Power Apps – Adding a file to the library – SharePoint REST API

As in the previous example, we will need the add attachments control. The difference is that we no longer need the form. The control can be copied from any list editing form and saved outside of it.

We add the Attachments control to the application. We’ll call it:

AttachedFile

Add an IMAGE control. It does not have to be visible in the interface, it will be used without user intervention.

We add the IMAGE control to the application. Let it be called:

ImageHelper

The Image property of the ImageHelper control, the ImageHelper.Image value, is set to:

Last(AttachedFile.Attachments).Value

The above code takes into account only the last of the attachments added with the control.

If a maximum of one file is to be handled, it is worth changing the value of MaxAttachments in the AttachedFile control to 1

When we plan to handle many files, the presented solution should be adjusted accordingly.

We also need a button that will place the file in the document library.

We add a BUTTON control to the application.

What is important to us is what is in its properties

OnSelect

Data preparation

Set(
    varRawJSON,
    JSON(ImageHelper.Image, JSONFormat.IncludeBinaryData)
);


Set(
    varBase64File,
    Mid(
        varRawJSON,
        Find(",", varRawJSON) + 1,
        Len(varRawJSON) - Find(",", varRawJSON) - 1
    )
);

The goal of the code is to get a pure base64 format for the contents of the file. For a txt file with content like the code above, the variables will be:

varRawJSON

"data:text/plain;base64,U2V0KA0KICAgIHZhclJhd0pTT04sDQogICAgSlNPTihJbWFnZUhlbHBlci5JbWFnZSwgSlNPTkZvcm1hdC5JbmNsdWRlQmluYXJ5RGF0YSkNCik7DQoNCg0KU2V0KA0KICAgIHZhckJhc2U2NEZpbGUsDQogICAgTWlkKA0KICAgICAgICB2YXJSYXdKU09OLA0KICAgICAgICBGaW5kKCIsIiwgdmFyUmF3SlNPTikgKyAxLA0KICAgICAgICBMZW4odmFyUmF3SlNPTikgLSBGaW5kKCIsIiwgdmFyUmF3SlNPTikgLSAxDQogICAgKQ0KKTsNCg=="

varBase64File

U2V0KA0KICAgIHZhclJhd0pTT04sDQogICAgSlNPTihJbWFnZUhlbHBlci5JbWFnZSwgSlNPTkZvcm1hdC5JbmNsdWRlQmluYXJ5RGF0YSkNCik7DQoNCg0KU2V0KA0KICAgIHZhckJhc2U2NEZpbGUsDQogICAgTWlkKA0KICAgICAgICB2YXJSYXdKU09OLA0KICAgICAgICBGaW5kKCIsIiwgdmFyUmF3SlNPTikgKyAxLA0KICAgICAgICBMZW4odmFyUmF3SlNPTikgLSBGaW5kKCIsIiwgdmFyUmF3SlNPTikgLSAxDQogICAgKQ0KKTsNCg==

I initialize the FolderName variable

In the same way, I initialize the variables FileName and FileContent

I’m replacing FileContent into binary form

base64ToBinary(variables('FileContent'))

Calling SharePoint REST API and uploading the file to the server

Finally, it is worth downloading the call result and returning to the application, for example, the URL of the newly added file

Our code in the OnSelect action is supplemented by calling the Power Automate flow

Set(
    var_ReturnValue,

        UploadFile_by_SharePointRESTApi.Run(

            "Documents_Library_Name",
            Last(AttachedFile.Attachments).Name,
            varBase64File
            
        ).serverrelativeurl

);