Use

Plugin description and use can be found in readme.txt.

A thorough description of how to install and use the plugin can be found here.

Packaged releases can be found on releases.

The latest release can be installed from WP CLI with:

wp plugin install https://github.com/ZeekInteractive/pay-invoices-with-amazon/releases/latest/download/piwa.zip --activate --force

Use as a Function

piwa() can be called with an array of arguments in plugins, mu-plugins, templates, or a theme's functions.php.

The below example adds payment buttons of various types at the end of Post content if various Categories are assigned.

The existance of Plugin Name: makes it possible to place it in wp-content/plugins/ or a folder within wp-content/plugins to activate or deactivate within WP Admin > Plugins. If placing within a theme's functions.php or another file that already opens with <?php, the first line <?php should be removed to avoid errors.

<?php
/**
 * Plugin Name: Pay Based on Category
 * Description: Display a message with payment buttons on Posts depending on assigned Category. If all the categories are assigned, all the buttons and messages will be added.
 * Version: 1.0
 *
 * @see https://developer.wordpress.org/reference/hooks/the_content/
 * @see https://developer.wordpress.org/reference/functions/is_singular/
 * @see https://developer.wordpress.org/reference/functions/has_category/
 * @see https://www.php.net/manual/en/function.function-exists.php
 */
add_filter(
	'the_content',
	function( $content ) {
		// If the PIWA plugin is not active or this is not a singular template of the "post" post type, do not modify the content.
		if (
			! function_exists( 'piwa' )
			|| ! is_singular( [ 'post' ] )
		) {
			return $content;
		}

		// If the post is in category Uncategorized, append a pay button where the user specifies the amount.
		if ( has_category( 'Uncategorized' ) ) {
			$content .= '<p>Thanks for reading!<br/>If you feel inclined to contribute, please use the form below.</p>' . piwa();
		}
		// If the post is in category Pay it Forward, append a pay button for $7.00 labeled "Pay it Forward".
		if ( has_category( 'Pay it Forward' ) ) {
			$content .= '<p>Thanks for reading!<br/>If you enjoyed this post, please pay it forward with a small donation:</p>' . piwa([
				'amount' => 7.00,
				'title'  => 'Pay it Forward',
			]);
		}
		// If the post is in category Invoice, append a pay button where the customer inputs an Invoice Number and amount.
		if ( has_category( 'Invoice' ) ) {
			$content .= '<p>Thank you for your business!<br/>To make a payment, please input an amount and the associated invoice number:</p>' . piwa([
				'show_customer_invoice_input' => true,
			]);
		}

		return $content;
	},
	10 // Default priority is 10. The latest possible priority is PHP_INT_MAX. Attaching to a priority lower than 10 may cause other filters, such as wpautop, to add paragraph tags incorrectly.
);

Development

Download & install dependencies

git clone git@github.com:ZeekInteractive/piwa.git
cd piwa
./bin/install

Payment Details (Debug Information)

Detailed information on checkout session status and technical responses from the API can be viewed by adding &details to the end of the Payment Listing admin screen URL.

For example: /wp-admin/edit.php?post_type=amazon-payment&details

Commands in bin:

Install

Updates and installs the Amazon SDK using composer for PHP minimum 5.6.20.

./bin/install

phpcs

• Installs and configures PHP Code Sniffer and PHP Code Beautifier with WordPress-Extra and ruleset.xml.
• Runs phpcbf to fix minor errors before generating reports.
• Runs phpcs with code context, specific rule names, highlighted lines, and icons indicating line, errors, warnings, rule names, and file names.
• Runs phpcs summary count by rule type.
• Outputs or runs commands which, if executed, will add // phpcs:ignore Rule.Name comments to lines which still have warnings.

Report:

./bin/phpcs

Patch:

• Adds comments to ignore all remaining warnings & re-runs the report.

./bin/phpcs --add-all-ignores && ./bin/phpcs

Report, including all warnings even if annotated with a comment to ignore:

./bin/phpcs --ignore-annotations

Tag

Tags the current commit on main with a release number and comment and pushes to origin. Deletes the old tag of the same name locally and on origin if it existed.

version=1.0.example
title='Title of the release'
./bin/tag "$version" "$title"

Package

Builds a .zip for installation or release with vendor included and development file patterns listed in bin/package-exclude.txt excluded. Outputs the zip to piwa.zip. Deletes an the old zip of that name if it existed. Runs ./bin/install.

./bin/package

Release

Edits a release on GitHub so the title is the tag title, the description is a link to the changelog, and uploads the zipped package. "1.0" is the tag to release. The .zip in the current directory will be uploaded.

version=1.0.example
./bin/release $version

Tag & Package & Release

version=1.0.example
title='Title of the release'
./bin/tag $version "$title" && ./bin/package && ./bin/release $version

Localization

Generate a new master piwa.pot

From the plugin root directory:

wp i18n make-pot . --no-location

This will overwrite the .pot. New strings can also be added by editing manually. All translatable strings are stored in src/i18n.php.

Compile .mo files when .po files have been edited.

Requires brew install msgfmt or similar.

From languages/:

for file in `find . -name "*.po"` ; do msgfmt -o ${file/.po/.mo} $file ; done

Also see developer.wordpress.org:localization.

Plugin Settings

Settings can be reset with:

wp option delete piwa

Settings can be hard-coded with the follow script, preferably placed in wp-content/mu-plugins/:

<?php
/**
 * Where to find keys & IDs:
 * @see https://pay.amazon.com/help/202022560
 */
foreach(
	[
		'sandbox_mode'       => 1,
		'merchant_id'        => '',
		'client_id_store_id' => '',
		'public_key_id'      => '',
	] as $key => $value
) {
	putenv( sprintf( 'piwa_%s=%s', $key, $value ) );
}