Execute only second package observer

Question

I have two packages installed in magento. First,Package1_Test1 second,Package2_Test2.
I have created one observer in Package1_Test1

path: community/Package1/Test1/etc/config.xml

<sales_convert_quote_item_to_order_item>
                <observers>
                    <package1_test1_identifier>
                        <type>model</type>
                        <class>package1_test1/observer</class>
                        <method>salesConvertQuoteItemToOrderItem</method>
                    </package1_test1_identifier>
                </observers>
</sales_convert_quote_item_to_order_item>

In Package2_Test2,I have created one observer

path: community/Package2/Test2/etc/config.xml

<sales_convert_quote_item_to_order_item>
                <observers>
                    <package2_test2_identifier>
                        <type>model</type>
                        <class>package2_test2/observer</class>
                        <method>salesConvertQuoteItemToOrderItem</method>
                    </package2_test2_identifier>
                </observers>
</sales_convert_quote_item_to_order_item>

It means that I have created same sales_convert_quote_item_to_order_item observer in both packages so my question is I want to run only second Package2_Test2 package observer rather then Package1_Test1.

Any dependency will work between two packages ?

Please help me,What I have to do ?

Answer 1

You can disable the observer on package1_test1 by placing code as below into package1_test2

Basically, you disable the observer in package1_test1

<events>
    <sales_convert_quote_item_to_order_item>
       <observers>
          <package1_test1_identifier>
              <type>disabled</type>
          </package1_test1_identifier>
       </observers>
    </sales_convert_quote_item_to_order_item>
</events>

If you want to use the code in package1_test1, you can simply extend (not rewrite) package1_test1 class from package1_test2, and then call it as a parent class.