Ajax Call Confusion - javascript

before we start apologies for the wording and lack of understanding - I am completely new to this.
I am hoping to run a php script using Ajax - I don't need to send any data to the php script, I simply need it to run on button press, after the script is run I need to refresh the body of the page. What I have so far:
HMTL Button with on click:
<font color = "white">Next Question</font>
JS Ajax call:
function AjaxCall() {
$.ajax({
url:'increment.php',
type: 'php',
success:function(content,code)
{
alert(code);
$('body').html(content);
}
});
}
this runs the php script but doesn't stay on the current page or refresh the body - has anyone got any ideas - apologies if this is completely wrong I'm learning - slowly.
Many thanks in advance.
**As a small edit - I don't want a user to navigate away from the page during the process

How about using load instead of the typical ajax function?
function AjaxCall() {
$(body).load('increment.php');
}
Additionally, if you were to use the ajax function, php is not a valid type. The type option specifies whether you are using GET or POST to post the request.
As far as the dataType option (which is what I think you mean), The Ajax doesn't care what technology the called process is using (like ASP or PHP), it only care about the format of the returned data, so appropriate types are html, json, etc...
Read More: http://api.jquery.com/jquery.ajax/
Furthermore, if you are replacing the entire body content, why don't you just refresh the page?

your ajax should be
function AjaxCall() {
$.ajax({
url:'increment.php',
type: 'post',
success:function(data)
{
console.log(data);
$('body').html(data);
}
});
}
if you want to learn ajax then you should refer this link
and if you just want to load that page then you can use .load() method as "Dutchie432" described.

If you are going to fire a javascript event in this way there are two ways to go about it and keep it from actually trying to follow the link:
<font color = "white">Next Question</font>
Note the return false;. This stops the following of the link. The other method would be:
<font color = "white">Next Question</font>
Note how this actually modifies the href to be a javascript call.

You can study about js and ajax here http://www.w3schools.com/ajax/default.asp will help a lot. Of course all js functions if called from internal js script should be inside <script></script> and if called from external you call the js gile like <script src"somejs.js"></script> and inside js there is no need for <script> tags again. Now all those function do not work by simply declaring them. So this:
function sayHello(){
alert("Happy coding");
}
doesn't work because it is just declared and not called into action. So in jQuery that you use after we declare some functions as the sayHello above we use:
jQuery(document).ready(function($){
sayHello();
});
Doing this we say that when everything is fully loaded so our DOM has its final shape then let the games begin, make some DOM manipulations etc
Above also you don't specify the type of your call meaning POST or GET. Those verbs are the alpha and omega of http requests. Typically we use GET to bring data like in your case here and POST to send some data for storage to the server. A very common GET request is this:
$.ajax({
type : 'GET',
url : someURL,
data : mydata, //optional if you want to send sth to the server like a user's id and get only that specific user's info
success : function(data) {
console.log("Ajax rocks");
},
error: function(){
console.log("Ajax failed");
}
});

Try this;
<script type="text/javascript">
function AjaxCall() {
window.location.reload();
}
</script>
<body>
<font color = "white">Next Question</font>
</body>

