Rewrite function from core model class

Question

I know this is a very simple question, but I couldn't get it to run, even if I read some tutorials.

I want to rewrite _saveProductCategories() from Mage_ImportExport_Model_Import_Entity_Product.

What I've done is create an empty class: app/core/local/MyNamespace/MyModule/Model/Import/Entity/Product.php with class name MyNamespace_MyModule_Model_Import_Entity_Product to extend the core model class. There I've put my implementation of the current function that I want to rewrite.

Then in the config.xml of myModule I have:

    <global>
            <models>
                <mymodule>
                    <class>MyNamespace_MyModule_Model</class>
                </mymodule>
                <importexport>
                    <rewrite>
                        <import_entity_product>MyNamespace_MyModule_Model_Import_Entity_Product</import_entity_product>
                    </rewrite>
                </importexport>
            </models>
...

But it still uses the function from the core code. What am I doing wrong?

Answer 1

To Future Readers:

The OP mentioned in their answer that they had a rewrite conflict with another third-party module. If you want your override to take precedence without refactoring third-party code you can add a module dependency.

In the app/etc/modules/MODULE_NAME.xml file add the following XML below the codePool tag

<depends>
    <DEPENDENT_MODULE_NAME/>
    ...
</depends>

List all the modules yours needs to take precedence over. Now your overrides will take effect rather than the other modules.

Note: If you do this you'll probably want to have your classes inherit from that module's classes so that you can preserve that module's functionality.

Answer 2

Ok, what I've done is correct. The problem was coming from the fact that a model class from a community module (that I use for the purposes of my custom module) is overriding the same class that I wanted to override in my custom module.

Therefore I rewrote that model class from the community module and it worked fine. :)

Answer 3

@Syspect: Rewriting the model class from the community module creates a dependency between the two modules. Now you may have problems if you need to modify one - you always have to be mindful of the other.

The dependency approach tbernard mentioned is better.