Programmer's Notes » framework http://programmersnotes.info Notes on the web-development and artificial intelligence. Thu, 25 Mar 2010 08:45:23 +0000 http://wordpress.org/?v=2.9.2 en hourly 1 What is a framework and why you should use one? http://programmersnotes.info/2010/03/14/what-is-a-framework-and-why-you-should-use-one/ http://programmersnotes.info/2010/03/14/what-is-a-framework-and-why-you-should-use-one/#comments Sun, 14 Mar 2010 12:53:49 +0000 Konstantin Mirin http://programmersnotes.info/?p=330 Yet Another Related Posts Plugin.]]> Building the best application…

Most of the beginners and, sometimes, even more advanced programmers, want to develop everything from scratch because they want have control over the every aspect of their application. I entirely understand this tendency. When you learned how to program and you can code nearly anything you want (this relates more closely to scripting languages like php, perl, js etc), you start to do something global. Something that will change the world. This may be a new CMS, a new framework, new blog of e-commerce engine. And when you start this, you want to code it in the most efficient way, optimizing every little thing: every function, every SQL query. At the same time, you want to reuse the code you’re writing. So you tend to create more general solutions than you really need. And this slows down the performance. And again you go into optimization, limiting the possible uses to some extent.
Finally, if you finish your application, it may be faster or better than similar ones (however, usually it is the same or worse), but remember how much time you spent developing it. Yes, you’re proud of yourself – you’ve created your own DB abstraction layer, that handles SQL injections in a very smart way. You’ve also developed your own ORM engine, that goes nicely with your DB abstraction layer. It is quite likely, that you’ve already created your very own template engine and a nice JS library that makes animation very easy. Great job, my fellow programmer!

…but is it really brilliant?

Now let’s stop for a moment and look back. Why you’ve started developing all that? Say you wanted to create a brand new blogging engine, that is better than Wordpress. You’ve spent several months (I can’t believe you’ve created nice DB abstraction, ORM and template engine in a week) to develop all that stack. And all you got is just another blog engine! Yes, it is cool and is capable of doing hundreds of things. You’ve even thought of the external API, so you can send SMS to be automatically published on your blog. But actually that’s just a blog!
Do you really think that the final result – blog engine was worth 2 months of the hard work and sleepless nights? If you answer “yes” and you haven’t got a feeling that something is wrong, then then you’re either mega-guru and develop only facebook- and google-scale projects or just a beginner who is still very proud of himself that he can code anything and you want to overemphasize this.
I think, every experienced developer was at that stage. I was there too. Moreover, I was there quite long and I regret of this.

So what is the framework?

By this time you may be quite bored and start thinking – what all that story has to deal with the framework. Actually the problem described above when you develop everything from scratch occurs when you don’t use any frameworks.
So what is the framework? Basically it is a set of libraries/classes, tied together that speed up the development of a certain type of applications. For example, MFC (Microsoft Foundation Classes), Qt, wxWidgets are frameworks that simplify the user interface development. It obvious that you should not draw 6 states of the button and change it on different events when it comes to placing the button on some form. You just use the ready-made class. But when it comes to the web-development, some developers think that they don’t need the ready-made (and well-tested!) DB abstraction layer, proven authorization classes. They want to develop it themselves. As a result, we often see low-quality and buggy applications. On the other hand, using frameworks does not necessarily gives you the excellent code, but it definitely helps you to get where you need much faster.

Use frameworks!

When you utilize good framework, you automatically get proven solutions in different spheres – DB connectivity, unit testing (most of frameworks provide tools for this or make it more simple), authentication, users and templates management. In addition, you also get a number of widgets, ready-made components for the problems you even don’t know about at the moment you start coding, but which usually come up during the development – caching, JS and CSS minimizing and publishing etc. Finally, you also get a bunch of extensions for a variety of tasks: RSS creation, CAPTCHA solutions, autocomplete widgets, treeview, drag&drop components to name a few.
The problem with framework usage for scripting languages is that they are quite simple and lots of developers don’t want to learn complex framework in order to achieve some simple task. And they are right… as long as their task is really simple. I think, “simple” is something that soesn’t require heavy DB usage, caching, user management, web-services integration and has very basic MVC implementation. That’s a simple homepage. All other projects should be developed with frameworks because that saves time and allows you to achieve better result.

Choosing the framework

But there is a little problem here :) What framework is “good”? I wrote about this in one of my previous posts where I explained why I chose Yii as a PHP framework for my project. Selecting wrong framework may result in project failure, so please refer to that post to see how I did that, maybe you’ll find that approach reasonable and join us in Yii community :)
And the last question I want to discuss here. The quality of code. I believe that using a framework with good design helps you to create better-structured applications that can be easily managed and supported. And the quality of code… I think this is up to programmer. It is definitely easier to create good application with properly designed framework just because you follow it’s patterns. However if you ignore the framework’s ideas and continue to create classes with static methods instead of simple functions, the framework is not very useful for you :)

