错误：在jquery函数中对服务器的Ajax调用

Question

I am trying to make an ajax call to a server in my local network installed with LAMP who is running wordpress. I am currently doing changes to files in a wordpress plugin.

I want to call a php file located into my server to get json data to build a chart from a sql request.

So I have ajaxStatistics.php where I coded the sql request and the json encode.

Now I am in statistics.js where I have my function to build a chart and this is where I do the ajax call :

jQuery(function() { 
    /**
     * call the ajaxStats.php file to fetch the result from db table.
     */
    $.ajax({
        url : "192.168.1.100/wp-content/plugins/pluginname/ajaxStatistics.php",
        type : "GET",
        success : function(data){
            console.log(data);
            ...

The result is an Uncaught TypeError: Cannot read property 'ajax' of undefined

at HTMLDocument.<anonymous> (statistics.js:92)
    at i (jquery.js?ver=1.12.4:2)
    at Object.fireWith [as resolveWith] (jquery.js?ver=1.12.4:2)
    at Function.ready (jquery.js?ver=1.12.4:2)
    at HTMLDocument.K (jquery.js?ver=1.12.4:2)

Answer 1

You are trying to access $ as jQuery before it gets initialized so to make it in proper way, you can use DOM load event of it like so...

$(document).ready(function(){
    function build_statistics() {
        $.ajax({
        url : "http://192.168.1.100/wp-content/plugins/pluginname/ajaxStatistics.php",
        type : "GET",
        success : function(data){
            console.log(data);
        }
    }
});

And then call it like

build_statistics()

Answer 2

That means that jquery has not been loaded.

Make sure that you have the script in your html, and also wrap the call to this function sendData inside a

$(document).ready(function(){
//do stuff
})

Answer 3

It seems like your $ variable is unreachable in your code.

Try this:

jQuery(function() { 
    /**
     * call the ajaxStats.php file to fetch the result from db table.
     */
    var $ = jQuery;

    $.ajax({
        url : "http://192.168.1.100/wp-content/plugins/pluginname/ajaxStatistics.php",
        type : "GET",
        success : function(data){
            console.log(data);
            ...

And also make sure to add a http or https in your url.