Sample Catalog

Let’s consider a web application that needs to add some data to the user’s session from an LDAP datastore and, separately, log an event to a file or database.
This catalog demonstrates a catalog with two commands you can invoke – “userchain” and “audit”:

<?xml version=“1.0” encoding=“utf-8” ?>

<catalog xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance”

         xmlns:xsd=“http://www.w3.org/2001/XMLSchema”

         xmlns=“http://zetetic.net/schemas/chain/catalog.xsd”>

  <chain name=“userchain”>

    <command name=“userinfo” typeName=“Demo.GetUpnCommand, Demo”>

    </command>

    <command name=“Surname” typeName=“Demo.LdapSearchCommand, Demo”>

	  <add key=“LdapItem” value=“sn” />

	  <add key=“SessionItem” value=“LASTNM” />

	  <add key=“Attributes” value=“sn” />

	  <add key=“Filter” value=“(|(uid={0})(sAMAccountName={0}))” />

	  <add key=“LdapConfig” value=“ldap1” />

    </command>

    <command name=“Groups” typeName=“Demo.LdapSearchCommand, Demo”>

	  <add key=“LdapItem” value=“distinguishedName” />

	  <add key=“SessionItem” value=“GROUPDNS” />

	  <add key=“Attributes” value=“1.1” />

	  <add key=“Filter” value=“(|(member={0})(uniqueMember={0}))” />

	  <add key=“LdapConfig” value=“ldap2” />

    </command>

  </chain>

  <command name=“audit” typeName=“Demo.SqlAuditor, Demo”>

	  <add key=“Connection” value=“MyConnectionString” />  

  </command>

</catalog>

As shown, you can reuse the same ICommand implementation class in multiple places with different configuration properties. The "key"s correspond to public properties of each command type/class. (See the general-purpose commands in Zetetic.Chain.Generic for a few quick examples.)

Usage of the catalog and its commands is straightforward:

ICatalog catalog = CatalogFactory.GetFactory().GetCatalog(“mycatalog.xml”);

IContext context = new ContextBase();

context[“just testing”] = true;
catalog[“userchain”].Execute(context);

catalog[“audit”].Execute(context);

That’s all there is to it. With well-designed commands and chains, you won’t have to change your application code to pull in more values from the hypothetical LDAP source. The automatic configuration/property mapper in Zetetic.Chain means it’s often easier and more natural-feeling to make this stuff more flexible than less!