When you should not use the frameworks

Frameworks are good, but you should clearly understand what are they doing and use them only when appropriate. As a rule, framework provides a set of generic tools that simplify creation of any project. Key work is any. These techniques give good result for a standard use. However when it comes to some specific things, especially if they are very demanding in terms of performance, it’s time to evaluate your tools from the point of view of this specific project.
Consider you have a framework designed for a web 2.0 applications. It works well for the most of the projects you create. However you’ve got to build an SMS portal. Unlike your usual applications, this doesn’t deal with HTTP a lot, it uses it’s own protocol. So 80-90% of your favourite framework’s tools will be useless here.
If you’re building very large application that will be working under the high load, you should evaluate your framework and either reconfigure it or refuse from using it at all. Most of the great websites like facebook, for example, don’t use standard frameworks, but in order to become “facebook”, you should gain popularity and using the framework for your first version ill bring you to the marketing and launch much faster and you’ll start earning money.
Similarly, if you’re building the business-card-like page, using the framework is a bit overkill :)

Summary

  1. Use frameworks because they simplify your development, help getting better code and simplify documenting your solution (framework documentation is already written!)
  2. Choose framework very carefully!
  3. When solving non-trivial tasks and develop extremely large applications, re-evaluate your framework’s features and decide if it really worth using it there.

Disclaimer

  1. All above is my own opinion, formed during the 5+ years of everyday web-development. Maybe this is not the absolute truth, but I believe it is somewhere near it :)
  2. Example with SMS portal was for illustration only, I’ve never developed ones and don’t know which protocols are used there. I’d be thankful if someone of my readers clarifies this.

And what do you think about it? I’d be thankful if you share your thoughts in comments. Thanks!

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]]> http://programmersnotes.info/2010/03/14/what-is-a-framework-and-why-you-should-use-one/feed/ 3 OOP in jQuery http://programmersnotes.info/2009/04/30/oop-in-jquery/ http://programmersnotes.info/2009/04/30/oop-in-jquery/#comments Thu, 30 Apr 2009 20:19:51 +0000 Konstantin Mirin http://konstantin.takeforce.net/?p=12 Yet Another Related Posts Plugin.]]> Intro

OOP is a great concept, it simplifies the programmer’s life, especially in the field of interface development. Nearly all modern web-interfaces use JS in some way – for field highlighting, validation, help etc. It’s OK when there are such simple things.
And now imagine, that we have a set of dialogue windows (HTML+CSS) for adding a comment, rating, sending to the friend. Each of these boxes has a number of functions – check if user is logged in(if not – show login form), send AJAX request, process response, show error/success messages, position the box on the page etc.

The problem

First idea I had about them is to use simple inheritance, create Box class, derive CommentBox, RatingBox and other classes, but it turned out, that jQuery (I used it there, because system is built using Yii framework, which uses jQuery for client-side coding) doesn’t support extending classes like, for example, ExtJS or YUI. Yes, it has $.extend() function, but it just copies the object, not actually extends class. Why it is not the same? Let’s look here:

  1. //namespace
  2. var Popups = {};
  3. //class constructor
  4. Popups.Box = function()
  5. {
  6.         //initialization here
  7. }
  8. Popups.Box.prototype = {
  9.         container:$(‘<div class="container"></div>’),
  10.         content:null,
  11.         create:function()
  12.         {
  13.                 //dom elements generation here
  14.         },
  15.         showHide:function()
  16.         {
  17.                 //some logic here
  18.         }
  19.         //other methods and properties go here
  20. }

Normally (in ExtJS, for example) when writing:

  1. Popups.CommentBox = $.extend(true,{}, Popups.Box, {
  2.         create:function()
  3.         {
  4.                 alert(‘overriden!’);
  5.         }
  6. })

I expect, that if I do:

  1. var c = new CommentBox();
  2. c.create();

I should get an alert window. However, this is not true for jQuery. It just copies everything and we get some messed things. So I gave this up and followed another pattern.

The solution

Box object became container for all boxes. I took care of messaging, determining if user is logged, and all other routines. It also serves as a factory, because all clicking icons go to the showHide method and it has to determine, which box to show and create this inner object.
And this inner object takes care of the box-specific logic. If it needs some common info, for example, the ID of the product it is called for, it calls the Box method (see LowCoupling GRASP principle here :) ). So in the Box I have:

  1.         getBoxType:function()
  2.         {
  3.                 //determine the box we’re dealing with by the link class
  4.                 var tg = $(this.event.target);
  5.                 if (tg.hasClass(‘f’))
  6.                         return ‘favourite’;
  7.                 else if (tg.hasClass(‘t’))
  8.                         return ‘friend’;
  9.                 else if (tg.hasClass(‘ra’))
  10.                         return ‘rate’;
  11.                 else if (tg.hasClass(‘c’))
  12.                         return ‘comment’;
  13.                 else if (tg.hasClass(‘r’))
  14.                         return ‘rss’;
  15.                 else if (tg.hasClass(‘add’))
  16.                         return ‘addTag’;
  17.                 else if (tg.hasClass(‘b’))
  18.                         return ‘bookmark’;
  19.                 return ”;
  20.         },
  21.         getInnerObj:function()
  22.         {
  23.                 if (!us.logged)//if user is not logged, we show him the login box instead of anything else
  24.                 {
  25.                         return new Popups.LoginObject(this);
  26.                 }
  27.                 var cls;
  28.                 this.type = this.getBoxType();
  29.                 switch (this.type)
  30.                 {
  31.                         case ‘favourite’:
  32.                                         cls = this.objects[this.type] = new Popups.FavouriteObject(this);
  33.                                 break;
  34.                         case ‘friend’:
  35.                                         cls = this.objects[this.type] = new Popups.FriendObject(this);
  36.                                 break;
  37.                         case ‘rate’:
  38.                                         cls = this.objects[this.type] = new Popups.RateObject(this);
  39.                                 break;
  40.                         case ‘comment’:
  41.                                         cls = this.objects[this.type] = new Popups.CommentObject(this);
  42.                                 break;
  43.                         case ‘rss’:
  44.                                         cls = this.objects[this.type] = new Popups.RssObject(this);
  45.                                 break;
  46.                         case ‘bookmark’:
  47.                                         cls = this.objects[this.type] = new Popups.BookmarkObject(this);
  48.                                 break;
  49.                         default:
  50.                                 cls = this.objects[this.type] = null;
  51.                 }
  52.                 return cls;
  53.         },
  54.         show:function()
  55.         {
  56.                 //some stuff
  57.                 var obj = this.getInnerObj();
  58.                 if (typeof obj == ‘object’ && obj != null)
  59.                 {
  60.                         this.content.append(obj.getContents());
  61.                 }
  62.         },

