<?php
/**
* GitHub's Gist site supports oEmbed but their oembed provider only
* returns raw HTML (no styling) and the first little bit of the code.
*
* Their JavaScript-based embed method is a lot better, so that's what we're using.
*
* Supported formats:
* Full URL: https://gist.github.com/57cc50246aab776e110060926a2face2
* Full URL with username: https://gist.github.com/jeherve/57cc50246aab776e110060926a2face2
* Full URL linking to specific file: https://gist.github.com/jeherve/57cc50246aab776e110060926a2face2#file-wp-config-php
* Full URL, no username, linking to specific file: https://gist.github.com/57cc50246aab776e110060926a2face2#file-wp-config-php
* Gist ID: [gist]57cc50246aab776e110060926a2face2[/gist]
* Gist ID within tag: [gist 57cc50246aab776e110060926a2face2]
* Gist ID with username: [gist jeherve/57cc50246aab776e110060926a2face2]
* Gist private ID with username: [gist xknown/fc5891af153e2cf365c9]
*
* @package automattic/jetpack
*/
wp_embed_register_handler( 'github-gist', '#https?://gist\.github\.com/([a-zA-Z0-9/]+)(\#file\-[a-zA-Z0-9\_\-]+)?#', 'github_gist_embed_handler' );
add_shortcode( 'gist', 'github_gist_shortcode' );
/**
* Handle gist embeds.
*
* @since 2.8.0
*
* @global WP_Embed $wp_embed
*
* @param array $matches Results after parsing the URL using the regex in wp_embed_register_handler().
* @param array $attr Embed attributes.
* @param string $url The original URL that was matched by the regex.
* @param array $rawattr The original unmodified attributes.
* @return string The embed HTML.
*/
function github_gist_embed_handler( $matches, $attr, $url, $rawattr ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
// Let the shortcode callback do all the work.
return github_gist_shortcode( $matches, $url );
}
/**
* Extract an ID from a Gist shortcode or a full Gist URL.
*
* @since 7.3.0
*
* @param string $gist Gist shortcode or full Gist URL.
*
* @return array $gist_info {
* Array of information about our gist.
* @type string $id Unique identifier for the gist.
* @type string $file File name if the gist links to a specific file.
* }
*/
function jetpack_gist_get_shortcode_id( $gist = '' ) {
$gist_info = array(
'id' => '',
'file' => '',
'ts' => 8,
);
// Simple shortcode, with just an ID.
if ( ctype_alnum( $gist ) ) {
$gist_info['id'] = $gist;
}
// Full URL? Only keep the relevant parts.
$parsed_url = wp_parse_url( $gist );
if (
! empty( $parsed_url )
&& is_array( $parsed_url )
&& isset( $parsed_url['scheme'] ) && isset( $parsed_url['host'] ) && isset( $parsed_url['path'] )
) {
// Not a Gist URL? Bail.
if ( 'gist.github.com' !== $parsed_url['host'] ) {
return array(
'id' => '',
'file' => '',
'ts' => 8,
);
}
// Keep the file name if there was one.
if ( ! empty( $parsed_url['fragment'] ) ) {
$gist_info['file'] = preg_replace( '/(?:file-)(.+)/', '$1', $parsed_url['fragment'] );
}
// Keep the unique identifier without any leading or trailing slashes.
if ( ! empty( $parsed_url['path'] ) ) {
$gist_info['id'] = trim( $parsed_url['path'], '/' );
// Overwrite $gist with our identifier to clean it up below.
$gist = $gist_info['id'];
}
// Parse the query args to obtain the tab spacing.
if ( ! empty( $parsed_url['query'] ) ) {
$query_args = array();
wp_parse_str( $parsed_url['query'], $query_args );
if ( ! empty( $query_args['ts'] ) ) {
$gist_info['ts'] = absint( $query_args['ts'] );
}
}
}
// Not a URL nor an ID? Look for "username/id", "/username/id", or "id", and only keep the ID.
if ( preg_match( '#^/?(([a-z0-9_-]+/)?([a-z0-9]+))$#i', $gist, $matches ) ) {
$gist_info['id'] = $matches[3];
}
return $gist_info;
}
/**
* Callback for gist shortcode.
*
* @since 2.8.0
*
* @param array $atts Attributes found in the shortcode.
* @param string $content Content enclosed by the shortcode.
*
* @return string The gist HTML.
*/
function github_gist_shortcode( $atts, $content = '' ) {
if ( empty( $atts[0] ) && empty( $content ) ) {
if ( current_user_can( 'edit_posts' ) ) {
return esc_html__( 'Please specify a Gist URL or ID.', 'jetpack' );
} else {
return '<!-- Missing Gist ID -->';
}
}
$id = ( ! empty( $content ) ) ? $content : $atts[0];
// Parse a URL to get an ID we can use.
