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.
My question is probably basic, but there is the question:
I have a javascript function which sends an array via ajax to process some information...
var second = $('form.contact').serialize();
var arry = {keystatus: varId, keyname: second}
In php, I added the data sent via ajax a array and wrote an echo to see in ajax success, displaying via console.log.
What do I get:
My php script:
$name = strip_tags($_POST['keystatus']);
$email = strip_tags($_POST['keyname']);
$teste['nome'] = $name;
$teste['email'] = $email;
echo json_encode($teste);
I needed to find a way to get separate, for example:
$_POST['keyname']['nome'] -> (in this example) discovery
$_POST['keyname']['email'] -> discovery#discovery.com
$_POST['keyname']['usuario'] -> discovery
You are currently adding the form data as a serialized string to an object, which you send. That's why it looks the way it does.
You can either build a new object with all data and send that object with ajax:
var data = {
keystatus: varId,
keyname: {
nome: $("#the_nome_input").val(),
email: $("#the_email_input").val(),
usuario: $("#the_usuario_input").val()
}
};
Or you can add the extra value (since it only seems to be one) as a hidden input field in your form:
// Add this to the form
<input type="hidden" value="" name="keystatus" id="keystatus" />
// In your js, add
$("#keystatus").val(varId); // Sets the value
var data = $("form.contact").serialize();
...now you can send data to your back end using ajax.
If you want to fetch your data like this: $_POST['keyname']['nome'] and use the second alternative, then you need to rename your input fields to: name="keyname[nome]", name="keyname[email]" and name="keyname[usuario]".
That will give you the correct data structure and values.
I am trying to send some json data from js to php, and pass it to mongo by REST.
The following outputs json string (that works fine later if I just put it as string in PHP file, please see snippet below).
JS to send json:
var s = JSON.stringify(send); //s contains previous data in arrays, etc
ic(s);
function ic(s){
var ajaxUrl = './iM.php';
$.getJSON(ajaxUrl,
{da: s},
function(data) {
console.log (data);
});
}
in iM.php:
$s = $_GET["da"]; // <-- doesn't work
//$s = '{"r":"pax","c":1,"w":["kiwi","melon"],"g":["cat","dog"]}'; //<-- works fine
$opts = array(
"http" => array(
"method" => "POST",
"header" => "Content-type: application/json",
"content" => $s,
),
);
$context = stream_context_create($opts);
$result = file_get_contents("https://api.mongolab.com/api/1/databases/$db/collections/$collection?apiKey=$key", false, $context);
var_dump($result); // Dumps the response document
At the firefox debugger, I can see the file is actually being called, however No data is added.
error_log file is created:
failed to open stream: HTTP request failed! HTTP/1.1 400 Bad Request
I also tried urlencode($s) in php, still not working.
$db, $collection and $key are defiend in php, no problem there.
What am I missing?
Basically JSON.stringify(send) function is designed in such way that it will make your json into what you are getting.
JSON.stringify(value[, replacer[, space]])
You should use this function properly. read the docs to know more.
Its basically useful if you have input value as JS array or JS object
which can be converted to single string.
You are getting '{/"r/":/"pax/",/"c/":1 in only case if you are trying to stringify a json which already in string format.
these:
var s = ['1','2','3'];
and
var s = "['1','2','3']";
are totally different things.
If you are sending an array or json object you can even send it directly
using the code above.
for example :
send = {"r":"pax","c":1,"w":["kiwi","melon"],"g":["cat","dog"]};
ic(send);
function ic(s){
var ajaxUrl = 'im.php';
$.getJSON(ajaxUrl,
{da: s},
function(data) {
console.log (data);
});
}
make sure to handle array at php side properly.
Like if you want return json, do:
$s = $_GET["da"]; //this will be array.
var jsonObject = json_encode($s);
or you can stringify it there and then provide.
or else just send string and then use json_decode to make it json in php
JavaScript jQuery post:
var animals = {
animalsArray: [],
tripId: <?php echo $_GET['id']; ?>
};
$('.student-check').each(function() {
animals.animalsArray.push($(this).attr('id'));
});
var sendMe = JSON.stringify(animals);
$.post("saveChanges.php", sendMe, function(response) {
console.log(response);
}, "json");
PHP handler:
echo json_encode(print_r($_POST, true));
// Array
// (
// )
Why is the array empty? I'm posting data but the response returns an empty array.
