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Adding support for etags in $.ajax() - and simplified the if-modified…

…-since implementation. Thanks to Lawrence for the patch! Closes ticket #4764.
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jeresig committed Jun 15, 2009
1 parent 030ae67 commit 28ab4d32247943e1ae3409b23fe69303df0bc9eb
Showing with 101 additions and 20 deletions.
  1. +18 −20 src/ajax.js
  2. +16 −0 test/data/etag.php
  3. +15 −0 test/data/if_modified_since.php
  4. +52 −0 test/unit/ajax.js
@@ -170,6 +170,7 @@ jQuery.extend({

// Last-Modified header cache for next request
lastModified: {},
etag: {},

ajax: function( s ) {
// Extend the settings, but re-extend 's' so that it can be
@@ -298,10 +299,13 @@ jQuery.extend({
if ( s.data )
xhr.setRequestHeader("Content-Type", s.contentType);

// Set the If-Modified-Since header, if ifModified mode.
if ( s.ifModified )
xhr.setRequestHeader("If-Modified-Since",
jQuery.lastModified[s.url] || "Thu, 01 Jan 1970 00:00:00 GMT" );
// Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
if ( s.ifModified ) {
if (jQuery.lastModified[s.url])
xhr.setRequestHeader("If-Modified-Since", jQuery.lastModified[s.url]);
if (jQuery.etag[s.url])
xhr.setRequestHeader("If-None-Match", jQuery.etag[s.url]);
}

// Set header so the called script knows that it's an XMLHttpRequest
xhr.setRequestHeader("X-Requested-With", "XMLHttpRequest");
@@ -363,16 +367,7 @@ jQuery.extend({
}

// Make sure that the request was successful or notmodified
if ( status == "success" ) {
// Cache Last-Modified header, if ifModified mode.
var modRes;
try {
modRes = xhr.getResponseHeader("Last-Modified");
} catch(e) {} // swallow exception thrown by FF if header is not available

if ( s.ifModified && modRes )
jQuery.lastModified[s.url] = modRes;

if ( status == "success" || status == "notmodified" ) {
// JSONP handles its own success callback
if ( !jsonp )
success();
@@ -467,13 +462,16 @@ jQuery.extend({

// Determines if an XMLHttpRequest returns NotModified
httpNotModified: function( xhr, url ) {
try {
var xhrRes = xhr.getResponseHeader("Last-Modified");
var last_modified = xhr.getResponseHeader("Last-Modified");
var etag = xhr.getResponseHeader("Etag");

// Firefox always returns 200. check Last-Modified date
return xhr.status == 304 || xhrRes == jQuery.lastModified[url];
} catch(e){}
return false;
if (last_modified)
jQuery.lastModified[url] = last_modified;

if (etag)
jQuery.etag[url] = etag;

return xhr.status == 304;
},

httpData: function( xhr, type, s ) {
@@ -0,0 +1,16 @@
<?php
error_reporting(0);
$ts = $_REQUEST['ts'];
$etag = md5($ts);
$ifNoneMatch = isset($_SERVER['HTTP_IF_NONE_MATCH']) ? stripslashes($_SERVER['HTTP_IF_NONE_MATCH']) : false;
if ($ifNoneMatch == $etag) {
header('HTTP/1.0 304 Not Modified');
die; // stop processing
}
header("Etag: " . $etag);
echo "OK: " . $etag;
?>
@@ -0,0 +1,15 @@
<?php
error_reporting(0);
$ts = $_REQUEST['ts'];
$ifModifiedSince = isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) ? stripslashes($_SERVER['HTTP_IF_MODIFIED_SINCE']) : false;
if ($ifModifiedSince == $ts) {
header('HTTP/1.0 304 Not Modified');
die; // stop processing
}
header("Last-Modified: " . $ts);
echo "OK: " . $ts;
?>
@@ -874,6 +874,58 @@ test("data option: evaluate function values (#2806)", function() {
})
});

test("jQuery.ajax - If-Modified-Since support", function() {
expect( 3 );

stop();

var url = "data/if_modified_since.php?ts=" + new Date();

jQuery.ajax({
url: url,
ifModified: true,
success: function(data, status) {
equals(status, "success");

jQuery.ajax({
url: url,
ifModified: true,
success: function(data, status) {
equals(status, "notmodified");
ok(data == null, "response body should be empty")
start();
}
});
}
});
});

test("jQuery.ajax - Etag support", function() {
expect( 3 );

stop();

var url = "data/etag.php?ts=" + new Date();

jQuery.ajax({
url: url,
ifModified: true,
success: function(data, status) {
equals(status, "success");

jQuery.ajax({
url: url,
ifModified: true,
success: function(data, status) {
equals(status, "notmodified");
ok(data == null, "response body should be empty")
start();
}
});
}
});
});

}

//}

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