3. März 2016

Generic Syntax Highlighting with Regular Expressions in pure PHP

Due to Google AMP (Accelerated Mobile Pages) , I have been looking for a way to effectively do Syntax Highlighting without Javascript in pure PHP.

I was about to write my own, when I found an older article from phoboslab. Thanks Dominic for saving me some time ;) Its not perfect, but close enough.

A simple Syntax Highlighting Class that does just that. The class was not working with PHP 5.4.x+, as it uses preg_replace() with the /e modifier.

It will not cover all, but its better than nothing :) I will also add a section to my my AMP tweaks article to showcase the integration of Geshi.

Here an updated version using the preg_replace_callback() function.

THE SYNTAX HIGHLIGHT CLASS

class SyntaxHighlight {
   
    static $tokens = array();// This array will be filled from the regexp-callback

    public static function process($s) {
        $s = htmlspecialchars($s);

        // Workaround for escaped backslashes
        $s = str_replace('\\\\','\\\\<e>', $s); 

        $regexp = array(

            // Punctuations
            '/([\-\!\%\^\*\(\)\+\|\~\=`\{\}\[\]\:\"\'<>\?\,\.\/]+)/'
            => '<span class="P">$1</span>',

            // Numbers (also look for Hex)
            '/(?<!\w)(
                (0x|\#)[\da-f]+|
                \d+|
                \d+(px|em|cm|mm|rem|s|\%)
            )(?!\w)/ix'
            => '<span class="N">$1</span>',

            // Make the bold assumption that an
            // all uppercase word has a special meaning
            '/(?<!\w|>|\#)(
                [A-Z_0-9]{2,}
            )(?!\w)/x'
            => '<span class="D">$1</span>',

            // Keywords
            '/(?<!\w|\$|\%|\@|>)(
                and|or|xor|for|do|while|foreach|as|return|die|exit|if|then|else|
                elseif|new|delete|try|throw|catch|finally|class|function|string|
                array|object|resource|var|bool|boolean|int|integer|float|double|
                real|string|array|global|const|static|public|private|protected|
                published|extends|switch|true|false|null|void|this|self|struct|
                char|signed|unsigned|short|long
            )(?!\w|=")/ix'
            => '<span class="K">$1</span>',

            // PHP/Perl-Style Vars: $var, %var, @var
            '/(?<!\w)(
                (\$|\%|\@)(\->|\w)+
            )(?!\w)/ix'
            => '<span class="V">$1</span>'

        );      
	
        $s = preg_replace_callback( '/(
                \/\*.*?\*\/|
                \/\/.*?\n|
                \#.[^a-fA-F0-9]+?\n|
                \<\!\-\-[\s\S]+\-\-\>|
                (?<!\\\)&quot;.*?(?<!\\\)&quot;|
                (?<!\\\)\'(.*?)(?<!\\\)\'
            )/isx' , array('SyntaxHighlight', 'replaceId'),$s);
			
        $s = preg_replace(array_keys($regexp), array_values($regexp), $s);

        // Paste the comments and strings back in again
        $s = str_replace(array_keys(SyntaxHighlight::$tokens), array_values(SyntaxHighlight::$tokens), $s);

        // Delete the "Escaped Backslash Workaround Token" (TM)
        // and replace tabs with four spaces.
        $s = str_replace(array('<e>', "\t"), array('', '    '), $s);

        return '<pre>'.$s.'</pre>' ;
    }

    // Regexp-Callback to replace every comment or string with a uniqid and save
    // the matched text in an array
    // This way, strings and comments will be stripped out and wont be processed
    // by the other expressions searching for keywords etc.
     static function replaceId($match) {
        $id = "##r" . uniqid() . "##";
	
        // String or Comment?
        if(substr($match[1], 0, 2) == '//' || substr($match[1], 0, 2) == '/*' || substr($match[1], 0, 2) == '##' || substr($match[1], 0, 7) == '<!--') {
            SyntaxHighlight::$tokens[$id] = '<span class="C">' . $match[1] . '</span>';
        } else {
           SyntaxHighlight::$tokens[$id] = '<span class="S">' . $match[1] . '</span>';
        }
		
        return $id;
    }
}

class SyntaxHighlight {

static $tokens = array();// This array will be filled from the regexp-callback

public static function process($s) {

$s = htmlspecialchars($s);

