problems overriding 3rd party extension block class

Question

the extension in question has the following structure:

• app
  • code
    • local
      • MST
        • Menupro
          • Block
            • Base.php

Base.php has:

class MST_Menupro_Block_Base extends Mage_Core_Block_Template {

my custom module

• app
  • code
    • local
      • Myname
        • BlockOverride
          • Block
            • Base.php

my Base.php has:

class Myname_BlockOverride_Block_Base extends Mage_Core_Block_Template {

In my module activation file Myname_BlockOverride.xml I have:

<?xml version="1.0"?>
    <config>
        <modules>
           <Myname_BlockOverride>
               <codePool>local</codePool>
                    <active>true</active>
                    <depends>
                        <MST_Menupro/>
                    </depends>
           </Myname_BlockOverride>
       </modules>
    </config>

module is verified as enabled and working because I am overriding some mage core classes also.

in:

• app
  • code
    • local
      • Myname
        • BlockOverride
          • etc
            • config.xml

i have:

<?xml version="1.0"?>
    <config>
        <modules>
            <Myname_BlockOverride>
                <version>0.1.0</version>
            </Myname_BlockOverride>
        </modules>

        <global>
            <blocks>
                <myname_blockoverride>
                    <class>Myname_BlockOverride_Block</class>
                </myname_blockoverride>
                <menupro>
                    <rewrite>
                        <base>Myname_BlockOverride_Block_Base</base>
                    </rewrite>
                </menupro>
            </blocks>
        </global>
    </config>

This question has been asked multiple times, like here https://stackoverflow.com/questions/24145976/how-to-rewrite-extend-a-magento-class-in-an-existing-third-party-extension and http://code.tutsplus.com/tutorials/understand-overriding-in-magento-blocks--cms-23325 and Rewrite a local Extension Module doesn't work

which i've dutifully followed through but seem to up against a brick wall. my overriding class file is never loaded (error_log at top of file does not fire).

any help greatly appreciated.

edit: i checked through the 3rd party extension for their block definition in config.xml and see

<blocks>
    <menupro>
        <class>MST_Menupro_Block</class>
    </menupro>
</blocks>

not sure if i'm missing a clue there somehow

Answer 1

Two mistakes I can find.

1. You placed your module files in wrong place
2. You rewrote the custom module's block class in wrong way.

Place files in correct location

Activation File : app/etc/modules/Myname_BlockOverride.xml

<?xml version="1.0"?>
<config>
    <modules>
       <Myname_BlockOverride>
           <codePool>local</codePool>
                <active>true</active>
                <depends>
                    <MST_Menupro/>
                </depends>
       </Myname_BlockOverride>
   </modules>
</config>

config file : app/code/local/Myname/BlockOverride/etc/config.xml

<?xml version="1.0"?>
<config>
    <modules>
        <Myname_BlockOverride>
            <version>0.1.0</version>
        </Myname_BlockOverride>
    </modules>

    <global>
        <blocks>
            <myname_blockoverride>
                <class>Myname_BlockOverride_Block</class>
            </myname_blockoverride>
            <menupro>
                <rewrite>
                    <base>Myname_BlockOverride_Block_Base</base>
                </rewrite>
            </menupro>
        </blocks>
    </global>
</config>

Rewrite Class : app/code/local/Myname/BlockOverride/Block/Base.php

<?php
class Myname_BlockOverride_Block_Base extends MST_Menupro_Block_Base
{

}

and that's it. Last and but not least, you need to clear your caches. Ready, Set, Goooooooo....

Answer 2

Your extension BlockOverride block.php should be

class Myname_BlockOverride_Block_Base extends MST_Menupro_Block_Base {

Answer 3

Although this is not a direct answer to this question which i never solved satisfactorily, I did work around this by moving the 3rd party extension to community pool and override it via file inheritance.