Structuring the bundle

At this point, we have an =E2=80=9Canonymous=E2=80=9D Symfony 2 = bundle.

Let=E2=80=99s start by creating the s= tructure for our FieldType. To make it easier to move around the code, we w= ill mimic to some extent the structure that is used in the kernel. Native FieldTypes are located inside= ezpublish-kernel (in vendor/ezsystems), in the <= /span>eZ/Publish/Core/FieldType folder. Each FieldType has i= ts own subfolder: TextLine<= /span>, Email, Url=E2=80=A6 we will use a structure quite close= from this.

From the tutorial repository, list the contents of the eZ/Publish/FieldType folder:

 eZ
=E2=94=94=E2=94=80=E2=94=80 Publish
   =E2=94=94=
=E2=94=80=E2=94=80 FieldType
       =E2=94=94=E2=94=
=80=E2=94=80 Tweet
           =E2=94=9C=E2=
=94=80=E2=94=80 Type.php
           =E2=94=
=94=E2=94=80=E2=94=80 Value.php

We have the two base classes required= by a FieldType: Type and Value= .

The Type class

The Type contains the logic = of the field type: validating data, transforming from various formats, desc= ribing the validators=E2=80=A6
A type class must implement . It may also extend the eZ\Publish\Core\FieldType\FieldType abstract class.


The Value class
The Value is used to represe=
nt an instance of our type within a Content item. Each Field will present i=
ts data using an instance of the Type=E2=80=99s Value class.
A value class must implement the eZ\Publish\SPI\FieldType\Value<=
/code> interface. It may also extend the=
 eZ\Publish\Core\FieldType\=
Value abstract class.