4 introduction-php-mvc-cakephp-m4-controllers-slides
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The document provides an overview of controllers in CakePHP and their role in the MVC framework. It discusses how controllers parse request URLs, interact with models to access data and pass it to views. It then demonstrates how to add common controller actions like create, read, update and delete to manage item data in a catalog application. These actions include querying models, validating input, redirecting users and displaying messages.
4 introduction-php-mvc-cakephp-m4-controllers-slides
- 2. CakePHP Request More Detailed Version of the CakePHP Request
- 3. Routes Parse the Request URL Extracts parameters e.g. controller, action, additional values passed in the URL. http://catalog/items/view/12 The Request URL Parameters are then Mapped to a Controller Action A specific action in a specific controller class. items controller view action (function) 12 value to use with the database
- 4. Controller The Controller Interacts With the Model Controller calls on the model if there is a need to gain access to the application’s data. Model interacts with the database and returns data back to the controller. The Controller then Interacts With the View Controller can use the data from the model and manipulate it for the benefit of the view After the controller has the prepared the data, the controller passes the data off to the view
- 6. A Tasty Example Model Route End User Controller View
- 7. What’s In Store? Continue Development of Our Catalog Web Site DVDs, Books, CDs, etc. Add to the Controller Add Actions (functions) to the ItemsController we made in “Getting Started” module Display a List all the Items Create and Delete an Item Update and Display a Detailed View of an Item Search the Items
- 8. Setting Variables Passing Variables to the View The set() method is used to pass variables to the view. First Parameter Second parameter Provide a name Provide the value or data Example Controller $this->set(‘pizza’, ‘pepperoni’); View Their favorite pizza is <? echo $pizza; ?>.
- 9. Query the Database Accessing the Database Model in Controller Access the Model via $this->ModelName Example $this->Item Retrieve Data from the Model Using find() Method Example
- 10. Query the Database find() Parameters First Parameter: all / first / count / neighbors / list / threaded Second Parameter: Array of Data Example conditions / fields / joins / limit / offset / order / page / group / callbacks
- 11. Single Query Query Based on ID findById() Example $this->ModelName->findById($id);
- 12. Throw an Exception CakePHP Has Many Error Exceptions http://book.cakephp.org/2.0/en/development/exceptions.html Handling Errors throw new NotFoundException Example throw new NotFoundException(__(“Your item was not found”));
- 13. Form Data CakeRequest Default request object in CakePHP. Passed by reference to the various layers of an application. Assigned to $this->request Example Holds all the data from the form (modified and unmodified) $this->request->data Check How the Data Was Sent is() Takes One Parameter post / get / put / delete / head / options / ajax / ssl / flash / mobile Example $this->request->is(‘post’);
- 14. Create & Save Adding a New Item Into a Database create() Resets the model state for saving new information. Clears out the model $id value Example $this->ModelName->create(); Saving the Data save() Parameters 1st : Array-formatted data to be saved. 2nd : Allows you to side step validation (bool) – optional 3rd : Supply a list of model fields to be saved. – optional Example $this->ModelName->save($this->request->data);
- 15. Redirect Sending a User to a Different Page Sometimes it is necessary redirect() Parameters: Example String action (if in same controller) Array controller & action Relative path $this->redirect(‘index’); $this->redirect(array( ‘controller’ => ‘Items’, ‘action’ => ‘index’)); $this->redirect(‘/Items/thanks’); More Redirect Examples http://book.cakephp.org/2.0/en/controllers.html#flow-control
- 16. Saving An Existing Entry Saving an Item Use the same save method that we utilized in the add() action, but we eliminate the need for the create() method to be called before hand. Example $this->ModelName->save($this->request->data); Override the ‘id’ in our model Example $this->ModelName->id = $id;
- 17. Populating the Form Editing a Form When you edit an item you need to populate the form with the content of the item you are editing. Example $item = $this>ModelName->findById($id); $this->request->data = $item;
- 18. Set and Display Message Session Component CakePHP provides a messaging system with the session component Adding the Session Component to Your Controller public $components = array('Session'); Using the Session Component Example $this->Session Access the Method setFlash() Parameter String message you want to display Example $this->Session->setFlash(__(“Your record was saved.”));
- 19. Does it Exist? Previous Determination $data = $this->ModelName->findById($id) if(!$data) Throw Exception Check to See if an Item Exists in the Database exists() Returns Bool Value Parameters $id (optional) Examples $this->ModelName->exists($id); $this->ModelName->id = $id; $this->ModelName->exists()
- 20. Delete Item Deleting an Item in the Database delete() Returns Bool Value Parameters $id (optional) Examples $this->ModelName->delete($id); $this->ModelName->id = $id; $this->ModelName->delete()
- 21. Render Method Normal Behavior Calls the view template of the same name as the action index() => index.ctp Called automatically at the end of the action in the controller Override Reuse, Plugins, Elements, etc. render() Parameter Name of the template you would like to use Example $this->render(‘index’); $this->render(‘/Cakes/index’); app/View/Cakes/index
- 22. Summary A Review of the MVC Framework Better understanding of the role of the controller Added Actions (Functions) to Our Items Controller Basic CRUD actions Create Read Update Delete Search