions.
for-each	XPath	Optional. The action is performed once for each node in the nodeset obtained by this expression. The actions are performed in the context of each of the nodes.
while-condition	string	Optional. An XPath expression that provides a looping condition for the action. This works like a standard while loop expression. While the condition is true, the loop will run. Useful to delete all table rows or copy any number of elements from one parent to another.
specific_action_setting	string	One or more attributes that sets any values required for the specific action.

Note that all actions are in the XForms namespace, and are preceded by the xforms: prefix. Futhermore, all action settings are written as attributes.

Parent topic:
XForms actions