// Workaround for escaped backslashes

$s = str_replace('\\\\','\\\\<e>', $s);

$regexp = array(

// Punctuations

'/([\-\!\%\^\*\+\|\~\=`\{\}\[\]\:\"\'<>\?\,\.\/]+)/'

=> '$1',

// Numbers (also look for Hex)

'/(?<!\w)(

(0x|\#)[\da-f]+|

\d+|

\d+(px|em|cm|mm|rem|s|\%)

)(?!\w)/ix'

=> '$1',

// Make the bold assumption that an

// all uppercase word has a special meaning

'/(?<!\w|>|\#)(

[A-Z_0-9]{2,}

)(?!\w)/x'

=> '$1',

// Keywords

'/(?<!\w|\$|\%|\@|>)(

and|or|xor|for|do|while|foreach|as|return|die|exit|if|then|else|

char|signed|unsigned|short|long

)(?!\w|=")/ix'

=> '$1',

// PHP/Perl-Style Vars: $var, %var, @var

'/(?<!\w)(

(\$|\%|\@)(\->|\w)+

)(?!\w)/ix'

=> '$1'

);

$s = preg_replace_callback( '/(

\/\*.*?\*\/|

\/\/.*?\n|

\#.[^a-fA-F0-9]+?\n|

\<\!\-\-[\s\S]+\-\-\>|

(?<!\\\)".*?(?<!\\\)"|

(?<!\\\)\'(.*?)(?<!\\\)\'

)/isx' , array('SyntaxHighlight', 'replaceId'),$s);

$s = preg_replace(array_keys($regexp), array_values($regexp), $s);

// Paste the comments and strings back in again

$s = str_replace(array_keys(SyntaxHighlight::$tokens), array_values(SyntaxHighlight::$tokens), $s);

// Delete the "Escaped Backslash Workaround Token" (TM)

// and replace tabs with four spaces.

$s = str_replace(array('<e>', "\t"), array('', ' '), $s);

return '<pre>'.$s.'</pre>' ;

}

// Regexp-Callback to replace every comment or string with a uniqid and save

// the matched text in an array

// This way, strings and comments will be stripped out and wont be processed

// by the other expressions searching for keywords etc.

static function replaceId($match) {

$id = "##r" . uniqid() . "##";

// String or Comment?

if(substr($match[1], 0, 2) == '//' || substr($match[1], 0, 2) == '/*' || substr($match[1], 0, 2) == '##' || substr($match[1], 0, 7) == '<!--') {

SyntaxHighlight::$tokens[$id] = '' . $match[1] . '';

} else {

SyntaxHighlight::$tokens[$id] = '' . $match[1] . '';

}

return $id;

}

THE CSS

pre { 
	font-family: 'Courier New', 'Bitstream Vera Sans Mono', 'monospace'; 
	font-size: 9pt;
	border-top: 1px solid #333;
	border-bottom: 1px solid #333;
	padding: 0.4em;
	color: #fff;
}
pre span.N{ color:#f2c47f; } /* Numbers */
pre span.S{ color:#42ff00; } /* Strings */
pre span.C{ color:#838383; } /* Comments */
pre span.K{ color:#ff0078; } /* Keywords */
pre span.V{ color:#70d6ff; } /* Vars */
pre span.D{ color:#ff9a5d; } /* Defines */

pre {

font-family: 'Courier New', 'Bitstream Vera Sans Mono', 'monospace';

font-size: 9pt;

border-top: 1px solid #333;

border-bottom: 1px solid #333;

padding: 0.4em;

color: #fff;

}

pre span.N{ color:#f2c47f; } /* Numbers */

pre span.S{ color:#42ff00; } /* Strings */

pre span.C{ color:#838383; } /* Comments */

pre span.K{ color:#ff0078; } /* Keywords */

pre span.V{ color:#70d6ff; } /* Vars */

pre span.D{ color:#ff9a5d; } /* Defines */

USAGE

echo SyntaxHighlight::process( $your_code );

1	echo SyntaxHighlight::process( $your_code );

@GitHub portalzine/UtilityBelt/SyntaxHighlight

Enjoy coding …

2. März 2016

Create and Manage multiple isolated PHP environments with virtPHP

“virtPHP is a tool for creating and managing multiple isolated PHP environments on a single machine. It’s like Python’s virtualenv, but for PHP.

virtPHP creates isolated environments so that you may run any number of PHP development projects, all using different versions of PEAR packages and different PECL extensions. You may even specify a different version of PHP, if your system has various installations of PHP.”

virtPHP @ Github

29. Februar 2016

AMP-WP Tweaks & Tips

The AMP (Accelerated Mobile Pages Project) plugin for WordPress is still pretty young and under heavy development.

