Alfresco create patch
When extending Alfresco having to write a patch is rather a common use case. Either you’ve changed your content model so you have to update a certain volume of documents. Or you want to apply new permissions, create new authorities, and so on. There might be a multitude of reasons for creating a patch. But in fact, what exactly is a patch?
Well, it’s pretty simple. It’s a piece of work you want to run once. Usually after a deploy (version/fix). The idea is to update the existing persistent items (Database, Solr, files system).
And really, that’s all. It can be done by a simple web script, however, web scripts can be run multiple times, and you still have to run it manually. In fact, Alfresco provides a component for that specific case. And it does more than running a piece of work once during start up. I find it really handy. so let’s see how it works.
Use Case
Let’s create a simple patch that will create a new authority zone.
Java class
createCustomZonePatch.java
public class CreateCustomAuthorityZonePatch extends AbstractPatch
{
private AuthorityService authorityService;
@Override
protected String applyInternal() throws Exception
{
authorityService.getOrCreateZone(CUSTOM_AUTHORITY_ZONE);
return "Patch xxxx Create Custom authority zone finished";
}
public void setAuthorityService(AuthorityService authorityService)
{
this.authorityService = authorityService;
}
}Simply extends AbstractPath and overrides the method applyInternal.
Spring context and properties
custom-context.xml
<bean id="patch.custom.createCustomAuthorityZone" class="com.custom.patch.CreateCustomAuthorityZonePatch" parent="basePatch">
<property name="id" value="patch.custom.createCustomAuthorityZone"/>
<property name="description" value="patch.custom.createCustomAuthorityZone.description"/>
<property name="fixesFromSchema" value="0"/>
<property name="fixesToSchema" value="${version.schema}"/>
<property name="targetSchema" value="100000"/>
<property name="authorityService" ref="AuthorityService"/>
</bean>i18n properties
patch.custom.createCustomAuthorityZone=Create custom authority zone
patch.custom.createCustomAuthorityZone.description=Patch description Create Custom authority zoneThe patch can be allowed only for a specific version this is why there are properties from/to/target. The values in my example are the defaults when you don’t want to specify a version. Thus, the patch will run next time Alfresco repository will start.
Additional information
The code will be ran in a transaction as System user. The result will be saved in the database in the table ALF_APPLIED_PATCHES.
SQL
select
*
from
alf_applied_patch
where
id = 'patch.custom.createCustomAuthorityZone'Result
id: "patch.custom.createCustomAuthorityZone"
description: "Patch description Create Custom authority zone"
fixes_from_schema: 0
fixes_to_schema: 8009
applied_to_schema: 8009
target_schema: 100000
applied_on_date: "2016-03-09 10:38:49.58"
applied_to_server: "5.0.0 (c r91299-b145) - Community"
was_executed: t
succeeded: t
report: "Patch xxxx Create Custom authority zone finished"