This tutorial will show you how to tap into the power of Seamless Donations’ extensibility functions and take control over many customization options offered inside the plugin.

Why hooks?

• Because updates will pummel your code and it makes code difficult to support and manage
• Never modify the WordPress core: that’s what plugins and themes are for
• Never modify the Seamless core: that’s what hooks, filters and actions, are for

Types of hooks

• actions: does an action
• filters: takes in a value, changes it, and outputs it
• Most Seamless Donations hooks are filters

Where do I put my code?

• functions.php: Often used with themes, not my first choice
• Your own custom plugin: How I do it, and what I recommend

How do I format a plugin?

• Put a folder in plugins, put a matching php file in that folder, put a header block in the PHP file
• Details on header block: https://codex.wordpress.org/File_Header
• Details on adding filters: https://codex.wordpress.org/Function_Reference/add_filter

Where do I find Seamless Donations hooks?

• Visit https://wordpress.org/plugins/seamless-donations/
• Scroll down to the For Developers section

Useful debugging utilities

• seamless_donations_debug_log()
• seamless_donations_debug_alert()

Sample project

1. Create a custom plugin unique to this installation: seamless-custom
2. Re-order the donation amounts so the smallest comes first
3. Set a default donation amount that’s not just the first item
4. Give donation amounts individual names
5. Change the payment code ‘cmd’ sent to PayPal from _donations to _xclick

Hooks used

• dgx_donate_giving_levels
• seamless_donations_form_donation_section
• seamless_donations_form_paypal_section