I'd like to use Zend_Tool (ZF 1.9) with my project, but I would like to be able to customize the default output of new files. For example, all Controllers should have a specific header pre-pended to the output with phpdoc markup and licensing information to avoid me having to add this as an extra step.
Also, for this particular project (but not all other projects), I need the controllers to extend something other than the default Zend controller as I have extended that for some specific functionality.
The documentation alludes to the ability to do these things, but it does not make it very clear.
From what I can tell I can set up a ~/.zf directory (on ***nix based systems) and include custom providers there. However, this will be machine-wide as opposed to limited to single project scope. Also, while this will add new providers it does not (seemingly) allow me to customize the functionality of existing providers.
Any help here would be greatly appreciated!
Essentially what Jacob was getting at: what you're talking seems like simple class extending. There's a really simple slideshow introduction to extending Zend Framework here:
http://www.slideshare.net/PHPBelgium/extending-zend-framework-presentation
There are also lots of other resources available online for extending Zend Framework. You can create separate source trees for your different projects, and functionality common to various projects can be added to abstract classes that are in common folders. Something like this isn't common, but I've found it works in those kinds of situations:
class My_Component_HelloProvider extends My_Common_Component_HelloProvider
{
public function say()
{
echo 'Hello from my provider!';
}
// public function do() is inherited
}
class My_Common_Component_HelloProvider
implements Zend_Tool_Framework_Provider_Interface
{
public function do()
{
// do something
}
}
Let me know if this is different from what you're trying to do, but there's no reason you can't build multiple applcation extensions from a single instance of ZF.
You can naturally continue to override when you define the specific classes. You can declare them to be based on your class, rather than the ZF class.
For specific projects, you can modify your classpath to be a custom version of ZF or possibly have a custom override folder. With a custom folder then your changes are not machine wide, but neither is your zend framework. on ***nix based systems, you can leverage symbolic links to keep yourself to one copy of ZF.
Are you trying to modify your source code to include the license headers and PHPdoc? If so, what I have done in the past is have a simple build step that adds the information you need. Each file type can have the appropriate header information. You can have nice tags to tell the system to ignore files, or only run on controllers.
Good Luck,
Jacob
Related
I'm trying to think of a way to create a plugin architecture for my own framework. I've read numerous topics and post here and on other sites. And basically i've came to the following solution which seems to be the only good option in PHP (currently).
The idea is that every class extends a sort of observer like class. So a Template class, BaseController etc. always extend a Plugin class.
class BaseController extends Plugin
{
public function __construct()
{
// Plugin check, notify all loaded plugins
$this->checkForEarlyHooks();
// Init some standard stuff
$this->view = new Template();
$this->baseLayout = 'layout.html';
$this->something = new Something();
// Plugin check, notify all loaded plugins
$this->checkForLateHooks();
}
}
So what basically happends here is that when an indexController extends a baseController a plugin check is done. In this case for the constructor. This can be convenient when you want to do a some sort of login check with a plugin, before an Action method is actually invoked.
The Plugin class can resolve from what class is got called from and knows for what functions to look for in the loaded plugins.
Also note that it checks the loaded plugin list 2 times. One before anything is loaded (early) in the constructor, and one when all vars are loaded (late).
I can also add variables to the "checkForLateHooks()" function. So the hook functions can manipulate those too, like the 'baseLayout' variable.
A hook function would look like this:
public function hookConstruct ( &$baseLayout )
{
$baseLayout = 'login.html';
}
Now basically my question is, is this approach any good? I know there are probably alot of other ways to do it too. But i mainly don't want to run into design problems later on. It seems like a good idea now, but you never know how things work out later on...
If i remember it right (from all the posts the i've read), this is kinda like WordPress does it (and some other frameworks).
UPDATE: answer now reflects the up-to-date links and better description.
There are certainly many different ways to design a plugin system and perhaps asking on https://softwareengineering.stackexchange.com/ would give you more ideas, but I'll try to help by sharing my ideas and experience.