There are little things that can help to fix current validation problems. I have a couple of fresh AMP pages, that are already indexed by Google.

0. RESOURCES

1. MISSING IMAGE (schema.org-NewsArticle)

The currently registered Microformats template (schema.org-NewsArticle) requires an image.
The AMP-WP documentation explains how to add a featured image to your pages (documentation).

I extended that a bit, to link a default attachment image, I uploaded before. This needs to be added to your themes functions.php.

function xyz_amp_add_custom_actions() {
    add_filter( 'the_content', 'xyz_amp_add_featured_image' );
}

function xyz_amp_add_featured_image( $content ) {

 $your_attachment_id = 2016;

 if ( has_post_thumbnail() ) {
  $image = sprintf( '<p class="xyz-featured-image">%s</p>', get_the_post_thumbnail() );
        
 }else{
 $image = sprintf( '<p class="xyz-featured-image">%s</p>', wp_get_attachment_image( $your_attachment_id, 1280) );
        $content = $image . $content ;
 }
 $content = $image . $content ;
 return preg_replace('/(<br>\s*){2,}/', '<br/>',$content);
}

function xyz_amp_add_custom_actions() {

add_filter( 'the_content', 'xyz_amp_add_featured_image' );

}

function xyz_amp_add_featured_image( $content ) {

$your_attachment_id = 2016;

if ( has_post_thumbnail() ) {

$image = sprintf( '%s', get_the_post_thumbnail() );

}else{

$image = sprintf( '%s', wp_get_attachment_image( $your_attachment_id, 1280) );

$content = $image . $content ;

}

$content = $image . $content ;

return preg_replace('/( \s*){2,}/', ' ',$content);

}

Next we adjust the Microformats definition. This needs to be added to your themes functions.php.

add_filter( 'amp_post_template_metadata', 'xyz_amp_modify_json_metadata', 10, 2 );

function xyz_amp_modify_json_metadata( $metadata, $post ) {
  if(empty($metadata['image'])){
    $your_attachment_id = 2016;
    $imgMeta = wp_get_attachment_metadata($your_attachment_id );
    $metadata['image'] = array(
        '@type' => 'ImageObject',
        'url' => wp_get_attachment_url( $your_attachment_id ),
        'height' => $imgMeta['height'],
        'width' =>  $imgMeta['width'],
    );
  }
    return $metadata;
}

add_filter( 'amp_post_template_metadata', 'xyz_amp_modify_json_metadata', 10, 2 );

function xyz_amp_modify_json_metadata( $metadata, $post ) {

if(empty($metadata['image'])){

$your_attachment_id = 2016;

$imgMeta = wp_get_attachment_metadata($your_attachment_id );

$metadata['image'] = array(

'@type' => 'ImageObject',

'url' => wp_get_attachment_url( $your_attachment_id ),

'height' => $imgMeta['height'],

'width' => $imgMeta['width'],

);

}

return $metadata;

}

2. ADD YOUR OWN AMP TEMPLATE

Read the AMP-WP documentation first :) This forces AMP-WP to override the core template with your own. Use the default template as a reference.

add_filter( 'amp_post_template_file', 'xyz_amp_set_custom_template', 10, 3 );

function xyz_amp_set_custom_template( $file, $type, $post ) {
    if ( 'single' === $type ) {
        $file = dirname( __FILE__ ) . '/amp/amp_template.php';
    }
    return $file;
}

add_filter( 'amp_post_template_file', 'xyz_amp_set_custom_template', 10, 3 );

function xyz_amp_set_custom_template( $file, $type, $post ) {

if ( 'single' === $type ) {

$file = dirname( __FILE__ ) . '/amp/amp_template.php';

}

return $file;

}

3. REMOVE NONE VALIDATING CONTENT

Normally the core sanitizer should take care of that. I am sure a filter will be added in the future. For now, this is a quick workaround. You can use a RegExp or DOMDocument to alter the amp-content in your custom template and filter things that break validation.