So instead of inheritance I implemented aggregation (Box aggregates CommmentObject, Favourite object etc).

Everything goes well until you want to to attach some method of current object as a handler to some event. For example:

  1. Popups.Box.prototype = {
  2.         //properties here
  3.         productID:0,
  4.  
  5.         create:function()
  6.         {
  7.                 this.form.submit(this.onSubmit);
  8.                 productID = this.parentBox.getItemID();
  9.         },
  10.         onSubmit:function()
  11.         {
  12.                 alert(this.productID);
  13.         }
  14. //other methods follow
  15. }

Right? Wrong! Because when submit event occurs, jQuery will call the onSubmit method, but this will refer to the form, not to the Box object! However, it is logical to put processing of the form into the same object. In ExtJS and YUI you can pass the scope parameter for every callback function, so you can control the “this” variable in the callback call. jQuery doesn’t allow this. I used the following workaround:

  1. Popups.Box.prototype = {
  2.         //properties here
  3.         productID:0,
  4.  
  5.         create:function()
  6.         {
  7.                 var ctx = this;
  8.                 this.form.submit(function(event){
  9.                         ctx.onSubmit(event);
  10.                 });
  11.                 productID = this.parentBox.getItemID();
  12.         },
  13.         onSubmit:function(event)
  14.         {
  15.                 alert(this.productID);
  16.         }
  17. //other methods follow
  18. }

If you need the object, that triggered an event, just pass “this” there:

  1. create:function()
  2. {
  3.         var ctx = this;
  4.         this.form.submit(function(event){
  5.                 ctx.onSubmit(this, event);
  6.         });
  7.         productID = this.parentBox.getItemID();
  8. },
  9. onSubmit:function(form, event)
  10.  
  11.         alert(this.productID);
  12. }

Having these 2 tricks you can use OOP approach to designing reusable interface components in a handy modern way.

Back to inheritance

Since I discovered the problem with inheritance, I want to develop a plugin, that fixes this, that will provide nice class inheritance model to take jQuery a step ahead. I was going to digg the ExtJS’s Ext.extend() code and find out how this is done correctly, but while preparing an article, I found this material, which is actually a guide for creation of such plugin: http://phrogz.net/JS/Classes/OOPinJS2.html. Unfortunately, I don’t have time for this now, but I plan to do this in the nearest future. If someone does this earlier, please let me know :)

Links

  • ExtJS – a component, interface-oriented JS framework
  • YUI – Yahoo library for the user interface. ExtJS was derived from it long ago. They are similar in extending and event processing (the “scope” I mentioned initially appeared in YUI)
  • jQuery – a lightweight VERY popular JS framework with an easily extensible structure, but lacks OOP techniques!

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]]> http://programmersnotes.info/2009/04/30/oop-in-jquery/feed/ 23 Handling Application Parameters in Yii – Using the Database http://programmersnotes.info/2009/03/04/handling-application-parameters-in-yii-using-the-database/ http://programmersnotes.info/2009/03/04/handling-application-parameters-in-yii-using-the-database/#comments Wed, 04 Mar 2009 09:48:22 +0000 Konstantin Mirin http://programmersnotes.info/?p=129 Yet Another Related Posts Plugin.]]> The problem

Nearly every large application has some configuration parameters – site admin email, cache time for different blocks, number of latest news, number of items per search or catalogue page etc.

Standard Way

Yii comes with the built-in mechanism for this. You can create a file with an associative array of all your variables, like this:

  1. <?php
  2. return array(
  3.                 ‘brandNew’ => 7, // number of days to consider new
  4.                 ‘onSale’ => 7, // number of days to consider on sale
  5.                 ‘favourites’ => array(
  6.                                 ‘max’ => 9//max number of last favourites to show
  7.                                 ),
  8.                 ’search’ => array(
  9.                                 ‘itemsPerPage’ => 20,
  10.                                 ‘tagsInFilter’ => 30,
  11.                                 ),
  12.                 ‘product’ => array(
  13.                                 ‘maxAlts’ => 5, //max alternatives
  14.                                 ),
  15.                 ‘cacheTime’ => array(
  16.                                 ‘assets’ => 1800,
  17.                                 ),
  18.         );
  19. ?>

Then put it somewhere, for example in /protected/config/params.php and configure your application to use it:

  1. return array(
  2.         // application components
  3.         ‘components’=>array(
  4. //components go here
  5.         ),
  6.  
  7.         // application-level parameters that can be accessed
  8.         // using Yii::app()->params['paramName']
  9.         ‘params’=>include(dirname(__FILE__).‘/params.php’),//<– here is our file
  10. );

Usage is simple, just refer to it as to array:

  1. echo Yii::app()->params[’siteAdmin’];

This is quite convenient when you just want to save some constants. End-user will not be able to change this from admin in any way. Sure, you can create the interface for editing this config and update the file, but much more flexible way is to store the configuration in DB.