$gist_info = jetpack_gist_get_shortcode_id( $id );
if ( empty( $gist_info['id'] ) ) {
if ( current_user_can( 'edit_posts' ) ) {
return esc_html__( 'The Gist ID you provided is not valid. Please try a different one.', 'jetpack' );
} else {
return '<!-- Invalid Gist ID -->';
}
} else {
// Add trailing .json to all unique gist identifiers.
$id = $gist_info['id'] . '.json';
}
// The file name can come from the URL passed, or from a shortcode attribute.
if ( ! empty( $gist_info['file'] ) ) {
$file = $gist_info['file'];
} elseif ( ! empty( $atts['file'] ) ) {
$file = $atts['file'];
} else {
$file = '';
}
// Replace - by . to get a real file name from slug.
if ( ! empty( $file ) ) {
// Find the last -.
$dash_position = strrpos( $file, '-' );
if ( false !== $dash_position ) {
// Replace the - by a period.
$file = substr_replace( $file, '.', $dash_position, 1 );
}
$file = rawurlencode( $file );
}
// Set the tab size, allowing attributes to override the query string.
$tab_size = $gist_info['ts'];
if ( ! empty( $atts['ts'] ) ) {
$tab_size = absint( $atts['ts'] );
}
if (
class_exists( 'Jetpack_AMP_Support' )
&& Jetpack_AMP_Support::is_amp_request()
) {
/*
* According to <https://www.ampproject.org/docs/reference/components/amp-gist#height-(required)>:
*
* > Note: You must find the height of the gist by inspecting it with your browser (e.g., Chrome Developer Tools).
*
* However, this does not seem to be the case any longer. The actual height of the content does get set in the
* page after loading. So this is just the initial height.
* See <https://github.com/ampproject/amphtml/pull/17738>.
*/
$height = 240;
$amp_tag = sprintf(
'<amp-gist layout="fixed-height" data-gistid="%s" height="%s"',
esc_attr( basename( $id, '.json' ) ),
esc_attr( $height )
);
if ( ! empty( $file ) ) {
$amp_tag .= sprintf( ' data-file="%s"', esc_attr( $file ) );
}
$amp_tag .= '></amp-gist>';
return $amp_tag;
}
// URL points to the entire gist, including the file name if there was one.
$id = ( ! empty( $file ) ? $id . '?file=' . $file : $id );
$return = false;
$request = wp_remote_get( esc_url_raw( 'https://gist.github.com/' . esc_attr( $id ) ) );
$request_code = wp_remote_retrieve_response_code( $request );
if ( 200 === $request_code ) {
$request_body = wp_remote_retrieve_body( $request );
$request_data = json_decode( $request_body );
wp_enqueue_style( 'jetpack-gist-styling', esc_url( $request_data->stylesheet ), array(), JETPACK__VERSION );
$gist = substr_replace( $request_data->div, sprintf( 'style="tab-size: %1$s" ', absint( $tab_size ) ), 5, 0 );
// Add inline styles for the tab style in the opening div of the gist.
$gist = preg_replace(
'#(\<div\s)+(id=\"gist[0-9]+\")+(\sclass=\"gist\"\>)?#',
sprintf( '$1style="tab-size: %1$s" $2$3', absint( $tab_size ) ),
$request_data->div,
1
);
// Add inline style to prevent the bottom margin to the embed that themes like TwentyTen, et al., add to tables.
$return = sprintf( '<style>.gist table { margin-bottom: 0; }</style>%1$s', $gist );
}
if (
// No need to check for a nonce here, that's already handled by Core further up.
// phpcs:disable WordPress.Security.NonceVerification.Missing
isset( $_POST['type'] )
&& 'embed' === $_POST['type']
&& isset( $_POST['action'] )
&& 'parse-embed' === $_POST['action']
// phpcs:enable WordPress.Security.NonceVerification.Missing
) {
return github_gist_simple_embed( $id, $tab_size );
}
return $return;
}
/**
* Use script tag to load shortcode in editor.
* Can't use wp_enqueue_script here.
*
* @since 3.9.0
*
* @param string $id The ID of the gist.
* @param int $tab_size The tab size of the gist.
* @return string The script tag of the gist.
*/
function github_gist_simple_embed( $id, $tab_size = 8 ) {
$id = str_replace( 'json', 'js', $id );
return '<script src="' . esc_url( "https://gist.github.com/$id?ts=$tab_size" ) . '"></script>'; // phpcs:ignore WordPress.WP.EnqueuedResources.NonEnqueuedScript
}