$attributes = $element->attributes;
while ($attributes->length) {
    $element->removeAttribute($attributes->item(0)->name);
}

$attributes = $element->attributes;

while ($attributes->length) {

$element->removeAttribute($attributes->item(0)->name);

}

I am using phpQuery for now, as it allows me to add quick fixes. DOMNode or QueryPath works nicely as well :) Will be looking at the core sanitizer and options later this week. All of this is currently added to the custom template.

 require('your-libs/phpQuery/phpQuery.php');
 $doc = phpQuery::newDocumentHTML($this->get( 'post_amp_content' ));

1 2	require('your-libs/phpQuery/phpQuery.php'); $doc = phpQuery::newDocumentHTML($this->get( 'post_amp_content' ));

Remove REL attributes that are not allowed. Only registered Microformat rel attributes are allowed.

$doc['.prettyphoto']->removeAttr("rel");

1

$doc['.prettyphoto']->removeAttr("rel");
Remove attribute ALIGN

$doc['*']->removeAttr("align");

1

$doc['*']->removeAttr("align");
Fix TARGET Attribute

$doc['a[target="new"]']->attr("target","_blank");

1

$doc['a[target="new"]']->attr("target","_blank");

Finally output the fixed content as HTML.

 echo  $doc->html(); // amphtml content; no kses

1	echo $doc->html(); // amphtml content; no kses

The above examples need to be tweaked to your specific content requirements.

The custom template “post_amp_content” before:

 echo $this->get( 'post_amp_content'); // amphtml content; no kses

1	echo $this->get( 'post_amp_content'); // amphtml content; no kses

The custom template “post_amp_content” after:

 require('your-libs/phpQuery/phpQuery.php');
 $doc = phpQuery::newDocumentHTML($this->get( 'post_amp_content' )); 
 $doc['.prettyphoto']->removeAttr("rel")->removeAttr("href");
 $doc['*']->removeAttr("align");
 $doc['a[target="new"]']->attr("target","_blank");
 echo  $doc->html(); // amphtml content; no kses

require('your-libs/phpQuery/phpQuery.php');

$doc = phpQuery::newDocumentHTML($this->get( 'post_amp_content' ));

$doc['.prettyphoto']->removeAttr("rel")->removeAttr("href");

$doc['*']->removeAttr("align");

$doc['a[target="new"]']->attr("target","_blank");

echo $doc->html(); // amphtml content; no kses

4. ADD PREVIOUS & NEXT POST NAVIGATION

From the AMP specification :”Note, that AMP document may also be linked to directly…”

This is being added to the custom template as well.

Next:

global $query_string; 
$posts = query_posts($query_string); if (have_posts()) : while (have_posts()) : the_post(); 

$next_post = get_next_post();
if (!empty( $next_post )): 
 echo '<a class="next" href="'.amp_get_permalink( $next_post->ID ).'"> &#8604; '.$next_post->post_title.'</a>';
endif;

global $query_string;

$posts = query_posts($query_string); if (have_posts()) : while (have_posts()) : the_post();

$next_post = get_next_post();

if (!empty( $next_post )):

echo '<a class="next" href="'.amp_get_permalink( $next_post->ID ).'"> ↜ '.$next_post->post_title.'</a>';

endif;

Previous:

$prev_post = get_previous_post();

if (!empty( $prev_post )): 
 echo '<a class="prev" href="'.amp_get_permalink( $prev_post->ID ).'"> &#8604; '.$prev_post->post_title.'</a>';
endif;

$prev_post = get_previous_post();

if (!empty( $prev_post )):

echo '<a class="prev" href="'.amp_get_permalink( $prev_post->ID ).'"> ↜ '.$prev_post->post_title.'</a>';

endif;

5. SYNTAX HIGHLIGHTING

You can find a simple pure PHP highlighter here. Not perfect, but a start. Don not forget to include the CSS :)

require_once("your-lib/SyntaxHighlight/SyntaxHighlight.php");
foreach(pq('pre') as $code)
{
 pq($code)->html(SyntaxHighlight::process(pq($code)->text()));
}

require_once("your-lib/SyntaxHighlight/SyntaxHighlight.php");

foreach(pq('pre') as $code)

{

pq($code)->html(SyntaxHighlight::process(pq($code)->text()));

}

I will extend on this as new validation errors or tweaks come up. The core sanitizer of AMP-WP still needs some work and should allow us to do some of the above directly, when the content is parsed / converted for AMP.

