Hello. This is copy of my Yii Tutorial from forum:
[Total fresher in PHP frameworks and Yii, I don't understand
"Total fresher in PHP frameworks and Yii, I don't understand
In the forum you can ask me questions and I will try to answer them. I will also
post there new PDF versions (usefull as offline version). The same content as in
PDFs will be here.
**Give me a few days or weeks and I will completely rewrite and reformat current
version of PDF here. It can't be done in one day :-(**
I'm writing this tutorial because when I was beginning with Yii I was totally
lost. I didn't understand anything. I didn't know why I needed the demo project,
where I should place my PHP scripts, what it means MVC, what should the folder
structure look like etc. No tutorial for beginners was available.
This tutorial is meant for beginners who have never worked with any PHP
framework or with Yii. Who are able to create website with standard PHP, MySQL
etc., but are completely lost while beginning with Yii.
I suppose the reader is familiar with PHP and databases (DB). He should be able
to write SQL query, use DB in PHP and create at least a simple web using PHP,
HTML, CSS and DB.
If you don’t know anything about PHP and DB, I recommend that you stop reading
and have a look at it.
And what’s also important is OOP (Object oriented programming). This means
classes, overriding functions, using constructor, public and private methods and
properties, etc… Can be practiced in PHP, Java, C# …
2. MVC - Architecture description
First of all, we will generally look at the MVC abbreviation used above.
MVC (Model-View-Controller) is a type of application
architecture. It’s used in Yii framework. When your application uses MVC
architecture, it is divided into 3 basic parts.
**M** = Model = Part that defines relations among data in DB and rules that must
be followed when saving data do DB. It also gives us
tools to read/save data from/to DB.
**V** = View = Part that is used just to show data to user. It doesn’t write
to DB or count difficult things. It just receives data and shows them using
HTML, CSS, JS …
**C** = Controller = Part that processes and changes the data, handles user’s
actions, decides, counts, thinks and calls models and views … It simply acts.
![MVC Schema](http://racky.wz.cz/yii_manual/imgs/mvc_schema.png "MVC
Image 1) MVC schema
Notice the arrow directions in picture above. Controller can read/write data
from/to database only via Model. Controller also evaluates user inputs, combines
it with data, counts new values … and sends outputs and results to the View
and DB. View formats given data and shows them. (For example draws table etc.)
As we can see, the Controller is the central point. It’s the boss. Whatever
you do - Controller processes it and decides what to do next. Asks for
appropriate data from DB and does what you wanted to do. We can see that Model
and View don’t do anything, unless they are asked to. In some cases, Model and
View do not have to be used.
So let’s focus on Controller now.
### 2.1. Controller
Controller is initiated whenever you enter any
address in browser. When you use MVC architecture (in Yii
framework), addresses have special format. They include parameter that specifies
which controller will be used.
Yes, you can have more controllers. Each controller can be used to work in
different part of your web. One controller can work with user accounts, another
one with products you sell etc. And what does the web address look like when you
Parameter “r” says that you want to use Controller named “myController”.
And here we can see another speciality of MVC (or Yii). Addresses contain only
index.php. No other files. All the navigation is done by the “r” parameter
### 2.1.1. Action
Controller can have one or more sub-controllers. Each does something else. If
our controller edits users than his one
sub-controller can delete users, another one can add users, third one
changes them … These sub-controllers are called Actions.
You can (have to) specify action using the “r” parameter. As we saw above,
controller was specified like this: “?r=myController”. If our controller had
action called “myAction”, and if we wanted to run it, we would write this
We can rewrite this address for example like this:
If you do not specify action and run only controller like this
“?r=myController” than the default action will be run. The default action
has to be specified in the controller using function actionIndex().
### 2.2. Model
Model is very simple thing in Yii. You don’t have to write a single line of
its code, it can be created automatically using command line. Each table in DB
has its own model. This model has the same (or similar) name like the table.
Each model has 2 important functions. Find data and Save data. That’s all we
usually need. When you need to read data from DB to controller you just write
and that’s it. No SQL queries, no fetching array (as you would have to do in
PHP). That’s the advantage of Yii and its object-oriented access to DB. When
you want to write to table, the command looks cca like this:
ModelName.column = value;
That’s it again.
Another thing that the Model provides is relations. These relations enable you
to “tunnel” through one table to another. Important are Foreign Keys.
