RE: max file size - validator - javascript
Its to do with the browser security manager, in i.e. anyway, you can't script the File field in any fashion with regards to file location, size etc.. You'll need to write an applet and do some io to do the checking if you need to validate client side. In Netscape their are ways round this with special javascript functions that have access to disk client side. Devedge.com is where I was reading this. However in a public domain the lowest common denominator is what your looking for. The problem with the applet is if you have more fields than just a file field to submit then your going to want to have the applet make the actual http post. Once it validates your file field it can call a javascript function which can then pass the rest of the form element values into the applet for posting to your server. You won't be able to do the reverse, again due to the security manager. -Original Message- From: Joe Germuska [mailto:[EMAIL PROTECTED] Sent: 24 January 2005 15:22 To: Nathan Coast; Struts Users Mailing List Subject: Re: max file size - validator - javascript At 3:01 PM +0800 1/24/05, Nathan Coast wrote: >Hi, > >Does the validator support max file size for an uploaded file? I >have found various threads covering how to specify the max file size >and how to check if it is exceeded but this all seems to be >server-side and outside of the validator mechanism >e.g. >http://www.mail-archive.com/user@struts.apache.org/msg12942.html > >I'm not even sure if it is possible to find the size of a file >upload within javascript. Obviously if it isn't possible from >javascript, it can't be implemented in the validator (not in the >client at least). I don't believe there is any standard client-side mechanism for enforcing something like this. Here's an unauthoritative reference: http://www.cs.tut.fi/~jkorpela/forms/file.html#restr Interestingly, the original File upload RFC (1867) suggested that the meaning of "maxlength" in a "file" type input element be used as a hint to the maximum acceptable upload size. However, the HTML 4 spec clearly says that in this context, "maxlength" refers to the length of the file path (a silly thing to enforce, since the client-side file path should be immaterial to the server.) Furthermore, I would think there would be scoping/timing problems, as before the form is submitted, the browser wouldn't want to fool with the file, because it might be lag-inducing, and once the form is submitted, there's no longer a chance for JavaScript to execute. Seems like a shortcoming of the spec to not permit page authors to specify this in the tag, but it's probably because they didn't want to clutter the element spec with too many modal details. (Although there is the rarely-used "accept" element which is supposed to accept an enumeration of permitted MIME types for the upload.) Joe -- Joe Germuska [EMAIL PROTECTED] http://blog.germuska.com "Narrow minds are weapons made for mass destruction" -The Ex - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: max file size - validator - javascript
At 3:01 PM +0800 1/24/05, Nathan Coast wrote: Hi, Does the validator support max file size for an uploaded file? I have found various threads covering how to specify the max file size and how to check if it is exceeded but this all seems to be server-side and outside of the validator mechanism e.g. http://www.mail-archive.com/user@struts.apache.org/msg12942.html I'm not even sure if it is possible to find the size of a file upload within javascript. Obviously if it isn't possible from javascript, it can't be implemented in the validator (not in the client at least). I don't believe there is any standard client-side mechanism for enforcing something like this. Here's an unauthoritative reference: http://www.cs.tut.fi/~jkorpela/forms/file.html#restr Interestingly, the original File upload RFC (1867) suggested that the meaning of "maxlength" in a "file" type input element be used as a hint to the maximum acceptable upload size. However, the HTML 4 spec clearly says that in this context, "maxlength" refers to the length of the file path (a silly thing to enforce, since the client-side file path should be immaterial to the server.) Furthermore, I would think there would be scoping/timing problems, as before the form is submitted, the browser wouldn't want to fool with the file, because it might be lag-inducing, and once the form is submitted, there's no longer a chance for JavaScript to execute. Seems like a shortcoming of the spec to not permit page authors to specify this in the tag, but it's probably because they didn't want to clutter the element spec with too many modal details. (Although there is the rarely-used "accept" element which is supposed to accept an enumeration of permitted MIME types for the upload.) Joe -- Joe Germuska [EMAIL PROTECTED] http://blog.germuska.com "Narrow minds are weapons made for mass destruction" -The Ex - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: max file size - validator - javascript
On Mon, 24 Jan 2005 15:01:37 +0800, Nathan Coast <[EMAIL PROTECTED]> wrote: > Hi, > > Does the validator support max file size for an uploaded file? I have > found various threads covering how to specify the max file size and how > to check if it is exceeded but this all seems to be server-side and > outside of the validator mechanism > e.g. > http://www.mail-archive.com/user@struts.apache.org/msg12942.html The validator mechanism is server side, or client side, so it will work. > > I'm not even sure if it is possible to find the size of a file upload > within javascript. Obviously if it isn't possible from javascript, it > can't be implemented in the validator (not in the client at least). > > cheers > Nathan > -- > Nathan Coast > Managing Director > Codeczar Ltd > mob : (852) 9049 5581 > tel : (852) 2834 8733 > fax : (852) 2834 8755 > web : http://www.codeczar.com > > - > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
max file size - validator - javascript
Hi, Does the validator support max file size for an uploaded file? I have found various threads covering how to specify the max file size and how to check if it is exceeded but this all seems to be server-side and outside of the validator mechanism e.g. http://www.mail-archive.com/user@struts.apache.org/msg12942.html I'm not even sure if it is possible to find the size of a file upload within javascript. Obviously if it isn't possible from javascript, it can't be implemented in the validator (not in the client at least). cheers Nathan -- Nathan Coast Managing Director Codeczar Ltd mob : (852) 9049 5581 tel : (852) 2834 8733 fax : (852) 2834 8755 web : http://www.codeczar.com - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