6. OTHER AMP ARTICLES

Make Syntax Highlighting work in AMP-WP using GeSHi

Time to get AMP ready

Enjoy coding …

26. Februar 2016

Time to get AMP ready

Google’s AMP is here to save us from slow mobile content delivery, by enforcing strict standards and limiting what is allowed within AMP pages. The pages only allow a subset of tags and introduce their own tags for fast prefetching of content (images, videos … AMP Specs)

THIS IS AMP

“The Accelerated Mobile Pages (“AMP”) Project is an open source initiative that came out of discussions between publishers and technology companies about the need to improve the entire mobile content ecosystem for everyone – publishers, consumer platforms, creators, and users.

Today, the expectation is that content should load super fast and be easy to explore. The reality is that content can take several seconds to load, or, because the user abandons the slow page, never fully loads at all. Accelerated Mobile Pages are web pages designed to load instantaneously – they are a step towards a better mobile web for all.”

AMP CACHE & VALIDATION

AMP pages are cached within the AMP Cache, providing even faster delivery of your content. The core libs validate your implementation and highlight any problems by pushing errors to the console.

INTEGRATION

The documentation lists all components currently supported within a page and experimental components in development as well.

I have already added AMP support to our blog posts:

Google’s Webmaster Tools also integrates a new section for AMP, to see how they perform.

WHAT AMP IS NOT

AMP is not supposed to replace your webpage, but offer a faster access point to presented content. It will not solve all use cases, but offer better performance for your simple reading pleasure for now. Its a start and lets see how it evolves ;)

Enjoy coding …

24. Februar 2016

Visual Composer to Bootstrap Grid Cleanup

Simple way to do some Visual Composer Grid cleanup, when you are using Bootstrap within your theme. This removes and cleans up classes.

add_filter('vc_shortcodes_css_class', function ($class_string, $tag) {
  $tags_to_clean = [
	  'vc_row',
	  'vc_column',
	  'vc_row_inner',
	  'vc_column_inner'
  ];
  if (in_array($tag, $tags_to_clean)) {
	
	  $class_string = str_replace(' wpb_row', '', $class_string);
	  $class_string = str_replace(' vc_row-fluid', '', $class_string);
	  $class_string = str_replace(' vc_column_container', '', $class_string);
	  $class_string = str_replace('wpb_column', '', $class_string);
	  
          // replace vc_, but exclude any custom css 
          // attached via vc_custom_XXX (negative lookahead)
	  $class_string = preg_replace('/vc_(?!custom)/i', '', $class_string);
          
          // replace all vc_
          // $class_string = preg_replace('/vc_/i', '', $class_string);
  }
  $class_string = preg_replace('|col-sm|', 'col-sm', $class_string);
  return $class_string;
}, 10, 2);

add_filter('vc_shortcodes_css_class', function ($class_string, $tag) {

$tags_to_clean = [

'vc_row',

'vc_column',

'vc_row_inner',

'vc_column_inner'

];

if (in_array($tag, $tags_to_clean)) {

$class_string = str_replace(' wpb_row', '', $class_string);

$class_string = str_replace(' vc_row-fluid', '', $class_string);

$class_string = str_replace(' vc_column_container', '', $class_string);

$class_string = str_replace('wpb_column', '', $class_string);

// replace vc_, but exclude any custom css

// attached via vc_custom_XXX (negative lookahead)

$class_string = preg_replace('/vc_(?!custom)/i', '', $class_string);

// replace all vc_

// $class_string = preg_replace('/vc_/i', '', $class_string);

}

$class_string = preg_replace('|col-sm|', 'col-sm', $class_string);

return $class_string;

}, 10, 2);

Visual Composer for WordPress
Bootstrap / Bootstrap Sass

Enjoy coding …

18. Februar 2016

Serializing to JSON

VALID JSON (JavaScript Object Notation)

JSON validator – JSONLint / JSONFormatter

{"employees":[
    {"firstName":"John", "lastName":"Doe"},
    {"firstName":"Anna", "lastName":"Smith"},
    {"firstName":"Peter", "lastName":"Jones"}
]}

{"employees":[

{"firstName":"John", "lastName":"Doe"},

{"firstName":"Anna", "lastName":"Smith"},

{"firstName":"Peter", "lastName":"Jones"}

]}

PURE JS CONVERSION

Polyfill for older browsers – JSON3

var JSON = JSON.stringify(OBJECT, null, 2);

1	var JSON = JSON.stringify(OBJECT, null, 2);

PHP CONVERSION

Make sure content within the object complies to UTF-8, if not encode it before !