Relation is something like SQL Join. When every employee has in its table the ID
of his department, you can easily get info about this department by writing
something like this:
Where **$employee** is 1 particular employee selected by some criteria, the word
**department** is name of the relation (leading from model of employees to model
of departments) and **departmentName** is columns in
table of departments.
### 2.3. View
As I wrote above, view has no intelligence. It just receives data from
Controller and shows them. This is the only place where we use HTML, CSS,
WHILEs, Ifs, models … But the only aim is to show data to user.
Correction: Described View is an ideal view. In praxis it’s sometimes
easier not to send data from Controller to it, but to
read data from DB in View (using model) and show then.
3. What is it framework and why to use it
In a shortcut. Framework is a set of functions that can ease your work.
Functions are usually grouped into Classes. One example for all. In Yii
framework there is available class named CHtml. It’s obvious, that it provides
functions for creating HTML code. (Tables, lists, forms...). You don’t have to
use HTML and solve its validity. You just call function
and it creates this html code:
<form method=”post” action=”thisScriptName”>
And why to use frameworks? It makes your work easier. You don’t have to
program every single detail, framework does something
for you automatically. Yii for example integrates form-validation functions, it
handles user logging and much more. You just have to discover its possibilities
and learn to work with them. But it’s the hardest thing. (Sometimes it’s
faster to create your own function than to try to understand a prepared
solution) And that’s why I write this manual. To show some possibilities in
one place and in praxis so you won’t have to google the basics.
4. Yii framework
Yii framework has its [web] and
All you need to do (if you want to use it) is to download and extract it to your
localhost-folder. You of course need a PHP and MySQL server (I use
[WAMP]. If you want to try it, turn off Skype for the moment when
Wamp is starting. Otherwise it won’t start.)
### 4.1. The demo project and folder structure
Now you have Yii “installed” (= you copied all files to localhost-folder).
And what next? It may look useless now… The best way
to become a friend with Yii is to try the Demo project, go through it and look
what it’s code looks like. Every manual describes it, but doesn’t explain
why you should use the Demo project. I didn’t understand why everybody was
pushing me into some boring demo project, while I wanted to do a real one.
The demo project is good because you will see the folder structure, which is
important. When you walk through the code and files, you will understand how you
can send data from Controller to View or how forms are validated. You will see
how works navigation using the “r” parameter etc.
These: [Hello World], [First project] and [Blog]
could help you. Manuals describe basic work with Yii like creating demo project,
relations among tables etc …
In demo project (as same as in any other Yii project) is important folder
"protected". It contains 3 subfolders: **models**, **controllers**,
**views**. There are stored PHP scripts that power your web.
- You will find there only 2 "fictive" models. I say
"fictive" because they are not connected
to DB. Demo project does not work with DB at all. These models are more like a
definition of logics for HTML forms. When a HTML form is confirmed on webpage,
it's content is checked (_validated_) using rules specified in these models. The
validation is done for example in actionContact(). (see bellow)
- The validation rules are specified in rules() method.
- Items of form are defined as properties of model class.
- Captions for form items are in method attributeLabels().
- There is almost no difference between "fictive" and
They look 99% the same.
- If your model should work with database, it would not extend class CFormModel,
but CActiveRecord and it would contain method tableName().
Actually, you will see only 1 controller - SiteController.php. Open it in any
text editor and have a look at methods:
- actionIndex() - it only renders view "index"
- actionContact() - is creates a new instance of model ContactForm,
assignes it data from POST and tests them (all of this is described in next
Finally it renders view "contact" and sends it variable
$model as a parameter.
- actionLogout() - you can see how to call system variables and methods of Yii
and how you can redirect to a different URL.
- These are the only important things for you in controller.
You will see 2 subfolders:
- layouts: contains mainly file main.php with definition of the whole website
layout, menu items, logo etc.
- site: contains views used in SiteController. Take a look at login.php file.
This view is called from actionContact() and it receives $model as a parameter.
You will see that you can start using this variable without any other
definition. Just write $model.
Last important file is "protected/config/main.php". There is
definition of DB connection, of your application name etc. You
will add lines to this file in order to run new
(hidden) functions of Yii.