Related

Calling a static method from cshtml file

I'm trying to work on a clickable DIV from some vertical tab panel. What I want is when clicking on a specific DIV call a static method to do some tasks, so I did this:
<div class="tabbable tabs-left">
<ul class="nav nav-tabs">
<li onclick="myEvent()">Tuttle</li>
then, my JavaScript code:
<script>
function clickEvet() {
alert("alert test message");
#MyProject.myMethod()
}
</script>
Calling the function "clickEvent()" works. The problem is that #MyProject.myMethod() is called no matter what, in other words, #MyProject.myMethod() is being executed as soon the page loads. I want it only when I click on my div.
This is from a cshtml file and I'm using .net 4.5
SOLUTION:
I'm editing my question to post the answer for future references...:
Thanks to other comments I finally understood how to work with Ajax and make it work. Here is the solution:
<script>
function vaxGUID() {
$.ajax({
type: 'POST',
url: "/VAXBean/bmx",
data: '{"Name":"AA"}',
contentType: 'application/json; charset=utf-8',
dataType: 'html',
success: function (data) {
bmx = "http://www.vitalbmx.com";
$('a.varURL').attr('href', bmx);
GUID = data;
alert("Good response - " + data + " - " + bmx);
},
error: function (data, success, error) {
alert("Error : " + error);
}
});
return false;
}
</script>
With this Ajax method I'm making the call to some static method in the background
I want it only when I click on my div. <= When you click on the DIV that is being done in the browser after the request has been sent. There is no way for the browser to call directly back inside a method in your application. The HTML has already been generated and sent by the server in the request to the client and that is where that communication cycle stops.
If you want a click (or any other event) to do something specifically on the server you need to do one of these standard actions that are used to communicate back to the server.
Create an AJAX request back to your MVC Controller to get data (or whatever).
Create a link (standard url)
Create a form post back
And of course the #MyProject.myMethod() executes every time your page is rendered because your razor view is a code file that is being interpreted line by line so it can be rendered and sent to the client that requested it. What would be valid here is if myMethod output some javascript or something that the browser could understand and do something with, that is what would be expected.
You can't do it. All # (Razor) expressions is resolved during page rendering on server. That's why you method is called.
Probably, you need to make an Ajax call.
Look for a more detailed explanation here:
How do I call a static method on my ASP.Net page, from Javascript?

How to display a json data from a existing url using ajax call

I Am new in working with json and jquery. I am trying to study the basics of json and jquery by working on some example. So I use existing json data in http://api.androidhive.info/contacts for my example. I want to display this data in my HTML page. My code is:
<html>
<head>
<title>jQuery Ajax Example with JSON Response</title>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js" type="text/javascript"></script>
<script>
$(document).ready(function(){
$(':submit').on('click', function() { // This event fires when a button is clicked
alert("submitt worked.");
$.ajax({ // ajax call starts
url: 'http://api.androidhive.info/contacts/', // JQuery loads serverside.php
type: "GET",
dataType: 'json', // Choosing a JSON datatype
success: function (msg) {
alert("ajax worked.");
JsonpCallback(msg);
},
})
function JsonpCallback(json)
{
for (var i in json.contacts) {
$('#wines').append('contacts: ' + json.contacts[i] + '<br/>');
}
}
return false; // keeps the page from not refreshing
});
});
</script>
</head>
<body>
<form method="post" action="">
<button value="all" type="submit">Get!</button>
</form>
<div id="wines">
<!-- Javascript will print data in here when we have finished the page -->
</div>
</body>
</html>
can any one please give me some brief introduction to JSON and how it's working ?
Thanks in advance.
You are iterating the JSON wrong, in your case since you are using jQuery (as mentioned) you can use the $.each(json, callback); helper fron jQuery, you can see the documentation here Jquery $.each documentation
For an example implementation I've created this JSFIDDLE LINK
for you. Have a great day ahead. Don't forget that JSON means
Javascript Object Notation
It's an object.
$.each(jsonData.contacts, function(k, v)
{
console.log(v.name);
$('#name').append('<li>'+v.name+'</li>');
});
jQuery
Am try to study the basics of json and jquery
Is a Javascript library with lots of very usefull methods. If you want to create a dynamic website it is very recommended to look into jQuery. There are many site with great explanation on what jQuery can do. As far as your example is concerned: There is an issue when passing variables/data from one framework to another or even when simply storing data. Here comes JSON.
JSON
Or JavaScript Object Notation (JSON) is used to solve exactly that problem. What is basically does is take all the desired data (array, variable, object, string etc.) and writes it in a human readable and for other frameworks readable fashion. I use JSON to store data in files when no database is available or when passing data from one framework to another (like JS <-> PHP).
Your example code
What happens here:
$(':submit').on('click', function() { // This event fires when a button is clicked
alert("submitt worked."); // not yet
$.ajax({ // ajax call starts
url: 'http://api.androidhive.info/contacts/', // JQuery loads serverside.php --> this I don't know
type: "GET", // communication type
dataType: 'json', // Choosing a JSON datatype
success: function (msg) { // here, the whole content of the url is read, idealy it is in JSON format ofc
alert("ajax worked."); // hoorray
JsonpCallback(msg);
},
})
There is the serverside.php file that receives a GET command and returns HTML. All the HTML content is in JSON type (so no <stuff>, i.e. no actual HTML) and your success function returns that content in the msg variable. Typically you use something like
var obj = JSON.parse(text);
to convert the JSON data to Javascript variables. Read this here JSON in Javascript
JSONP
Now what if you want to do some domain crossing (as you suggested), then I strongly recommend to read this here What is JSONP all about? . It explains what JSONP is all about