I'll share some of my own experiences which I've learned through a series of my own frameworks. Currently Agile UI and Agile Data both support many wasy to be extended, but I'll focus on the "Components"
HOOKS
When you look to inject code into the existing object, a hook is a standard way to go. It's the best option for extending the application or flow with an established structure.
While refactoring my frameworks, I've separated hook implementation into a separate trait and documented it here: http://agile-core.readthedocs.io/en/develop/hook.html
Host application:
... some code here ..
$this->hook('beforeInit');
$this->init();
$this->hook('afterInit');
... code goes on ..
Plugin:
$host_app->addHook('beforeInit', function($object) {
echo "About to execute init of $object";
});
UI COMPONENTS
Components present a different design pattern, which is suitable for the User Interfaces. You start with the page/app layout which is then broken down into Menu, Header, Footer, Content.
A component is an object which can be associated with Layout or the other component. Each component is capable of rendering and passing extra HTML/JS to its parent. Most of components would also be an interractive objects.
This approach is called "Render Tree" and application execution goes through 2 stages - "initialization of a render tree" and then "rendering".
Host Application:
$layout->menu = new \atk4\ui\Menu();
$layout->add($layout->menu, 'TopMenu');
The above code show how a new Component (Menu) can be initialized and inserted into the $layou. Furthermore the HTML output of $menu is directed into {$TopMenu} tag, which is defined in the HTML template of Layout.
Plug-in can interact with the render tree by:
adding more components anywhere in the tree
affecting existing components (e.g. add new menu item)
destroying any of the existing components
When those approaches are combined, you can use something like this:
$app->addHook('afterInitLayout', function($app) {
$app->layout->menu->destroy(); // remove default menu
$app->layout->menu = new \plugin\SuperMenu();
$app->layout->add($app->layout->menu);
});
This can be used to replace standard menu with a more powerful implementation from your add-on.
My implementation of components is documented here:
http://agile-ui.readthedocs.io/en/latest/view.html#initializing-render-tree
UI / DATA SEPARATION
Although perhaps not so much answer for a question, but another powerful way to extending is a separation of concerns. All of the UI components in Agile UI do not know how to do anything with data.
While many UI generators require developer to manually build them up and link up with data, I am injecting "Model" object like this:
$form->setModel(new User($db)); // populates name, surname and gender fields
Demo: http://ui.agiletoolkit.org/demos/form2.php (2nd form)
In this approach object User contains enough meta-data for the Form to populate it's fields, captions perform validation and also save/load data.
Since "User" class can also be declared in an add-on it makes a pretty powerful way to extend existing functionality by adding support for new data entities.
OTHER APPROACHES
Some other approaches to extend with add-ons include:
Factory:
The ability to resolve class specified as a string into namespace / file:
$api->add('MyClass');
Gives ability for add-on to re-route standard classes but is not very friendly with type-hinting in IDEs.
New types / Traits:
Add-on can provide new classes adding Persistences, Table Columns, Form Fields, Actions etc.
CONCLUSION
I think add-on deign boils down to:
simplicity of installation and use
does add-on need to operate out-of-the-box?
avoiding conflicts between add-ons
defining different add-on types - authentication, UI, behaviour
can add-on extend another add-on
will add-on fit application design, data and architecture?
give a lot of power to add-ons without sacrificing performance
Have a look at PHPPlugin on https://github.com/gheevel/PHPPlugin. A simple PHP plugin framework inspired by eclipse and jira plugin architectures. Basically, your application can define extension points and plugin instances can register on those extension points for providing extra functionality. Works well in combination with composer and/or symfony.
I have an object oriented framework that uses a page design, where each page extends a view of the framework. So, for instance, my index page for a site is actually a class that implements the abstract class View provided by the framework. I hook the framework by including a startup script at the top of the page and after some processing the framework creates an instance of the page and processes its view data. To add flexibility to the system, I don't require the class name to be the name of the file itself. This allows me to create something like a support class and have it behave as the index for the /support/ subdomain.
