Good evening to everyone,
I would like to ask you, how could I customize the file upload code of the relevant form so that, when the user uploads a file, in each activity or resource the file type to be recognized and an appropriate pop-up window be displayed for some predefined file types.
I have noticed that a similar process occurs when uploading a profile picture. If someone uploads e.g.: a PDF file, an error pop-up window is displayed. At this point, a check is performed, during the update/save process. Although, I want it to happen the moment the user uploads a file to the upload field (logically, one step before). Also, I do not want to restrict the file types that can be uploaded, I just want to use the file type recognition process, so that according to this process, the appropriate message to be displayed in a pop-up window.
So far, I have not found the implementation of this procedure.
Thank you in advance, for your answers!