This article will describe how you can use List or Library control from the form to create Child elements and bind them to Parent.
This means that you can add new Items or Documents from the Form straight into related SharePoint List or Document Library, and automatically attach them to the current Item or Document with a Lookup. When you open this Item again, you will only see bound elements in List or Library control.
This can serve as alternative to attachments or to create complex relationships between items.
With List or Library control this is very easy to do, just follow the steps described below.
Design forms for both Parent and Child Lists, including New, Edit and Display forms. Document Libraries only need Edit and Display forms.
Do not add the lookup to the Child form, as you don’t want users to change it manually.
Finally, add List or Library control to the Parent forms. In SETTINGS → DataSource, select List: Child List and Lookup Field: Parent lookup.
This will ensure that when you open Parent Edit or Display Form, you will only see connected items in the List or Library control.
Connecting Child to Parent happens automatically, in Edit and Display forms it happens straight away, but in New Form, you must first save Parent and then added items will be tied to Parent. All this happens automatically without any additional configuration.
You can upload multiple documents at once - simply select multiple files on your machine. Uploaded documents also get connected to Parent via Lookup, so this functionality is the same for both Lists and Libraries.