The Database Way

To make the life easier, I’ve created an extension, that can be used as an application component. Extension can be downloaded from the Yii extension page. Here I’ll give an overview of it’s work.

First thing to note, it implements IApplicationComponent, so it should implement init() method where initialization is performed. In this method we check if there are any parameters to load. If so – we try to load them. If there is an exception, it means, that no table is present, so we create it and initialize the parameters that should be preloaded with null values

  1. /**
  2.  * Initializes component, creates table if it doesn’t exist and populates preloaded attributes
  3.  * @throws CException Throws exception if table does not exist and auto creation is set to false
  4.  */
  5. public function init()
  6. {
  7.         $this->_init = true;
  8.         $db = $this->getDbConnection();
  9.         $this->preload = $this->preprocessParams($this->preload);
  10.         if (!empty($this->preload) || $this->autoLoad)
  11.         {
  12.                 $sql = ‘SELECT name, value FROM ‘.$this->paramsTableName;
  13.                 if (sizeof($this->preload))
  14.                         $sql .= ‘ WHERE name IN (\’‘.implode(‘\’,\’‘, $this->preload).‘\’)’;
  15.                 $cmd = $db->createCommand($sql);
  16.                 try
  17.                 {
  18.                         $reader = $cmd->query();
  19.                         foreach ($reader as $row)
  20.                         {
  21.                                 $this->add($row[‘name’], $row[‘value’]);
  22.                         }
  23.                 }
  24.                 catch (CException $e)
  25.                 {
  26.                         //table is not present
  27.                         $createTable = true;
  28.                         //if there is no table, then attributes are empty.
  29.                         for ($i = 0, $s = sizeof($this->preload); $i < $s; $i++)
  30.                         {
  31.                                 $this->add($this->preload[$i], null);
  32.                         }
  33.                 }
  34.         }
  35.         else
  36.         {
  37.                 //check if table exist
  38.                 if ($db->createCommand(‘SHOW TABLES LIKE \’‘.$this->paramsTableName.‘\’‘)->query()->rowCount <= 0)
  39.                         $createTable = true;
  40.         }
  41.         if ($createTable === true)
  42.         {
  43.                 if($this->autoCreateParamsTable)
  44.                         $this->createParamsTable($db,$this->paramsTableName);
  45.                 else
  46.                         throw new CException(Yii::t(‘xparam’,‘Params table "{tableName}" does not exist.’,
  47.                                 array(‘{tableName}’=>$this->paramsTableName)));
  48.         }
  49. }

If parameter is requested, in the __get() method we reuse the parent’s (CAttributesCollection) contains() method, which checks if we have this parameter in the collection already. If so – we simply return it. If not – we call the loadParam() method, it loads if from DB and adds to the component collection. If there is no attribute, it throws an exception. We catch it in the __get() and call the parent::__get(). Here is the code:

  1. /**
  2.  * Returns a property value or an event handler list by property or event name.
  3.  * This method overrides the parent implementation by returning
  4.  * a parameter value if the it exist in the collection or loading it from DB
  5.  * if not.
  6.  *
  7.  * @param string the property name or the event name
  8.  * @return mixed the property value or the event handler list
  9.  * @throws CException if the property/event is not defined.
  10.  */
  11. public function __get($name)
  12. {
  13.         if($this->contains($name))
  14.                 return $this->itemAt($name);
  15.         else
  16.         {
  17.                 try
  18.                 {
  19.                         return $this->loadParam($name);
  20.                 }
  21.                 catch (CException $e)
  22.                 {
  23.                         return parent::__get($name);
  24.                 }
  25.         }
  26. }
  27.  
  28. /**
  29.  * Returns parameter from DB or cache if it was requested earlier
  30.  *
  31.  * @param string $name
  32.  */
  33. protected function loadParam($name)
  34. {
  35.         if ($this->caseSensitive)
  36.         $name = strtolower($name);
  37.         $db = $this->getDbConnection();
  38.         $res = $db->createCommand(‘SELECT value FROM ‘.$this->paramsTableName.‘ WHERE name=\’‘.$name.‘\’‘)->query();
  39.         if ($res->rowCount == 1)
  40.         {
  41.                 $row = $res->read();
  42.                 $this->add($name,$row[‘value’]);
  43.                 return $row[‘value’];
  44.         }
  45.         else
  46.         {
  47.                 throw new CException(Yii::t(‘xparam’,‘XDbParam->{name} does not exist!’,
  48.                         array(‘{name}’=>$name)));
  49.         }
  50. }

Setter method simply updates the collection. We check if the parameter is already present in DB. If so – we update it. If not – we create it. And, if everything was OK, we add the parameter to the internal collection ($this->add($name,$value)):

