I'm am improving Magento plugin that my friend wrote and I need to add a logic where I check each order and if the total sum is less than
x then get this order details like
phone number etc. And with these order details create XML and send out this XML to an external provider. At the same time send out to the customer the invoice and add to order comments in admin panel with some text like
order placed from external provider. And do this only if the order total sum is less or equals than
I haven't done plugin from scratch myself, but the current plugin is made by a friend who due to some reasons can't continue and help me with that then I need to make it myself. What my current knowledge is that I know how to make additional tabs and fields in
Admin -> Configuration. So there I currently have set up the field enable/disable the plugin and a text field
make order from an external provider if the sum is less than x.
What I'm unfamiliar is how to observe all the going through orders? And get out the order total amount from that as well as order details I stated above. Also, I need to change the order status to processing and add a comment with my text. I guess the XML creation and sending out to the external provider is standard PHP task (use Varien/Zend in Magento) and is not related to Magento architecture.
Any tutorials for that, examples or your hints would be appreciated. I don't really want to dive deep into Magento architecture and read whole books, but just need to get this done. I tried to google about that but didn't get any good examples/tutorials maybe cause I don't write the problem in better Magento architecture/terms.