Solving Design Problems by Design Patterns

Today i am gonna describe design patterns. The very first question that can arise in anyone’s mind is What is design pattern? Where we use it? Why we use it? Hold on… Lets go through this one by one.

What is a design pattern?

In simple sentence, a design pattern is a way to design our software/application. Each design pattern addresses a problem or set of problem and describe a solution for it. So these design patterns help us understand those problems and solve them effectively.

Designing object-oriented software is hard, and designing a good, reusable object-oriented software is even harder. We need to find objects, factor them into classes at the right granularity, define class interfaces and establish relationship among them to make a good software. Our software design should be flexible enough that can handle future problems and for modifications. This means it’s impossible to find exactly right design for any software but we can make it in such a way that can cover maximum solutions for future issues.

Why and where we use it?

It’s one of the most time taking process in any software design, as per my experience. And it takes a long time for someone to learn these design patterns from scratch. An experienced architect never solve any problem from first rules rather they use experience that have helped them in past. Consequently, we find recurring patterns of classes and their communications. These patterns solve some specific design problems and make object-oriented designs more flexible, elegant and reusable, which is the main philosophy behind object oriented systems.

So at this point now we are able to define what is a design pattern? Its a description of communicating objects and classes that are customized to solve a general design problem in a particular context.

So basically a design pattern has following elements –

  1. 1. Problem
  2. 2. Solution
  3. 3. Future consequences

Still one question can come into ones’ mind that How these design patterns solve design problems?

Well its a vast topic and lets walk through it.

Design patterns solve many problems object-oriented designers face.

Followings are few of them –

Designing appropriate objects – The most complex part of any object-oriented design is decomposing a system into objects. This is difficult because of many factors like our object should be reusable, it should address future problems, should be flexible etc. Think of a scenario where an architect designs a bad software, how costly that can be for the organization in future? So design patterns helps you identify your problems and create objects that can capture them.

Determining Object Level – Objects can vary in size. They can represent anything from hardware to the complete application. So how do we decide what should be an object? Design pattern solves this problem also.

In this context let me introduce you with very common terms of object-oriented design. Every operation declared by an object specifies the operation’s name, the objects it takes as parameters, and the return value. This is known as the operation’s signature. The set of all signatures defined by an object’s operations is called the interface to the object. An object’s interface characterizes the complete set of requests that can be sent to the object. An object is the set of operations it can perform and set of states it can be in. There are several kind of design patterns e.g. Abstract, Factory, Singleton etc. I will try to cover them in my next posts.

Content Source: http://www.raakeshkumar.in/

Configure Codeigniter with Twig

In my recent project i tried to integrate codeigniter with twig template engine with php-activerecord and so thought to share with everyone.

First you need to have codeigniter downloaded and extracted then download php-activerecord. Now lets integrate both:

1- Extract active record and put it inside /libraries folder so the directory structure becomes /application/libraries/php-activerecord.
2- Create a class Activerecord.php inside libraries folder itself with the following contents

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
 $db_values) {
                // Convert to dsn format
                $dsn[$name] = $db[$name]['dbdriver'] .
                    '://'   . $db[$name]['username'] .
                    ':'     . $db[$name]['password'] .
                    '@'     . $db[$name]['hostname'] .
                    '/'     . $db[$name]['database'];
            }
        } 
        
        // Initialize ActiveRecord
        ActiveRecord\Config::initialize(function($cfg) use ($dsn, $active_group){
            $cfg->set_model_directory(APPPATH.'/models');
            $cfg->set_connections($dsn);
            $cfg->set_default_connection($active_group);
        });
        
    }
}
 
/* End of file Activerecord.php */
/* Location: ./application/libraries/Activerecord.php */
 $db_values) {
            	// Convert to dsn format
            	$dsn[$name] = $db[$name]['dbdriver'] .
            		'://'   . $db[$name]['username'] .
            		':'     . $db[$name]['password'] .
            		'@'     . $db[$name]['hostname'] .
            		'/'     . $db[$name]['database'];
            }
        } 
        
        // Initialize ActiveRecord
        ActiveRecord\Config::initialize(function($cfg) use ($dsn, $active_group){
            $cfg->set_model_directory(APPPATH.'/models');
            $cfg->set_connections($dsn);
            $cfg->set_default_connection($active_group);
        });
        
    }
}

/* End of file Activerecord.php */
/* Location: ./application/libraries/Activerecord.php */

3- Configure your config/database.php file to match with your database settings.

