Code generalization, mainly in connection with invoice numbers for other plugins

-) Add filters to query whether a third-party plugin claims responsibility for invoice numbers
-) Add filter to get the configuration link for this plugin
-) Move all configuration / documentation links to a class-wide property to avoide duplication
-) Generic function to check whether order/invoice numbers are enabled

ordernumbers_woocommerce.php

@@ -330,7 +330,7 @@ class OpenToolsOrdernumbers extends OpenToolsOrdernumbersBasic {
 	}
 	
 	function thirdparty_get_invoicenumber($default, $orderid) {
-		if (get_option('customize_invoice', 'no')!='no') {
+		if ($this->invoicenumbers_activated()) {
 			$_of = new WC_Order_Factory();
 			$order = $_of->get_order($orderid);
 			$number = $this->get_or_create_number($orderid, $order, 'invoice');
@@ -381,7 +381,7 @@ class OpenToolsOrdernumbers extends OpenToolsOrdernumbersBasic {
 	 * The action to actually create the number and store it as post meta with the order 
 	 */
 	function thirdparty_wpo_wcpdf_create_number($type, $orderid) {
-		if ($type=='invoice' && (get_option('customize_'.$type, 'no')!='no') ) {
+		if ($type=='invoice' && $this->invoicenumbers_activated() ) {
 			$_of = new WC_Order_Factory();  
 			$order = $_of->get_order($orderid);
 			$number = $this->get_or_create_number($orderid, $order, $type);
@@ -398,11 +398,12 @@ class OpenToolsOrdernumbers extends OpenToolsOrdernumbersBasic {
 	 */
 	function thirdparty_wpo_wcpdf_remove_options() {
 		global $wp_settings_fields;
-		if (get_option('customize_invoice', 'no')!='no') {
+		if ($this->invoicenumbers_activated()) {
 			$wp_settings_fields['wpo_wcpdf_template_settings']['invoice']['display_number']['title'] = $this->helper->__('Display invoice number');
 			$wp_settings_fields['wpo_wcpdf_template_settings']['invoice']['display_number']['args']['description'] = $this->helper->__('The <a href="admin.php?page=wc-settings&tab=checkout&section=ordernumber">Open Tools Ordernumber plugin</a> has invoice numbers enabled and will generate invoice numbers for this plugin.' );
 			unset($wp_settings_fields['wpo_wcpdf_template_settings']['invoice']['next_invoice_number']);
 			unset($wp_settings_fields['wpo_wcpdf_template_settings']['invoice']['invoice_number_formatting']);
+			unset($wp_settings_fields['wpo_wcpdf_template_settings']['invoice']['yearly_reset_invoice_number']);
 		} else {
 			$wp_settings_fields['wpo_wcpdf_template_settings']['invoice']['display_number']['args']['description'] = $this->helper->__('To let the Open Tools ordernumber plugin create invoice numbers with your desired format, please enable invoices in <a href="admin.php?page=wc-settings&tab=checkout&section=ordernumber">that plugin\'s configuration page</a>.' );
 		}
@@ -430,7 +431,7 @@ class OpenToolsOrdernumbers extends OpenToolsOrdernumbersBasic {
 		// TODO: Modify the invoice number section text to hint at the installed order number plugin and how to enable it!
 		global $wp_settings_fields;
 return;
-		if (get_option('customize_invoice', 'no')!='no') {
+		if ($this->invoicenumbers_activated()) {
 // bewpi_template_settings -> invoice_number ->
 //   -) bewpi_invoice_number_type
 //   -) bewpi_reset_counter

ordernumbers_woocommerce_basic.php

@@ -18,6 +18,11 @@ class OpenToolsOrdernumbersBasic {
 	public $ordernumber_meta = "_oton_number_";
 	public $ordernumber_new_placeholder = "[New Order]";
 	public $plugin_basename = '';
+	public $plugin_config_link = 'admin.php?page=wc-settings&tab=checkout&section=ordernumber';
+	public $plugin_url = 'https://wordpress.org/plugins/woocommerce-basic-ordernumbers/';
+	public $plugin_url_advanced = 'http://open-tools.net/woocommerce/advanced-ordernumbers-for-woocommerce.html';
+	public $plugin_url_docs = 'http://open-tools.net/documentation/advanced-order-numbers-for-woocommerce.html';
+	public $plugin_url_support = 'http://open-tools.net/support-forum/ordernumbers-for-woocommerce.html';
 	
