Caching a jquery ajax response in javascript/browser
cache:true only works with GET and HEAD request.
You could roll your own solution as you said with something along these lines :
var localCache = {
data: {},
remove: function (url) {
delete localCache.data[url];
},
exist: function (url) {
return localCache.data.hasOwnProperty(url) && localCache.data[url] !== null;
},
get: function (url) {
console.log('Getting in cache for url' + url);
return localCache.data[url];
},
set: function (url, cachedData, callback) {
localCache.remove(url);
localCache.data[url] = cachedData;
if ($.isFunction(callback)) callback(cachedData);
}
};
$(function () {
var url = '/echo/jsonp/';
$('#ajaxButton').click(function (e) {
$.ajax({
url: url,
data: {
test: 'value'
},
cache: true,
beforeSend: function () {
if (localCache.exist(url)) {
doSomething(localCache.get(url));
return false;
}
return true;
},
complete: function (jqXHR, textStatus) {
localCache.set(url, jqXHR, doSomething);
}
});
});
});
function doSomething(data) {
console.log(data);
}
Working fiddle here
EDIT: as this post becomes popular, here is an even better answer for those who want to manage timeout cache and you also don't have to bother with all the mess in the $.ajax() as I use $.ajaxPrefilter(). Now just setting {cache: true} is enough to handle the cache correctly :
var localCache = {
/**
* timeout for cache in millis
* @type {number}
*/
timeout: 30000,
/**
* @type {{_: number, data: {}}}
**/
data: {},
remove: function (url) {
delete localCache.data[url];
},
exist: function (url) {
return !!localCache.data[url] && ((new Date().getTime() - localCache.data[url]._) < localCache.timeout);
},
get: function (url) {
console.log('Getting in cache for url' + url);
return localCache.data[url].data;
},
set: function (url, cachedData, callback) {
localCache.remove(url);
localCache.data[url] = {
_: new Date().getTime(),
data: cachedData
};
if ($.isFunction(callback)) callback(cachedData);
}
};
$.ajaxPrefilter(function (options, originalOptions, jqXHR) {
if (options.cache) {
var complete = originalOptions.complete || $.noop,
url = originalOptions.url;
//remove jQuery cache as we have our own localCache
options.cache = false;
options.beforeSend = function () {
if (localCache.exist(url)) {
complete(localCache.get(url));
return false;
}
return true;
};
options.complete = function (data, textStatus) {
localCache.set(url, data, complete);
};
}
});
$(function () {
var url = '/echo/jsonp/';
$('#ajaxButton').click(function (e) {
$.ajax({
url: url,
data: {
test: 'value'
},
cache: true,
complete: doSomething
});
});
});
function doSomething(data) {
console.log(data);
}
And the fiddle here CAREFUL, not working with $.Deferred
Here is a working but flawed implementation working with deferred:
var localCache = {
/**
* timeout for cache in millis
* @type {number}
*/
timeout: 30000,
/**
* @type {{_: number, data: {}}}
**/
data: {},
remove: function (url) {
delete localCache.data[url];
},
exist: function (url) {
return !!localCache.data[url] && ((new Date().getTime() - localCache.data[url]._) < localCache.timeout);
},
get: function (url) {
console.log('Getting in cache for url' + url);
return localCache.data[url].data;
},
set: function (url, cachedData, callback) {
localCache.remove(url);
localCache.data[url] = {
_: new Date().getTime(),
data: cachedData
};
if ($.isFunction(callback)) callback(cachedData);
}
};
$.ajaxPrefilter(function (options, originalOptions, jqXHR) {
if (options.cache) {
//Here is our identifier for the cache. Maybe have a better, safer ID (it depends on the object string representation here) ?
// on $.ajax call we could also set an ID in originalOptions
var id = originalOptions.url+ JSON.stringify(originalOptions.data);
options.cache = false;
options.beforeSend = function () {
if (!localCache.exist(id)) {
jqXHR.promise().done(function (data, textStatus) {
localCache.set(id, data);
});
}
return true;
};
}
});
$.ajaxTransport("+*", function (options, originalOptions, jqXHR, headers, completeCallback) {
//same here, careful because options.url has already been through jQuery processing
var id = originalOptions.url+ JSON.stringify(originalOptions.data);
options.cache = false;
if (localCache.exist(id)) {
return {
send: function (headers, completeCallback) {
completeCallback(200, "OK", localCache.get(id));
},
abort: function () {
/* abort code, nothing needed here I guess... */
}
};
}
});
$(function () {
var url = '/echo/jsonp/';
$('#ajaxButton').click(function (e) {
$.ajax({
url: url,
data: {
test: 'value'
},
cache: true
}).done(function (data, status, jq) {
console.debug({
data: data,
status: status,
jqXHR: jq
});
});
});
});
Fiddle HERE Some issues, our cache ID is dependent of the json2 lib JSON object representation.
Use Console view (F12) or FireBug to view some logs generated by the cache.
I was looking for caching for my phonegap app storage and I found the answer of @TecHunter which is great but done using localCache.
I found and come to know that localStorage is another alternative to cache the data returned by ajax call. So, I created one demo using localStorage which will help others who may want to use localStorage instead of localCache for caching.
Ajax Call:
$.ajax({
type: "POST",
dataType: 'json',
contentType: "application/json; charset=utf-8",
url: url,
data: '{"Id":"' + Id + '"}',
cache: true, //It must "true" if you want to cache else "false"
//async: false,
success: function (data) {
var resData = JSON.parse(data);
var Info = resData.Info;
if (Info) {
customerName = Info.FirstName;
}
},
error: function (xhr, textStatus, error) {
alert("Error Happened!");
}
});
To store data into localStorage:
$.ajaxPrefilter(function (options, originalOptions, jqXHR) {
if (options.cache) {
var success = originalOptions.success || $.noop,
url = originalOptions.url;
options.cache = false; //remove jQuery cache as we have our own localStorage
options.beforeSend = function () {
if (localStorage.getItem(url)) {
success(localStorage.getItem(url));
return false;
}
return true;
};
options.success = function (data, textStatus) {
var responseData = JSON.stringify(data.responseJSON);
localStorage.setItem(url, responseData);
if ($.isFunction(success)) success(responseJSON); //call back to original ajax call
};
}
});
If you want to remove localStorage, use following statement wherever you want:
localStorage.removeItem("Info");
Hope it helps others!
All the modern browsers provides you storage apis. You can use them (localStorage or sessionStorage) to save your data.
All you have to do is after receiving the response store it to browser storage. Then next time you find the same call, search if the response is saved already. If yes, return the response from there; if not make a fresh call.
Smartjax plugin also does similar things; but as your requirement is just saving the call response, you can write your code inside your jQuery ajax success function to save the response. And before making call just check if the response is already saved.