i am passing variable from javascript php with the following code by using cookie.
<script type="text/javascript">
function gTest() {
var country = 'hello testing';
document.cookie = 'name=document.write(country);' ;
document.write(country);
}
gTest();
</script>
<?php
echo "<br>";
var_dump($_COOKIE['name']);
?>
it works fine if we change to
document.cookie = 'name=hello' ;
i want to pass variable value to php in same page...i don't want to send to another page.
thanks
$_COOKIE is populated with the data sent from the browser to the server.
The JS to change the cookie won't run until the response is sent back and the JavaScript is executed.
The values in $_COOKIE won't update until you make a new HTTP request.
You can use XHR.
JavaScript (using jQuery):
$.ajax('script.php', {
data: { 'name': 'hello' }
});
PHP:
var_dump($_GET['name']);
You cant.
Ok, I think I got to explain. On your page, there is the Javascript first, then the PHP code, but it doesnt execute in that order.
First the server execute the PHP code, send the page as HTML and the javascript is executed on the client side.
If you really dont want to reload the whole page, the only way to do it is to use an ajax request to a page where your PHP code is. Simply use JQuery and replace your PHP code with this :
$('#result').load('showCookie.php');
Content of showCookie.php will be your var_dump and the page will do exactly what you want, except that you have called an additional page with JQuery.
Related
The code looks like this:
PHP file
<?php
...
$arrayName = ['ArrayValue_0', ..., 'ArrayValue_n'];
...
php?>
JavaScript
$('.elementClass').each(function(index, id) {
$(id).html('<?php echo $arrayName[index - 1]?>');
});
But you can't just insert a JavaScript variable like that into php tags so index is never received.
I know this can be done via AJAX but is there any other way? Thanks in advance.
Additional info:
I've been told to do this in PHP so there's no posibility of switching the array to a JS file.
You can define arrayName variable in JS and initialize it with the value from the server:
var arrayName = <?php echo json_encode($arrayName); ?>;
$(".elementClass").each(function(index, id) {
$(id).html(arrayName[index-1]);
});
What you're trying to do will not work. For example this:
$(id).html('<?php echo $arrayName[index - 1]?>');
The above will never, ever work, because PHP is run on a server, not on your user's browser.
What you need to do is send the variable somehow to the server. You have a plethora of options:
Use a form and read a $_POST variable
Append it to a URL and read a $_GET variable
Use AJAX and asynchronously send that variable to the server
Return the whole array from PHP to your Javascript code
etc. etc.
Remember, PHP runs on the server, which renders the page, which then in turn is read by your browser where you run Javascript. You can't paste PHP code into the page and expect it to be parsed by PHP!
You need to get back to the server if you wish to get info from it (PhP runs on the server), so either you create a javascript variable on-the-fly when loading the page with the complete content of your PhP array , either you use ajax to get back to the server without refreshing the whole page.
I want the value of JavaScript variable which i could access using PHP.
I am using the code below but it doesn't return value of that variable in PHP.
// set global variable in javascript
profile_viewer_uid = 1;
// php code
$profile_viewer_uid=$_POST['profile_viewer_uid'];
this gives me the following error :-
A PHP Error was encountered
Severity: Notice
Message: Undefined index: profile_viewer_uid
Another php code i used which give empty value
$profile_viewer_uid = "<script language=javascript>document.write(profile_viewer_uid);</script>
When I echo it shows nothing.
Add a cookie with the javascript variable you want to access.
document.cookie="profile_viewer_uid=1";
Then acces it in php via
$profile_viewer_uid = $_COOKIE['profile_viewer_uid'];
You will need to use JS to send the URL back with a variable in it such as:
http://www.site.com/index.php?uid=1
by using something like this in JS:
window.location.href=”index.php?uid=1";
Then in the PHP code use $_GET:
$somevar = $_GET["uid"]; //puts the uid varialbe into $somevar
Here is the Working example: Get javascript variable value on the same page.
<script>
var p1 = "success";
</script>
<?php
echo "<script>document.writeln(p1);</script>";
?>
You might want to start by learning what Javascript and php are. Javascript is a client side script language running in the browser of the machine of the client connected to the webserver on which php runs. These languages can not communicate directly.
Depending on your goal you'll need to issue an AJAX get or post request to the server and return a json/xml/html/whatever response you need and inject the result back in the DOM structure of the site. I suggest Jquery, BackboneJS or any other JS framework for this. See the Jquery documentation for examples.
If you have to pass php data to JS on the same site you can echo the data as JS and turn your php data using json_encode() into JS.
<script type="text/javascript>
var foo = <?php echo json_encode($somePhpVar); ?>
</script>
If you want to use a js variable in a php script you MUST pass it within a HTTP request.
There are basically two ways:
Submitting or reloading the page (as per Chris answer).
Using AJAX, which is made exactly for communicating between a web page (js) and the server(php) without reloading/changing the page.