  1. /**
  2.  * Sets value of a component property.
  3.  * This method overrides the parent implementation by adding a new param
  4.  * value to the collection and updating the DB.
  5.  * @param string the property name or event name
  6.  * @param mixed the property value or event handler
  7.  * @throws CException If the property is not defined or read-only.
  8.  */
  9. public function __set($name,$value)
  10. {
  11.         if ($this->caseSensitive)
  12.                 $name = strtolower($name);
  13.         $db = $this->getDbConnection();
  14.         if ($db->createCommand(‘SELECT name FROM ‘.$this->paramsTableName.‘ WHERE name=\’‘.$name.‘\’‘)->query()->rowCount >= 1)
  15.         {
  16.                 $sql = ‘UPDATE `’.$this->paramsTableName.‘` SET `value`=:value WHERE `name`=:name’;
  17.                 $cmd = $db->createCommand($sql);
  18.                 $cmd->bindValue(‘:value’, $value, PDO::PARAM_LOB);
  19.                 $cmd->bindValue(‘:name’, $name, PDO::PARAM_STR);
  20.         }
  21.         else
  22.         {
  23.                 $sql = ‘INSERT INTO `’.$this->paramsTableName.‘`(name, value) VALUES(:name, :value)’;
  24.                 $cmd = $db->createCommand($sql);
  25.                 $cmd->bindValue(‘:name’, $name, PDO::PARAM_STR);
  26.                 $cmd->bindValue(‘:value’, $value, PDO::PARAM_LOB);
  27.         }
  28.         $cmd->execute();
  29.         $this->add($name,$value);
  30. }

When configuring the extension or using load() or purge() method, we can specify parameters either as array or as comma-separated string. This is achieved by the preprocessing method, which also converts parameter names to lowercase and they are case insensitive (if this is required by the caseSensitive property, it must be set to true). Here is it:

  1. /**
  2.  * Sets value of a component property.
  3.  * This method overrides the parent implementation by adding a new param
  4.  * value to the collection and updating the DB.
  5.  * @param string the property name or event name
  6.  * @param mixed the property value or event handler
  7.  * @throws CException If the property is not defined or read-only.
  8.  */
  9. public function __set($name,$value)
  10. {
  11.         if ($this->caseSensitive)
  12.                 $name = strtolower($name);
  13.         $db = $this->getDbConnection();
  14.         if ($db->createCommand(‘SELECT name FROM ‘.$this->paramsTableName.‘ WHERE name=\’‘.$name.‘\’‘)->query()->rowCount >= 1)
  15.         {
  16.                 $sql = ‘UPDATE `’.$this->paramsTableName.‘` SET `value`=:value WHERE `name`=:name’;
  17.                 $cmd = $db->createCommand($sql);
  18.                 $cmd->bindValue(‘:value’, $value, PDO::PARAM_LOB);
  19.                 $cmd->bindValue(‘:name’, $name, PDO::PARAM_STR);
  20.         }
  21.         else
  22.         {
  23.                 $sql = ‘INSERT INTO `’.$this->paramsTableName.‘`(name, value) VALUES(:name, :value)’;
  24.                 $cmd = $db->createCommand($sql);
  25.                 $cmd->bindValue(‘:name’, $name, PDO::PARAM_STR);
  26.                 $cmd->bindValue(‘:value’, $value, PDO::PARAM_LOB);
  27.         }
  28.         $cmd->execute();
  29.         $this->add($name,$value);
  30. }

And, finally, load and purge methods:

  1.  
  2. /**
  3.  * Loads several params from DB at once. If nothing specified, all parameters
  4.  * are loaded. This saves queries if you plan to use all that params in the
  5.  * next lines.
  6.  *
  7.  * @param array|string $params
  8.  * @throws CException
  9.  */
  10. public function load($params = array())
  11. {
  12.         $params = $this->preprocessParams($params);
  13.         $db = $this->getDbConnection();
  14.         $sql = ‘SELECT name, value FROM ‘.$this->paramsTableName;
  15.         if (sizeof($params) > 0)
  16.         {
  17.                 $sql .= ‘WHERE name IN (\’‘.implode(‘\’,\’‘, $params).‘\’)’;
  18.         }
  19.         $cmd = $db->createCommand($sql);
  20.         $reader = $cmd->query();
  21.         foreach ($reader as $row)
  22.         {
  23.                 $this->add($row[‘name’], $row[‘value’]);
  24.                 $loaded++;
  25.         }
  26.         if ($loaded < sizeof($params))//this will not be thrown if loading all attributes
  27.         {
  28.                 throw new CException(Yii::t(‘xparam’,‘Some of the requested params do not exist!’));
  29.         }
  30. }
  31.  
  32. /**
  33.  * Deletes specified params (or all params if none specified) from the parameters table
  34.  *
  35.  * @param array|string $params Comma-separated list of params or array of param names
  36.  */
  37. public function purge($params = array())
  38. {
  39.         $sql = ‘DELETE FROM ‘.$this->paramsTableName;
  40.         if (sizeof($params) > 0)
  41.         {
  42.                 $params = $this->preprocessParams($params);
  43.                 $sql .= ‘ WHERE name IN (\’‘.implode(‘\’,\’‘, $params).‘\’)’;
  44.         }
  45.         $db = $this->getDbConnection();
  46.         $db->createCommand($sql)->execute();
  47.         if (sizeof($params) > 0)
  48.         {
  49.                 for ($i = 0, $s = sizeof($params); $i < $s; $i++)
  50.                 {
  51.                         $this->remove($params[$i]);
  52.                 }
  53.         }
  54.         else
  55.                 $this->clear();
  56. }

