3 ms·

I can't upvote you enough. Too few people realize that the server returned mimetype actually tells the browser how to handle the content.

Terretta 12y ago
Oh how I wish that were true. It's what's intended, but it's not what's true. Usually this bites on video, but it even bites on, say, SVG: http://stackoverflow.com/questions/10261460/internet-explorer-ignoring-mime-type http://stackoverflow.com/questions/10261460/internet-explore... Ostensibly, this is to protect users. Quoting TechNet: When files are served to the client, Internet Explorer uses the following pieces of information to decide how to handle the file: 1. File name extension, the corresponding ProgID and CLSID for the registered handler of that file name extension. 2. Content-Type from the HTTP header (MIME type), the corresponding ProgID, and CLSID for the registered handler of that Content or MIME type. 3. Content-Disposition from the HTTP header. 4. Results of the MIME sniff. -- http://technet.microsoft.com/en-us/library/cc787872(v=ws.10).aspx http://technet.microsoft.com/en-us/library/cc787872(v=ws.10)...
- simoncion 12y ago
  If IE chooses to use file extension over MIME type, then it is broken and should be ignored. Yes, I'm aware that this is probably a workaround for broken web servers, or brain-dead server admins. This workaround should never have been deployed, as it breaks interactions with non-broken web servers.
  - Arnavion 12y ago
    It's not just IE that plays loose like this. Chrome will ignore even the Content-Type header if it can see the content is an audio or video file. For example, upload a .wav to puush and open it in FF and Chrome. FF will show a dump of the bytes interpreted as text because the server sent it with Content-Type: text/plain. Chrome will show an <audio> element. You can't call either browser broken here. One is doing what the spec says is correct. The other is doing what the user says is correct.

Terretta 12y ago

Oh how I wish that were true. It's what's intended, but it's not what's true. Usually this bites on video, but it even bites on, say, SVG: http://stackoverflow.com/questions/10261460/internet-explorer-ignoring-mime-type http://stackoverflow.com/questions/10261460/internet-explore... Ostensibly, this is to protect users. Quoting TechNet: When files are served to the client, Internet Explorer uses the following pieces of information to decide how to handle the file: 1. File name extension, the corresponding ProgID and CLSID for the registered handler of that file name extension. 2. Content-Type from the HTTP header (MIME type), the corresponding ProgID, and CLSID for the registered handler of that Content or MIME type. 3. Content-Disposition from the HTTP header. 4. Results of the MIME sniff. -- http://technet.microsoft.com/en-us/library/cc787872(v=ws.10).aspx http://technet.microsoft.com/en-us/library/cc787872(v=ws.10)...

simoncion 12y ago
If IE chooses to use file extension over MIME type, then it is broken and should be ignored. Yes, I'm aware that this is probably a workaround for broken web servers, or brain-dead server admins. This workaround should never have been deployed, as it breaks interactions with non-broken web servers.
- Arnavion 12y ago
  It's not just IE that plays loose like this. Chrome will ignore even the Content-Type header if it can see the content is an audio or video file. For example, upload a .wav to puush and open it in FF and Chrome. FF will show a dump of the bytes interpreted as text because the server sent it with Content-Type: text/plain. Chrome will show an <audio> element. You can't call either browser broken here. One is doing what the spec says is correct. The other is doing what the user says is correct.