Convert images to Shortcode

converter.php

<?php namespace Vralle\Plugin\Shortcode\Img;
/*-------------------------------------------------------------------
 * Convert images to Shortcode
 *-----------------------------------------------------------------*/
function html_to_shortcode( $content ) {

	// Returns, if content is empty
	if( empty( $content ) )  return $content;

	if( 'content_save_pre' === current_filter() )
		$content = stripslashes( $content );

	// Ignore DOMDocument errors On
	libxml_use_internal_errors(true) AND libxml_clear_errors();

	$html = new \DOMDocument( '1.0', 'UTF-8' );

	// Load HTML as Document Fragment
	// $html->loadHTML( mb_convert_encoding( $content, 'HTML-ENTITIES', 'UTF-8' ), LIBXML_HTML_NODEFDTD | LIBXML_HTML_NOIMPLIED );
	$html->loadHTML( mb_convert_encoding( $content, 'HTML-ENTITIES', 'UTF-8' ) );

	$imgs = $html->getElementsByTagName( 'img' );

	// Exit, If nothing
	if( $imgs->length === 0 )
		return $content;


	// DOMDocument has a strange result for DOM manipulation in Loop. But strange Loop work perfect)
	for( $i = $imgs->length - 1; $i >= 0; $i-- ) {

		$image_attr_arr = [];
		$link_attr_arr = [];

		foreach( $imgs[$i]->attributes as $attr ) {

			$image_attr_arr[ $attr->nodeName ] = $attr->nodeValue;

		}

		// Go to next image, if empty
		if ( empty( $image_attr_arr[ 'src' ] ) ) {

			continue;

		} else {

			// convert relative url to absolute
			$image_attr_arr[ 'src' ] = rel2abs( $image_attr_arr[ 'src' ] );
		}

		// Check parent link
		$parent = $imgs[$i]->parentNode;

		// If link:
		if( 'a' === $parent->nodeName ) {

			// Save attributes
			foreach( $parent->attributes as $attr ) {

				if ( 'href' === $attr->nodeName ) {

					$link_attr_arr[ 'url' ] = $attr->nodeValue;

				} else {

					$link_attr_arr[ 'link_' . $attr->nodeName ] = $attr->nodeValue;
				}
			}

		}

		// Get Attachment ID and Size
		$attachment = get_attachment_id( $image_attr_arr['src'] );

		// Set id
		if( !empty( $attachment['id'] ) ) {

			$image_attr_arr['attachment'] = $attachment['id'];
			$image_attr_arr['size'] = $attachment['size'];

			unset( $image_attr_arr['width'] );
			unset( $image_attr_arr['height'] );
			unset( $image_attr_arr['alt'] );

		} else {

			// remove id attrs
			if( !empty( $image_attr_arr['class'] ) ) {

				$image_attr_arr['class'] = preg_replace( '/wp-image-\d+/i', '', $image_attr_arr['class'] );
				$image_attr_arr['class'] = preg_replace( '/size-\w+/i', '', $image_attr_arr['class'] );
			}

			unset( $image_attr_arr['attachment'] );
			unset( $image_attr_arr['size'] );

			// Check broken Images
			if ( $size = @getimagesize( $src ) ) {

				list( $width, $height ) = $size;

				if ( empty( $image_attr_arr['width'] ) ) {
					$image_attr_arr['width'] = $width;
				}

				if ( empty( $image_attr_arr['height'] ) ) {
					$image_attr_arr['height'] = $height;
				}
			}
		}

		// Set align
		if( !empty( $image_attr_arr['class'] ) ) {

			if( preg_match( '/align(\w+)/i', $image_attr_arr['class'], $align ) ) {

				$image_attr_arr['align'] = $align[1];

				// remove align from class
				$image_attr_arr['class'] = str_replace( $align[0], '', $image_attr_arr['class'] );

			}
		}

		unset( $image_attr_arr['class'] );

		// links checker
		if( !empty( $link_attr_arr['url'] ) ) {

			$link_attr_arr['url'] = rel2abs( $link_attr_arr['url'] );

			if( isset( $image_attr_arr['attachment'] ) ) {

				// Check link to post
				if ( $link_attr_arr['url'] === get_attachment_link( $image_attr_arr['attachment'] ) ) {

					$link_attr_arr['linkto'] = 'post';

				// Check link to file
				} elseif ( $link_attr_arr['url'] === wp_get_attachment_url( $image_attr_arr['attachment'] ) ) {

					$link_attr_arr['linkto'] = 'file';
				}

				// Remove url
				unset( $link_attr_arr['url'] );

			} else {

				$link_attr_arr['linkto'] = 'custom';

				// Cleanup rel attrs
				if( !empty( $link_attr_arr['rel'] ) ) {

					$link_attr_arr['rel'] = preg_replace( '/attachment[\s+]?/i', '', $link_attr_arr['rel'] );
					$link_attr_arr['rel'] = preg_replace( '/wp-att-[\d+][\s+]?/i', '', $link_attr_arr['rel'] );
				}
			}
		}

		$output  = '[img';

		foreach ( $image_attr_arr as $name => $value ) {
			$output .= sprintf( ' %s="%s"', sanitize_key( $name ), esc_attr( $value ) );
		}
	
		if( !empty( $link_attr_arr ) ) {

			foreach ( $link_attr_arr as $name => $value ) {
				if( false !== array_search( $name, ['url', 'target', 'linkto'] ) ) {
					$output .= sprintf( ' %s="%s"', sanitize_key( $name ), esc_attr( $value ) );
				} else {
					$output .= sprintf( ' link_%s="%s"', sanitize_key( $name ), esc_attr( $value ) );
				}
			}
		}

