Is this a proper Content-Type header

apache-2.2http-headers

I have a pretty good understanding of the Content-Type header for most cases. I understand that for the following four examples, you would normally follow the MIME-type with charset=your-charset-here.

Content-Type "text/plain; charset=utf-8"
Content-Type "text/html; charset=utf-8"
Content-Type "text/javascript; charset=utf-8"
Content-Type "text/xml; charset=utf-8"

… and with images, no charset:

Content-Type "image/gif"
Content-Type "image/x-icon"
etc.

But what about these two? Should they or shouldn't they include the charset?

Content-Type "application/x-javascript"
Content-Type "application/xml"

I realize it's okay if they don't include the charset, but I would like to include it, if it's possible. They are just text-based files, after all.

Best Answer

Content-Type "text/xml; charset=utf-8"

This is redundant. For XML, the <?xml?> declaration takes precedence over the Content-Type header. If the XML Declaration is omitted you've got UTF-8 anyway.

I would normally leave the charset out for XML. Given that XML has its own perfectly good inline character encoding mechanism, the Content-Type header is unneeded and can only get in the way by accidentally choosing the wrong type for files without an encoding specified that are treated as UTF-8 everywhere else.

The one time you do need a charset parameter for XML is when you're serving a non-ASCII-compatible character set, usually UTF-16, where otherwise the parser wouldn't get as far as reading <?xml. But it's pretty rare you'd ever want to do that. UTF-16 isn't a great file storage/over-the-wire format.

Content-Type "application/xml"

The application/xml media type is specified by RFC3023, and a charset parameter has been explicitly defined for it. So you can use charset if you want (though as per the above, I generally don't want).

Content-Type "application/x-javascript"

Is an unofficial type so there is no specification to say whether a charset parameter exists or what it might do. This type should probably be avoided in favour of text/javascript (traditional) or application/javascript (defined by RFC4329).

In practice, setting a charset on your JavaScript resources isn't necessarily enough, as IE completely ignores it.

Summary of the precedence (highest to lowest) given to scripting character set mechanisms:

IE: <script charset> attribute, charset of parent page
Opera: charset of script file, charset of parent page
Mozilla, Webkit: charset of script file, <script charset> attribute, charset of parent page

Related Solutions

Tomcat – Apache2 – mod_expire and mod_rewrite not working in httpd.conf – serving content from tomcat

Probably the ProxyPass / directive you have in your config routes all requests to the Tomcat backend, bypassing all your mod_rewrite directives. You can try to remove the ProxyPass directive and use RewriteRule with the [P] flag after your other rewrites:

mod_rewrite: P|proxy

For the expire headers the situation is worse — in another similar question a solution was not found.

Option +FollowSymLinks would be needed for using mod_rewrite in .htaccess files; in your case it is not required, because you can put everything in the Apache config. Moving rules from config to .htaccess is pointless and can only make things slower. However, there is an important difference between .htaccess and the Apache config — in .htaccess patterns in RewriteRule are matched against relative filesystem paths (which never start with /), while in the VirtualHost context these patterns are matched against the URL path after the hostname, which always starts with /. Therefore at least one of your rules is incorrect:

RewriteRule ^content/(js|css)/([a-z]+)-([0-9]+)\.(js|css)$ /content/$1/$2.$4

should be

RewriteRule ^/content/(js|css)/([a-z]+)-([0-9]+)\.(js|css)$ /content/$1/$2.$4

(note the additional slash in the beginning).

Iis – Force encoding with IIS 7

You can manually set the content type for specific file extensions in the web.config file for each web site where this is needed. In the root for the site, find the web.config file and add the remove and mimeMap lines as below (or create the entire file if it doesn't already exist).

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <staticContent>
            <remove fileExtension=".html" />
            <mimeMap fileExtension=".html" mimeType="text/html; charset=UTF-8" />
        </staticContent>
    </system.webServer>
</configuration>

Sample taken from a discussion on the IIS Forums which addressed this question.

Best Answer

Related Solutions

Tomcat – Apache2 – mod_expire and mod_rewrite not working in httpd.conf – serving content from tomcat

Iis – Force encoding with IIS 7

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