Hi Ralph,
Certainly Klaus's approach will work. Here is another that works.
As you know, image files have "signatures" in their headers to identify
what kind of files they are:
https://en.wikipedia.org/wiki/List_of_file_signatures
(the "ISO 8859-1" column)
Once you know the signatures of the image file types you want to allow,
you could do something like this:
on mouseUp
answer file "Pick an image file:"
if it is empty then exit to top
answer isSupportedImage(it)
end mouseUp
function isSupportedImage pPath
# Allow JPG, PNG and GIF images.
put byte 1 to 12 of url ("binfile:" & pPath) into tHeader
switch
case "JFIF" is in tHeader
case "PNG" is in tHeader
case "GIF" is in tHeader
return true
break
default
return false
break
end switch
end isSupportedImage
I have used this approach in projects before and it seems to work reliably.
Phil Davis
On 2/17/20 1:08 PM, Ralph DiMola via use-livecode wrote:
What's the best way to know if I set the filename of an image control and
the file is either not an image or in an unsupported format? I'm getting
https links to unknown images so I check images before app deployment.
After resizing an image is there a way to know the original dimensions? Just
wondering? I now save the original x/y sizes in properties so I know them
after a resize.
Thanks
Ralph DiMola
IT Director
Evergreen Information Services
[email protected]
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Phil Davis
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