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.
Related
I have an index HTML page that grabs a user's username and password from a form.
I want to base 64 encode this before passing it to a php file that makes a request to a server with the encoded credentials.
I tried doing something like:
<script>
// The below function calls the PHP file responsible for retrieving campaign details.
function getCampaignDetails() {
var username = $('#username').val(); //This successfully returns the username.
var password = $('#password').val(); //This successfully returns the password.
var authentication_string = <?php $username = urldecode($_GET['username']); $password = urldecode($_GET['password']); echo base64_encode($username.':'.$password); ?>;
$.ajax({
type: "GET",
url: "http://localhost/testing/get_campaign_details.php",
headers: { 'Access-Control-Allow-Origin': '*' },
data: {
"authentication_string": authentication_string
},
});
}
</script>
But I get an error about an unexpected token < which I'm assuming is a syntax error in the authentication_string value. If I add quotes around this value, the php doesn't execute and I get the whole string as is passed to the php file, rather than the encoded credentials.
Is there a way to use PHP in a basic HTML file that grabs a JavaScript variable value, uses a PHP function to get a new value, and then pass back this new value to the data in an Ajax request from the HTML file that is then subsequently utilized by another PHP file?
Or is there a way to base 64 encode something using an HTML/JavaScript function instead of PHP function?
Best,
You need to add quotation marks around the php that you're running to get the authentication_string.
var authentication_string = "<?php $username = urldecode($_GET['username']); $password = urldecode($_GET['password']); echo base64_encode($username.':'.$password); ?>";
Javascript is expecting a value that it can assign to the variable authentication_string after the = like an int or a string. When it see's < it doesn't know what to do with it so it throws an unexpected token error.
As a sidenote - passing a username and password in the querystring (the url) is not a good idea. Even though they are encoded it's better to keep those kind of things away from prying eyes. There's a post here that might be helpful on how to handle sensitive data like that. Best way to pass a password via GET or POST
I'm trying to create a js that send data to a php.
My first problem is that I get get back a html code if I insert this to the php.
This is only for understand the idea. So the js should send the "param" to the php and the php should return the result6 variable in this case, but I get a html code...
$('#f_field').change (function()
{
var param = 28;
$.post('check_mutet.php', param, function(result6) {
alert(result6);
});
});
while check_mutet.php contains this
<?php
$result6=666;
echo $result6;
Thank you for your help, as you can see I'm rather noob :)
param is a plain string (it starts out as a number, but will be converted to a string by the time it gets through to HTTP).
This will be available as STDIN in PHP, which you can read as described in answers to this question.
However, you should encode the data into a structured format that is easier to use.
The traditional format for this is application/x-www-form-urlencoded, which is the default format sent by HTML forms.
If you pass an object to jQuery post, it will encode the data in that format for you:
var param = 28;
var data = { example: param };
$.post('check_mutet.php', data, function(result6) {
Then you can read it through the POST superglobal in PHP:
<?php
$result = $_POST['example'];
After form submission I want to redirect to another page where I need values from the Previous submitted form.
So in my redirect script I want to pass those values in GET
I am doing this :
<script>
var id = <?php echo $data['base_ini_id']."?&ext=".$data['ext']; ?>
window.location.replace("./edit_ini_custom/"+id);
</script>
OR Is there anything else with which I can do as required?
Get variables are (always) passed through the URL. So basically you should use:
var redirectUrl = "yourUrlWithVariables";
window.location.replcae(redirectUrl);
Now depending on the format of your target URL, the way you compose the target URL. Here are some common examples:
Format 1: baseUrl.com/page?paramName1=paramValue1¶mName2=paramValue2
var baseId = '<?=$data['base_ini_id'];?>';
var extId = '<?=$data['ext'];?>';
var baseUrl = "baseUrl.com/edit_ini_custom?base_ini_id="+baseId+"&ext="+extId;
Format 2: baseUrl.com/page/paramValue
var extId = '<?=$data['ext'];?>';
var baseUrl = "baseUrl.com/edit_ini_custom/"+extId;
Format 3: baseUrl.com/page/paramName/paramValue
var extId = '<?=$data['ext'];?>';
var baseUrl = "baseUrl.com/edit_ini_custom/ext/"+extId;
Format 4: baseUrl.com/page/paramName1/paramValue1/paramName2/paramValue2
var baseId = '<?=$data['base_ini_id'];?>';
var extId = '<?=$data['ext'];?>';
var baseUrl = "baseUrl.com/edit_ini_custom/base_ini_id/"+baseId+"/ext/"+extId;
Note that this are only guidelines, and in any case after you parse and build the target URL, you must call window.location.replace(baseUrl). Other option is just use:
window.location = baseUrl;
but using this will add that redirection to the history allowing users to hit "back", which I'm not sure is something you'd like.
