I have the following form and javascript function on my web page. This is a dummy function that I am using to test whether what I would like to do is possible.
What I am attempting to do is have a form send an AJAX request to the server, so that the server can update the database while the page itself continues along it's predetermined path. I am in a tight time crunch, so I unfortunately do not have time to rewrite the entire page to better support this. The problem that I have is the xmlhttp object does not seem to return properly. I get a readyState of 4 but a status of 0. can someone please explain what I need to do?
Here's my code:
ajax.php
<html>
<head>
<script type="text/javascript">
function test(){
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange=function(){
document.getElementById("new").innerHTML+="<b>"+xmlhttp.readyState+"</b> "+xmlhttp.status;
if (xmlhttp.readyState==4 && xmlhttp.status==200){
document.getElementById("hello").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","response.php",true);
xmlhttp.send();
}
</script>
</head>
<body>
<?php
if ($_POST){
echo $_POST['hello'];
}
?>
<form action="ajax.php" method="post">
<input type="text" name="hello" />
<input type="submit" value="submit" onclick="test();" />
</form>
<div id="hello"></div>
<h3>debug</h3>
<div id="new"></div>
</body>
</html>
response.php
<?php
echo "Hello there";
?>
EDIT
Please note that I do not want to prevent the default behavior. In fact, the forn must be submitted as usual. I simply want to add an AJAX request to the process.
You can't trigger an AJAX request and allow the form to submit at the same time. Incomplete AJAX requests are cancelled when the page reloads (as is the case when the form is submitted). You'll either have to not submit the form at all, or wait until your AJAX call has completed before submitting the form. If you wanted to go the second route, you could make the following changes to your code:
<html>
<head>
<script type="text/javascript">
function test(){
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange=function(){
document.getElementById("new").innerHTML+="<b>"+xmlhttp.readyState+"</b> "+xmlhttp.status;
if (xmlhttp.readyState==4 && xmlhttp.status==200){
document.getElementById("hello").innerHTML=xmlhttp.responseText;
**document.getElementById("ajaxform").submit();**
}
}
xmlhttp.open("GET","response.php",true);
xmlhttp.send();
}
</script>
</head>
<body>
<?php
if ($_POST){
echo $_POST['hello'];
}
?>
<form action="ajax.php" method="post" **id="ajaxform"**>
<input type="text" name="hello" />
<input type="submit" value="submit" onclick="test();**return false;**" />
</form>
<div id="hello"></div>
<h3>debug</h3>
<div id="new"></div>
</body>
</html>
Changes/additions are marked with **.
Note that there are a few practices in there I don't like, in particular using the onsubmit, etc attributes of HTML tags to attach Javascript event handlers.
I know this doesn't directly answer your question but if you are strapped for time then I would suggest just using jQuery to handle the AJax.
You can attach it to a button press and then call some code: http://api.jquery.com/jQuery.ajax/
I can dig out some code examples if you need them.
Once the submit button is pressed the browser will submit data to the server and a new page will be loaded. You can bind the submit event of the form and in the event make the ajax call but you will have 2 problems.
The browser may redirect before all ajax data is sent
You have no idea if the ajax call was successful or not
I would try sending the data you are sending via ajax in the same form data using hidden inputs. If both calls are aimed at different urls then try this:
var ajaxSent = false;
$('#myForm').submit(function(e){
if (!ajaxSent){
e.preventDefault();
$.ajax({
url: "ajaxUrl",
// data, method, etc
success: function(){
ajaxSent = true;
$('#myForm').trigger('submit');
}
}
// else submit the form
});
Related
This site has been really helpful while writing this program. Unfortunately, I hit a snag at some point, and have boiled the problem down quite a bit since. At this point, I am looking at three files, a .html that contains a form, a .js that contains my event handlers, and a .php that receives my post variables and contains new content for the form.
I am getting the post data from the initial text input just fine. The new form content is set as I would expect. However, after this form content is set to a new input of type button with a class of button, the post method in my button class handler is not setting post data on login.php as I expect it to.