I was initially passing the page's class name into the framework via the framework's constructor, but this added a few more steps to the top or bottom of the page. I currently obtain the class name via a pages table in the database identified by a filtered requested URI. I use this table to build navigation and adding an extra table column was practically free. This works OK as long as I have a database connection, but I'm trying to implement static page support for status messages and error reporting, and I need another method for creating an instance of the page's class. If I use the standard convention of naming the class the file's name, then I know I have a dependable way of extrapolating the class name. I don't really want to name all my classes index just for presentation reasons. What is some advice or some standards for how object oriented frameworks are initialized?
View.inc
<?php
abstract class View
{
abstract function getView();
}
?>
Startup.inc
<?php
require_once("View.inc");
require_once("CoreController.inc");
$Framework = new CoreController();
$Framework->Initialize();
exit;
?>
index.php
<?php
require_once("Startup.inc");
class Index extends View
{
public function getView()
{
echo "<pre>View Data</pre>";
}
}
?>
Within my framework I have a TemplateController that processes the page. The page class is known because it is mapped via another class. Without a database however, I would like to discover the class within, say, index.php without changing the way it's currently set up. Here is the actual code within the TemplateController.
//Get the View Class from Page
$view = $page->getPageClass();
//We need to catch View creation failure
$this->Page = new $view($this->Framework);
//Initialize the Page View
$this->Page->Initialize();
//Cache the Page View
$this->cacheView($this->Page, $page->getPageName(), $this->SiteID.TCS_PAGE_SORTID);
In the snippet above $view is the actual name of the class that was mapped from another controller. I'm passing a reference to the framework to the view's constructor and the rest is really irrelevant. I'm trying to come up with a similar mapping technique to identify the page class in the event the database is down. I like the one include line for the framework startup and would like to keep it that simple.
At the top of the TemplateController I have to also reinclude the actual page, since my startup script is at the top, the actual class is not included even though it is the requested page.
include($_SERVER['SCRIPT_FILENAME']);
Please review Stack Overflow question Identifying class names from $_SERVER['SCRIPT_FILENAME'] for more information on what I'm attempting to do.
Here is my checklist of page routing:
Adding new page must be quick
You must not be able to add page unintentionally
Application with million pages should not be slower or more bloated than application with 2 pages
Provide simple way and let people enhance it if they want
Allow easy re-factoring, such as moving several pages into different location
Make framework detect everything. Don't force user to specify base URL, etc.
Create simple to understand page names (hello/world).
Clean illegal characters from the URL
Make it possible to add static pages easy
Provide a way to generate URLs from page names.
Allow user to use pretty URLs by changing what appears before and after the page in the URL
And most importantly
- Stop copying, think about the best approach.
All of those suggestions I have used in the PHP UI framework - Agile Toolkit where I am a contributor.
Relevant sources: Agile Toolkit - a PHP Framework with jQuery, Agile Toolkit - PageManager.php, Agile Toolkit - URL.php and Agile Toolkit - PathFinder.php.
We wanted to make it really simple for developers. And secure too. And flexible. Therefore the "page" class is selected based on the URL. How? Quite easy:
/hello.html -> page_hello
/hello/world.html -> page_hello_world
Class then is mapped into filename. page/hello/world.php
Then there are cases when we want to use dynamic URLs too, such as: /article/234
Many frameworks implement a complex techniques here (arrays, regular expressions, front-controllers). We don't. There is mod_rewrite for this. Just rewrite this into page=article&id=234 and it works. And scales.
Apart from pages, there are other classes, but those classes can't be accessed directly. Therefore pages live under the /page/ folder, do distinguish them and maintain security.
Then comes the designer saying - "I won't write PHP". So we introduce static pages. If class page_hello_world is not defined, we'll look into template/skin/page/hello/world.html. That's a easy shortcut for designers and non-developers to add a new page.