A basic example can be:
var profile_viewer_uid = 1;
$.ajax({
url: "serverScript.php",
method: "POST",
data: { "profile_viewer_uid": profile_viewer_uid }
})
And in the serverScript.php file, you can do:
$profile_viewer_uid = $_POST['profile_viewer_uid'];
echo($profile_viewer_uid);
// prints 1
Note: in this example I used jQuery AJAX, which is quicker to implement. You can do it in pure js as well.
PHP runs on the server. It outputs some text. Then it stops running.
The text is sent to the client (a browser). The browser then interprets the text as HTML and JavaScript.
If you want to get data from JavaScript to PHP then you need to make a new HTTP request and run a new (or the same) PHP script.
You can make an HTTP request from JavaScript by using a form or Ajax.
These are two different languages, that run at different time - you cannot interact with them like that.
PHP is executed on the server while the page loads. Once loaded, the JavaScript will execute on the clients machine in the browser.
In your html form make a hidden field
<input type="hidden" id="scanCode" name="SCANCODE"></input>
Then in your javascript update the field value by adding;
document.getElementById("scanCode").setAttribute('value', scanCode);
This could be a little tricky thing but the secure way is to set a javascript cookie, then picking it up by php cookie variable.Then Assign this php variable to an php session that will hold the data more securely than cookie.Then delete the cookie using javascript and redirect the page to itself.
Given that you have added an php command to catch the variable, you will get it.
You need to add this value to the form data that is submitted to the server. You can use
<input type="hidden" value="1" name="profile_viewer_uid" id="profile_viewer_uid">
inside your form tag.
I'd like to use the variable bradio in the "Having" clause of my query but i don't know how to get the content of the jquery variable and passe it into my sql query. This is a fragment of my php file. Can you tell me how can I do this?
Thanks
$conn = mysql_connect("localhost","form-test","pass");
$db = mysql_select_db("form-test",$conn);
?>
<script type="text/javascript">
jQuery.noConflict();
jQuery(function()
{
jQuery('#event_form_field-<?php echo $event_id; ?>').click(function()
{
var bradio= jQuery("input[type=radio]:checked").val()
alert(bradio); });});
</script>
<?php
$query2 = "SELECT COUNT(wp_events_answer.answer) as rep, wp_events_answer.attendee_id as idq, wp_events_question.quota as quota2, wp_events_attendee.event_id as ev, wp_events_answer.answer as answ, wp_events_question.id as qst3
FROM wp_events_answer, wp_events_attendee, wp_events_question
WHERE wp_events_answer.question_id = wp_events_question.id AND wp_events_answer.attendee_id = wp_events_attendee.id
HAVING answer =
GROUP BY answ;";
$result2 = mysql_query($query2) or die(mysql_error());
while($row2 = mysql_fetch_row($result2)) {
}
?>
You can't mix both PHP and javascript code in one page using the method above. The problem is because PHP is executed on the server, well before any javascript can be run on the client. Therefore, the two cannot speak to each other.
The solution here is to make an AJAX request to a PHP script on your server and pass the value of the radio control to it. This would then return the required data and you can then use javascript to display this on your page.
For example:
$.post(
'myScript.php',
'bradio=' + jQuery("input[type=radio]:checked").val(),
function(data) {
// process your result here
}
);
Write the query in another php file and pass the variable using an GET or POST or maybe ajax call
No you cannot pass a js variable to php in this way. The php code is executed before the page has sent to the browser while the js code is executed after: you need instead an ajax call with the bradiovalue passed along the request (get or post)
Either you need to send an POST Request and reload the page or you need to pass the variable via AJAX to the current page and change the output on the fly. Via jquery it's pretty simple to send an AJAX request via http://api.jquery.com/jQuery.ajax/
You will need to make a request from javascript ($.get or $.post) and pass value of this radio button as a parameter. Then, on PHP side you will be able to get it from $_GET or $_POST array.
I have a javascript variable which holds some information and I want that to assign in a PHP variable. Here is what I am using:
<script type="text/javascript">
function redirectToFacebook()
{
var facebookMessage = encodeURI(document.getElementById('txt_msg').value);
}
</script>
<?php
$_SESSION['sess_facebook_message'] = facebookMessage;
?>
Any help is really appriciable.
Thanks in advance
Because PHP runs on the server, and JavaScript in the client, there is no way to set a PHP session variable after JavaScript works with it, as PHP has done executing before the page was even sent.
However...
If you use JavaScript to make a request (AJAX, imagehack or otherwise) to a PHP script that sets the variable, you can.
For example...
JavaScript:
function something() {
// do something with somevar
somevar = 'content';
// make an AJAX request to setvar.php?value=content
}
PHP:
$_SESSION['somevar'] = $_GET['somevar'];
Make sure you take security issues of client-generated data into account, though.
