Is it possible to get document id of uploaded file(a!fileUploadField()) within same interface without submitting a form?

Can you describe why you would want to do this? You can get a temporary ID immediately after uploading on a form by using the saveInto on your file upload field. However, the document won't be stored in Appian until the form is submitted, so the ID would be meaningless without submitting the form.

Can you describe why you would want to do this? You can get a temporary ID immediately after uploading on a form by using the saveInto on your file upload field. However, the document won't be stored in Appian until the form is submitted, so the ID would be meaningless without submitting the form.

When user upload excel file i need to read that excel file and show the data in grid without submitting a form

Ah okay, that isn't possible. Since the file isn't uploaded until form submit, you can't access any data from the file until they submit. One thing you could do is to create multiple forms that are activity chained together: https://docs.appian.com/suite/help/latest/Process_Model_Recipes.html#using-activity-chaining-to-display-multiple-forms-in-succession

Your first form could include the file upload and a "Next" button. Then, that button would submit the form, you could extract the data from the excel file in process and then display it on the next form that you have chained to it. It's not quite as elegant as displaying the data immediately after upload, but it would probably still work.

Hello Peter Lewis is there any other way on achieving this today? Is it possible to call a process using a!startProcess in the fileUpload saveInto, pass the document, store it and then access it in the Appian interface?

That sounds potentially over complicated - what's your use case?

It won't work by calling a!startProcess on the saveInto because the document won't exist until the original form is complete. I second Mike's question - what's your use case here?