What if a page is not found? Api->pageNotFound() is called. Feel free to redefine and load pages from SQL or display 404 page with a picture of a pink elephant.
And then there are some pages which come from add-ons. We don't want to enable them by default, but instead let users add them to their app somewhere. How?
class page_hello_world extends Page_MegaPage
Next question, is how we handle sub-pages of that page, since sometimes all the functionality can't fit on single page. Well, let's add support for page_edit() method (or any page_XX) as an alias for a sub-page inside those classes. Now add-on developer can include a multifunctional page which can be extended, customized and placed anywhere in the application.
Finally there are hackers, who want to do something really fast. For them we apply same technique to the API. You can define function page_hello_world in the API, and you don't need class.
Some might say that there are too many ways to do a simple thing. Oh well.
I hope that this was helpful.
Use __autoload(). Most major PHP frameworks use autoloading to streamline class loading.
You need some way to map a URL to an object, which is usually handled by a routing component in most frameworks. Might want to take a look at libraries such as https://github.com/chriso/klein.php, or the routing components of the major Frameworks out there (Zend, Symfony, etc.).
Why not to use information from URL to detect correct class? Since you won't use database for static pages, you have to somehow store mapping between URL and class in file. I.e. you will have a file mapping.php:
return array(
'about' => 'AboutView',
'copyright' => 'CopyrightView',
);
Here, about and copyright are URL components and values represent appropriate child classes of View. You can have URL's like http://example.com/index.php?page=about and use rewriting capabilities of webserver to make them look good.
You will change implementation of Page::getPageClass() in order to return correct view class. Depending on URL it will use static mappings from the file above or use database.
What's the problem with this approach?
I'm starting to write a application in php with one of my friends and was wondering, if you have any advice on how to implement module support into our application.
Or is there a way how to automatically load modules written in php by a php application? Or should i just rely on __autoload function?
And we don't need plugins that are installable via a web interface, we just need some clever way to associate web pages of our project to some classes (they will render the page) so index.php can call the right class and retrieve it's generated sub-page.
And we are not using any kind of framework, for now at least.
Re your comment: Autoloading in conjunction with strict file naming would be totally enough in this case IMO.
You could define a specific namespace (not in the new PHP 5.3 namespace way, just in the sense of a common prefix to names), e.g. Module_* for module class names.
You could then organize your modules in directories with class files that contain exactly one class definition, for example:
/modules/Mail/index.php // defines class Module_Mail
/modules/Database/index.php // defines class Module_Database
/modules/Image/index.php // defines class Module_Image
Your autoloader function would then, whenever a Module_* class is requested:
$Database = new Module_Database("localhost", .....);
include the correct file from the right directory.
That's the way e.g. the Zend Framework does it, and does so pretty well.
Consider choosing a more specific namespace than Module_ to assure interoperability with other scripts and applications if that is an option in the future.
Slightly related: In a PHP project, how do you organize and access your helper objects?
It sounds like you are looking for a way to organise the different tasks that each page needs to carry out. In this case, take a look at the MVC pattern. It provides a simple way to seperate your data access (models) and how you render/present information (views).
You can map pages to functions with ease. If you store the information in an array of mapped values, and then use a function to compare the requested URL with each of the URLs in the array. Such an array could look like this:
$urls = array(
'/' => 'index',
'/aboutus/' => 'aboutUs',
);
There are several articles that discuss how to implement it in PHP in a couple of hours. This article is a very simple guide. I am not a fan of their use of the registry pattern but reading through should provide you with enough information as to how you can implement it yourself.
Regarding autoloading, you can also use spl_autoload_register, to define several (more than one) autoload functions, so each module can set up it's own implementation of autoloading.
All you need here is an MVC architecture, with one Controller class associated with each "module".
If you are not against using a framework, go for Zend MVC
It allows you to have the following principle :
An URL like this : http://yoursite.com/my-module/edit
Will more or less automatically call the editAction method in the MyModuleController class.