If you want to pass variables from the browser (javascript) to your backend server (PHP), you need to either:
1) Load a new page with Javascript parameters encoded either as POST or GET
2) Asynchronously call a PHP script (AJAX call) encoding the parameters as POST or GET
A simple example using a GET request (you simply append your parameters to the URL):
<script>
window.location = '/some-url?' + document.getElementById('text_msg').value;
</script>
You probably want to assign this piece of code to a button or something...
what you are trying to achieve is not possible due to API limitation.It does not provide that.
may be you can try to redirect with javascript and pass variables form php to js. They way yout tru it, it can't work.
may be, im realy not shure
try this.
<?php
function redirectToFacebook() {
var facebookMessage = ?>
<script>
document.write(encodeURI(document.getElementById('txt_msg').value));
</script>
<?php
}
?>
or using cookies.
I want to call a PHP function when pressing on a button, sort of like:
<?php
function output(){
// do something
}
?>
<input type="button" value="Enter" onclick="output()"/>
I tried to make something like:
<input type="button" value="Enter" onclick="test.php?execute=1"/>
where test.php is current page and then by php
<? if(isset(&execute)){ echo "Hello"; } ?>
but it doesn't work.
Since PHP runs on the webserver, and buttons (and JavaScript in this case) appear on the client, you have to make an HTTP request to the server.
The easiest way to do this is to use a form. No JavaScript is required. You can add JavaScript (although it should be layered on top of a working non-JS version). Using JavaScript to make an HTTP request without leaving the page is known as Ajax, and generally achieved with the XMLHttpRequest object. There are various libraries such as YUI and jQuery that can do some of the heavy lifting for you.
I think using an AJAX call would do sort of what you are asking. I don't know PHP very well but you can use the following example, and add another variable with the data you are passing in to the server to indicate which function you want to call on the server. On the server you can add some "IF" statements that will call a certain function based on the name passed in and return the result.
Here is what you could use on in your javascript client using the jQuery library as a helper to do the AJAX call:
<input type="button" value="Enter" onclick="output()"/>
<script type="text/javascript">
function output(){
$.ajax({
type: "POST",
url: "submit_data.php",
data: "username=" + "SomeUser"
+ "&email=" + "someEmail#google.com"
+ "&functionName=" + "theFunction1",
success: function(html){
alert('sucess! Result is:' + html);
}
});
}
</script>
and you can use code such as this to catch the data your javascript is passing in. In this example you would want to call this file name as "submit_data.php" to match the javascript above:
<?php
// Variables
$Username = $_POST['username'];
$Email = $_POST['email'];
$FunctionName = $_POST['functionName'];
//Add code here to choose what function to call and echo the result
// If $FunctionName equals 'theFunction1' then execute theFunction1
// If $FunctionName equals 'theFunction2' then execute theFunction2
echo "You called A Page!";
?>
Here I am doing nothing with the "username" and "email" simply grabbing it and storing them into holding variables. But you can easily add extra functionality here, such as checking for a name of a function that you want to run.
PHP is server side and javascript is client side. So I'm not sure if that is really what you want to be doing??
Perhaps you could explain why you want to specifically call a php function?
I googled PHP function from button and found this question on webdeveloper.com
It doesn't use Javascript.
This is PHP you're talking about, not ASP.NET. In PHP, there is no such thing as a button click event. PHP runs entirely on the server and has absolutely no knowledge of client-side events.
Your first try won't work because the PHP code only runs when the page first loads. It does not run when you call a JavaScript function. Your second example won't work because JavaScript and PHP can't talk directly to eachother like that. Trying to directly call a PHP function from JavaScript just doens't make sense. Remember, PHP only runs on the server. By the time you get to the point where JavaScript can run, the PHP code has long since completed its work.
If you want to do something when a button is clicked, you have to explicitly make a request back to the server. You can do this by just POSTing the form as CTphpnwb suggested. Just be aware that this will reload the page and you will have to manually save and restore the page state, e.g. repopulate input boxes. There is no built-in magic that will do this for you.
Alternatively, you can get all AJAXy and do the POST in JavaScript. However, you will have to write the JavaScript to send the request and process the response, and write the server-side PHP code to handle the request. This gets a little awkward to do in a single page.
From : http://www.dreamincode.net/forums/showtopic72353.htm
You cannot directly invoke a PHP function from Javascript this way :
PHP code is executed on the server
HTML / Javascript are interpreted on the client-side.
One the HTML page has been generated and sent to the client (the browser), there is nothing more PHP can do.
One solution would be to use an Ajax request :
Your onclick event would call a Javascript function
This Javascript function would launch an Ajax request : a request sent to the server
The server would then execute some PHP code
And, then, return the result of that execution to the client
And you'd be able to get that result in your Javascript code, and act depending on what was returned by the server.
There are plenty of solutions to do an Ajax request :
You can re-invent the wheel ; not that complex, I should say -- but see the next point
If already using a Javascript framework, like jQuery, Prototype, ... Those provide classes/methods/functions to do Ajax requests
Googling a bit will get you lots of tutorials/examples, about that ;-)