 	protected $helper = null;
 	protected $settings = array();
@@ -51,6 +56,15 @@ class OpenToolsOrdernumbersBasic {
 	 */
 	protected function initializeHooks() {
 		$helper = OrdernumberHelperWooCommerce::getHelper();
+		// Information for other plugins
+		add_filter( 'opentools_ordernumbers_activated', 		array( &$this, 'ordernumbers_activated'));
+		add_filter( 'opentools_invoicenumbers_activated', 		array( &$this, 'invoicenumbers_activated'));
+		add_filter ('woocommerce_invoice_number_by_plugin', array( &$this, 'invoicenumbers_activated'));
+		add_filter ('woocommerce_order_number_by_plugin', array( &$this, 'ordernumbers_activated'));
+		add_filter ('woocommerce_invoice_number_configuration_link', array( &$this, 'invoicenumbers_config_link'));
+		add_filter ('woocommerce_order_number_configuration_link', array( &$this, 'ordernumbers_config_link'));
+		
+		
 		// CONFIGURATION SCREENS
 		add_filter( 'woocommerce_get_sections_checkout',				array( &$this, 'add_admin_section'));
 		// The checkout settings page assumes all subpages are payment gateways, so we have to override this and manually pass our settings:
@@ -107,7 +121,7 @@ class OpenToolsOrdernumbersBasic {
 				'desc_tip'	=> true,
 				'id' 		=> 'opentools_ordernumbers_upgrade',
 				'type' 		=> 'opentools_ordernumbers_upgrade',
-				'link'		=> 'http://open-tools.net/woocommerce/advanced-ordernumbers-for-woocommerce.html',
+				'link'		=> $this->plugin_url_advanced,
 			),
 		);
 		return $settings;
@@ -116,7 +130,7 @@ class OpenToolsOrdernumbersBasic {
 		$settings = array();
 		$settings[] = array(
 				'name' 		=> $this->helper->__( 'Configure Order Numbers'),
-				'desc'		=> $this->helper->__( 'Configure the format and the counters of the order numbers in WooCommerce. For help, check out the plugin\'s <a href="http://open-tools.net/documentation/advanced-order-numbers-for-woocommerce.html">documentation at OpenTools</a>.'),
+				'desc'		=> sprintf( $this->helper->__( 'Configure the format and the counters of the order numbers in WooCommerce. For help, check out the plugin\'s <a href="%s">documentation at OpenTools</a>.'), esc_attr($this->plugin_url_docs)),
 				'type' 		=> 'title',
 				'id' 		=> 'ordernumber_options'
 			);
@@ -166,12 +180,42 @@ class OpenToolsOrdernumbersBasic {
 	protected function initializeSettingsOther() {
 		return array();
 	}
+	
+	
+	/**
+	 * Filters for other plugins to get information about this one, e.g.
+	 * indicating whether invoice/order numbers are to be created by this plugin
+	 * and getting the link to the configuration page.
+	 */
+	
+	public function numbers_activated($type) {
+		return (get_option('customize_'.$type, 'no')!='no');
+	}
+	public function ordernumbers_activated($default=false) {
+		return $this->numbers_activated('ordernumber');
+	}
+	public function invoicenumbers_activated($default=false) {
+		return $this->numbers_activated('invoice');
+	}
+	
+	public function invoicenumbers_config_link($default=null) {
+// 		if ($this->invoicenumbers_activated())
+			return $this->plugin_config_link;
+// 		else
+// 			return $default;
+	}
+	public function ordernumbers_config_link($default=null) {
+// 		if ($this->invoicenumbers_activated())
+			return $this->plugin_config_link;
+// 		else
+// 			return $default;
+	}
 
 	/**
 	 * Add settings link to plugins page
 	 */
 	public function ordernumber_add_settings_link( $links ) {
-		$link = '<a href="admin.php?page=wc-settings&tab=checkout&section=ordernumber">'. $this->helper->__( 'Settings' ) . '</a>';
+		$link = '<a href="'.esc_attr($this->plugin_config_link).'">'. $this->helper->__( 'Settings' ) . '</a>';
 		// Prepend the settings link:
 		array_unshift( $links, $link );
 // 		$links['settings'] = $link;
@@ -179,15 +223,15 @@ class OpenToolsOrdernumbersBasic {
 	}
 	public function ordernumber_plugin_row_meta( $links, $file ) {
 		if ($file==$this->plugin_basename) {
-			$links['docs'] = '<a href="' . esc_url(  'http://open-tools.net/documentation/advanced-order-numbers-for-woocommerce.html' ) . '" title="' . esc_attr( $this->helper->__( 'Plugin Documentation' ) ) . '">' . $this->helper->__( 'Plugin Documentation' ) . '</a>';
-			$links['support'] = '<a href="' . esc_url( 'http://open-tools.net/support-forum/ordernumbers-for-woocommerce.html' ) . '" title="' . esc_attr( $this->helper->__( 'Support Forum' ) ) . '">' . $this->helper->__( 'Support Forum' ) . '</a>';
+			$links['docs'] = '<a href="' . esc_url( $this->plugin_url_docs ) . '" title="' . esc_attr( $this->helper->__( 'Plugin Documentation' ) ) . '">' . $this->helper->__( 'Plugin Documentation' ) . '</a>';
+			$links['support'] = '<a href="' . esc_url( $this->plugin_url_support ) . '" title="' . esc_attr( $this->helper->__( 'Support Forum' ) ) . '">' . $this->helper->__( 'Support Forum' ) . '</a>';
 		}
 		return (array)$links;
 	}
 	
 	public function basic_ordernumber_plugin_row_meta( $links, $file ) {
 		if ($file==$this->plugin_basename && !$this->is_advanced) {
-			$links['advanced'] = '<a href="' . esc_url( 'http://open-tools.net/woocommerce/advanced-ordernumbers-for-woocommerce.html' ) . '" title="' . esc_attr( $this->helper->__('Purchase Advanced Version')) . '">' . $this->helper->__('Purchase Advanced Version') . '</a>';
+			$links['advanced'] = '<a href="' . esc_url( $this->plugin_url_advanced ) . '" title="' . esc_attr( $this->helper->__('Purchase Advanced Version')) . '">' . $this->helper->__('Purchase Advanced Version') . '</a>';
 		}
 		return (array)$links;
 	}
@@ -383,7 +427,7 @@ class OpenToolsOrdernumbersBasic {
 	}
 
 	function generateNumber($orderid, $order, $type='ordernumber') {
-		if (get_option('customize_'.$type, 'no')!='no') {
+		if ($this->numbers_activated($type)) {
 			$fmt     = get_option ($type.'_format',  "#");
 			$ctrsettings = array(
 				"${type}_format"  => '',