Usage Instructions

Using the extension is simple. Like any extension, you should unzip it to the /protected/extensions/ folder and then set it up as an application component. To do this, you should add it with any name to the components array in the application configuration:

  1. ‘par’=>array(
  2.     ‘class’ => ‘application.extensions.dbparam.XDbParam’,
  3.     ‘connectionID’ => ‘db’,//id of the connection component, just the same as with CDbCache
  4. //  ’preload’ => ‘test,test2′, //comma-separated string or array of params to be loaded anyway. Other params are loaded only when requested.
  5. //  ’autoLoad’ => true, //setting to true enables loading of all attributes present in DB in the beginning
  6. //  ’caseSensitive’ => true, //setting to true makes all parameters case sensitive
  7.     ),

‘par’ is the ID of the component, you will refer to it in any place of the application by it’s ID:

  1.  
  2. Yii::app()->par->test = ‘1234′;//set parameter. If it is not present, it will be created
  3. echo Yii::app()->par->test;//output parameter. If it is not present, exception is thrown
  4.  
  5. //load several parameters in one query. Useful if you;re going to use them in the next lines
  6. Yii::app()->par->load(array(‘test’, ‘test2′));
  7. //OR
  8. Yii::app()->par->load(‘test,test2′);
  9. //OR
  10. Yii::app()->par->load();//load all parameters
  11.  
  12. //delete the specified parameters or all of them if none specified
  13. Yii::app()->par->purge(‘test,test2′);//delete test and test 2
  14. //OR
  15. Yii::app()->par->purge(array(‘test’, ‘test3′));//delete test and test 3
  16. //OR
  17. Yii::app()->par->purge();//delete ALL parameters!

That’s it! Enjoy!

UPDATE: Updated on March, 5 2009 according to the Jonah’s comments an this discussion. Version 3 is planned with great functionality :)

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]]> http://programmersnotes.info/2009/03/04/handling-application-parameters-in-yii-using-the-database/feed/ 30 Registering group of JS files in Yii http://programmersnotes.info/2009/03/03/registering-group-of-js-files-in-yii/ http://programmersnotes.info/2009/03/03/registering-group-of-js-files-in-yii/#comments Tue, 03 Mar 2009 13:27:32 +0000 Konstantin Mirin http://programmersnotes.info/?p=123 Yet Another Related Posts Plugin.]]> The problem…

In Yii you can have all your JS and CSS files together with your PHP. For example, you have some view in /views/user/create.php and you can have your css & js in /views/user/assets/css/ and /views/user/assets/js/. That’s quite convenient when you reuse your views/controllers/components from application to application. But these directories are not accessible from the web, so there is publishing mechanism there. You should do:

  1. $files = array(‘Box’, ‘CommentObject’, ‘FavouriteStore’, ‘FavouriteObject’, ‘FriendObject’, ‘RateObject’, ‘init’, ‘rateComment’, ‘TagObject’);
  2. foreach ($files as $file)
  3. {
  4.         $path = CHtml::asset(dirname(__FILE__).‘/product/assets/’.$file.‘.js’);
  5.         $cs->registerScriptFile($path);
  6. }

Yes, it’s simple, but why should I do these routines all the time!

…and solution

Luckily, in Yii you can change everything. When we write

  1. Yii::app()->clientScript

we access the clientScript application component. This is default component, it is created from the class CClientScript. So we can extend this CClientScript and replace it in the application configuration file with our class. OK, here is /protected/components/AdvancedClientScript.php file:

