What is a Handler?

A hanlder is a peice of code a developer writes that is triggered during the processing of an "OpenLinks Feed" Configuraion file when special processing is needed. We create handlers to enable non-standard data processing (prior to, or after data insert.  For example, if you want to update other db tables after importing this data

A handler does not have to be related to a database update can be anything you need as it call a distinct java class for processing during the execution of the XML source file.

Example code:

Below we can see some example code with the highlighted text indicating the call to a handler

<?xml version="1.0" encoding="UTF-8"?>
<openlinks>
   <incomingfeed>
      <feedsource>file:E:\\stores\\HEN\\_tmp\\XML\\CategoryLevel.xml</feedsource>
      <element rootpath="//product">
         <table>elements_products</table>
         <keymapping>
            <xpath>/product/code</xpath>
            <column>ATTR_ModelNumber</column>
         </keymapping>
         <mapping>
            <xpath>/product/title</xpath>
            <column>ATTR_Headline</column>
         </mapping>
         <mapping>
            <xpath>/product/description/text()</xpath>
            <column>ATTR_description</column>
         </mapping>
         <mapping>
            <xpath>/product/unit</xpath>
            <column>ATTR_Unit</column>
         </mapping>
         <mapping>
            <xpath>/product/image</xpath>
            <column>ATTR_Image</column>
         </mapping>
      </element>
      <element rootpath="//product/items/item" handler="ci.henselite.feed.ItemHandler">
         <table>elements_flex20</table>
         <keymapping validator="maxlength:100">
            <xpath>/item/code</xpath>
            <column>ATTR_Code</column>
         </keymapping>
         <mapping>
            <xpath>/item/title</xpath>
            <column>ATTR_Title</column>
         </mapping>
         <mapping>
            <xpath>/item/price</xpath>
            <column>ATTR_Price</column>
         </mapping>
         <mapping>
            <xpath>/item/attributes/attribute[@name='Size']</xpath>
            <column>ATTR_Size</column>
         </mapping>
         <mapping>
            <xpath>/item/attributes/attribute[@name='Weight']</xpath>
            <column>ATTR_Weight</column>
         </mapping>
         <mapping>
            <xpath>/item/attributes/attribute[@name='Grip']</xpath>
            <column>ATTR_Grip</column>
         </mapping>
         <mapping>
            <xpath>/item/attributes/attribute[@name='Colour']</xpath>
            <column>ATTR_Colour</column>
         </mapping>
      </element>
   </incomingfeed>
</openlinks>