And that’s it!! You are done… And can use this easily in your application. All you now need to do is , load the library whenever you want to use it. And to get rid of this you can simple put a line in your config/autoload.php

1
$autoload['libraries'] = array('activerecord');
$autoload['libraries'] = array('activerecord');

Now lets configure codeigniter with twig engine.

For this first get Twig. After extracting you can place this too in your application/libraries folder so that your directory structure becomes

1
2
3
 application/
..libraries/
..Twig
 application/
..libraries/
..Twig

Afterward, you need to create a file named Twig.php in libraries directory and place following code into that

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
CI =& get_instance();
        $this->CI->config->load('twig');
 
        ini_set('include_path',
        ini_get('include_path') . PATH_SEPARATOR . APPPATH . 'libraries/Twig');
        require_once (string) "Autoloader" . EXT;
 
        log_message('debug', "Twig Autoloader Loaded");
 
        Twig_Autoloader::register();
 
        $this->_template_dir = $this->CI->config->item('template_dir');
        $this->_cache_dir = $this->CI->config->item('cache_dir');
 
        $loader = new Twig_Loader_Filesystem($this->_template_dir);
 
        $this->_twig = new Twig_Environment($loader, array(
                'cache' => $this->_cache_dir,
                'debug' => $debug,
        ));
                $this->_config['title_separator'] = ' | ';
            foreach(get_defined_functions() as $functions) {
                    foreach($functions as $function) {
                        $this->_twig->addFunction($function, new Twig_Function_Function($function));
                    }
            }
    }
 
    public function add_function($name) 
    {
        $this->_twig->addFunction($name, new Twig_Function_Function($name));
    }
        
        public function add_functions($names) 
    {
            foreach ($names as $name)
                $this->_twig->addFunction($name, new Twig_Function_Function($name));
    }
 
    public function render($template, $data = array()) 
    {
        $template = $this->_twig->loadTemplate($template);
        return $template->render($data);
    }
 
    public function display($template, $data = array()) 
    {
        $template = $this->_twig->loadTemplate($template.'.html.twig');
        /* elapsed_time and memory_usage */
        $data['elapsed_time'] = $this->CI->benchmark->elapsed_time('total_execution_time_start', 'total_execution_time_end');
        $memory = (!function_exists('memory_get_usage')) ? '0' : round(memory_get_usage()/1024/1024, 2) . 'MB';
        $data['memory_usage'] = $memory;
        $template->display($data);
    }
        public function title()
    {
        if(func_num_args() > 0)
        {
            $args = func_get_args();
 
            // If at least one parameter is passed in to this method, 
            // call append() to either set the title or append additional
            // string data to it.
            call_user_func_array(array($this, 'append'), $args);
        }
 
        return $this;
    }
        public function append()
    {
        $args = func_get_args();
        $title = implode($this->_config['title_separator'], $args);
 
        if(empty($this->_globals['title']))
        {
            $this->set('title', $title, TRUE);
        }
        else
        {
            $this->set('title', $this->_globals['title'] . $this->_config['title_separator'] . $title, TRUE);
        }
 
        return $this;
    }
        public function set($key, $value, $global = FALSE)
    {
        if(is_array($key))
        {
            foreach($key as $k => $v) $this->set($k, $v, $global);
        }
        else
        {
            if($global)
            {
                $this->_twig->addGlobal($key, $value);
                $this->_globals[$key] = $value;
            }
            else
            {
                $this->_data[$key] = $value;
            }   
        }
 
        return $this;
    }
}
CI =& get_instance();
		$this->CI->config->load('twig');

		ini_set('include_path',
		ini_get('include_path') . PATH_SEPARATOR . APPPATH . 'libraries/Twig');
		require_once (string) "Autoloader" . EXT;

		log_message('debug', "Twig Autoloader Loaded");

		Twig_Autoloader::register();