Hope this helps
The form that's already submitted (in the previous page) cannot be accessed, as such, from the next page.
So, in short, the answer to your question is NO.
You need to implement in one of the ways:-
Store the values in the user's session object (if you already have login implemented)
Use a Http Cookie or Browser's localStorage to store the value
Persist the value to the server and fetch in the subsequent page, as hidden variables.
You can do a PHP redirect by setting the header Location
header("Location: ".$data['base_ini_id']."?&ext=".$data['ext']);
This will be a convenient way i guess than the one you suggested.
Finally Got an Answer:
<script>
var id = <?php echo $data['base_ini_id']; ?>
window.location.replace("./edit_ini_custom/"+id+"/"+<?php echo $data['ext']; ?>);
</script>
I can pass the PHP Variable as PARAMETER And On the Function Where I need it i Just Have to Do :
public function edit_ini_custom($id,$ext)
{
echo $ext;
//code
}
Im new in programming and Im trying to make a program that would register a selected space in my database. I want to convert js variable str into $phpvar php variable. Please help me
$('#btnShowNew').click(function () {
var str = [], item;
$.each($('#place li.' + settings.selectingSeatCss + ' a'), function (index, value) {
item = $(this).attr('title');
str.push(item);
});
<?php
include "accounts/config.php";
$phpvar='"+str+"';
mysql_query("INSERT INTO sample (sample) VALUES ('".$phpvar."')");
//echo $phpvar;
?>;
})
});
As the previous speakers already explained, you need to think in terms of client-side running code and server-side running code.
Whenever you want to share a state between those two parts of your application you need some communication mechanism.
Client -> Server
For this you need to make a HTTP request. This can either be a post or a AJAX call. For the latter one just have a look at jquery.ajax as you're obviously already using jQuery anyway.
$.post({
"savesample.php",
{myPostVar: str}
}).done(function() {
alert("sample saved.");
});
Of course you need a serverside script to handle this request:
<?php
$yourVar = $_POST["myPostVar"];
// TODO use mysqli::escape_string or similar!!
mysql_query("INSERT INTO sample (sample) VALUES ('".$yourVar."')");
?>
Server -> Client
This is a lot easier. You can of course use ajax again (GET requests on your php file, which generates a nice javascript-compliant output like JSON).
Or just write your variable to an inline-script-tag:
<script>
<![CDATA[
var yourJsvar = '<?= $yourPhpVar ?>';
]]>
</script>
Further Reading
As your php file is an open gate for all kinds of misuse you should secure it using one-time authorization tokens. Once you are used to the basic concepts, go on with the following topics:
CORS
SQL injection
Authenticated AJAX calls
You'll want to POST to a PHP listener. You don't want PHP tags inside of a JS function in this way. The only reason for PHP tags inside of a JS function would be if you were getting data from PHP to JS, not the other way around.
Look up Jquery post for more information.
The order in which languages run is PHP -> HTML -> CSS -> Javascript. You can NOT go backwards from that order.
On the other hand, you can send Javascript information through an AJAX call. AJAX is an Asynchronous Javascript call which can communicate with PHP!
So for instance (using JQuery)
$.ajax({
url:"someurl",
type:"POST or GET",
data:{query:"SELECT * FROM table"}, //Any data to pass along? Like strings or data?
datatype:"JSON", //This is the return type of the information you want if any
success: successfulHandlerfunction()
error: errorHandlerfunction()
});
That is just some basic grounds. You can find more information on AJAX calls through http://www.w3schools.com/ajax/
I hope this helps!