Passing a Javascript variable back to php, when no submit button functionality is used

I have a fairly complex PHP script in place, and I need to embed a very small JavaScript prompt inside of this code.
This is my criteria / requirement:
I want this JavaScript code to execute when a certain set of criteria is met.
I do NOT want to execute this code with any kind of submit button.
I currently have the PHP code calling the JavaScript prompt correctly.
The JavaScript comment / variable is being initialized, and stored properly, within the JavaScript code itself.
The parent PHP code is waiting for the JavaScript input, and does not continue until the prompt text has been entered.
But, I have not been able to figure out how to pass the JavaScript variable back to the parent PHP code.
What I have so far is very simple, but it is working exactly as I intended:
function getReprNotes() {
?>
<script>
var REPRNOTES = prompt('Please enter any appropriate reprocessing request notes');
alert(REPRNOTES);
</script>
<?php
}
getReprNotes()
Note that I want to pass the REPRNOTES text / variable back to the parent script.
Can anyone tell me how I need to do this, using the above code?
Keep in mind javascript is client side scripting, and php is server side. The only way for you to send information to PHP is by making a call to the server, the best way to do this from the client using javascript without submitting a form is by is using AJAX.
Take a look at these tutorials: 5 Ways to make AJAX calls with jquery and 24 best practices for AJAX implementations.
This is what AJAX calls are for. Split your PHP into two and have the javascript issue an ajax call which triggers the second. If you can use jQuery then you want to make a $.ajax() call: https://api.jquery.com/jQuery.ajax/
If you can't or don't want to use jQuery you can still make ajax calls through XMLHttpRequest objects: http://www.w3schools.com/Ajax/default.asp
$.ajax({
url: '/to-some-url',
data: 'data=' + value,
type: 'POST',
success: function (response, textStatus, jqXHR) {
if (jqXHR.status > 0) {
// do something here
}
}
});
You can use jquery ajax method to pass javascript variable value to php by post(or get). But I don't understand what you really want to achieve

Run (JS) function if server responded something specific

On one of my pages I have "tracking.php" that makes a request to another server, and if tracking is sucessful in Firebug Net panel I see the response trackingFinished();
Is there an easy way (built-in function) to accomplish something like this:
If ("tracking.php" responded "trackingFinished();") { *redirect*... }
Javascript? PHP? Anything?
The thing is, this "tracking.php" also creates browser and flash cookies (and then responds with trackingfinished(); when they're created). I had a JS that did something like this:
If ("MyCookie" is created) { *redirect*... }
It worked, but if you had MyCookie in your browser from before, it just redirected before "track.php" had the time to create new cookies, so old cookies didn't get overwritten (which I'm trying to accomplish) before the redirection...
The solution I have in mind is to redirect after trackingFinished(); was responded...
I think the better form in javascript to make request from one page to another, without leaving the first is with the ajax method, and this one jQuery make it so easy, you only have to use the ajax function, and pass a little parameters:
$.post(url, {parameter1: parameter1value, param2: param2value})
And you can concatenate some actions:
$.post().done(function(){}).fail(function(){})
And isntead of the ajax, you can use the $.post that is more easy, and use the done and fail method to evaluate the succes of the information recived
As mentioned above, AJAX is the best way to communicate between pages like this. Here's an example of an AJAX request to your track.php page. It uses the success function to see if track.php returned 'trackingFinished();'. If it did then it redirects the page 'redirect.php':
$.ajax({
url: "track.php",
dataType: "text",
success: function(data){
if(data === 'trackingFinished();'){
document.location = 'redirect.php';
}
}
});
The example uses JQuery.

