I am trying to read the post request parameters from my HTML. I can read the get request parameters using the following code in JavaScript.
$wnd.location.search
But it does not work for post request. Can anyone tell me how to read the post request parameter values in my HTML using JavaScript?
POST data is data that is handled server side. And Javascript is on client side. So there is no way you can read a post data using JavaScript.
A little piece of PHP to get the server to populate a JavaScript variable is quick and easy:
var my_javascript_variable = <?php echo json_encode($_POST['my_post'] ?? null) ?>;
Then just access the JavaScript variable in the normal way.
Note there is no guarantee any given data or kind of data will be posted unless you check - all input fields are suggestions, not guarantees.
JavaScript is a client-side scripting language, which means all of the code is executed on the web user's machine. The POST variables, on the other hand, go to the server and reside there. Browsers do not provide those variables to the JavaScript environment, nor should any developer expect them to magically be there.
Since the browser disallows JavaScript from accessing POST data, it's pretty much impossible to read the POST variables without an outside actor like PHP echoing the POST values into a script variable or an extension/addon that captures the POST values in transit. The GET variables are available via a workaround because they're in the URL which can be parsed by the client machine.
Use sessionStorage!
$(function(){
$('form').submit{
document.sessionStorage["form-data"] = $('this').serialize();
document.location.href = 'another-page.html';
}
});
At another-page.html:
var formData = document.sessionStorage["form-data"];
Reference link - https://developer.mozilla.org/en-US/docs/Web/API/Window/sessionStorage
Why not use localStorage or any other way to set the value that you
would like to pass?
That way you have access to it from anywhere!
By anywhere I mean within the given domain/context
If you're working with a Java / REST API, a workaround is easy. In the JSP page you can do the following:
<%
String action = request.getParameter("action");
String postData = request.getParameter("dataInput");
%>
<script>
var doAction = "<% out.print(action); %>";
var postData = "<% out.print(postData); %>";
window.alert(doAction + " " + postData);
</script>
You can read the post request parameter with jQuery-PostCapture(#ssut/jQuery-PostCapture).
PostCapture plugin is consisted of some tricks.
When you are click the submit button, the onsubmit event will be dispatched.
At the time, PostCapture will be serialize form data and save to html5 localStorage(if available) or cookie storage.
I have a simple code to make it:
In your index.php :
<input id="first_post_data" type="hidden" value="<?= $_POST['first_param']; ?>"/>
In your main.js :
let my_first_post_param = $("#first_post_data").val();
So when you will include main.js in index.php (<script type="text/javascript" src="./main.js"></script>) you could get the value of your hidden input which contains your post data.
POST is what browser sends from client(your broswer) to the web server. Post data is send to server via http headers, and it is available only at the server end or in between the path (example: a proxy server) from client (your browser) to web-server. So it cannot be handled from client side scripts like JavaScript. You need to handle it via server side scripts like CGI, PHP, Java etc. If you still need to write in JavaScript you need to have a web-server which understands and executes JavaScript in your server like Node.js
<script>
<?php
if($_POST) { // Check to make sure params have been sent via POST
foreach($_POST as $field => $value) { // Go through each POST param and output as JavaScript variable
$val = json_encode($value); // Escape value
$vars .= "var $field = $val;\n";
}
echo "<script>\n$vars</script>\n";
}
?>
</script>
Or use it to put them in an dictionary that a function could retrieve:
<script>
<?php
if($_POST) {
$vars = array();
foreach($_POST as $field => $value) {
array_push($vars,"$field:".json_encode($value)); // Push to $vars array so we can just implode() it, escape value
}
echo "<script>var post = {".implode(", ",$vars)."}</script>\n"; // Implode array, javascript will interpret as dictionary
}
?>
</script>
Then in JavaScript:
var myText = post['text'];
// Or use a function instead if you want to do stuff to it first
function Post(variable) {
// do stuff to variable before returning...
var thisVar = post[variable];
return thisVar;
}
This is just an example and shouldn't be used for any sensitive data like a password, etc. The POST method exists for a reason; to send data securely to the backend, so that would defeat the purpose.
But if you just need a bunch of non-sensitive form data to go to your next page without /page?blah=value&bleh=value&blahbleh=value in your url, this would make for a cleaner url and your JavaScript can immediately interact with your POST data.
You can 'json_encode' to first encode your post variables via PHP.
Then create a JS object (array) from the JSON encoded post variables.
Then use a JavaScript loop to manipulate those variables... Like - in this example below - to populate an HTML form form:
<script>
<?php $post_vars_json_encode = json_encode($this->input->post()); ?>
// SET POST VALUES OBJECT/ARRAY
var post_value_Arr = <?php echo $post_vars_json_encode; ?>;// creates a JS object with your post variables
console.log(post_value_Arr);
// POPULATE FIELDS BASED ON POST VALUES
for(var key in post_value_Arr){// Loop post variables array
if(document.getElementById(key)){// Field Exists
console.log("found post_value_Arr key form field = "+key);
document.getElementById(key).value = post_value_Arr[key];
}
}
</script>
function getParameterByName(name, url) {
if (!url) url = window.location.href;
name = name.replace(/[\[\]]/g, "\\$&");
var regex = new RegExp("[?&]" + name + "(=([^&#]*)|&|#|$)"),
results = regex.exec(url);
if (!results) return null;
if (!results[2]) return '';
return decodeURIComponent(results[2].replace(/\+/g, " "));
}
var formObj = document.getElementById("pageID");
formObj.response_order_id.value = getParameterByName("name");
One option is to set a cookie in PHP.
For example: a cookie named invalid with the value of $invalid expiring in 1 day:
setcookie('invalid', $invalid, time() + 60 * 60 * 24);
Then read it back out in JS (using the JS Cookie plugin):
var invalid = Cookies.get('invalid');
if(invalid !== undefined) {
Cookies.remove('invalid');
}
You can now access the value from the invalid variable in JavaScript.