JS
$('#btnShowNew').click(function () {
var str = [], item;
$.each($('#place li.' + settings.selectingSeatCss + ' a'), function (index, value) {
item = $(this).attr('title');
str.push(item);
});
$.ajax({
type: "POST",
url: "save.php",
data: {items: str},
success: function(responce) {
alert(responce);
}
});
});
Create save.php file
<?php
include "accounts/config.php";
$items = $_POST['items']; // Validation HERE!!!
foreach ($items as $item) {
// Insert to DB
}
echo 'Saved';
?>
Separate languages = separate files. (if you can...)
In PHP always check user input.
Use PDO.
This is not possible because the js code is client side and php is server side. What you would need to do is to make an ajax request to a php script in order to send the data for the variable. Here is an example:
Client(browser):
$.ajax({url:"http://domain.com/accounts/config.php?variableToSend=variableValue",success:function(result){
alert("Variable was successfully sent.");
}});
Server(Apache)
config.php
<?php
$varToSend = $_GET["variableToSend"]
//Do whatever you want with the variable
?>
I am developing a php page containing a drop down select button. On changing its value, I am calling a javascript method and passing value selected in drop down. Now I want to use the value passed to get further details from MySql using PHP. How can I write PHP code withing javascript?
I am a beginner to PHP. Suggest me a simple and easiest way to do this
For onchange event of dropdown, you can call php page using ajax and passing your params and get the output.
Try to use ajax like this (http://www.w3schools.com/php/php_ajax_database.asp)
and this (http://coursesweb.net/ajax/multiple-select-dropdown-list-ajax_t)
Front-end client side script (Javascript) can't directly 'invoke' or run PHP code. This is because of the separation between client side (browser) and server side (server) components of a web page. When you make a normal request to a server to return a page (eg. index.html), it will return the content of the page and terminate the execution.
What you're trying to achieve is something called AJAX, which is described on Wikipedia. There's also a pretty good and basic example of how to run a PHP script from Javascript.
In basic terms, AJAX is an asynchronous execution of the server side component of a web page. You can target a page 'test.php' with an ajax request, much the same was as you would when you open the page in your browser, and the content of the page would be returned.
To get the additional content, you can use either a POST ($_POST) or GET($_GET) request to send details back to the server. Typically when you're performing a search, you would use GET. If you're performing an update or create, you would use POST.
So your page URL might be something like http://mywebsite.dev/ajax.php?select=apples (where mywebsite.dev is the development URL). If you have a table of apple types, your MySQL query would be:
$type = $_GET['select'];
// Do some filtering on $type, eg. mysql_real_escape_string() and a few others
SELECT fruit.types FROM fruit WHERE fruit.main_type = '$type';
And then return a formatted JSON object back to the browser:
$return = Array(
0 => 'Pink Lady',
1 => 'Sundowner',
2 => 'Granny Smith',
...
);
$json = json_encode($return);
// expected result
{['Pink Lady'],['Sundowner'],['Granny Smith']};
You can always give extra indexes to arrays (multi-dimensional) or use stdClass to give better structure.
Then in your Javascript you use a for loop to iterate over the json object to build a new list of options.
var output = '';
for (var i = 0, k = json.length; i < k; i++) {
output += '<option value="' + json[i] + '">' + json[i] + '</option>';
}
Hope that helps.
Hi for this you need to use ajax.
try :
index.php code : This script will grab data from from using jquery and post it to search.php file via ajax
<html>
<head>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
$('#userid').change(function(){
userid=this.value;
$.ajax({
url:'search.php',
data : 'userid='+userid,
type:'POST',
success:function(result){
$('#result_div').html(result);
}
});
});
});
</script>
</head>
<body>
<form name='getUserData' id='getUserData' action='#' method='GET'>
Select User : <select id='userid' name='userid'>
<option value='1'>Lokendra</option>
<option value='2'>Amit</option>
<option value='3'>Nitin</option>
<option value='4'>Rishabh</option>
</select>
</form>
<div id='result_div'></div>
</body>
</html>
search.php code : This file will contain you business logic . and return value to ajax success method. You can fill retrun result any container.
<?php
$userArray=array(
1 => 'Lokendra',
2 => 'Amit',
3 => 'Nitin',
4 => 'Rishabh',
);
$postedData=$_REQUEST;
// Fire your select query here and diplay data
if(isset($postedData['userid'])){
echo "Selected User name =>".$userArray[$postedData['userid']];die;
}
?>
Dont forget to accept answer if it helps you. :)