**Important for Windows:**
To use command line commands mentioned in manuals (you need them to create the
demo project and to use the best things Yii offers = mainly models and relations
between them), you will have to modify the “environmental variables”. Right
click “This computer” choose “Properties”, than “Advanced” tab and
click on button “Environmental Variables”.
A new window with 2 list-boxes will appear. In the lower one find row with
variable named “Path”. Add to its value something like this: (yii framework
folder path and php path)
C:\Program Files\wamp\www\yii\framework ; C:\Program
5. Using Yii in praxis
Here will be examples of commonly used functions, useful tricks etc. These
things are hard to be figured out just so. I will paste here everything I
have discovered so far.
### 5.1. Create demo project and set it up
If you are a rookie, first of all, you should create the demo project, set
connection to your DB  and understand how it works. When
you already are a friend with Yii, you could be able to create folder structure
just by yourself.
### 5.2. Create Databse for your project
Very important thing is database. You should design it first. Before writing any
code. When this is done, you will use command line to generate part of your
application automatically. Command line can generate models, views and
controllers. (I generate only models because I want to make it my
See this. It’s 4th part of a Yii tutorial .
In this tutorial  is said, how you should name tables and columns
to be able to generate relations among tables automatically. But names are not
so important. More useful is to declare relations in DB when designing it. If
you use PhpMyAdmin, just create a table with foreign keys (FKs) and go to the
“Structure” tab and under the list of columns you will find link to
relations creation. When you click it a new screen appears and you can set
foreign keys (FKs) relations. Or use software mentioned bellow to design whole
DB (I recommend).
When SQL relations are defined, Yii’s console will
recognize them and will automatically create relations among Models. Otherwise
you would have to declare these relations manually. Which is not impossible, but
more comfortable is to have it in DB definition.
#### 5.2.1. DB design tool
Very interesting thing is that relations will be created automatically when you
define foreign keys using SQL relations. I recommend for example software
“MySQL Workbench” 
which is freeware. It allows you to design your DB including SQL relations using
graphical tool (ER diagram). You can also enter default data to your tables.
It’s very comfortable mainly when you need to delete DB and create it again,
or when it has to be redesigned. You see everything on one screen.
![MySQL Workbench screenshot](http://racky.wz.cz/yii_manual/imgs/workbench.gif
"MySQL Workbench screenshot")
Image 2) MySQL Workbench in action - ER creation
To create relation between 2 tables, create first the tables. Then you will need
only 1 button from the toolbar that’s on the left side of the screen. It’s
the one on the bottom. Its caption is “Place relation using existing
columns”. No other relations will be needed. Click this button and you will be
asked to select FK column in any table. Select it and click the button in
the black box that appeared few seconds ago. Then you click
appropriate PK column in another table and you’re done with this relation.
"MySQL Workbench Toolbar")
![MySQL Workbench "Pick relation"
"MySQL Workbench "Pick relation" msgbox")
When you’re done with DB design, you just export the whole DB into an SQL script and paste it to your DB editor (for example PhpMyAdmin), or in new
version you can export DB directly to MySQL using shortcut Ctrl+G I
think. Finally you run the command “yiic shell” and create models. Simple
I recommend that you go to menu Tools / Options and set “History size” to ca
10-30 steps. Default value is 0, which means unlimited number of undo steps. But
it slows down the application very very much.
In versions released in year 2011 I noticed their instability under Win XP SP3.
So be patient.
![MySQL Workbench screenshot](http://racky.wz.cz/yii_manual/imgs/workbench1.jpg
"MySQL Workbench screenshot")
#### 5.2.1. Run Yiic shell
When your DB is ready, set the DB connection in file
yourProject/protected/config/main.php. Than go to your web-project folder using
Command line and write command: yiic shell. It will enable the Yii console and
you will be able to create model for 1 table like this: model tableName, or for
all tables at once like this: model *
You can use command: “crud TableName” to generate administration for our
table. Than you can, of course, change generated
forms and web pages to fit your requirements.
#### 5.2.2. Define relations in models manually
Now, when you created models for all tables, it may be necessary to define relations (if they
were not generated automatically or when you need more of them). This
can be done using function relations() in model file.. see the
[video], time 12:15 or manual .
What is the
relation? As I wrote above, it’s an SQL Join.
You specify Primary key (PK) and foreign key (FK) using these relations
Yii can then “tunnel” from Employee to his job description via Jobs FK
in the Employees table.
