Form OnSave event (Client API reference) in model-driven apps

The OnSave event occurs when:

  • The user selects the Save icon in the lower right corner of the form, even when there is no changed data to be saved.
  • Code executes the method, even when there is no changed data to be saved.
  • The user navigates away from the form and there is unsaved data in the form.
  • The auto-save option is enabled, 30 seconds after data has changed and there is unsaved data in the form.
  • Code executes the method and there is unsaved data in the form.
  • Code executes the method passing a true value as the first parameter and there is unsaved data in the form.

To determine which button was clicked to perform the save, use the getSaveMode method.

You can cancel the save action by using the preventDefault method within the event arguments object. The preventDefault method is accessible by using the getEventArgs method that is part of the execution context. Execution context is automatically passed to the form event handler.

Asynchronous event handler support

The OnSave event has ability to wait for promises returned by event handlers to settle before saving, allowing the OnSave event to be asynchronous ("async").

The OnSave event becomes async when a promise is returned by an OnSave event handler and support is enabled. Enable the support by updating the customization.xml file for the app you want. More information: Enable Async OnSave.

Saving of the record happens when each promise returned by a handler are resolved. For any promises that are returned, there is a 10-second limit for each promise, after that the platform considers promises to be timed out. This timeout is applied per promise. For example, if we have five promises returned, the total wait time is 50 seconds.

If the promise is rejected or timed out, the save operation continues to behave similarly to the current script errors. Use the preventDefault method within the event arguments object in that particular handler if you want to prevent the save event to happen if there is a script error/rejected promise or handler times out.

You can also cancel the save operation irrespective of the error in the handler or not using the preventDefault method within the event arguments object. If this method is called, the Async OnSave event will still wait for all the promises to settle, but the save will not occur. This means the logic within .then() & .catch() will still execute.

The OnSave event will only wait for one promise returned per handler. If multiple promises are required, it is recommended to wrap all the promises in the Promise.all() method and return the single resulting promise. For multiple handlers that all return a promise, we recommend you to create one handler that calls all the events and return a single promise that wraps all required promises. This is to minimize wait times caused by the timeout.

Example scenario on when to use async OnSave handlers

Consider creating a Work Order Service Task, you need to validate that the Customer Asset selected has the same account listed in the Work Order. Fetching the account on the Work Order and Customer Asset are both asynchronous processes and need to be completed before the validation can occur.

In this scenario, since there are multiple async processes and both calls return a single promise by wrapping both in the Promise.all() method.


The preventDefault can only be used synchronously. For example, in the following handler:

function myHandler(context) {
return new Promise((resolve) => {
setTimeout( () => {
}, 1000);

Enable Async OnSave using app setting

An app setting is a platform component that allows you to override a setting on an app. App setting should have a unique name and must be in the format solutionpublisherprefix_appname_settingname.

To enable the async OnSave event handlers for a specific app, add the below XML in the customization.xml file. This should be added in the existing AppModule node in your customization.xml file.

Setting the <value>true</value> enables async OnSave event handler support for that specific app. Any form within this app will be able to get access to the async OnSave functionality.

   <appsetting uniquename="MyAppName_AsyncOnSave">

You can verify that the configuration has been successfully installed using the following request:

GET$filter=(uniquename eq 'MyAppName_AsyncOnSave')
Accept: application/json
Authorization: Bearer ey...

Related article

Grid OnSave Event