		$this->_template_dir = $this->CI->config->item('template_dir');
		$this->_cache_dir = $this->CI->config->item('cache_dir');

		$loader = new Twig_Loader_Filesystem($this->_template_dir);

		$this->_twig = new Twig_Environment($loader, array(
                'cache' => $this->_cache_dir,
                'debug' => $debug,
		));
                $this->_config['title_separator'] = ' | ';
	        foreach(get_defined_functions() as $functions) {
            		foreach($functions as $function) {
                		$this->_twig->addFunction($function, new Twig_Function_Function($function));
            		}
        	}
	}

	public function add_function($name) 
	{
		$this->_twig->addFunction($name, new Twig_Function_Function($name));
	}
        
        public function add_functions($names) 
	{
            foreach ($names as $name)
                $this->_twig->addFunction($name, new Twig_Function_Function($name));
	}

	public function render($template, $data = array()) 
	{
		$template = $this->_twig->loadTemplate($template);
		return $template->render($data);
	}

	public function display($template, $data = array()) 
	{
		$template = $this->_twig->loadTemplate($template.'.html.twig');
		/* elapsed_time and memory_usage */
		$data['elapsed_time'] = $this->CI->benchmark->elapsed_time('total_execution_time_start', 'total_execution_time_end');
		$memory = (!function_exists('memory_get_usage')) ? '0' : round(memory_get_usage()/1024/1024, 2) . 'MB';
		$data['memory_usage'] = $memory;
		$template->display($data);
	}
        public function title()
	{
		if(func_num_args() > 0)
		{
			$args = func_get_args();

			// If at least one parameter is passed in to this method, 
			// call append() to either set the title or append additional
			// string data to it.
			call_user_func_array(array($this, 'append'), $args);
		}

		return $this;
	}
        public function append()
	{
		$args = func_get_args();
		$title = implode($this->_config['title_separator'], $args);

		if(empty($this->_globals['title']))
		{
			$this->set('title', $title, TRUE);
		}
		else
		{
			$this->set('title', $this->_globals['title'] . $this->_config['title_separator'] . $title, TRUE);
		}

		return $this;
	}
        public function set($key, $value, $global = FALSE)
	{
		if(is_array($key))
		{
			foreach($key as $k => $v) $this->set($k, $v, $global);
		}
		else
		{
			if($global)
			{
				$this->_twig->addGlobal($key, $value);
				$this->_globals[$key] = $value;
			}
			else
			{
			 	$this->_data[$key] = $value;
			}	
		}

		return $this;
	}
}

I would like to take you through the functions defined in this file first. Well, first two functions are to add function to twig which will help you call php/codeigniter functions in your template files.

Function title is to add title to the page and function append is to append title to the title you have defined earlier. For example we can create a base title of the website something like “Google” and then append strings to it to appear something like “Google | About” and in these cases append function is very useful.

Set function is used to set a variable which can be accessed in template files and if you set “global=TRUE”, you can access it in your all template files. These all functions may look trivial but actually these are very useful to separate your logic(Controllers) from view completely as view files are only responsible to display data and it’s controller who should handle all the logic behind those data.

Now finally you need to create a file twig.php in your config directory with following contents:

1
2
3
4
5
6
7
<?php 
if (!defined(&#039;BASEPATH&#039;)) exit(&#039;No direct script access allowed&#039;);
// Below line is to define the location of all your view files.
// For me i wanted to put them in views directory.
$config[&#039;template_dir&#039;] = APPPATH.&#039;views&#039;;
// This is important to locate your cache folder. Although it&#039;s not that much important but as a good practice you should create application/cache/twig directory.
$config[&#039;cache_dir&#039;] = APPPATH.&#039;cache/twig&#039;;
<?php 
if (!defined(&#039;BASEPATH&#039;)) exit(&#039;No direct script access allowed&#039;);
// Below line is to define the location of all your view files.
// For me i wanted to put them in views directory.
$config[&#039;template_dir&#039;] = APPPATH.&#039;views&#039;;
// This is important to locate your cache folder. Although it&#039;s not that much important but as a good practice you should create application/cache/twig directory.
$config[&#039;cache_dir&#039;] = APPPATH.&#039;cache/twig&#039;;

And that’s it 🙂 You are done with it.