  1. <?php
  2. class AdvancedClientScript extends CClientScript
  3. {
  4.         /**
  5.          * Registeres all files within the directory as JS
  6.          *
  7.          * @param string $path Path to the directory with files. With trailing ‘/’
  8.          * @param bool $makeAssets Wether or not publish file as asset. If the directory is under /protected/, you should set true (default)
  9.          * @param int $position Position where to put the file. @see CClientScript::registerScriptFile
  10.          */
  11.         public function registerScriptDirectory($path, $makeAssets = true, $position = self::POS_HEAD)
  12.         {
  13.                 $id = md5(serialize($path.$makeAssets.$position));
  14.                 $data = Yii::app()->cache->get($id);
  15.                 if($data === false)
  16.                 {
  17.                         $di = new DirectoryIterator($path);
  18.                         foreach ($di as $file)
  19.                         {
  20.                                 if (!$file->isDot() && !$file->isDir())
  21.                                 {
  22.                                         $data[] = $makeAssets ? CHtml::asset($path.$file->getFileName()) : $path.$file->getFileName();
  23.                                 }
  24.                         }
  25.                         Yii::app()->cache->set($id, $data, 1800);
  26.                 }
  27.                 foreach ($data as $file)
  28.                 {
  29.                         $this->registerScriptFile($file, $position);
  30.                 }
  31.         }
  32.  
  33.         /**
  34.          * Registeres all files within the directory as CSS
  35.          *
  36.          * @param string $path Path to the directory with files. With trailing ‘/’
  37.          * @param bool $makeAssets Wether or not publish file as asset. If the directory is under /protected/, you should set true (default)
  38.          * @param int $position Position where to put the file. @see CClientScript::registerCssFile
  39.          */
  40.         public function registerCSSDirectory($path, $makeAssets = true, $position = self::POS_HEAD)
  41.         {
  42.                 $id = md5(serialize($path.$makeAssets.$position));
  43.                 $data = Yii::app()->cache->get($id);
  44.                 if($data === false)
  45.                 {
  46.                         $di = new DirectoryIterator($path);
  47.                         foreach ($di as $file)
  48.                         {
  49.                                 if (!$file->isDot() && !$file->isDir() && (stristr($file->getFileName(), ‘.css’) !== false))
  50.                                 {
  51.                                         $data[] = $makeAssets ? CHtml::asset($path.$file->getFileName()) : $path.$file->getFileName();
  52.                                 }
  53.                         }
  54.                         Yii::app()->cache->set($id, $data, 1800);
  55.                 }
  56.                 foreach ($data as $file)
  57.                 {
  58.                         $this->registerCssFile($file, $position);
  59.                 }
  60.         }
  61.  
  62.         /**
  63.          * Registeres all files inthe passed array as JS
  64.          *
  65.          * @param array $files Array of file names
  66.          * @param string $basePath Path to the container directory
  67.          * @param bool $makeAssets Wether or not publish file as asset. If the directory is under /protected/, you should set true (default)
  68.          * @param int $position Position where to put the file. @see CClientScript::registerScriptFile
  69.          */
  70.         public function registerScriptFiles($files = array(), $basePath = -1, $makeAssets = true, $position = self::POS_HEAD)
  71.         {
  72.                 if (sizeof($files) <= 0) return;
  73.                 if ($basePath === -1) $basePath = dirname(__FILE__);
  74.                 $id = md5(serialize(implode($files).$basePath.$makeAssets.$position));
  75.                 $data = Yii::app()->cache->get($id);
  76.                 if($data === false)
  77.                 {
  78.                         for ($i = 0, $s = sizeof($files); $i < $s; $i++)
  79.                         {
  80.                                 $data[] = $makeAssets ? CHtml::asset($path.$files[$i]) : $path.$files[$i];
  81.                         }
  82.                         Yii::app()->cache->set($id, $data, 1800);
  83.                 }
  84.                 foreach ($data as $file)
  85.                 {
  86.                         $this->registerScriptFile($file, $position);
  87.                 }
  88.         }
  89.  
  90.         /**
  91.          * Registeres all files inthe passed array as CSS
  92.          *
  93.          * @param array $files Array of file names
  94.          * @param string $basePath Path to the container directory
  95.          * @param bool $makeAssets Wether or not publish file as asset. If the directory is under /protected/, you should set true (default)
  96.          * @param int $position Position where to put the file. @see CClientScript::registerCssFile
  97.          */
  98.         public function registerCssFiles($files = array(), $basePath = -1, $makeAssets = true, $position = self::POS_HEAD)
  99.         {
  100.                 if (sizeof($files) <= 0) return;
  101.                 if ($basePath === -1) $basePath = dirname(__FILE__);
  102.                 $id = md5(serialize(implode($files).$basePath.$makeAssets.$position));
  103.                 $data = Yii::app()->cache->get($id);
  104.                 if($data === false)
  105.                 {
  106.                         for ($i = 0, $s = sizeof($files); $i < $s; $i++)
  107.                         {
  108.                                 $data[] = $makeAssets ? CHtml::asset($path.$files[$i]) : $path.$files[$i];
  109.                         }
  110.                         Yii::app()->cache->set($id, $data, 1800);
  111.                 }
  112.                 foreach ($data as $file)
  113.                 {
  114.                         $this->registerScriptFile($file, $position);
  115.                 }
  116.         }
  117. }
  118. ?>

I’ve added 4 methods there:

  • registerScriptDirectory – registers all files in the specified directory as JS files (no check is performed)
  • registerCssDirectory – registers all files in the specified directory as CSS files
  • registerScriptFiles – same as first, but deals with an array of files
  • registerCssFiles – same as second, but deals with an array of files

And no we’ll replace default component with ours. My config is in the /protected/config/main.php:

  1. // application components
  2. ‘components’=>array(
  3.         ‘clientScript’ => array(
  4.                 ‘class’ => ‘application.components.AdvancedClientScript’ //here we specified the path to our component
  5.         ),
  6.         //other components follow
  7.         ……
  8. ),

In order to make it work, you should enable caching. This is quite simple. I’ll show, how to use caching in DB:

  1. You should have your DB connection configured. See details here.
  2. Add new component to the application config:
    1. …
    2. ‘cache’ => array(
    3.         ‘class’ => ’system.caching.CDbCache’,
    4.         ‘connectionID’ => ‘db’//this is id of the DB module. If you didn’t change anything, it should have name "id"
    5. ),
    6. …

We’re done! Now we can publish the files simply calling:

  1. Yii::app()->clientScript->registerScriptDirectory(dirname(__FILE__).‘/user/assets/ui/’);

Note, that the code I wrote uses caching and when I call

  1. Yii::app()->cache->set($id, $data, 1800);

I cache this for 30 mins (1800 seconds). However, it is much more flexible to have either constant or file with parameters.

UPDATE: Post updated after discussion in the Yii forum according to the Maxximus advice.

