AddField
========

.. code-block:: yaml

   addField:
     field: "private int x"
     target: "parentClass"

.. contents::

Description
-----------

Sensei provides the ``addField`` action to add a field to a class.

Configuration options
---------------------

field
~~~~~

This is simply the code for the field to add. When the action is executed, Sensei does a quick parse to
see if a field with the same name already exists. If that is the case, the action will have no effects.

A trailing semicolon does not have to be included in this code.

.. _addFieldPositionExampleOfTargetInAction:

position
~~~~~~~~

The ``position`` option allows configuring the place where the field will be inserted. This can be
``top`` for at the top of the class, or ``before`` or ``after`` to place it before or after an element
that matches a given specification, respectively.

When using ``before`` or ``after``, the ``fallback`` property can be supplied to configure a fallback
behavior that will be used when the given specification does not match. Each fallback can have another
fallback.

.. code-block:: yaml

    availableFixes:
    - name: "Add field"
      actions:
      - addField:
          field: "private int example;"
          position:
            after:
              field:
                name: "logger"
            fallback:
              top: {}

When the ``position`` option is not specified, or none of the given positions and fallbacks are
available, the most appropriate location will automatically be determined by sets of predefined default
positions as listed below.

Defaults
^^^^^^^^

There are 2 sets of defaults, based on the detected type of the field to insert.

a) If the field to insert has a ``static`` modifier:

  1) after the last static field
  2) if none, before the first static method
  3) if none, before the first field
  4) if none, before the first method or constructor
  5) if none, after the opening brace of the class

b) If the field to insert does not have a ``static`` modifier:

  1) after the last non-static field
  2) if none, before the first constructor or non-static method
  3) if none, after the last static field
  4) if none, after the last static method
  5) if none, after the opening brace of the class

target
~~~~~~

Fields can only be added to classes, so the target will always be either ``parentClass`` or, when the
marked element is a class, ``self``.