Subscribe a user to a plan based on a donation amount with Direct Stripe.

ds-plan-based-on-donation-amount.php

<?php
/*
 * Plugin Name: DS custom code
 * Description:  Create subscriptions based on donation amount
 * Author: Nicolas Figueira
 * Version: 0.0.1
 *
 * To use this as a plugin :
 * – Edit the code with the css ID you set for your button
 * – Zip the file
 * – Go to Add new plugin page of your WordPress admin
 * – Click the Upload Plugin button and upload the zipped file
 * – Activate the plugin and test
 *
 *** Also unset the capture option on the donation button in order not to capture the first payment twice
 *** or add a trial period to the subscription ( "trial_period_days" => 30, )
 */
add_action('direct_stripe_before_success_redirection', function( $answer_id, $post_id, $button_id ) {

	if( $button_id !== 'MyButtonID' ){ // Replace MyButtonID with your the CSS ID set on the button that will convert donation amount to subscriptions

		return $answer_id;

	} else {

		$charge = \Stripe\Charge::retrieve($answer_id);

		$new_plan = Stripe\Plan::create([
			"amount" => $charge->amount,
			"interval" => "month",
			"product" => [
				"name" => "Plan set by donation of " . $charge->customer
			],
			"currency" => "eur",
			"id" => "special-" . $answer_id
		]);

		$subscription = Stripe\Subscription::create([
			"customer" => $charge->customer,
			"items" => [
				[
					"plan" => $new_plan,
				],
			]
		]);


		return $answer_id;
	}

}, 10, 3 );