The node under models
should match the same one in app\code\community\Dhl\Intraship\etc\config.xml
:
<?xml version="1.0"?>
<config>
<modules>
<Dhl_Intraship>
<version>13.07.04</version>
</Dhl_Intraship>
</modules>
<!-- some more code here -->
<global>
<models>
<intraship> <!-- this is the node you have to look at -->
<class>Dhl_Intraship_Model</class>
<resourceModel>intraship_mysql4</resourceModel>
</intraship>
<!-- some more code here -->
</models>
<!-- some more code here -->
<global>
</config>
And the node under rewrite
have to match the path of the file you want to rewrite under the folder Model : so in you case it is just gateway
. But if you were to rewrite app\code\community\Dhl\Intraship\Model\Path\To\Some\Model.php
the node would have been path_to_some_model
So it should looks like that :
<?xml version="1.0"?>
<config>
<modules>
<mycompany_intraship>
<version>0.1.0</version>
</mycompany_intraship >
</modules>
<global>
<models>
<intraship>
<rewrite>
<gateway>MyCompany_Intraship_Model_Gateway</gateway>
</rewrite>
</intraship>
</models>
</global>
</config>