Here is my code:
Contents of interface.html page:
<!DOCTYPE html>
<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
</head>
<body>
<form id="interface" action="login.php" method="post">
<input type="text" value="enter username here" name="user"/>
<button id="submit">submit</button>
</form>
<script src='events.js'></script>
</body>
</html>
Contents of events.js file:
$("#submit").click(function(){
$.post(
$("#interface").attr("action"),
$(":input").serialize(),
function(info){$("#interface").html(info);}
);
});
$(".button").click(function(){
var $this=$(this);
$.post(
$("#interface").attr("action"),
{data:$this.val()},
function(info){$("#interface").html(info);}
);
});
$("#interface").submit(function(){
return false;
});
Contents of login.php file:
<?php
if(isset($_POST['user'])){
echo '<input type="button" class="button" value="set data"/>';
}else if(isset($_POST['data'])){
echo 'data is set';
}
?>
You need to wait until the button exists to bind an event to it. Additionally, i'd switch from click to submit and drop the click event binding on .button completely.
//$("#submit").click(function () {
$("#interface").submit(function (e) {
e.preventDefault();
var $form = $(this), data = $form.serialize();
if ($form.find(".button").length && $form.find(".button").val() ) {
data = {data: $form.find(".button").val()};
}
$.post($form.attr("action"), data, function (info) {
$form.html(info);
});
});
//$("#interface").submit(function () {
// return false;
//});
Since the form is not being replaced, and the event is on the form, you no longer need to re-bind anything.
I have a form in HTML to apply a Discount Coupon to a current shopping cart.
I would like the user to just click on APPLY (after entering the coupon code) and then without refreshing the page, to have some PHP code run so it computes the corresponding discount.
Here is my form:
<form action="">
<input type="text" name="couponCode">
<input type="submit" value="Apply">
</form>
PHP to be run:
if (isset($_REQUEST['couponCode']) && $_REQUEST['couponCode']!='')
{
$couponCode = $_REQUEST['couponCode'];
if ($couponCode == "TEST1")
{
$discount=0.2;
}
}
How would this be done using javascript?
You need to use either the onsubmit event of the form or the onclick event of the button.
In the event handler, you assemble a URL and "get" it. For example:
<script type="text/JavaScript">
function submitCouponCode()
{
var textbox = document.getElementById("couponCode");
var url =
"https://www.example.com/script.php?couponCode=" + encodeURIComponent(textbox.value);
// get the URL
http = new XMLHttpRequest();
http.open("GET", url, true);
http.send(null);
// prevent form from submitting
return false;
}
</script>
<form action="" onsubmit="return submitCouponCode();">
<input type="text" id="couponCode">
<input type="submit" value="Apply">
</form>
Use jQuery AJAX. When it's complete, refresh your page as needed.
You can use Jquery to do an AJAX post you your PHP script, and then use JS to change the contents of the calling page.
http://api.jquery.com/jQuery.post/
It's simple with jQuery. You just have to use the right tag. If you use an "a" tag the page will refresh.
<button id="MyButton">Click Me!</button>
<script>
$("#MyButton").click( function(){
$.post("somefile.php");
});
</script>
I wrote an array to pass variables in the GET to a search page. The search page only has 4 fields but I'm only passing the most important variables, first name and last. Here is the array:
<?php echo "<td><a href='" . matry::base_to('test/trace', array('first'=>$patient->first , 'last' =>$patient->last)) . "'><ul class='controls'>
<li id='check_orders'><`span class='symbols'>L</span><span class='label'>Skip Trace</span></li>
</ul></a></td>";?>
When the page loads i'm just echoing the _GET to pre populate the first and last input fields on that page..
What I'm looking for is a script that will execute the search with the first and last name fields populated as that page loads automatically. Additionally, when the search is executed it's populating in an iframe. (forgot about that part)~!
I tried using:
<script>document.getElementById('stack').submit();</script>
<form action='http://xxxx.yyyyyyy.com/stuffhere' name='es' target="my_iframe" id="stack">
with no avail.
Your <script> is running before the <form> exists.
Move the <script> below the <form>.
You are calling the submit function before the form is even loaded on the page.
Place the script tag after the closing form tag or call submit on document ready or window onload.
<form id-"stack">
... form fields...
