svn commit: r1586444 - /httpd/httpd/trunk/docs/manual/mod/mod_headers.html.en

[co...@apache.org]

Author: covener
Date: Thu Apr 10 19:34:40 2014
New Revision: 1586444

URL: http://svn.apache.org/r1586444
Log:
xforms

Modified:
    httpd/httpd/trunk/docs/manual/mod/mod_headers.html.en

Modified: httpd/httpd/trunk/docs/manual/mod/mod_headers.html.en
URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/docs/manual/mod/mod_headers.html.en?rev=1586444&r1=1586443&r2=1586444&view=diff
==============================================================================
--- httpd/httpd/trunk/docs/manual/mod/mod_headers.html.en (original)
+++ httpd/httpd/trunk/docs/manual/mod/mod_headers.html.en Thu Apr 10 19:34:40 2014
@@ -194,6 +194,12 @@ Header merge Cache-Control no-store env=
         <pre class="prettyprint lang-config">Header set Set-Cookie testcookie "expr=-z %{req:Cookie}"</pre>
 
       </li>
+      <li>
+        Append a Caching header for responses with a HTTP status code of 200
+        <pre class="prettyprint lang-config">Header append Cache-Control s-maxage=600 "expr=%{REQUEST_STATUS} == 200"</pre>
+
+      </li>
+
     </ol>
 </div>
 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
@@ -216,22 +222,22 @@ Header merge Cache-Control no-store env=
     modified.</p>
 
     <p> The optional <var>condition</var> argument determines which internal
-    table of responses headers this directive will operate against.  Other
-    components of the server may have stored their response headers in either
-    the table that corresponds to <code>onsuccess</code> or the table that
-    corresponds to <code>always</code>.  "Always" in this context refers to
-    whether headers you add will be sent during both a successful and unsucessful
-    response, but if your action is a function of an existing header, you
-    will have to read on for further complications.</p>
-
-    <p> The default value of <code>onsuccess</code> may need to be changed to
-    <code>always</code> under the circumstances similar to those listed below.
+    table of responses headers this directive will operate against. Despite the
+    name, the default value of <code>onsuccess</code> does <em>not</em> limit 
+    an <var>action</var> to responses with a 2xx status code.  Headers set under
+    this condition are still used when, for example, a request is <em>successfully</em>
+    proxied or generated by CGI, even when they have generated a failing status code.</p>
+
+    <p>When your action is a function of an existing header, you may need to specify
+    a condition of <code>always</code>, depending on which internal table the
+    original header was set in.  The table that corresponds to <code>always</code> is
+    used for locally generated error responses as well as successful responses.  
     Note also that repeating this directive with both conditions makes sense in
     some scenarios because <code>always</code> is not a superset of
     <code>onsuccess</code> with respect to existing headers:</p>
 
     <ul>
-       <li> You're adding a header to a non-success (non-2xx) response, such
+       <li> You're adding a header to a locally generated non-success (non-2xx) response, such
             as a redirect, in which case only the table corresponding to
             <code>always</code> is used in the ultimate response.</li>
        <li> You're modifying or removing a header generated by a CGI script,
@@ -242,6 +248,10 @@ Header merge Cache-Control no-store env=
             <code>onsuccess</code> condition.</li>
     </ul>
 
+    <p>Separately from the <var>condition</var> paramete described above, you 
+    can limit an action based on HTTP status codes for e.g. proxied or CGI 
+    requests. See the example that uses %{REQUEST_STATUS} in the section above.</p>
+
     <p>The action it performs is determined by the first
     argument (second argument if a <var>condition</var> is specified).
     This can be one of the following values:</p>
@@ -394,8 +404,10 @@ Header merge Cache-Control no-store env=
     <p>Except in <a href="#early">early</a> mode, the
     <code class="directive">Header</code> directives are processed just
     before the response is sent to the network. These means that it is
-    possible to set and/or override most headers, except for those headers
-    added by the HTTP header filter, such as Content-Type.</p>
+    possible to set and/or override most headers, except for some headers
+    added by the HTTP header filter.  Prior to 2.2.12, it was not possible 
+    to change the Content-Type header with this directive.</p>
+
 
 </div>
 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>