Now you have to create some view files. You can do it at your own also but in my case i created a folder called _layouts inside views(directory you had configured earlier to handle template files) directory and another directory to place my pages. So my directory structure becomes

1
2
3
views/
.._layouts/
..pages/
views/
.._layouts/
..pages/

So first i created a file application.html.twig in my _layouts/ folder like this.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
    
        
        <!--[if lt IE 9]>-->
        
        
        <title>{% block title %}{% endblock %}</title>
    
    
 
        {% block content %}
 
        {% endblock %}
 
    
    
        
        <!--[if lt IE 9]>-->
        
        
        <title>{% block title %}{% endblock %}</title>
    
    

        {% block content %}

        {% endblock %}

    

You see these {% block %} thing? The first one is used to display the title you had set in your controller using that “title” and “append” function we discussed earlier. And the second one to display the page content which will come later.

Now create another file index.html.twig in pages directory with the following contents:

1
2
3
4
5
6
7
{% extends "_layouts/application.html.twig" %}
{% block title %}{{title}}{% endblock %}
{% block content %}
 
    Default template data.
 
{% endblock %}
{% extends "_layouts/application.html.twig" %}
{% block title %}{{title}}{% endblock %}
{% block content %}

    Default template data.

{% endblock %}

So now your template files are ready. You can extend this application.html.twig file from anywhere in your views directory. Now you need to call these files from your controller. It’s simple as following:

1
2
3
4
5
twig->title('Dashboard'); 
        //Following line will load your index.html.twig from views/pages
        $this->twig->display('pages/index');
    }
}
twig->title('Dashboard'); 
        //Following line will load your index.html.twig from views/pages
        $this->twig->display('pages/index');
    }
}

Now one last line needs to be added in your autoload.php and that is:

1
$autoload['libraries'] = array('activerecord','twig');
$autoload['libraries'] = array('activerecord','twig');

And that’s it.. I hope you enjoyed this. Also if you are looking for Codeigniter Web Development services connect with us at Dignitech Media Works

Please feel free to comment or ask me any query.

Content Source:http://www.raakeshkumar.in/

Resizing Images Dynamically in Codeigniter

We are posting very interesting thing which we believe could be a great help for people who wanna develop scalable applications with lots of images.

We have often seen that when people upload images on websites, they tend to create thumbnails as to make those images appear better on websites. Even we used to do this but recently we analyzed that this method obviously solves our in-hand problem but let say if we want to change the design of our website in future and want different sized image. One way to solve this problem is to keep your original image and run scripts to resize all your images to desired size but we thought to solve this problem with a different approach which is to not resize the images at all and keep it as is.

Now the question is, how do we fit our images in my website?

To solve this problem we created a Codeigniter Class(However it can be used for other frameworks as well with some changes) which would resize our images on the fly. Lets see how:–

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
<?php
 
/**
 * This is a custom image manupulation library developed by raakesh.
 * @license GNU GPL
 * @author raakesh
 * Released under public license hence author takes no warranty of this code out of this project scope. However, modification of this code is allowed under GNU GPL license.
 */
class Image {
 
    // Declare all public variables
    var $image;
    var $image_type;
    var $image_name;
 
    // Function to render final image to the browser
    public function display() {        
        $this->load($_GET['image']);
        $this->image_name = $_GET['image'];
        if($this->image_type == IMAGETYPE_JPEG)
            $this->check_orientation ($_GET['image']);
        if(isset($_GET['w']) and !isset($_GET['h']))
            $this->resizeToWidth ($_GET['w']);
        if(!isset($_GET['w']) and isset($_GET['h']))
            $this->resizeToHeight ($_GET['h']);
        if(isset($_GET['w']) and isset($_GET['h']))
            $this->crop($_GET['w'], $_GET['h']);            
        $this->output($this->image_type);
    }
 