		$output .= ']';

		// Create output
		$shortcode = $html->createTextNode( $output );

		if( !empty( $link_attr_arr ) ) {

			$parent->parentNode->replaceChild( $shortcode, $parent );

		} else {

			$imgs[$i]->parentNode->replaceChild( $shortcode, $imgs[$i] );
		}

	}

	$html->saveHTML( $html );

	$content = $html->textContent;

	if( 'content_save_pre' === current_filter() )
		return addslashes( $content );

	return $content;
}
add_filter( 'content_save_pre', __NAMESPACE__ . '\\html_to_shortcode', 1 );
// add_filter( 'content_edit_pre', __NAMESPACE__ . '\\html_to_shortcode' );


function shortcode2html( $content ) {

	preg_match_all( '/' . get_shortcode_regex( ['img'] ) . '/', $content, $matches, PREG_SET_ORDER );

	// See 'sub matches' for get_shortcode_regex in /wp-includes/shortcodes.php

	if ( empty( $matches ) )
		return $content;

	foreach ( $matches as $shortcode ) {

		$attrs = shortcode_parse_atts( $shortcode[3] );

		$attr_img_string = '';
		$attr_link_string = '';


		// Setup Image Classes as WP Editor Attributes
		$classes_arr = !empty( $attrs['class'] ) ? explode( ' ', $attrs['class'] ) : [];

		if( !empty( $attrs['attachment'] ) ) {

			// Pass Attachment ID to WP Editor
			$wp_id = 'wp-image-' . intval( $attrs['attachment'] );

			if( false === array_search( $wp_id, $classes_arr ) )
				$classes_arr[] = $wp_id;

			// Pass Size to WP Editor
			$wp_size = 'size-' . $attrs['size'];

			if( false === array_search( $wp_size, $classes_arr ) )
				$classes_arr[] = $wp_size;

			// Pass Link to WP Editor
			if( !empty( $attrs['linkto'] ) ) {

				if ( 'file' === $attrs['linkto'] ) {

					$attrs['url'] = wp_get_attachment_url( $attrs['attachment'] );

				} elseif ( 'post' === $attrs['linkto'] ) {

					$attrs['url'] = get_attachment_link( $attrs['attachment'] );
				}
			}
		}

		// Pass align to WP Editor
		if( !empty( $attrs['align'] ) ) {

			$wp_align = 'align' . $attrs['align'];

			if( false === array_search( $wp_align, $classes_arr ) )
				$classes_arr[] = $wp_align;

			// Remove Shortcode Attribute
			unset( $attrs['align'] );
		}

		// Remove Shortcode Attributes
		unset( $attrs['attachment'] );
		unset( $attrs['size'] );
		unset( $attrs['linkto'] );

		$attrs['class'] = trim( implode( ' ', $classes_arr ) );


		// list to string:
		foreach( $attrs as $name => $value) {

			if( 'url' === $name ) {

				$attr_link_string .= ' href="' . $value . '"';

				continue;

			} elseif( false !== strpos( $name, 'link_' ) ) {

				$name = str_replace( 'link_', '', $name );
				$attr_link_string .= sprintf( ' %s="%s"', $name, $value );

				continue;
			}

			$attr_img_string .= sprintf( ' %s="%s"', $name, $value );
		}

		$html = '<img' . $attr_img_string . '>';

		if( ! empty( $attr_link_string ) ) {
			$html = '<a' . $attr_link_string . '>' . $html . '</a>';
		}

		// Replace the shortcode:
		$content = str_replace( $shortcode[0], $html, $content );
	}

    return $content;
}
add_filter( 'content_edit_pre', __NAMESPACE__ . '\\shortcode2html' );

search_attachment_by_url.php

<?php
/*
 * Get an attachment ID given a URL.
 * @param string $url
 * @return array( ['id'], ['size'] )
 */
function get_attachment_id( $url ) {

	$attachment = [];

	$uploads = wp_upload_dir();

	// Search Uploads URL. Return as $mat[1]
	if ( preg_match( '|^' . preg_quote( $uploads['baseurl'] ) . '(.*)$|i', $url, $mat ) ) {

		$file = pathinfo( $mat[1] );

		$query = get_posts( [ 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'posts_per_page' => '-1' ] );

		// exit if attachment posts not found(
		if( empty( $query ) ) return;

		foreach( $query as $post ) {

			// Get all file data
			$image_meta = get_post_meta( $post->ID, '_wp_attachment_metadata', true );

			// 1. Check File URL.
			if( false === strpos( $image_meta['file'], ltrim( $file['dirname'], '/' ) ) )
				continue;

			// Check match the base file
			if( $file['basename'] === basename( $image_meta['file'] ) ) {

				// 2. URL verified. Filename verified. Win!
				$attachment['id'] = $post->ID;
				$attachment['size'] = 'file';

				// We are win!
				break;

			}

			// Search matching available sizes
			foreach( $image_meta['sizes'] as $key => $value ) {

				if( $file['basename'] === basename( $value['file'] ) ) {

					// 3. URL verified. Filename verified. Win!
					$attachment['id'] = $post->ID;
					$attachment['size'] = $key;
					// We are win!
					break 2;
				}
			}
		}
	}

	return $attachment;
}