Add options screen and filters for number of pages. Refactor how Quicktags are...

Add options screen and filters for number of pages. Refactor how Quicktags are inserted to support variable number of pages. Fixes #2.

automatically-paginate-posts.php

@@ -29,8 +29,12 @@ class Automatically_Paginate_Posts {
 	private $post_types;
 	private $post_types_default = array( 'post' );
 
+	private $num_pages;
+	private $num_pages_default = 2;
+
 	//Ensure option names match values in this::uninstall
 	private $option_name_post_types = 'autopaging_post_types';
+	private $option_name_num_pages = 'autopaging_num_pages';
 
 	private $meta_key_disable_autopaging = '_disable_autopaging';
 
@@ -57,6 +61,7 @@ class Automatically_Paginate_Posts {
 
 	/**
 	 * Set post types this plugin can act on, either from Reading page or via filter
+	 * Also sets default number of pages to break content over, either from Reading page or via filter
 	 *
 	 * @uses apply_filters, get_option
 	 * @action init
@@ -65,6 +70,11 @@ class Automatically_Paginate_Posts {
 	public function action_init() {
 		//Post types
 		$this->post_types = apply_filters( 'autopaging_post_types', get_option( $this->option_name_post_types, $this->post_types_default ) );
+
+		//Number of pages to break over
+		$this->num_pages = absint( apply_filters( 'autopaging_num_pages_default', get_option( $this->option_name_num_pages, $this->num_pages_default ) ) );
+		if ( 0 == $this->num_pages )
+			$this->num_pages = 2;
 	}
 
 	/**
@@ -77,6 +87,7 @@ class Automatically_Paginate_Posts {
 	 */
 	public function uninstall() {
 		delete_option( 'autopaging_post_types' );
+		delete_option( 'autopaging_num_pages' );
 	}
 
 	/**
@@ -103,9 +114,11 @@ class Automatically_Paginate_Posts {
 	 */
 	public function action_admin_init() {
 		register_setting( 'reading', $this->option_name_post_types, array( $this, 'sanitize_supported_post_types' ) );
+		register_setting( 'reading', $this->option_name_num_pages, array( $this, 'sanitize_num_pages' ) );
 
 		add_settings_section( 'autopaging', 'Automatically Paginate Posts', '__return_false', 'reading' );
-		add_settings_field( 'autopaging-post-types', __( 'Supported post types', 'autopaging' ), array( $this, 'settings_field_post_types' ), 'reading', 'autopaging' );
+		add_settings_field( 'autopaging-post-types', __( 'Supported post types:', 'autopaging' ), array( $this, 'settings_field_post_types' ), 'reading', 'autopaging' );
+		add_settings_field( 'autopaging-num-pages', __( 'Number of pages to split content into:', 'autopaging' ), array( $this, 'settings_field_num_pages' ), 'reading', 'autopaging' );
 	}
 
 	/**
@@ -164,6 +177,36 @@ class Automatically_Paginate_Posts {
 		return $post_types_sanitized;
 	}
 
+	/**
+	 * Render dropdown for choosing number of pages to break content over
+	 *
+	 * @uses get_option, apply_filters, esc_attr, selected
+	 * @return string
+	 */
+	public function settings_field_num_pages() {
+		$num_pages = get_option( $this->option_name_num_pages, $this->num_pages_default );
+		$max_pages = apply_filters( 'autopaging_max_num_pages', 10 );
+
+		?>
+			<select name="<?php echo esc_attr( $this->option_name_num_pages ); ?>">
+				<?php for( $i = 2; $i <= $max_pages; $i++ ) : ?>
+					<option value="<?php echo intval( $i ); ?>"<?php selected( (int) $i, (int) $num_pages ); ?>><?php echo intval( $i ); ?></option>
+				<?php endfor; ?>
+			</select>
+		<?php
+	}
+
+	/**
+	 * Sanitize number of pages input
+	 *
+	 * @param int $num_pages
+	 * @uses apply_filters
+	 * @return int
+	 */
+	public function sanitize_num_pages( $num_pages ) {
+		return max( 2, min( intval( $num_pages ), apply_filters( 'autopaging_max_num_pages', 10 ) ) );
+	}
+
 	/**
 	 * Add autopaging metabox
 	 *
@@ -222,7 +265,7 @@ class Automatically_Paginate_Posts {
 	 * Only applied if the post type matches specified options and post doesn't already contain the Quicktag.
 	 *
 	 * @param array $posts
-	 * @uses is_admin, get_post_meta
+	 * @uses is_admin, get_post_meta, absint, apply_filters
 	 * @filter the_posts
 	 * @return array
 	 */
@@ -230,6 +273,12 @@ class Automatically_Paginate_Posts {
 		if ( ! is_admin() ) {
 			foreach( $posts as $the_post ) {
 				if ( in_array( $the_post->post_type, $this->post_types ) && ! preg_match( '#<!--nextpage-->#i', $the_post->post_content ) && ! (bool) get_post_meta( $the_post->ID, $this->meta_key_disable_autopaging, true ) ) {
+					//In-time filtering of number of pages to break over, based on post data. If value is less than 2, nothing should be done.
+					$num_pages = absint( apply_filters( 'autopaging_num_pages', absint( $this->num_pages ), $the_post ) );
+
+					if ( $num_pages < 2 )
+						continue;
+
 					//Start with post content, but alias to protect the raw content.
 					$content = $the_post->post_content;
 
@@ -245,20 +294,49 @@ class Automatically_Paginate_Posts {
 						//Explode content at double line breaks
 						$content = explode( "\r\n\r\n", $content );
 
-						//Determine where to insert Quicktag and insert
-						$insert_before = ceil( count( $content ) / 2 );
+						//Count number of paragraphs content was exploded to
+						$count = count( $content );
 
-						$content[ $insert_before ] = '<!--nextpage-->' . $content[ $insert_before ];
+						//Determine when to insert Quicktag
+						$insert_every = $count / $num_pages;
+						$insert_every_rounded = round( $insert_every );
+
+						//If number of pages is greater than number of paragraphs, put each paragraph on its own page
+						if ( $num_pages > $count )
+							$insert_every_rounded = 1;
+
+						//Set initial counter position.
+						$i = $count - 1 == $num_pages ? 2 : 1;
+
+						//Loop through content pieces and append Quicktag as is appropriate
+						foreach( $content as $key => $value ) {
+							if ( $key + 1 == $count )
+								break;
+
+							if ( ( $key + 1 ) == ( $i * $insert_every_rounded ) ) {
+								$content[ $key ] = $content[ $key ] . '<!--nextpage-->';
+								$i++;
+							}
+						}
 
 						//Reunite content
 						$content = implode( "\r\n\r\n", $content );
 
 						//And, overwrite the original content
 						$the_post->post_content = $content;
+
+						//Clean up
+						unset( $count );
+						unset( $insert_every );
+						unset( $insert_every_rounded );
+						unset( $key );
+						unset( $value );
 					}
 
 					//Lastly, clean up.
+					unset( $num_pages );
 					unset( $content );
+					unset( $count );
 				}
 			}
 		}