When you make
relation from list of employees to their
jobs and name this relation ‘job’, you can
then write this in Controller to get employee’s job:
$Employee = Employees::model()->findByPk($employeeId);
$myJobName = $Employee->job->jobName;
Employees = model of table created using yiic shell.
jobName = column in Jobs table.
job = relation name.
$Employee = 1 returned record from table Employees - only one because we were
searching by PK. If we searched using findAll() it would return list of records
and it would be necessary to walk through them using foreach.
In your model should be cca this function:
public function relations()
'job' => array(self::BELONGS_TO, 'JobsTableName', 'id_job'),
But I’m not sure with the BELONGS_TO. Second
possibility is HAS_ONE. See links and explanations. And as I am never
sure, I recommend to specify relations in DB a generate them using command
### 5.3. How to create your first controller
You just need one file in folder: protected /
controllers. The file must be named like
this: “NameController.php”. First letter of the Name is upper case as same
as the first letter of Controller. It’s necessary for Linux servers.
Example. You want to create controller named “My first”. The filename will
And what’s inside?
class MyfirstController extends Controller
public function actionIndex()
… here is your code for this action …
public function actionMyaction()
… here is your code for this action …
public function getEmployeeName()
As you can see, controller is a Class and contains definitions of action and
non-action functions. Default and important action is actionIndex(); It’s used
when you don’t specify any action in “r” parameter (as mentioned above).
You can add any action you want. For example “My action” as shown
above. The “r” parameter of “actionMyaction”
would look like this:
What does mean the row where is written following?
It tells the action to run a view. View is the part of your application,
where you use HTML, CSS formatting etc. and it’s used to show anything to
user. Vide infra. (You can also try function renderPartial() – can
Yii will look for this view in folder Views/Myfirst. Where “Myfirst” is name
of controller. Yes, every controller has its own set (folder) of views.
#### 5.3.1. Controller - Notes from praxis
In controller, you may want to use a Session so you can send
data among scripts without using forms, POST or GET. (Session is a PHP term, use
Google to understand) If you want to use session in Yii, you just write this:
Yii::app()->session[“varName”] = $value; That’s it. Session variable will be automatically registered, session
will be started, etc.
22.214.171.124. USING RELATIONS
If you use relations, you can
access one table from another one using command like this:
$employees = $department->get_employees; //(get_employees = relation name)
You can also specify which employees you want to get - by DB column name:
Or you can join tables and order it by any column:
and relation2.tableColumnName = 3', 'order'=>'relation1.tableColumnName'));
Explanation: Model named MainMenu has relation named “relation1” which is
pointing to another model (to another table in DB). The target model has
relation named “relation2” referring to a third table. Using following
command we join 3 tables:
126.96.36.199. SETTING HTML PAGE TITLE
Every action in every controller does something different. So it’s good to set
page title in every action. You can do this by this command:
$this->pageTitle = ‘My page title’
If you want to use your project name in this title or anywhere else, you can use
this system variable:
It’s value is set in file: protected/config/main.php
### 5.4. View
View is a very simple thing so I will just show some "tricks".
#### 5.4.1. Grouped drop down list
Html code can be generated semi-automatically using static class CHtml. You
can create for example drop-down-list like this:
Instead of this:
<select name="selectName" id="selectName">
You can write this:
echo CHtml::dropDownList($name, $select, $data, $htmlOptions);
• $name = name that will be used in $_POST when
form is send
• $select = string with selected value
• $data = content - interesting think, see bellow
• $htmlOptions = classical array of attributes:
$data = CHtml::listData( Model::model()->findAll(),'id_item','item_descr' )
Method listData() just generates following array:
array(‘value1’=>’caption1’, ‘value2’=>’caption2’ … )
$data is a set of <option> tags. Basically it’s simple mixed Array with
“name=>value” pairs. This Array can be created automatically using
• $listOfItems = it’s clear, you use for example:
• $valueColumn = what column will be used to
fill the value of <option>
• $captionColumn =
what column will be used to fill the caption of <option>
... to be continued
7. Used links
 Configure Yii:
 Tables in DB:
 Relations between models:
 MySQL Workbench
 Ajax Yii documentation
 Ajax Yii coockbock + discussion
 Mode: method rules()
 Active Record