Menu Action
                There are two methods In Odoo for navigating to different pages. Both the user interface and the code can be used to generate menus. You add menus and associated actions using XML based upon the code. Therefore, inside the views folder, you should create a new XML file.
                Menu:
                The menu item tag can be used to create new menus. The attribute name specifies how the menu's name will be displayed. Additionally, you can provide the menu's sequence, which refers to the order in which you want the menu to appear. Only if the menu item or any of its submenus has an action will it appear on the screen.
                For example:
                <menuitem id="menu_root_hospital" name="Hospital Management"/>
                
                   
                
                Sub Menu
                You can create a submenu for the main menu. For creating a submenu, a parent menu is required.
                For example:
                <menuitem id="menu_hospital_menu" name="Hospital" action="hospital_action" parent="menu_root_hospital"/>
<menuitem id="menu_patient_menu" name="Patient" action="patient_action"
        parent="menu_hospital_menu"/>
                Two submenus are here. The main menu has a hospital submenu.
The Hospital menu includes Hospital Management and Patients.
Patient menus have actions, so when a menu item is clicked, the accompanying action is displayed.
                
                   
                
                Next is to define the action. The menu or its submenu should have an action for viewing the menu.
                For example:
                <record id="patient_action" model="ir.actions.act_window">
            <field name="name">Patient</field>
            <field name="res_model">patient.info</field>
            <field name="view_mode">tree,form</field>
            <field name="help" type="html">
            <p class="o_view_nocontent_smiling_face">No patients     found. Let's create one!</p>
          <p>To get things done, use activities and status on    patients.</p>
         </field>
         </record>
                    From the action:
                    name: Name of the action
                    res_model: Name of the action
                    view_mode: The viewing mode, in this case, list and form and must desire to provide views that correspond to the view modes.
                    Help: If there is no data, a message inside the help will be displayed.
                    Menus from The UI:
                    Using the user interface, it is also able to construct and modify menus and submenus. For that, Go to > Settings > Technical > User Interface > Menu Items. 
                    
                     
                    
                    To create a menu from the UI, Go to > Menu Items > Create  
                    
                     
                    
                    Here to create a menu in the new module hospital_management,
                    Menu - Name of the menu
                    Parent Menu -  The parent menu
                    Sequence -  Sequence of the menu item.
                    Action -  Specify the action.
                    Access Rights  -   Giving access privileges allows you to restrict access to a certain user group
                    Submenus -  You can add a submenu here if you want to expand the menu. When you visit the corresponding module after saving the form, the menus are now visible.
                    
                     
                    
                    In this menu, Report is a recent addition.
                    In this manner, the UI can be used to construct new menus and submenus.
                    Widgets
                    There are two options for accessing different pages in Odoo. Both the user interface and the code can be used to generate menus. You add menus and associated actions using XML, according to the code. Therefore, inside the views folder, you should first create a new XML file.
                    widget="many2many_checkboxes"
                    
                     
                    
                    2. Status bar
                    Use this widget to display the status. Code is 
                    widget="statusbar"
                    
                     
                    
                    3. Percentpie
                    This widget will display the progress chart. The code is
                    
                     
                    
                    4. Guage
                    Similar to the percentpie widget, this one also allows you to enter a maximum value in the max field.
                    For example:
                    <field name="int_field" widget="gauge" options="{'max_field': 'another_int_field'}"/>
                    5. Progressbar
                    By using this widget, you will get the progress. You can use the 
                    widget="progressbar"
                    
                     
                    
                    6. Many2many Tags
                    It will display multiple items as tags. Code is 
                    widget="many2many_tags"
                    
                     
                    
                   7. Handle
                   By using this widget, you can drag the lineup and down. You can use the code 
                   widget="handle"
                   
                     
                   
                  8. Many2many Binary
                  You can attach files by using this widget. Code is 
                  widget="many2many_binary" 
                  9. Selection
                  It displays a list of items by using the code 
                  widget="selection" 
                  10. Radio
                  This widget is used to get the radio button effect. Code is 	 
                  widget="radio" 
                  
                    