Structuring the bundle

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

Let=E2=80=99s start by creating the structure for our Field Type. To mak= e it easier to move around the code, we will to some extent mimic the struc= ture that is used in the kernel. Native Field Types are located inside ezpublish-kernel (in vendor/ezsystems), in the = eZ/Publish/Core/FieldType folder. Each Field Type has its own subfo= lder: TextLine, Email, Url, etc. = We will use a structure quite close to 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 Field Type: Type and Value.


The Type class
The Type contains the logic of the Field Type: validating data, transfor=
ming from various formats, describing the validators, etc.
 A Type class=
 must implement  eZ\Publish\SPI\FieldType\FieldType . It may a=
lso extend the  eZ\Publish\Core\FieldType\FieldType abstract c=
lass.
The Value class
The Value is used to represent an instance of our type within a Content =
item. Each Field will present its data using an instance of the Type=E2=80=
=99s Value class.
 A value class must implement the  eZ\Publish\SP=
I\FieldType\Value  interface. It may also extend the  eZ\Publi=
sh\Core\FieldType\Value  abstract class.