Forum Discussion

Qrew Trainee

3 years ago

Thumbnail pictures refreshing slowly

My thumbnail pictures created with this: If(Length([Attachment File])=0,"","<img width=\"30\" src=\""&URLRoot()&"up/"&Dbid()&"/a/r"&[Attachment ID#]&"/e7/v0\"/>") refresh unbearably slowly. When...

APIs and custom code

Ask about Quickbase functionality

MarkShnier__You
3 years ago
OK, try this and see if it eliminates the caching issue. I was able to test this and change the file attachment and the "old" way stayed cached, but the new way immediately used the new image.

"<img src=" & URLRoot() & "up/" & Dbid()
& "/g/r" & QB32Encode([Record ID#])
& "/e" & QB32Encode(12) // 12 is the fid of the file attachment field
& "/va/" & URLEncode([Picture]) // my file field is called [picture]
& " width=30>"

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Mark Shnier (YQC)
mark.shnier@gmail.com
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MarkShnier__You

Qrew Legend

I have a partial answer to avoid caching when the image file name has changed.

The format we all use is this

URLRoot() & "up/" & Dbid() & "/a/r" & [Record ID#] & "/e15/v0/

but if you click an attachment it ill open up with this as the URL

h t t p s://mycompany.quickbase.com/up/xxxxxx/g/rd/ei/va/Mark%20Ski%20Pix.jpeg

I have a theory that
the g is a constant
The rd is r plus the Base32 Encode of the [Record ID#]
The ei is e plus the Base32 encode of the field ID# of the file attachment
the va is a constant
The last part is the URLEncode of the file name.

I will try that when I get a chance, maybe later tonight if i get my real work done first.

If the file path changes then the image would not be cached.

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Mark Shnier (YQC)
mark.shnier@gmail.com
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MarkShnier__You

Qrew Legend

3 years ago

OK, try this and see if it eliminates the caching issue. I was able to test this and change the file attachment and the "old" way stayed cached, but the new way immediately used the new image.

"<img src=" & URLRoot() & "up/" & Dbid()
& "/g/r" & QB32Encode([Record ID#])
& "/e" & QB32Encode(12) // 12 is the fid of the file attachment field
& "/va/" & URLEncode([Picture]) // my file field is called [picture]
& " width=30>"

------------------------------
Mark Shnier (YQC)
mark.shnier@gmail.com
------------------------------

LaszloM
Qrew Trainee
3 years ago
Fabulous!
Thank You very much Mark!

László

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Laszlo M
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MikeTamoush
Qrew Commander
3 years ago
Mark,

Did you finally solve the caching issue?! I will try this as well.....thanks!

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Mike Tamoush
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- MarkShnier__You
  Qrew Legend
  3 years ago
  Yes, I believe I have successfully reverse engineered into the required syntax to access the image by file name name and not just by the current file in the field. I'm recreating the same URL that you get when you click on the file attachment of the image and it opens up in the browser.
  
  ------------------------------
  Mark Shnier (YQC)
  mark.shnier@gmail.com
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  - SimonH
    Qrew Cadet
    3 years ago
    Nice work on the URL breakdown.
    Although after playing around I realized that the actual filename makes no difference in the url, all you need is the part up until the "v"
    The "va" is actually "v" & QB32Encode("file revision number") and so 0 which always points to the latest version is "va". However you can leave all that out entirely and still get the latest version by default.
    
    Another thing i noticed is that if you use the option to restore a files previous version, that does not trigger a record edit or refresh, so the last modified timestamp will not update, and interestingly enough neither will the text value for the image file name.
    This could break Mark's formula as it relies on the correct file name file name changing.
    If however you edit the record to upload a new file the new name will be reflected and the date modified will update. In which case my solution posted above using a cache busting parameter, actually will work even if the file name stays the same
    
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    Simon H
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