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@WebReflection
Created August 24, 2011 19:03
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hot to mock script requests
document.createElement = function (
createElement, // the native one
createResponse // the function "in charge"
) {
return function (nodeName) {
var result, src;
// if we are creating a script
if (/^script$/i.test(nodeName)) {
// result will be a place holder
result = createElement.call(
document,
"meta"
);
// we need to monitor the src property
Object.defineProperty(result, "src", {
get: function () {
return src;
},
// when set ...
set: function ($src) {
// we can check periodically ...
function T() {
// if the placeholder is in DOM
if (result.parentNode) {
// in this case we can put a real script
result = result.parentNode.insertBefore(
createElement.call(
document,
"script"
),
result
);
// and set the encoded src
result.src = "data:text/javascript;base64," +
btoa(createResponse.call(result, src))
;
} else {
// no DOM, no loading ... try later
setTimeout(T, 100);
}
}
// store the src
src = $src;
// and start checking
T();
}
});
} else {
// just return the element
result = createElement.call(
document,
nodeName
);
}
return result;
};
}(
document.createElement,
// must return a string
function (src) {
// this points to the current script
// src is the address
// if we know the callback ...
if (/callback=([^&]+)/.test(src)) {
return RegExp.$1 + '(' +
JSON.stringify({dummy:"data"})
+ ')';
}
}
);
// example
function test(data) {
alert(data.dummy);
}
document.documentElement.insertBefore(
document.createElement("script"),
document.documentElement.lastChild
).src = "page.php?callback=test";
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