Upload file and remove the old

Wappler General How To
#1

I have a page to insert record, that works perfectly, with a file field for uploading an PDF (not required)
Then I have a page to update records
My problem, which I could not solve with Wappler, occurs when a new PDF file is chosen for upload
I need to delete the old file from the server, if it exists
I can’t understand if I do to delete it before or after the new upload and how is it better to set the sequence of actions?
Can anyone help me?
Thank you

2019: The Year in Review
#2

If the file has the same name, then just overwrite it:

image
(in File Upload Properties)

If it has a different name, I wouldn’t have thought it would make much difference at what point you delete the old file.

#3

Of course it does not have the same name and theoretically should be eliminated only after successful uploading

#4

In addition to Tom’s reply, if the file names are different:

Before the update, after the upload step, add a condition and check if the file upload uploaded a file. You want to delete the old file if a new one is uploaded:

– Upload step

– Condition (check upload step if it uploaded a file)

THEN

  • run a database query, filter by the record ID you are updating.
  • repeat step (repeats query)
    • if file exists (file name/path from the query)
      • file delete
    • if file doesn’t exist
      • do nothing

ELSE

  • do nothing

Update step and everything else goes here

2 Likes
#5

so is the name stored in a database or is the pdf stored in a unique directory so the file name can be identified easily, you dont say

1 Like
#6

Thank you
I had thought of such a procedure, but now it is clearer to me

1 Like
#7

If it has the same purpose - eg supposing you had a link to a terms page which could be downloaded as a PDF - then it may be best if it does have the same name. In this case, various things are simpler: you just overwrite the old file and don’t need to update links etc… But of course it depends on the circumstances.

#8

It’s true but if it’s the client who uploads the pdf …

#9

That shouldn’t make any difference - just rename the file as it’s uploaded.

Eg I often upload text files to import into a MySQL database. It’s simpler for me if the upload filename is fixed. It doesn’t matter what the original file is called.

1 Like
#10

Yes that’s a great idea indeed :slight_smile:

#11

It’s a nice idea, but each record has a different file
I can rename the file with ID prefix
example -> 3456_filename.pdf

#12

Yes you can use any dynamic expression in the file name template :slight_smile:

#13

One last consideration
Should the file be renamed before uploading or after?

#14

You cannot rename a file BEFORE uploading :slight_smile:
You rename it in the upload step.

#15

Ok but does the rename action overwrite the existing file or is it necessary to delete the old file?

#16

It renames the file you are uploading and saves it with the new name.

#17

Perfect thanks
Another step forward with Wappler

#18

Hi Tom
I’m trying to rename the file when uploading, but obviously my configuration is not correct
These are the two server actions
Do you know where I’m wrong?

37
54

{{$_POST.id}+’_bollo’}.{pdf}

#19

Why not use the template field in the upload step, so you rename the file directly on upload? You don’t need a separate rename step with a file upload.

Also, your expression is wrong.
It should be: {{$_POST.id}}_bollo.{ext}

#20

I didn’t realize that it could be renamed directly.
Perfect but it is necessary to remove the point before the extension, otherwise it is double
But now I have two problems:

  • The file name is not registered in the database
  • Unfortunately the insertion of the record number ID does not work because in fact being an insert page is not yet assigned