I am planning on doing a research on how to implement a plug-in architecture in PHP. I have tried searching the web for possible references, but I thought that maybe my search for a good reference would be faster and more relevant if I asked here.
Has anyone here tried using plug-in architecture for web projects?
Thanks,
Erwin
I have written wordpress plugins and the magic that they rely on is "Variable Function Names". For instance this is valid php, in which the function call phpinfo() will be called:
$func_name="phpinfo";
$func_name();
This allows developer to "Hook" function calls, as in override them with their own functions without having change the rest of the application. Linux Kernel modules are all about "hooking", they wouldn't work without this behavior.
Unfortunately for PHP variable function names are a disgusting hack that consumes a lot of resources. All functions in a name space are put in a list and this list has to be searched though before the function is called, this is O(log2(n)). Also keep in mind that Variable Function Names can not be accelerated properly in HipHop although the code will still be transformed into valid C++. A better approach would be to re-declare functions like you can in python which would be O(1) complexity, but the PHP development team HATES this idea (Yes, I've asked for this feature!).
Good luck!
There are a lot of concepts that can be considered a 'plugin'. You can write a plugin system using:
Event dispatchers (see the Symfony Event Dispatcher)
Middlewares (see Silex middlewares)
Observer OO pattern (see Google / Wikipedia)
And many others
You could take a look at how Zend Framework implemented their Plugin Loader component.
Basically you set path´s to where plugins are stored and the loader tries to load the first plugin found in a LIFO way.
What about these two classes
Plugin Handler/Loader
Plugin
and there are some rules
Plugin Handler/Loader is a singleton class and manages all child clases of Plugin Class.
Any plugins should have to be inherited from Plugin Class.
Plugin Class would have pre-defined properties and methods which can be overwritten by its child classes, so alternate method to hook system (but i am not sure of any major difference in results).
For example say Plugin class has a property of url_routes with default value of an empty array, the child class can then overwrite and add any required urls in this array.
Plugin Handler/Loader will then add these url routes from child class to underlying system.
don't forget about function __autoload. you can dynamically load components.
like:
SomeModule::test();
function __autoload($class)
{
$class = preg_replace('/^\W/', '', strtolower($class));
include 'modules/'.$class.'.php';
}
straight to the point :
I am using Kohana, and I am looking at another script written in plain PHP. In the script, I have a class ShoppingCart. If I am to convert the script to Kohana, where am I to put the class, its methods and its properties?
Is it in my existing default controller? Or should I put it in a separate controller? Or as noobie as it may sound, will I put it in the model?
That depends on the specifics of the class I suppose. To be honest I don't know anything about Kohana, but there's probably a place for "vendor files" somewhere. Maybe it's best to place it there and write wrapper functions for it in your controller. If the class already integrates well with Kohana you may instead choose to use it as a controller or model directly. Or you might want to take the time to rewrite it to make it work as a controller...
Only you can evaluate the best place for it, there's no hard and fast rule here.
Kohana has a folder for 3rd party libraries. The main one is under system/vendor, you can put it in you application/ as well.
Many PHP class loaders require details like your filename should be the same as the class name (at least that's what I read in the Kohana documentation) if you want the classes to be automatically loaded.
If you need to use 3rd party code in your app it's recommended that you create a folder in your app / module folder called 'vendor' and place all of that code there.
You can then include the files by calling:
include kohana::find_file('vendor', 'filename');
If needs be you can also create a wrapper for the external library, a good example of this is the email helper which uses the 3rd party Swift email library.
If you're porting your own class to kohana then you need to work out what the class will be doing and categorise it accordingly.
If the class will be fetching items from some kind of database then you should make it a model. Libraries are usually sets of code that you want reuse across controllers / models, such as authentication, calendar generation etc. Controllers are used for passing data from models to your views / libraries.
See the docs for more info
As per kohana convention, you should place custom classes in application/libraries folder. However for this, you need to know how to get the class to work after putting it there. If you can't figure that out, you can do anything like putting it in your controller or making another controller of it, etc.