Changeset 7915

Timestamp:

Feb 24, 2021, 8:24:44 AM (2 years ago)

Author:

Nicklas Nordborg

Message:

References #2237: Implement extension mechanism for query filtering

Added information to the documentation.

File:

• trunk/doc/src/docbook/developer/extensions.xml (modified) (1 diff)

trunk/doc/src/docbook/developer/extensions.xml

@@ -2492 +2492 @@
     </sect2>
     
+    <sect2 id="extensions_developer.query_filters">
+      <title>Query filters</title>
+      
+      <para>
+        This extension point makes it possible to extend filtering
+        functionality for queries that are generated by list pages via the
+        <methodname>ItemContext.configureQuery()</methodname> method in the 
+        <classname docapi="net.sf.basedb.core">ItemContext</classname> class.
+        
+        Actions should implement the <interfacename 
+        docapi="net.sf.basedb.core.query">QueryFilterAction</interfacename> 
+        interface. This interface allows an extension to filter a query based
+        on a single column filter, a filter row or a combination of everything.
+      </para>
+      
+      <para>
+        Note that the <methodname>ActionFactory.prepareContext()</methodname> is
+        called for all filter extensions at all times. It is recommended that 
+        the implementation checks the current context for the type of items in the
+        list and if there is a filter in a column that the extension should handle.
+        An extension may override the default implementation of any filter, but this
+        is not recommended. The recommended design is to combine the filter
+        extension with a custom column that uses the <code>!x.</code> prefix
+        as the column id. Here is an example from the Variant Search extension 
+        (<ulink url="http://baseplugins.thep.lu.se/wiki/net.sf.basedb.varsearch"
+        >http://baseplugins.thep.lu.se/wiki/net.sf.basedb.varsearch</ulink>):
+      </para>
+      
+      <programlisting language="java">
+<![CDATA[
+public boolean prepareContext(InvokationContext<? super QueryFilterAction> context) 
+{
+   // Enabled in the RAWBIOASSAY list page
+   // and if the !x.lucene column is present with a filter
+   // and if the service database is running
+   ItemContext ctx = context.getClientContext().getCurrentItem();
+   return ctx.getItemType() == Item.RAWBIOASSAY && 
+      ctx.hasExtensionFilter("lucene") && 
+      VarSearchService.getInstance().isRunning();
+}
+]]>
+</programlisting>
+      
+      
+    </sect2>
+    
     <sect2 id="extensions_developer.login-manager">
       <title>Login manager</title>