PHP/Flash Upload

Toot4fun

I have a page on my site where I allow users to upload files. In addition to the actual file, the user is required to enter data about the file (keyword(s), description, etc). The page that I have now is 100% PHP and does almost everything that I need - data validation, SQL INSERT, file upload, etc. However, my problem with the current setup is this: I have imposed a 5MB limit on the uploaded files. Unfortunately, PHP does not have access to the local file system, so it is unable to check the file size before the upload. PHP has to upload the file to the server, then determine if it's too large. If a user selects a 100MB file, this entire file has to get uploaded before the user knows that it's too large (this usually times out anyway, but you see my point).

After doing some research, it seems like I'll have to use another langauge (Flash in my case) to get the file size before the upload. Since I'm not a Flash programmer, this has been a little more challenging than I had anticipated. What I would like to do is keep the keyword and description fields as regular HTML <input>s and only have the file selection be in Flash. I found a few examples of this integration, but when I try to do the same with my page, the file does not get uploaded.

Does anyone have any experience with this scenario?

Thanks!!

MarkR

You can't bypass the security restrictions inherent in the browser. You aren't allowed to inspect local files in any way, even determine if they exist, in Javascript, Flash, or anything else client-side.

Unfortunately due to limitations of the HTTP protocol you can't tell how big a file is either before it's uploaded. If the user hits the web server's post-payload limit, the web server has no mechanism to report an error (this would violate HTTP), so it just has to abort the connection.

You can use the occasionally-supported method of using a specially named hidden field to hint to the browser as to the maximum upload size, but not all browsers will honour this (hopefully some do). If the browser ignores it, then the user will get an uninformative error (such as "connection reset").

Mark

Toot4fun

Unless I misunderstood what you meant, I would have to disagree with what you said about not being able to inspect local files in any way, because I have already accomplished this with Flash 8. With my movie, the user is able to browse their local file system and select a file. I have code in the onSelect() event that checks the size of this file (.size property). If it's greater than 5242880 (5M😎, then a message is presented to the user and the upload button remains disabled. If the file is less less than or equal to 5MB, the user is allowed to submit.

void_function

As Mark has noted, you can supply MAX filesize as a hint to the browser (value is in bytes), before the input field that accepts the file:

I am not sure, but I think PHP checks internally for the MAX_FILE_SIZE variable and rejects upload if the file is too big, so your users will not upload in vain. Do some experimenting.