Types of Actions

1.Window Actions (ir.actions.act_window)
2.URL Actions (ir.actions.act_url)
3.Client Actions (ir.actions.client)
4.Server Actions (ir.actions.server)
5.Report Actions (ir.actions.report.xml)



Defining Window Actions :


    <!-- actions opening Sinlgle views on models -->
   
    <record model="ir.actions.act_window" id="myodoo.action_window">
      <field name="name">Courses</field>
      <field name="res_model">myodoo.myodoo</field>
      <field name="view_type">form</field>
      <field name="view_mode">tree,form</field>
      <field name="help" type="html">
        <p class="oe_view_nocontent_create">Create the first course
        </p>
      </field>
    </record>

  <!-- actions for Multiple views on models -->

      <record model="ir.actions.act_window" id="project_task_work_window">
      <field name="name">Task work Summary</field>
      <field name="res_model">project.task.work</field>
      <field name="context">{'search_default_group_date_month':1,'search_default_group_user_id': 1}
      </field>
      <field name="view_mode">tree,form</field>
      <field name="search_view_id" ref="view_project_task_work_search_form"/>
            </field>
    </record> 


          <record model="ir.actions.act_window.view" id="view_project_task_work_tree_htp">
              <field name="sequence" eval="0"/>
              <field name="view_mode">tree</field>
              <field name="view_id" ref="view_project_task_work_tree"/>
              <field name="act_window_id" ref="project_task_work_window"/>
          </record>

<record model="ir.actions.act_window.view" id="view_project_task_work_form_htp">
              <field name="sequence" eval="1"/>
              <field name="view_mode">form</field>
              <field name="view_id" ref="view_project_task_work_form"/>
              <field name="act_window_id" ref="project_task_work_window"/>
          </record>  


Actions and menus are regular records in database, usually declared through data files. Actions can be triggered in three ways:
    by clicking on menu items (linked to specific actions)

    by clicking on buttons in views (if these are connected to actions)

    as contextual actions on object

Because menus are somewhat complex to declare there is a <menuitem> shortcut to declare an ir.ui.menu and connect it to the corresponding action more easily.

<record model="ir.actions.act_window" id="action_list_ideas">
    <field name="name">Ideas</field>
    <field name="res_model">idea.idea</field>
    <field name="view_mode">tree,form</field>
</record>
<menuitem id="menu_ideas" parent="menu_root" name="Ideas" sequence="10"
          action="action_list_ideas"/>

Note:The action must be declared before its corresponding menu in the XML file.
Data files are executed sequentially, the action's id must be present in the database before the menu can be created.