You are encoding the data as JSON, which isn't a format PHP handles natively for form submissions.
Remove var sendMe = JSON.stringify(animals); and pass animals to $.post instead of sendMe. jQuery will encode it using one of the standard formats supported by HTML forms and PHP.
Alternatively see this question for how to get the raw request body.
Also:
echo json_encode(print_r($_POST, true));
json_encode and print_r are both functions that take a data structure and express it as a string. Use one or the other, not both.
I am using AJAX to send inputs from a webpage to a PHP file to then be entered into a database. Here is my JavaScript file:
var pageLoaded = function () {
var submitButton = document.getElementById("submit");
if (submitButton) {
submitButton.addEventListener("click", submit, true);
}
};
var submit = function () {
var xhr, changeListener;
var form = document.getElementById('item_form');
var inputs = form.getElementsByTagName('input');
// create a request object
xhr = new XMLHttpRequest();
// initialise a request, specifying the HTTP method
// to be used and the URL to be connected to.
xhr.open("POST", "../php/add_item.php", true);
console.log(inputs[0].value); // debugging
// Sends the inputs to the add_item.php file
xhr.send(inputs);
};
window.onload = pageLoaded;
Here I am trying to send inputs from a form to a PHP file called add_item.php located "../php/add_item.php" in my file system.
I am pretty sure this code works and sends the inputs to the PHP file in an array.
My question is, how do I then use $_REQUEST within that file to be able to use the inputs within the array to send to a database? Or, what is the best way of doing this?
The xhr.send() method only accepts a string. If you want to send an array you have to flatten it into a string before posting. You can do this easily using the JSON.stringify() method in javascript, then use json_decode() function in PHP on receiving it.
Also for PHP to receive the data properly in the $_POST[] variable (or $_REQUEST if you must, but not recommended) you need to set a name for the POST variable and URL-encode your JSON text like this:
var json_array = JSON.stringify(inputs);
xhr.send('myJSONData=' + encodeURIComponent(json_array));
On the PHP side you shouldn't need to use urldecode() because the server stack expects to receive POSTed name-value pairs url-encoded. But you will need to use json_decode on the posted variable to get the array back, e.g.:
php_array = json_decode($_POST["myJSONData"]);
You will see other methods to do this, including setting the xhr POST content-type header to JSON, but in my experience this is the path of least resistance.
Also note whilst it is possible to send an "array" of objects in an HTML form like this:
<input type="text" name="myArray[]" value="val1">
<input type="text" name="myArray[]" value="val2">
<input type="text" name="myArray[]" value="val3">
<input type="text" name="myArray[]" value="val4">
which will result in an array being available within PHP in the variable $_POST["myArray"], there is no easy equivalent of this using the XHR object (AJAX method). JSON.stringify() is IMO the easiest way to go.
The variables inside the $_REQUEST are stored as an array. To access them you would do something similar to this:
echo $_REQUEST['input_1'];
To view all the variables (in a nice format) sent by the JS you could use this code:
echo "<pre>";
print_r($_REQUEST);
echo "</pre>";
You can't do it in the way you are doing it. You send "input" array which is incorrect. You should prepare array of input values. Morover, I'd recommend you to use JQuery.
$(function (){
$("#submit").click(function (){
//the way to get input values and names
var arr = [];
$("input").each(function (index,value){});
arr.push([$(value).attr('name'), $(value).val()];
});
// it can be replaced also via serialize() funciton
//ajax
$.post( "../php/add_item.php", arr)
.done(function( data ) {
//data has been send response is in data object
});
});
});
In PHP you can get these values via $_POST. $_REQUEST is not needed here because you use POST method. For example if you have input
<input name="xxx" value="test">
to print value of this input in PHP you need use this code
echo $_POST['xxx'];
If you don't want to use JQuery then you still need loop through inputs and prepare proper array to send it via XHR.