Delete a Customer Record in an MDK App

You will add an action bar item to the Customer Detail page called Trash and link it to an event.

1. In Customers_Detail.page, drag and drop an Action Bar Item to the upper right of the action bar.

   

   Action Bar Item is a button that users can use to fire actions when pressed. You can add an Action Bar Item only to the Action Bar (at the top of the page).

2. Click the link icon to open the object browser for the System Item property.

   Double click the Trash type and click OK.

   

3. Navigate to the Events tab. Click the dotted icon for the OnPress property and select the Create a rule/action.

   

4. Select the Object Type as Rule and keep the default Folders path.

   

   You could link OnPress property directly to OData delete action directly instead to this JavaScript file. Idea of linking to JavaScript file is to let you understand another way to achieve similar functionality.

5. In the Basic Information step, enter the Rule name as Customers_DeleteConfirmation and click Finish to complete the rule creation process.

   

6. Replace the generated code with below snippet.

   JavaScript

   Copy

   /**
   * Describe this function...
   * @param {IClientAPI} context
   */
   export default function Customers_DeleteConfirmation(context) {
       return context.executeAction('/demosampleapp/Actions/Customers_DeleteConfirmation.action').then((result) => {
           if (result.data) {
               return context.executeAction('/demosampleapp/Actions/Customers_DeleteEntity.action').then(
                   (success) => Promise.resolve(success),
                   (failure) => Promise.reject('Delete entity failed ' + failure));
           } else {
               return Promise.reject('User Deferred');
           }
       });
   }
   

   In above code there are references to Customers_DeleteConfirmation.action and Customers_DeleteEntity.action , those don’t exist in your metadata project yet. You will create these actions in next steps.

   

7. In the above rule, double-click on the red line highlighting missing reference for Customers_DeleteConfirmation.action. You will notice a bulb icon suggesting some fixes, click on it, select MDK: Create action for this reference, and click Message Action.

   

8. Provide the below information in the Customers_DeleteConfirmation.action:

   Field	Value
   Message	Delete current entity?
   Title	Delete Confirmation
   OKCaption	OK
   OnOK	--None--
   CancelCaption	Cancel
   OnCancel	--None--

   

   When user taps or clicks the Trash icon on the Customer Detail page, a message will be displayed to confirm if user wants to delete current record. On it’s confirmation, Customers_DeleteEntity.action is executed.

9. Similarly, fix the path reference for the missing Customers_DeleteEntity.action. Switch back to the Customers_DeleteConfirmation.js or open it again if it was closed. Double-click on the red line highlighting missing reference for Customers_DeleteEntity.action. You will notice a bulb icon suggesting some fixes, click on it, select MDK: Create action for this reference, and click ODataService DeleteEntity Action.

   

10. Provide the below information in the Customers_DeleteEntity.action:

    Property	Value
    Service	Select com_sap_edm_sampleservice_v4.service from the dropdown
    EntitySet	Select Customers from the dropdown
    ReadLink	click link icon and double click readLink

    

    This action will store deleted record locally for an offline application or delete directly back to the backed for online applications.

    The readLink is a direct reference to an individual entity set entry.

    You can find more details about Delete Entity Action.

When the above OData action is executed, you may want to display messages on its success and failure behavior. For example, on its success, you may want to display a success message and allow any execution to continue. On its failure, you may want to display an error.

1. In the Customers_DeleteEntity.action, scroll down and expand the Common Action Properties section. Click the link icon to open the object browser for the Success Action and bind it to CloseModalPage_Complete.action.

   

2. Create a message action for displaying a message in case deleting of a customer fails. In the Customers_DeleteEntity.action, click the Create a rule/action icon for the Failure Action.

   

3. Keep the default selection for the Object Type as Action and Folders path.

   

4. In the Template Selection step, choose Message in Category | click Message | Next.

   

5. In the Base Information step, provide the below information:

   Property	Value
   Name	DeleteCustomerEntityFailureMessage
   Type	Select Message from the dropdown
   Message	Delete entity failure - {#ActionResults:Customers_DeleteEntity/error}
   Title	Delete Customer
   OKCaption	OK
   OnOK	--None--
   CancelCaption	leave it blank
   OnCancel	--None--

   

   Customers_DeleteEntity is the Action Result value of the Customers_DeleteEntity.action. This reference is used to pass the results to subsequent actions in the chain. These actions can reference the action result as needed. In this case if there is a failure, you access the error property of the action result to display the OData failure message.

   This is the standard Binding Target Path (also called Dynamic Target Path) syntax used when you need to include a binding with other bindings or within a string as used in the message here.

   You could exclude above expression and can just display a generic message.

6. Click Finish to complete the action creation process.

   When Customers_DeleteEntity.action gets executed successfully then CloseModalPage_Complete.action will be triggered or if Customers_DeleteEntity.action fails then DeleteCustomerEntityFailureMessage.action will be triggered.

You will now deploy the updated project to your MDK client.

Click the Deploy option in the editor’s header area, and then choose the deployment target as Mobile Services .

Make sure you are choosing the right device platform tab above.

You can cross verify if this record has been deleted in the backend.

Backend URL can be found in Mobile Services Cockpit.

Mobile Applications → Native/MDK → click the MDK App myapp.mdk.demo → Connectivity → click Launch in Browser icon

It will open the URL in a new tab, remove ?auth=uaa and add /Customers at the end of the URL.