Adding support for etags in $.ajax() - and simplified the if-modified-since implementation. Thanks to Lawrence for the patch! Closes ticket #4764.

This commit is contained in:
John Resig 2009-06-15 13:36:12 +00:00
parent 030ae67715
commit 28ab4d3224
4 changed files with 101 additions and 20 deletions

View file

@ -170,6 +170,7 @@ jQuery.extend({
// Last-Modified header cache for next request // Last-Modified header cache for next request
lastModified: {}, lastModified: {},
etag: {},
ajax: function( s ) { ajax: function( s ) {
// Extend the settings, but re-extend 's' so that it can be // Extend the settings, but re-extend 's' so that it can be
@ -298,10 +299,13 @@ jQuery.extend({
if ( s.data ) if ( s.data )
xhr.setRequestHeader("Content-Type", s.contentType); xhr.setRequestHeader("Content-Type", s.contentType);
// Set the If-Modified-Since header, if ifModified mode. // Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
if ( s.ifModified ) if ( s.ifModified ) {
xhr.setRequestHeader("If-Modified-Since", if (jQuery.lastModified[s.url])
jQuery.lastModified[s.url] || "Thu, 01 Jan 1970 00:00:00 GMT" ); 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 // Set header so the called script knows that it's an XMLHttpRequest
xhr.setRequestHeader("X-Requested-With", "XMLHttpRequest"); xhr.setRequestHeader("X-Requested-With", "XMLHttpRequest");
@ -363,16 +367,7 @@ jQuery.extend({
} }
// Make sure that the request was successful or notmodified // Make sure that the request was successful or notmodified
if ( status == "success" ) { if ( status == "success" || status == "notmodified" ) {
// 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;
// JSONP handles its own success callback // JSONP handles its own success callback
if ( !jsonp ) if ( !jsonp )
success(); success();
@ -467,13 +462,16 @@ jQuery.extend({
// Determines if an XMLHttpRequest returns NotModified // Determines if an XMLHttpRequest returns NotModified
httpNotModified: function( xhr, url ) { httpNotModified: function( xhr, url ) {
try { var last_modified = xhr.getResponseHeader("Last-Modified");
var xhrRes = xhr.getResponseHeader("Last-Modified"); var etag = xhr.getResponseHeader("Etag");
// Firefox always returns 200. check Last-Modified date if (last_modified)
return xhr.status == 304 || xhrRes == jQuery.lastModified[url]; jQuery.lastModified[url] = last_modified;
} catch(e){}
return false; if (etag)
jQuery.etag[url] = etag;
return xhr.status == 304;
}, },
httpData: function( xhr, type, s ) { httpData: function( xhr, type, s ) {

16
test/data/etag.php Normal file
View file

@ -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;
?>

View file

@ -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;
?>

View file

@ -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();
}
});
}
});
});
} }
//} //}