$JSON = json_encode($OBJECT);

1	$JSON = json_encode($OBJECT);

Even DateTime is nicely encoded :)

class User {
    public $firstname = "";
    public $lastname  = "";
    public $birthdate = "";
}

$user = new User();
$user->firstname = "foo";
$user->lastname  = "bar";

// Returns: {"firstname":"foo","lastname":"bar"}
json_encode($user);

$user->birthdate = new DateTime();

/* Returns:
    {
        "firstname":"foo",
        "lastname":"bar",
        "birthdate": {
            "date":"2016-02-18 11:42:58",
            "timezone_type":3,
            "timezone":"Europe\/Berlin"
        }
    }
*/
json_encode($user);

class User {

public $firstname = "";

public $lastname = "";

public $birthdate = "";

}

$user = new User();

$user->firstname = "foo";

$user->lastname = "bar";

// Returns: {"firstname":"foo","lastname":"bar"}

json_encode($user);

$user->birthdate = new DateTime();

/* Returns:

{

"firstname":"foo",

"lastname":"bar",

"birthdate": {

"date":"2016-02-18 11:42:58",

"timezone_type":3,

"timezone":"Europe\/Berlin"

}

json_encode($user);

Enjoy coding …

5. Februar 2016

Get WordPress Page, Post or Custom Post-Type data anywhere you need it

Depending from where you want to access the page, post or custom post-type data, it might not always be available that easily.

WordPress provides an option to get your data through the page-slug.

The function is called get_page_by_path.

$page = get_page_by_path( basename ( $_SERVER['REQUEST_URI']),OBJECT, "your-post-type" );

1	$page = get_page_by_path( basename ( $_SERVER['REQUEST_URI']),OBJECT, "your-post-type" );

Enjoy coding …

2. Februar 2016

LMS meets SaaS

As I said before, Learning Management is really taking off and I get many client requests to do some kind of integration or custom solution for them.

In one of my latest articles I started listing solutions for WordPress, WordPress and the LMS universe.

But those solutions might not always be the best fit for your project. Many of them actually try too hard to be everything. The amount of cross linked functionality is getting insane and increases the point of failure.

In some cases a trimmed down solid solution might be the better way to go. SaaS (Software as a Service), part of the cloud trend, is providing more and more options, this includes the LMS arena. Stop worrying about the software and concentrate on your content again. The SaaS provider takes care of functionality, support, updates and delivery. This is nothing new, solutions like TalentLMS or Litmos LMS offer this for some time now.

Modern SaaS solutions provide Public APIs, that allow you to seamlessly integrate them with your current solution. So in case of a LMS, that part of your project could be handled by the SaaS provider, while e-commerce, social and other content areas remain under your full control.

One solution I am currently looking at is Intuo, which is a fresh startup out of Gent / Belgium. They provide a solid set of features and a clean API to handle single signons and content access. That would allow a seamless integration into WordPress for example :)

We are looking at a very crowded LMS market, but always nice to have options :)

Enjoy coding …

1. Februar 2016

Parse Alternatives

Now that Parse is phasing out (01/2017), people are looking for alternatives that offer:

Data Storage
Push Notifications
Usage Analytics
Dashboard
Social Integration
User Administration
Cloud Code Integration
Multiple Mobile Platform SDKs
Background Jobs
Crash Report

Collaborative list of Parse alternative backend service providers @ GitHub

26. Januar 2016

A PayPal Instant Payment Notification (IPN) toolkit for WordPress

All PayPal IPN data is saved and available in your WordPress admin panel.
Developer hooks are provided for triggering events based on the transaction type or payment status of the IPN.
Extend the plugin with your own plugins or theme functions

Author: Andrew Angell

BitBucket Repo