    function load($filename) {
        $image_info = getimagesize($filename);
        $this->image_type = $image_info[2];
        if ($this->image_type == IMAGETYPE_JPEG) {
            $this->image = imagecreatefromjpeg($filename);
        } elseif ($this->image_type == IMAGETYPE_GIF) {
            $this->image = imagecreatefromgif($filename);
        } elseif ($this->image_type == IMAGETYPE_PNG) {
            $this->image = imagecreatefrompng($filename);
        }
    }
 
    function output($image_type = IMAGETYPE_JPEG) {
        header('Cache-Control: max-age=86400, public');
        if ($image_type == IMAGETYPE_JPEG) {
            header('Content-Type: image/jpeg');
            imagejpeg($this->image, NULL, 60);
        } elseif ($image_type == IMAGETYPE_GIF) {
            header('Content-Type: image/gif');
            imagegif($this->image);
        } elseif ($image_type == IMAGETYPE_PNG) {
            header('Content-Type: image/png');
            imagepng($this->image, NULL, 6);
        }
    }
 
    function getWidth() {
        return imagesx($this->image);
    }
 
    function getHeight() {
        return imagesy($this->image);
    }
 
    function resizeToHeight($height) {
        $ratio = $height / $this->getHeight();
        $width = $this->getWidth() * $ratio;
        $this->resize($width, $height);
    }
 
    function resizeToWidth($width) {
        $ratio = $width / $this->getWidth();
        $height = $this->getheight() * $ratio;
        $this->resize($width, $height);
    }
    function resize($width, $height) {
        $new_image = imagecreatetruecolor($width, $height);
        imagealphablending($new_image, false);
        imagesavealpha($new_image, true);
        $transparent = imagecolorallocatealpha($new_image, 255, 255, 255, 127);
        imagefilledrectangle($new_image, 0, 0, $width, $height, $transparent);
        imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
        $this->image = $new_image;
    }
 
 
    function crop($thumb_width, $thumb_height) {
        $width = $this->getWidth();
        $height = $this->getHeight();
 
        $original_aspect = $width / $height;
        $thumb_aspect = $thumb_width / $thumb_height;
 
        if ($original_aspect >= $thumb_aspect) {
            // If image is wider than thumbnail (in aspect ratio sense)
            $new_height = $thumb_height;
            $new_width = $width / ($height / $thumb_height);
        } else {
            // If the thumbnail is wider than the image
            $new_width = $thumb_width;
            $new_height = $height / ($width / $thumb_width);
        }
 
        $new_image = imagecreatetruecolor($thumb_width, $thumb_height);
        imagealphablending($new_image, false);
        imagesavealpha($new_image, true);
        $transparent = imagecolorallocatealpha($new_image, 255, 255, 255, 127);
        imagefilledrectangle($new_image, 0, 0, $thumb_width, $thumb_height, $transparent);
// Resize and crop
 
        imagecopyresampled($new_image, $this->image, 0 - ($new_width - $thumb_width) / 2, // Center the image horizontally
                0 - ($new_height - $thumb_height) / 2, // Center the image vertically
                0, 0, $new_width, $new_height, $width, $height);
        $this->image = $new_image;
    }
    function check_orientation($source) {
        $exif = exif_read_data($source);        
        $ort = isset($exif['Orientation']) ? $exif['Orientation'] : '';
        switch ($ort) {
 
            case 2: // horizontal flip
 
                $this->ImageFlip();
 
                break;
 
            case 3: // 180 rotate left
 
                $this->image = imagerotate($this->image, 180, -1);
 
                break;
 
            case 4: // vertical flip
 
                $this->ImageFlip();
 
                break;
 
            case 5: // vertical flip + 90 rotate right
 
                $this->ImageFlip();
 
                $this->image = imagerotate($this->image, -90, -1);
 
                break;
 
            case 6: // 90 rotate right
 
                $this->image = imagerotate($this->image, -90, -1);
 
                break;
 
            case 7: // horizontal flip + 90 rotate right
 
                $this->ImageFlip();
 
                $this->image = imagerotate($this->image, -90, -1);
 
                break;
 
            case 8: // 90 rotate left
 
                $this->image = imagerotate($this->image, 90, -1);
 
                break;
            default :
                $this->image = $this->image;
                break;
        }
    }
 
    public function ImageFlip($x = 0, $y = 0, $width = null, $height = null) {
 
        if ($width < 1)
            $width = $this->getWidth();
        if ($height < 1)
            $height = $this->getHeight();
 
