It is possible to write ECAs for specific entities using an Entity Event Condition Action (EECA) For example, to trigger an Event, say a notification Service, when a field in an entity changes, you could write an EECA as we shall see in this recipe.
Triggering a notification Service using EECA can be done by following these steps:
- If one does not already exist, add an entry in the
ofbiz-component.xmlfile to identify the EECA definition file location as shown:<entity-resource type="eca" reader-name="main" loader="main" location="entitydef/eecas.xml"/>
- Create or add an EECA definition file with an XML version declaration and an XML XSD schema declaration, as shown here:
<?xml version="1.0" encoding="UTF-8"?> <entity-eca xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation= "http://ofbiz.apache.org/dtds/entity-eca.xsd">
- Add one or more EECA definitions to the EECA definition file. Don't forget to close each
ecaelement declaration with a closing tag (</eca>).<!-- To maintain FinAccount.actualBalance and FinAccount.availableBalance --> <eca entity="FinAccountTrans" operation="create-store" event="return"> <action service="updateFinAccountBalancesFromTrans" mode="sync"/> </eca>
- Be sure to close all XML element tags.
- Save and close the EECA definition file.
- Restart OFBiz to make the changes effective.
EECA rules are checked before and/or after a call to access the database. Services defined by the action element are invoked when the configured entity is accessed by way of the operation attribute setting.
Commonly used EECA attribute values are shown in the following table:
|
eca tag (Required) | ||
|---|---|---|
|
Attribute name |
Required? |
Description |
|
|
Yes |
The name of the entity on which this operation and Event are to be applied to. |
|
|
Yes |
Valid values: |
|
|
Yes |
Valid Values: |
To configure action elements for an EECA, the following configuration attribute values are supported:
|
action tag (Required) | ||
|---|---|---|
|
Attribute name |
Required? |
Description |
|
|
Yes |
The name of the Service to call if this operation is encountered. |
|
|
Yes |
Valid values: |
|
|
No |
Values to pass to the Service being called as a result of this ECA. |
To add one or more triggering conditions, add condition element declarations with the appropriate settings:
|
condition Tag (optional) Used to trigger actions based on one or more Entity fields meeting the specified conditions. | ||
|---|---|---|
|
Attribute name |
Required? |
Description |
|
|
Yes |
The name entity field. |
|
|
Yes |
Valid values: |
|
|
No |
Valid values: Default: |
set elements are used to equate entity field(s) or context variables to values. set declarations may be configured as shown:
|
set Tag (optional) Use the | ||
|---|---|---|
|
Attribute name |
Required? |
Description |
|
|
Yes |
Indicates the value is an entity field. |
|
|
No |
The name of the field. |