It depends of what you define as JavaScript. Nowdays we actually have JS at server side programs such as NodeJS. It is exacly the same JavaScript that you code in your browser, exept as a server language.
So you can do something like this: (Code by Casey Chu: https://stackoverflow.com/a/4310087/5698805)
var qs = require('querystring');
function (request, response) {
if (request.method == 'POST') {
var body = '';
request.on('data', function (data) {
body += data;
// Too much POST data, kill the connection!
// 1e6 === 1 * Math.pow(10, 6) === 1 * 1000000 ~~~ 1MB
if (body.length > 1e6)
request.connection.destroy();
});
request.on('end', function () {
var post = qs.parse(body);
// use post['blah'], etc.
});
}
}
And therefrom use post['key'] = newVal; etc...
POST variables are only available to the browser if that same browser sent them in the first place. If another website form submits via POST to another URL, the browser will not see the POST data come in.
SITE A: has a form submit to an external URL (site B) using POST
SITE B: will receive the visitor but with only GET variables
$(function(){
$('form').sumbit{
$('this').serialize();
}
});
In jQuery, the above code would give you the URL string with POST parameters in the URL.
It's not impossible to extract the POST parameters.
To use jQuery, you need to include the jQuery library. Use the following for that:
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.1/jquery.min.js" type="text/javascript"></script>
We can collect the form params submitted using POST with using serialize concept.
Try this:
$('form').serialize();
Just enclose it alert, it displays all the parameters including hidden.
<head><script>var xxx = ${params.xxx}</script></head>
Using EL expression ${param.xxx} in <head> to get params from a post method, and make sure the js file is included after <head> so that you can handle a param like 'xxx' directly in your js file.
I was trying to make a Json Object of some variables Which I am using as Session variables, But I am not geting the proper Response To make it as Json Object ..
Some Code which I tried (for Reference) Sharing Below..
//Passing the Variable To another PHP File
session_start();
$_SESSION['EmailIds']=$strEmailIds;
$_SESSION['SCHOOL_NAME']=$SCHOOL_NAME;
//sending data to another php page ..
header('Location: ../SecondPage.php');
In second file SecondPage.php Where i was Using This Session..
session_start();
$SCHOOL_NAME = $_SESSION['SCHOOL_NAME'];//1
$EmailIds= $_SESSION['EmailIds'];//1 <br>
Now trying to make this Session Variable in Json OBject...????
var OBJ = jsonObj.(SCHOOL_NAME+EmailIds);// Confuse with THis Line<br>
Actuaaly Not Getting What is the Good Approach To make this variables as Json Objects..
AS I Made this Json Object I can Use This AS another Purpose Like to send as Ajax Data and etc..
You can use json_encode method like this :
$someArray; //can be array of your values or $_SESSION
$jsonObj = json_encode($someArray);
get session data in an array like :
$data['SCHOOL_NAME'] = $_SESSION['SCHOOL_NAME'];
$data['EmailIds']= $_SESSION['EmailIds'];
then encode it like
$json_obj = json_encode($data);
function show_selling_price(sp,co)
{
$r=sp;
var e="select * from tbl where id='$r'; ?>";
document.getElementById('selling_price_'+co).value=e;
}
//php assign value does not work why?
//Please correct above code with proper description
You can not set a PHP variable from JavaScript. For example this is not possible:
var js_var = 10;
$php_var = js_var;
However you can set a JS variable from PHP:
var js_var = <?php echo $php_var ?>;
PHP is executed on the server side and then the result shows up on the browser.
JavaScript is executed on the client side once the server returns the response.
If you really need to pass a JS var then use AJAX to submit vars to the server.
It is not possible to assign a javascript variable to a php variable like your example above.
Javascript is a client side language whilst PHP is a server side language.
What you can do is to echo out php variables to a javascript code before it is rendered at the visitors web browser like:
<script>
var text = "<?php echo $variable; ?>";
</script>
If you are setting a variable in Javascript first, and then want to pass it on to PHP, you either have to use ajax, or use a html-form to post the information to the server
i need to capture the value of an javascript code. To be more precise the document.location.href, but i need to do this with PHP.
Actually i'm doing this:
$html = file_get_html("http://server.camgate.ru/snapshot.php?camid=111013191059");
$element = $html->find('img');
$img = $element->src;
and it shows progress.gif, that's cool, the problem is that i need to get the href of the javascript inside that webpage to show the image inside.
Like this:
$url = "http://server.camgate.ru/snapshot.php?camid=111013191059";
$html = file_get_html($url);
$element = $html->find('script');
$link = $element->href;
$data[] = array("camara" =>"Camara 1", "imagen"=>$link);
the $html shows this:
<script> \n width=document.body.clientWidth; \ndocument.location.href = \"http:\/\/camgate.ru\/showpix.php?id=111013191059&m=1013&d=171013&pix=171013035306.jpg\"; \n<\/script>
So i need to get the url posted there. But if i use the $element->href it shows null.
How can i get it?
Thanks in advance
You can draw Javascript with PHP but you can't do the reverse. If you need to pass data back to your PHP, the only way would be to use AJAX. Either that, or figure out the URL end on the PHP end beforehand.
Is there any way in Javascript to get the parameters ume modified URL with htaccess?
As an example: www.website.com/argument/1/argument/2
Where "/argument/2" = &product_id=2
There is some way to pick up these parameters in JavaScript?
You can export these properties by simply printing the map as JSON. I'm going to show this in PHP.
<script>
var GET = <?= json_encode($_GET); ?>;
</script>
Then you can access the values as GET['product_id'].