</form>
<script>document.getElementById('stack').submit();</script>
or
<script>$(function(){$('#stack').submit();})</script>
Please imagine this simple example:
<html>
<head>
<script type="text/javascript">
function body_onload() {
var form = document.getElementById('theform');
form.submit();
}
</script>
</head>
<body onload="body_onload()">
<form id="theform" action="action.php">
<input type="hidden" name="query" id="query" value="foo" />
</form>
</body>
</html>
It will submit the form after the page has loaded.
But are you really searching for a non AJAX solution?
Try this, been using this on a redirect page for a while. This of course needs to be below the from so it is run after the browser process the form.
<script type="text/javascript">
function send(o)
{
var f = document.getElementById("theForm");
f.submit();
}
send();
</script>
If you want to submit the form when the page loads you should change your code to this:
<script>window.onload = function(){ document.getElementById('stack').submit(); }</script>
However this will redirect the user (as if they have clicked a form submit button). To avoid this you will need to use AJAX (I recommend using jQuery to do this). See example below:
$(document).ready(function(e) {
var form_data = $("#form_id").serialize();
var form_url = $("#form_id").attr("action");
var form_method = $("#form_id").attr("method").toUpperCase();
$.ajax({
url: form_url,
type: form_method,
data: form_data,
cache: false
});
});
See this page for more info on using AJAX
I have an HTML form that currently just posts the data directly to a PHP file. I want to update the code so that the submit button sends the data to a JavaScript function so that I can create an AJAX function. Is it possible for the submit button to activate a JavaScript function rather than posting to a php file? The only thing I have come up with is below, which quite obviously does not work:
<html>
<head>
<script type="text/javascript">
function ajax(){
//...
}
</script>
</head>
<body>
<form action="ajax();">
<!-- ... -->
<input type="submit" value="Submit" />
</form>
</body>
</html>
You can give the "submit" input a "click" handler that explicitly prevents the default behavior from being carried out.
<input type='submit' value='Submit' onclick='ajax(event)'>
Then in the function:
function ajax(event) {
if ('preventDefault' in event) event.preventDefault();
event.returnValue = false; // for IE before IE9
// ...
}
edit #Esailija points out correctly that another option is to handle the "submit" event on the <form> element instead. The function would look pretty much the same, in fact exactly the same, but you'd wire it up like this:
<form id='yourForm' onsubmit='ajax(event)'>
That will also trap things like the "Enter" key action, etc.
Of course you can. But it's more useful to call your Javascript function in the input like this :
<input type="submit" value="Submit" onclick="ajax();" />
And remove the action part in the form.
I jQuery you can use event.preventDefault(); otherwise just use return false;
http://jsfiddle.net/mKQmR/
http://jsfiddle.net/mKQmR/1/
Pointy is correct... just add a click handler to the submit button, however make sure the last line of the click handler returns "false" to prevent the form from actually being posted to the form's action.
<html>
<head>
<script type="text/javascript">
function ajax(){
//...
return false;
}
</script>
</head>
<body>
<form action="thispage.htm">
<!-- ... -->
<input type="submit" value="Submit" onclick="ajax();" />
</form>
</body>
</html>
I am using the following code to effect an iframe that allows an ajax file upload on submit of the form without refresh.
This works as expected
window.onload=init;
function init() {
document.getElementById('form').onsubmit=function() {
document.getElementById('form').target = 'iframe';
}
}
What i would like to do is the same thing but 'onchange' of the file field input, i.e. when the user has chosen a file, to autmatically trigger the init() function and thus upload the file. I have tried with this code:
document.getElementById('file').onchange=function(){...
This doesn't work, and i'm completely stuck. Any ideas?
Many thanks
This should work for you
<script type="text/javascript">
window.onload = function() {
// add old fashioned but reliable event handler
document.getElementById('file_input').onchange = function() {
// submit the form that contains the target element
this.form.submit();
}
}
</script>
<iframe name="my_iframe"></iframe>
<form target="my_iframe"
action="your/file.ext"
method="post"
enctype="multipart/formdata">
<input type="file" name="my_file" id="file_input">
<!-- for no js users -->
<noscript>
<br/>
<input type="submit">
</noscript>
</form>
i think something like .live() will solve your issue hopefully, comment if you want more info on how to use it...
Give the file input element an id and:
$(document).ready(function(){
$(element).change(function(e){
fileInfo = e.currentTarget.files[0];
init();
});
});