oxjs/source/Ox/js/Request.js
2012-05-25 11:41:51 +02:00

211 lines
7 KiB
JavaScript

'use strict';
/*@
Ox.get <f> Get a remote file
# fixme: remote? same-origin-policy? jsonp?
(url, callback) -> <u> undefined
url <s> Remote URL
callback <f> Callback function
data <s> The contents of the remote resource
@*/
Ox.get = function(url, callback) {
var req = new XMLHttpRequest();
req.open('GET', url, true);
req.onreadystatechange = function() {
if (req.readyState == 4) {
if (req.status == 200) {
callback(req.responseText);
} else {
throw new Error(
'Cannot get URL "' + url + '" (Status: ' + req.status + ')'
);
}
}
};
req.send();
};
/*@
Ox.getJSON <f> Get and parse one or more remote JSON files
# fixme: remote? same-origin-policy?
(url, callback) -> <u> undefined
url <s|[s]> One or more remote URLs
callback <f> Callback function
data <o> The parsed contents of the remote resource(s)
For multiple URLs, keys are file names, values are contents
@*/
Ox.getJSON = function(url, callback) {
var urls = Ox.makeArray(url);
Ox.loadAsync(urls, function(url, callback) {
Ox.get(url, function(data) {
var result = {};
result[url] = JSON.parse(data);
callback(result);
});
}, function(results) {
callback(urls.length == 1 ? results[url] : results);
});
}
/*@
Ox.getJSONP <f> Get and parse one or more remote JSONP files
(url, callback) -> <u> undefined
url <s|[s]> One or more remote URLs,
{callback} gets replaced with jsonp callback function name
callback <f> Callback function
data <o> The parsed contents of the remote resource(s)
For multiple URLs, keys are file names, values are contents
@*/
Ox.getJSONP = function(url, callback) {
var urls = Ox.makeArray(url);
Ox.loadAsync(urls, function(url, callback) {
var id = 'callback' + Ox.uid();
Ox.getJSONP[id] = function(data) {
delete Ox.getJSONP[id];
callback(data);
}
Ox.$('body').append(Ox.$('<script>').attr({
'src': url.replace('{callback}', 'Ox.getJSONP.' + id),
'type': 'text/javascript'
}));
}, function(results) {
callback(urls.length == 1 ? results[url] : results);
});
}
/*@
Ox.getJSONC <f> Get and parse a remote JSONC file
JSONC is JSON with JavaScript line or block comments
(url, callback) -> <u> undefined
url <s> Remote URL
callback <f> Callback function
data <s> The parsed contents of the remote resource
@*/
Ox.getJSONC = function(url, callback) {
Ox.get(url, function(data) {
callback(JSON.parse(Ox.minify(data)));
});
};
/*@
Ox.loadFile <f> Loads a file (image, script or stylesheet)
(file="script.js", callback) -> <u> undefined
(file="stylesheet.css", callback) -> <u> undefined
(file="image.png", callback) -> <u> undefined
file <s> Local path or remote URL
callback <f> Callback function
image <e> DOM element (if the file is an image)
@*/
Ox.loadFile = (function() {
// fixme: this doesn't handle errors yet
// fixme: rename to getFile?
var cache = {};
return function(files, callback) {
Ox.loadAsync(files, function(file, callback) {
loadFile(file, function(images) {
callback(images ? {file: images} : {});
});
}, callback);
}
function loadFile(file, callback) {
var element,
head = document.head || document.getElementsByTagName( "head" )[0] || document.documentElement,
request,
type = file.split('.').pop(),
isImage = type != 'css' && type != 'js';
if (!cache[file]) {
if (isImage) {
element = new Image();
element.onload = addFileToCache;
element.src = file;
} else {
if (!findFileInHead()) {
element = document.createElement(
type == 'css' ? 'link' : 'script'
);
element[type == 'css' ? 'href' : 'src'] = file + '?' + Ox.random(1000000);
element.type = type == 'css' ? 'text/css' : 'text/javascript';
if (/MSIE/.test(navigator.userAgent)) {
// fixme: find a way to check if css/js have loaded in msie
setTimeout(addFileToCache, 2500);
} else {
if (type == 'css') {
element.rel = 'stylesheet';
waitForCSS();
} else {
element.onload = addFileToCache;
}
}
head.appendChild(element);
} else {
addFileToCache();
}
}
} else {
callback();
}
function addFileToCache() {
if (isImage) {
// for an image, save the element itself,
// so that it remains in the browser cache
cache[file] = element;
callback(element);
} else {
cache[file] = true;
callback();
}
}
function findFileInHead() {
return Ox.toArray(
document.getElementsByTagName(type == 'css' ? 'link' : 'script')
).map(function(element) {
return element[type == 'css' ? 'href' : 'src'] == file;
}).reduce(function(prev, curr) {
return prev || curr;
}, false);
}
function waitForCSS() {
var error = false;
try {
element.sheet.cssRule;
} catch (e) {
error = true;
setTimeout(function() {
waitForCSS();
}, 25);
}
!error && addFileToCache();
}
};
}());
/*@
Ox.loadAsync <f> Runs an asynchonous function on array elements
(arr, map, callback) -> <u> undefined
arr <s|a> String or array of either strings or arrays of strings
Multiple strings in the same array will be processed simultaneously, but
multiple arrays of strings will be processed in that order.
callback <f> Callback function
results <o> Results
@*/
Ox.loadAsync = function(arr, map, callback) {
arr = Ox.makeArray(arr);
var i = 0, n = arr.length, results = {};
if (arr.some(Ox.isArray)) {
iterate();
} else {
arr.forEach(function(item) {
map(item, function(result) {
Ox.extend(results, result);
++i == n && callback(results);
});
});
}
function iterate() {
Ox.loadAsync(arr.shift(), function(result) {
Ox.extend(results, result);
arr.length ? iterate() : callback(results);
});
}
};