        // Truecolor provides better results, if possible.
        if (function_exists('imageistruecolor') && imageistruecolor($this->image)) {
 
            $tmp = imagecreatetruecolor(1, $height);
        } else {
 
            $tmp = imagecreate(1, $height);
        }
 
        $x2 = $x + $width - 1;
 
        for ($i = (int) floor(($width - 1) / 2); $i >= 0; $i--) {
 
            // Backup right stripe.
            imagecopy($tmp, $this->image, 0, 0, $x2 - $i, $y, 1, $height);
 
            // Copy left stripe to the right.
            imagecopy($this->image, $this->image, $x2 - $i, $y, $x + $i, $y, 1, $height);
 
            // Copy backuped right stripe to the left.
            imagecopy($this->image, $tmp, $x + $i, $y, 0, 0, 1, $height);
        }
 
        imagedestroy($tmp);
 
        return true;
    }
 
}
 
?>
<?php

/**
 * This is a custom image manupulation library developed by raakesh.
 * @license GNU GPL
 * @author raakesh
 * Released under public license hence author takes no warranty of this code out of this project scope. However, modification of this code is allowed under GNU GPL license.
 */
class Image {

    // Declare all public variables
    var $image;
    var $image_type;
    var $image_name;

    // Function to render final image to the browser
    public function display() {        
        $this->load($_GET['image']);
        $this->image_name = $_GET['image'];
        if($this->image_type == IMAGETYPE_JPEG)
            $this->check_orientation ($_GET['image']);
        if(isset($_GET['w']) and !isset($_GET['h']))
            $this->resizeToWidth ($_GET['w']);
        if(!isset($_GET['w']) and isset($_GET['h']))
            $this->resizeToHeight ($_GET['h']);
        if(isset($_GET['w']) and isset($_GET['h']))
            $this->crop($_GET['w'], $_GET['h']);            
        $this->output($this->image_type);
    }

    function load($filename) {
        $image_info = getimagesize($filename);
        $this->image_type = $image_info[2];
        if ($this->image_type == IMAGETYPE_JPEG) {
            $this->image = imagecreatefromjpeg($filename);
        } elseif ($this->image_type == IMAGETYPE_GIF) {
            $this->image = imagecreatefromgif($filename);
        } elseif ($this->image_type == IMAGETYPE_PNG) {
            $this->image = imagecreatefrompng($filename);
        }
    }

    function output($image_type = IMAGETYPE_JPEG) {
        header('Cache-Control: max-age=86400, public');
        if ($image_type == IMAGETYPE_JPEG) {
            header('Content-Type: image/jpeg');
            imagejpeg($this->image, NULL, 60);
        } elseif ($image_type == IMAGETYPE_GIF) {
            header('Content-Type: image/gif');
            imagegif($this->image);
        } elseif ($image_type == IMAGETYPE_PNG) {
            header('Content-Type: image/png');
            imagepng($this->image, NULL, 6);
        }
    }

    function getWidth() {
        return imagesx($this->image);
    }

    function getHeight() {
        return imagesy($this->image);
    }

    function resizeToHeight($height) {
        $ratio = $height / $this->getHeight();
        $width = $this->getWidth() * $ratio;
        $this->resize($width, $height);
    }

    function resizeToWidth($width) {
        $ratio = $width / $this->getWidth();
        $height = $this->getheight() * $ratio;
        $this->resize($width, $height);
    }
    function resize($width, $height) {
        $new_image = imagecreatetruecolor($width, $height);
        imagealphablending($new_image, false);
        imagesavealpha($new_image, true);
        $transparent = imagecolorallocatealpha($new_image, 255, 255, 255, 127);
        imagefilledrectangle($new_image, 0, 0, $width, $height, $transparent);
        imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
        $this->image = $new_image;
    }


    function crop($thumb_width, $thumb_height) {
        $width = $this->getWidth();
        $height = $this->getHeight();