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]]> http://programmersnotes.info/2009/03/03/registering-group-of-js-files-in-yii/feed/ 3 Yii – the framework of my choice http://programmersnotes.info/2009/02/24/yii_framework_of_my_choice/ http://programmersnotes.info/2009/02/24/yii_framework_of_my_choice/#comments Tue, 24 Feb 2009 06:08:46 +0000 Konstantin Mirin http://konstantin.takeforce.net/?p=4 Yet Another Related Posts Plugin.]]> Long journey to the framework…

I’m developing web-applications since 2004, I am crazy about nice architecture and first-class CSS+JS frontend. On the server side, I was using my framework, quite basic one. And all my projects were based on it.

In the October 2008 I finished one of my projects using my own framework. Then looked at it critically, then saw description of the Zend Framework (it had so many features, that mine didn’t!), and decided to move from my own development to the better product.

Main requirements to the framework were:

  • 100% OO architecture. I don’t like to work with Drupal or jQuery. I enjoy ExtJS, for example. And I wanted the same nicely designed PHP framework. Nice OOP in PHP began from the PHP5, so all frameworks, that were initially written in PHP4 and not completely rebuilt to PHP 5 are not considered.
  • Component/modular architecture
  • Event-driven programming. I enjoyed this thing in ExtJS and wanted to write PHP code in the similar way
  • Excellent documentation. Again, I compare this to the ExtJS docs, which are VERY nice. So I wanted every little feature explained and documented.
  • Active community. It’s never possible to cover everything in the documentation, so active community is a VERY big plus.

Sure, framework must be free.
Initially, I was choosing between ZendFramework, CodeIgniter, Symfony, CakePHP. However, fully PHP5 are only ZF and Symfony. Yes, I know, that both Cake and CI have PHP5 classes, but they are not designed for PHP5. CI, in particular, states:

Note: CodeIgniter will run on PHP 5. It simply does not take advantage of any native features that are only available in that version.

But neither ZF nor Symfony had event-driven programming, so I found one more framework – PRADO. I liked all it’s features, expecially component approach and event-driven programming, but on the prado forums I found an announcement, that Main team members has developed a completely new framework, that took best things from PRADO, but has significantly better performance. Yes, it’s Yii, the framework of my choice.

OK, I’m here, but what’s that?

From the official site:

The name Yii (pronounced as [i:]) stands for easy, efficient and extensible.

I studied the definitive guide. (By the way, it is now available in 9 languages. Translation is done by the community. German and Russian translations are almost finished, others coming soon)
I immediately liked it’s:

  • 100% OO architecture. It is really good application design.
  • Authentication & roles mechanism
  • Caching techniques
  • DB access, which is based on PDO
  • Active record and relational active record implementation
  • Validation – that is really, really nice. To create quite complex register form (check if login is unique, if email is unique, email match with confirmation, passwords match, validate integer/string values, check empty fields and give nice error messages for each field you need only template (view) and model with rules defined. It took me 10-15 mins to do that!)
  • Component concept. Just to give an idea, why is it nice – you can define getter and setter methods for properties, you can define read-only properties for components, define and invoke events, attach event handlers and additional features to the class without modifying it, just by attaching additional behaviour to it

And, yes, Yii is quite fast. And in combination with it’s advanced caching it can be used for the high-loaded websites, I’m developing one with it now

By the way, Yii is the only PHP framework selected for the Great Indian Development Award voting. I voted for it, maybe you’ll like it also? Try it and vote for it!

I voted for GIDS

P.S. If you’re Russian, join us in the Russian discssion board, I reply all threads there and clarify all questions.

More info

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]]> http://programmersnotes.info/2009/02/24/yii_framework_of_my_choice/feed/ 13 Yii framework – tips when going production http://programmersnotes.info/2009/02/20/yii-framework-tips-when-going-production/ http://programmersnotes.info/2009/02/20/yii-framework-tips-when-going-production/#comments Fri, 20 Feb 2009 07:17:43 +0000 Konstantin Mirin http://konstantin.takeforce.net/?p=7 Yet Another Related Posts Plugin.]]> Yii is a great framework. It gives excellent built-in functionality, but, from my experience, is quite sensitive to the server configuration. Mostly because it relies on the newest technologies.

So here is a list of things to check when you experience strange things (blank screen without any messages is the worst one that may happen):

  • Check PHP version. Yii needs 5.1 at least. When using some specific PDO or other features in your application, ensure they’re available in the server’s PHP installation.
  • Check MySQL version. Should be at least 5. If it differs from development one (e.g. server has 5.0.21 and you have 5.0.51), then pay attention to the CDbConnection::emulatePrepare. Actually if you’re using MySQL, you’d better turn it on because MySQL doesn’t cache prepared statements and has buggy support for some types of qeries (e.g. SHOW)
  • If you’re using automated timestamps insertion like described in Yii Cookbook, you may encounter problems, when using different PDO or MySQL version. If you see your queries fail, try using
    1. date(‘Y-m-d H:i:s’)

    instead of

    1. new CDbCommand(‘NOW()’)
  • When you can’t see any output, configure logging. If log is emply also, try die(‘message’) in all possible places. Starting from the entry script, continuing to your controller’s action. In some cases PHP crash is possible, which leads to immediate application termination, which makes both Yii logging and PHP’s echo ineffective and only die() workds fine
  • When using different PHP version, PDO versin may be different also. If you have application crashes when using bindParam(), try using bindValue() instead. This helps sometimes
  • Don’t forget to switch off YII_DEBUG in the index.php (entry script). However, if you encounter any problems, switch it back to help debugging

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