What is the recommended practice to check if the jQuery Ajax function is present and recognized by the browser, does anyone know?
// forma 1
if (!$.ajax) {
alert ('Status xhr: não suporta Ajax');
return false;
}
// forma 2
if (typeof $.ajax !== 'function') {
alert ('Status xhr: não suporta Ajax');
return false;
}
In many of the examples on the Mozilla MDN site the condition for testing functions according to form 1 is well used,
Use jQuery.support.ajax or $.support.ajax
if (!$.support.ajax) {
alert("Status xhr: não suporta Ajax");
}
I got the code at link
<script type="text/javascript">
var xmlhttp;
function checkAJAXSupport() {
if (window.XMLHttpRequest) { // Mozilla, Safari, ...
xmlhttp= new XMLHttpRequest();
alert("Yes. Your browser must be one among them - Mozilla, Safari, Chrome, Rockmelt, IE 8.0 or above");
} else if (window.ActiveXObject) { // IE
try {
xmlhttp= new ActiveXObject("Msxml2.XMLHTTP");
alert("Yes. Your browser must be IE");
}
catch (e) {
try {
xmlhttp= new ActiveXObject("Microsoft.XMLHTTP");
alert("Yes. Your browser must be IE");
}
catch (e) {}
}
} if (!xmlhttp) {
alert("No. Giving up Cannot create an XMLHTTP instance. Your browser is outdated!");
return false;
}
}
</script>
You can use When in your request
$.when( $.ajax ).then(function( data, textStatus,
jqXHR ) {
alert( jqXHR.status ); // Alerts 200
})
.catch(function() {
alert ('Status xhr: não suporta Ajax');
})
First you can create a variable to make a ajax request whatever
Dai inside the function you are testing the possible browsers, if not accept returns an error
function ajaxFunction() {
var xmlHttp;
try {
// Firefox, Opera 8.0+, Safari
xmlHttp=new XMLHttpRequest();
}
catch (e) {
// Internet Explorer
try {
xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
}
catch (e) {
try {
xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
}
catch (e) {
alert("Your browser does not support AJAX!");
return false;
}
}