On Forms, PNGs, WAFiles, and ByteArrays

> I wrote a simple form to upload images to the server, and I would like to
> create thumbnails for them automatically.
>
> The way I ended up doing it is as follows:
>
> saveEntry
>     | aForm newForm |
>
>     " add original file under name blahblahPng or whatever the image type is
> "
>     UGFileLibrary addFileNamed: title,'Png' contents: uploadedFile contents.
>
>     aForm := (PNGReadWriter createAFormFrom: uploadedFile contents) first.
>
>     " create thumbnail and save under name blahblahThumbPng "
>     newForm := aForm scaledToSize: (Point x: 50 y: 50).
>
>     " what I would have liked to do here is add the thumbnail to the file
> library "
>
>     " add item to art section "
>     UGArt addImage: (
>         (UGArtItem
>             title: title path: title,'Png') artist: self session user;
> imageForm: aForm; thumbForm: newForm; yourself
>     ).
>
> As you can see, I ended up using WAImageTag #form: rather than a url from
> the file library (or server directory, preferably). So what I would like to
> know are two things:
>
> 1) Forms are big? So throwing them around is cumbersome?
> 2) Is there a way to convert a Form back to a PNG without the whole mime
> thing?

> Date: Mon, 11 Jan 2010 07:06:35 +0100
> Subject: Re: [Seaside] On Forms, PNGs, WAFiles, and ByteArrays
> From: [hidden email]
> To: [hidden email]
>
> 2010/1/11 Robert Sirois <[hidden email]>:
> > I wrote a simple form to upload images to the server, and I would like to
> > create thumbnails for them automatically.
> >
> > The way I ended up doing it is as follows:
> >
> > saveEntry
> >     | aForm newForm |
> >
> >     " add original file under name blahblahPng or whatever the image type is
> > "
> >     UGFileLibrary addFileNamed: title,'Png' contents: uploadedFile contents.
> >
> >     aForm := (PNGReadWriter createAFormFrom: uploadedFile contents) first.
> >
> >     " create thumbnail and save under name blahblahThumbPng "
> >     newForm := aForm scaledToSize: (Point x: 50 y: 50).
> >
> >     " what I would have liked to do here is add the thumbnail to the file
> > library "
> >
> >     " add item to art section "
> >     UGArt addImage: (
> >         (UGArtItem
> >             title: title path: title,'Png') artist: self session user;
> > imageForm: aForm; thumbForm: newForm; yourself
> >     ).
> >
> > As you can see, I ended up using WAImageTag #form: rather than a url from
> > the file library (or server directory, preferably). So what I would like to
> > know are two things:
> >
> > 1) Forms are big? So throwing them around is cumbersome?
> > 2) Is there a way to convert a Form back to a PNG without the whole mime
> > thing?
>
> I haven't tried it but something along those lines should work:
>
> UGThumbnailLibrary
> addFileNamed: title,'Png'
> contents: (ByteArray streamContents: [ :stream |
> (PNGReadWriter on: stream) nextPutImage: (aForm scaledToSize:
> (Point x: 50 y: 50))])
>
> And then simply linking it with:
>
> html image url: UGThumbnailLibrary / (title,'Png')
>
> Note that WAFileLibrary is not intended for production purposes. We
> recommend you store them on the file system and let Apache do it's
> magic. I can also recommend Smagick for doing the thumbnail. If you
> are on Seaside 3.0 you have the option to let the server save uploads
> directly to the disk without it hitting the image.
>
> [1] http://www.squeaksource.com/SqueakAddOns.html
>
> Cheers
> Philippe
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