Load .txt file using JQuery or Ajax

How can I fix the script below so that it will work EVERY TIME! Sometimes it works and sometimes it doesn't. Pro JQuery explains what causes this, but it doesn't talk about how to fix it. I am almost positive it has to do with the ajax ready state but I have no clue how to write it. The web shows about 99 different ways to write ajax and JQuery, its a bit overwhelming.
My goal is to create an HTML shell that can be filled with text from server based text files. For example: Let's say there is a text file on the server named AG and its contents is PF: PF-01, PF-02, PF-03, etc.. I want to pull this information and populate the HTML DOM before it is seen by the user. A was ##!#$*& golden with PHP, then found out my host has fopen() shut off. So here I am.
Thanks for you help.
JS - plantSeed.js
var pageExecute = {
fileContents:"Null",
pagePrefix:"Null",
slides:"Null",
init:function () {
$.ajax({
url: "./seeds/Ag.txt",
success: function (data){
pageExecute.fileContents = data;
}
});
}
};
HTML - HEAD
<script type="text/javascript">
pageExecute.init();
</script>
HTML - BODY
<script type="text/javascript"> alert(pageExecute.fileContents); </script>
Try this:
var pageExecute = {
fileContents:"Null",
pagePrefix:"Null",
slides:"Null",
init: function () {
$.ajax({
url: "./seeds/Ag.txt",
async: false,
success: function (data){
pageExecute.fileContents = data;
}
});
}
};
Try this:
HTML:
<div id="target"></div>
JavaScript:
$(function(){
$( "#target" ).load( "pathToYourFile" );
});
In my example, the div will be filled with the file contents. Take a look at jQuery .load() function.
The "pathToYourFile" cand be any resource that contains the data you want to be loaded. Take a look at the load method documentation for more information about how to use it.
Edit: Other examples to get the value to be manipulated
Using $.get() function:
$(function(){
$.get( "pathToYourFile", function( data ) {
var resourceContent = data; // can be a global variable too...
// process the content...
});
});
Using $.ajax() function:
$(function(){
$.ajax({
url: "pathToYourFile",
async: false, // asynchronous request? (synchronous requests are discouraged...)
cache: false, // with this, you can force the browser to not make cache of the retrieved data
dataType: "text", // jQuery will infer this, but you can set explicitly
success: function( data, textStatus, jqXHR ) {
var resourceContent = data; // can be a global variable too...
// process the content...
}
});
});
It is important to note that:
$(function(){
// code...
});
Is the same as:
$(document).ready(function(){
// code
});
And normally you need to use this syntax, since you would want that the DOM is ready to execute your JavaScript code.
Here's your issue:
You've got a script tag in the body, which is asking for the AJAX data.
Even if you were asking it to write the data to your shell, and not just spout it...
...that's your #1 issue.
Here's why:
AJAX is asynchronous.
Okay, we know that already, but what does that mean?
Well, it means that it's going to go to the server and ask for the file.
The server is going to go looking, and send it back. Then your computer is going to download the contents. When the contents are 100% downloaded, they'll be available to use.
...thing is...
Your program isn't waiting for that to happen.
It's telling the server to take its time, and in the meantime it's going to keep doing what it's doing, and it's not going to think about the contents again, until it gets a call from the server.
Well, browsers are really freakin' fast when it comes to rendering HTML.
Servers are really freakin' fast at serving static (plain-text/img/css/js) files, too.
So now you're in a race.
Which will happen first?
Will the server call back with the text, or will the browser hit the script tag that asks for the file contents?
Whichever one wins on that refresh is the one that will happen.
So how do you get around that?
Callbacks.
Callbacks are a different way of thinking.
In JavaScript, you perform a callback by giving the AJAX call a function to use, when the download is complete.
It'd be like calling somebody from a work-line, and saying: dial THIS extension to reach me, when you have an answer for me.
In jQuery, you'll use a parameter called "success" in the AJAX call.
Make success : function (data) { doSomething(data); } a part of that object that you're passing into the AJAX call.
When the file downloads, as soon as it downloads, jQuery will pass the results into the success function you gave it, which will do whatever it's made to do, or call whatever functions it was made to call.
Give it a try. It sure beats racing to see which downloads first.
I recommend not to use url: "./seeds/Ag.txt",, to target a file directly. Instead, use a server side script llike PHP to open the file and return the data, either in plane format or in JSON format.
You may find a tutorial to open files here: http://www.tizag.com/phpT/fileread.php

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