set($variable, $value);
string $variable;
mixed $value;

The principal use of this function is to extract data from a controller and transfer it to a view.
It can be used to transfer single values, whole arrays and so on etc. The moment you utilize set(), the variable can be accessed in your view: doing set(name, john) in your controller makes the variable name available in the view.

validateErrors() – displays the number of all the errors produced by an unsuccessful save.
validate() – this function is used to validate a model data respecting the rules of validation defined in to the model.

render($action, $layout, $file) – this function may not always be needed because render is called by default when every controller action ends, so the view specific to your action is rendered. On the other side, you can call this function to render the view anywhere in the controller code.

The controllers of your application are classes that extends the Cake ApplicationController class, which also extends a core Controller class. Controllers may comprise many kinds of actions: functions that are utilized in your web application to show off data in views.

ApplicationController class can be described in /app/appController.php and it may include methods that are distributed among controllers. It itself extends the Controller class which is a standardized in Cake Library.

A controller has an action as it’s single functionality. The Dispatcher directs it automatically if any incoming page request details in routes configuration. Going back to our example with the rental-library, our BooksController is supposed to include the view(), rent(), and search() actions.
The controller should be situated in /app/controllers/bookscontroller.php and include:

You should be capable to access these actions using the example URLs:
http://www.yourwebsite.com/books/view/Tom-Sawyer
http://www.yourwebsite.com/books/rent/12332/B-213ed
http://www.yourwebsite.com/books/search/Mark+Twain

The data displayed on this pages can be easily formated from the views area, for example for the rent() action we will have: /app/views/books/rent/index.thtml and so on.

Now create a component called image.php and inside it you will have the code that will handle getting the file extension and resizing the uploaded image (app/controllers/components/image.php):

Now let's see the view that will show the input type file element and the form (app/views/controller_name/upload.thtml):

At the end comes the last part and the "hardest", when comes to write the controller code (app/controllers/images_controller.php):

This is all.
This script above need to have GD installed on the server.

Now we need a small component to verify the email address to be a valid one and also to contain the code necessary for the email sending. The component (app/controllers/components/email.php) is looking like this:

And now becomes the logic part, the controller (app/controllers/controller_name.php):

After we define the association between 2 models Cake will automatically fetch the data between the “glued” models. For example if the Car model is related to the Image model and is using a hasOne association type when we will retrieve the data using findAll for example in a controller there will be retrived both Car and Image records: $this->Car->findAll()
To use this types of relations correctly is indicated to use naming conventions like:

- Foreign Keys: singular-model-name_id. For example, a foreign key in the "images" table pointing back to the Car a given Image belongs to would be named "car_id".
- Tables name should be at plural
- Model names should be singular form of the tables names.

Example of association and querying data with hasOne between two models Car model and Image model in this cases:

Location: app/models/car.php

When we will retrieve data using find() or findAll() calls upon Car model we should see our associated Image model data as well.

To post data in this form to a controller for example is very easy using HTML helpers that are implemented in Cake. Everything we need to care about is that form elements are looking like: data[Modelname][fieldname] .

For example to acces a certain variable in a controller we will use;

The input form in the view will look something like this:

In a form construction using helpers is best to respect the model structure using to give names to form elements the same names like fields we want to fill in the database.
Using this convention data sent from forms will be formatted automatically and will look putted in $this->data within you controller, so saving data becomes very easy.

Example of saving data:

In the example above we are saving data in the Car model.
If you want to validate your data you can easily do this using your model.
Example:

Cake will check variables: name, model and year not to be empty.
In on of the next posts I will describe how easy is to save data in multiple related models.

For example to retrive all the data from a table you will use following:

With the “set function” the $var value will be send to the view. In the case above all the fields of the table will be retrieve.

Examples using findAll()

To sort the data by a certain field we can use:

For ascending:

Descending:

Only first 10 results:

The second results page:

Putting some conditions in the query:

Example without parameters:

Example of calling an element with parameters:

This pieces of code need to be inserted in your view.

You can customize as you want your template by uploading images and styles in the webroot directory app/webroot which becomes your site root from now on.

Example:

After this is done you will see that cake changed the default layout with the one of yours and also the content of the page is cake successfully installation text. Now we have to insert in the new layout our own content. A quick way to do this is creating a controller in app/controllers named as we want but according to cake rules it has to be a plural, for example sites_controller.php . Inside of the controller we will have following code:

var $uses = array(); I use this because I don’t want Cake engine to look for a model regarding this controller. If you omit this line you will get a “missing model” error.

Browsing the http://example.com/sites/index it should reveal a page having your layout applied but with an error of ”missing view”. To get rid of that error you have to create a file called index.thtml in the app/views/sites/ (you have to create the directory also) file that will be the view for your index action of your Sites controller.
If you want visitors to point directly to a certain action of a controller when they enter your website you can do that using “Route Configuration”. Routing is like a mod_rewrite with the help of which you can map URLs to controllers actions and params and back. Routes are configured in app/config/routes.php .
You can find more information about this at the Chapter Configuration on Cake’s Manual.

In our case our routing rule should look like this:

‘/’ – represents the URL we want to map, the domain itself in this case;
‘sites’ – is the controller we wish to invoke
‘index’ – the action we wish to invoke

Now when we point on http://example.com/ Cake engine should display the following page http://example.com/sites/index (sites controller with the index action).