        $original_aspect = $width / $height;
        $thumb_aspect = $thumb_width / $thumb_height;

        if ($original_aspect >= $thumb_aspect) {
            // If image is wider than thumbnail (in aspect ratio sense)
            $new_height = $thumb_height;
            $new_width = $width / ($height / $thumb_height);
        } else {
            // If the thumbnail is wider than the image
            $new_width = $thumb_width;
            $new_height = $height / ($width / $thumb_width);
        }

        $new_image = imagecreatetruecolor($thumb_width, $thumb_height);
        imagealphablending($new_image, false);
        imagesavealpha($new_image, true);
        $transparent = imagecolorallocatealpha($new_image, 255, 255, 255, 127);
        imagefilledrectangle($new_image, 0, 0, $thumb_width, $thumb_height, $transparent);
// Resize and crop

        imagecopyresampled($new_image, $this->image, 0 - ($new_width - $thumb_width) / 2, // Center the image horizontally
                0 - ($new_height - $thumb_height) / 2, // Center the image vertically
                0, 0, $new_width, $new_height, $width, $height);
        $this->image = $new_image;
    }
    function check_orientation($source) {
        $exif = exif_read_data($source);        
        $ort = isset($exif['Orientation']) ? $exif['Orientation'] : '';
        switch ($ort) {

            case 2: // horizontal flip

                $this->ImageFlip();

                break;

            case 3: // 180 rotate left

                $this->image = imagerotate($this->image, 180, -1);

                break;

            case 4: // vertical flip

                $this->ImageFlip();

                break;

            case 5: // vertical flip + 90 rotate right

                $this->ImageFlip();

                $this->image = imagerotate($this->image, -90, -1);

                break;

            case 6: // 90 rotate right

                $this->image = imagerotate($this->image, -90, -1);

                break;

            case 7: // horizontal flip + 90 rotate right

                $this->ImageFlip();

                $this->image = imagerotate($this->image, -90, -1);

                break;

            case 8: // 90 rotate left

                $this->image = imagerotate($this->image, 90, -1);

                break;
            default :
                $this->image = $this->image;
                break;
        }
    }

    public function ImageFlip($x = 0, $y = 0, $width = null, $height = null) {

        if ($width < 1)
            $width = $this->getWidth();
        if ($height < 1)
            $height = $this->getHeight();

        // Truecolor provides better results, if possible.
        if (function_exists('imageistruecolor') && imageistruecolor($this->image)) {

            $tmp = imagecreatetruecolor(1, $height);
        } else {

            $tmp = imagecreate(1, $height);
        }

        $x2 = $x + $width - 1;

        for ($i = (int) floor(($width - 1) / 2); $i >= 0; $i--) {

            // Backup right stripe.
            imagecopy($tmp, $this->image, 0, 0, $x2 - $i, $y, 1, $height);

            // Copy left stripe to the right.
            imagecopy($this->image, $this->image, $x2 - $i, $y, $x + $i, $y, 1, $height);

            // Copy backuped right stripe to the left.
            imagecopy($this->image, $tmp, $x + $i, $y, 0, 0, 1, $height);
        }

        imagedestroy($tmp);

        return true;
    }

}

?>

When i have to use this class, i can simply call it using

1
<?= base_url() ?>image/display?image=url-of-your-image&w=width&h=height
<?= base_url() ?>image/display?image=url-of-your-image&w=width&h=height

With this solution you don’t have to worry about creating different thumbnails for images as well as future design changes. Also read about Secure Image Uploading im PHP.

We hope this will solve your problems. Comments & suggestions are invited.

Content Source: http://www.raakeshkumar.in/


Fatal error: Uncaught Error: Call to undefined function twentyseventeen_get_svg() in /home/dignitech/dignitech.com/public_html/wp-content/themes/dignitech/archive.php:45 Stack trace: #0 /home/dignitech/dignitech.com/public_html/wp-includes/template-loader.php(74): include() #1 /home/dignitech/dignitech.com/public_html/wp-blog-header.php(19): require_once('/home/dignitech...') #2 /home/dignitech/dignitech.com/public_html/index.php(17): require('/home/dignitech...') #3 {main} thrown in /home/dignitech/dignitech.com/public_html/wp-content/themes/dignitech/archive.php on line 45