Clarification of a some code
- by Legend
I have come across a website that appears to use Ajax but does not include any js file except one file called ajax.js which has the following:
function run(c, f, b, a, d) {
var e = null;
if (b && f) {
document.getElementById(b).innerHTML = f
}
if (window.XMLHttpRequest) {
e = new XMLHttpRequest()
} else {
if (window.ActiveXObject) {
e = new ActiveXObject(Microsoft.XMLHTTP)
}
}
e.onreadystatechange = function () {
if (e.readyState == 4) {
if (e.status == 200 || e.statusText == "OK") {
if (b) {
document.getElementById(b).innerHTML = e.responseText
}
if (a) {
setTimeout(a, 0)
}
} else {
console.log("AJAX Error: " + e.status + " | " + e.statusText);
if (b && d != 1) {
document.getElementById(b).innerHTML = "AJAX Error. Please try refreshing."
}
}
}
};
e.open("GET", c, true);
e.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
e.send(null)
}
Like you might have guessed, the way it issues queries inside the page with queries like this:
run('page.php',loadingText,'ajax-test', 'LoadSamples()');
I must admit that this is the first time I've seen a page from which I could not figure how things are being done. I have a few questions:
Is this Server-Side Ajax or
something similar? If not, can someone
clarify what exactly is this?
Why does one use this? Is it for hiding the design details? (which are otherwise revealed in plain text by javascript)
How difficult would it be to convert my
existing application into this design
pattern? (maybe a subjective question but any short suggestion will do)
Any suggestions?
