On 4/16/08, tedd <tedd.sperling@xxxxxxxxx> wrote: > > At 10:53 AM -0400 4/16/08, Andrew Ballard wrote: > > > On Wed, Apr 16, 2008 at 9:59 AM, tedd <tedd.sperling@xxxxxxxxx> wrote: > > > > > I saw one the other day that caught my eye -- will look into it. > > > > > > > > The first problem I see implementing the approach is the JavaScript > > sandbox. JavaScript is allowed to read the text of the input file > > field (and thus know the file name and path once a file has been > > selected); it cannot access the disk to actually get to the image or > > do anything with it. From here, I'm thinking there are a couple things > > you could do with JavaScript. The first would be to embed the image > > into the web page using an IMG tag, which would allow you to determine > > the pixel dimensions (but not the actual file size). The second would > > be what Gmail seems to do, and actually upload the form to their > > server with some sort of AJAX request, at which time your server could > > return information on the size of the file. However, if the file is > > too large, you're back to the original problem of needing to increase > > the RAM limit in PHP. > > > > The second problem is, as I said, I'm not aware of any JavaScript that > > can manipulate the image. JavaScript can cause the display of an image > > to be resized within the browser, but that doesn't actually affect the > > stored file. I don't know, but I guess if you could actually get to > > the bits, you could probably write an algorithm in JavaScript to > > resize an image by manipulating the bits, but I think it would be > > dreadfully slow if it would even run without running out of resources. > > > > I think the only pure-client options are either Java (which would > > require special permissions to get out of its own sandbox) or ActiveX. > > > > If you know of some other approach, I'd be interested to see how it > > works. > > > > Andrew > > > > > Andrew: > > I think you are right -- I wasn't able to resize the image. Here's the > link that caught my eye, but it doesn't work as described: > > http://javascript.internet.com/forms/image-upload-preview.html > > Cheers, > > tedd > -- > It worked for me using IE on XP. David
