I want to retrieve a value from a HTML selection drop-down and store it into a PHP variable. I'm sure this has to be done in AJAX, but I'm not sure on the details. Is it possible to get that value of the option field and store it into a PHP variable this way?
$("#files").change(function() {
$.ajax({
type: "POST",
url: "parse.html",
data: {$'files'= $(this).val()},
success: function(response) {
//lolwut?
}
});
});
I want to store it in a php variable $x is what I just labeled it. The selection is title files.
Thanks.
You're pretty close. The data portion of the AJAX call should contain a key/value pair. Example:
data: {selectVal : this.value},
Now on your PHP backend, you can retrieve the variable with:
$selectValue = $_POST['selectVal'];
Do with it what you want, and you can return whatever you want to the client-side as well with echo. Whatever you echo back can now be picked up in the AJAX success callback under your variable response.
Also, set your url to your PHP page url.
Related
I am new to php and am trying to update a hidden field value inside a php function and can't see to find a solution that works.
In template.php I have:
<input type="hidden" id="variable_ID" name="variable_name" value="variable_value">
This works fine.
However I need to update the value of the variable to the record ID of inserted record in a function in functions.php eg
function myFunction() {
$insert_record = $mydb->query("INSERT INTO `Table`(`Name`) VALUES ('John')");
$get_record_id = $mydb->insert_id;
// *** Set Hidden field value to $get_record_id here ***
}
I have tried a myriad of things but can't seem to find a solution.
Any pointers on how to solve this problem?
Here is the solution I used - thanks to #Steven and #El_Vanja for direction.
(I may need to change the question title now though because what I actually needed to do was return a variable to javascript from PHP using Ajax. I didn't need to use hidden fields).
PHP
function myFunction() {
$insert_record = $mydb->query("INSERT INTO `Table`(`Name`) VALUES ('John')");
$get_record_id = $mydb->insert_id;
echo json_encode($get_record_id);
exit;
}
JS
jQuery.ajax({
url: ajax_url,
type:'POST',
data: {
action: "myFunction",
anydata:"to be posted"},
success: process_record_ID
});
function process_record_ID(data_returned_from_myFunction){
recordID = data_returned_from_myFunction;
}
Hope this helps others!
Notes
I believe that we have to declare 'process_record_ID' as a separate function outside of AJAX because AJAX is asynchronous. If we define the function in the success handler, the function runs in AJAX before the value is actually returned from PHP.
In the AJAX success handler, we don't need to explicitly list the 'data_returned_from_myFunction' variable in the call to process_record_ID function. When the data is returned to the AJAX success handler from PHP, it still gets sent to the function.
Additional answer
You're correct AJAX is an asynchronous construct which means that certain tasks can be carried out before you might expect them to (from a synchronous perspective).
For example we can (as per the code in the original answer) use jQuery to update the value of a field directly in the success handler.
We can't update a JS variable directly, i.e:
some_variable = response.value;
If you attempt it the variable some_variable will likely be undefined.
The difference comes down to callbacks:
Callbacks allow the asynchronous function to call a function after it completes. Where as setting a variable happens on the spot.
There are two easy ways to solve this issue then:
Create a function outside of the AJAX request and allow it to callback that function once the AJAX request has completed -- as you've already discovered.
Use the complete option inside of your AJAX request.
Using a call back
Firstly we need to define out variable to be updated and the function which we will use to update it:
var inserted_id = "";
function update_id(data){
inserted_id = data.record_id;
}
Then we can make out AJAX call:
$.ajax({
type : "POST",
url : "/url/to/functions.php",
data : {data:"to be posted"},
dataType: 'json',
success : update_id
});
N.B.
Calling update_id in this fashion means we pass the entirety of the returned JSON object; not just the returned number.
Alternatively...
var inserted_id = "";
function update_id(data){
inserted_id = data;
}
$.ajax({
type : "POST",
url : "/url/to/functions.php",
data : {data:"to be posted"},
dataType: 'json',
success : function(response){
update_id(response.record_id);
}
});
This method is effectively the same but we only pass the returned number to the update_id function.
Using complete
complete works the same way as success however activates once the AJAX request is... complete...
var inserted_id = "";
$.ajax({
type : "POST",
url : "/url/to/functions.php",
data : {data:"to be posted"},
dataType: 'json',
complete: function(data) {
inserted_id = data.responseJSON.record_id;
}
});
Original answer
Having not seen the rest of your code giving a complete answer is tricky. However, this should set you on the right track:
PHP
Firstly, in your PHP you need to make sure and output the data that you want returned to the webpage. In this case we want to return the insert id of the newly created record; to do this we're going to output a JSON object so that the AJAX call can interpret the value and update the page:
function myFunction() {
$mydb->query("INSERT INTO `Table`(`Name`) VALUES ('John')");
echo json_encode(["record_id" => $mydb->insert_id]);
exit;
}
N.B.
We don't want any output other than the JSON string. Hence exit has been used after the echo. You may want/need to adjust the echo and exit to fit with the rest of your code etc.
JS
Now that we have our PHP returning usable data to our ajax call (which should look something like the below) we can take the returned data aka response and update the value of the hidden field accordingly.
$.ajax({
type : "POST",
url : "/url/to/functions.php",
data : {data:"to be posted"},
dataType: 'json',
success : function(response) {
$("#id_of_hidden_field").val(response.record_id);
}
});
I've read all the articles but cant seem to get my ajax response into a PHP variable. Please can you advice. I want to assign rowid to a PHP variable.
$(document).on('click', '#updateid', function() {
var vallab = $('#idval').val();
var rowid;
$.ajax({
url:'a.php',
type: 'POST',
async: false,
data: {labid: vallab},
success: function(data){
// console.log(data);
rowid = data;
}
});
console.log(rowid);
return rowid;
});
my a.php code is below
<?php
# Fetch the variable if it's set.
$lab_id = (isset($_POST["labid"])) ? $_POST["labid"] : null;
echo $lab_id;
?>
I am getting the response back with the id, and want to use it on that page
I want to pass rowid into a PHP function so I need to get the value of rowid.
Please can you advice?
I cant seem to get my ajax response into a PHP variable
Well, the AJAX response came FROM a PHP file, right? So why don't you do whatever you need to do with the response right in that PHP file?
$.ajax({
url:'THIS IS YOUR PHP FILE',
type: 'POST',
data: {THIS IS THE DATA YOU SEND TO PHP},
success: function(data){
console.log(data); //THIS IS THE RESPONSE YOU GET BACK
}
});
You can't use it. Javascript is a scripting language which run in browser when the dom is loaded and elements are visible.
PHP is a serverside language and run on server before the page is loaded.
You need to understand the lifecycle of your application. Your php code executes once, it runs the full script from top to bottom when the page loads. At the point the script starts if can only access the post that came with the request (e.g if you clicked submit on a form then the 'action' of the form receives the post). Any number of things can happen in your script, but once it's finished the php is gone, and so is the post (in basic terms). So you no longer have any access to the php which created this page.
Ajax allows you to update a section of your page - it sends a request to your sever and runs some php code - you must understand that this is a new and separate request, so the new post submission only exists in the lifecycle of this new execution and is in now way linked to the page that has already finished loading. Now you could ask Ajax to call your original script, but that wouldn't affect your page at all because the page does not reload. What you would get is a strange looking response which you (probably) couldn't do anything useful with.
Ajax allows small specific changes to the page, so when you get your response (which I assume you get in a format you want since you don't ask about it and you have a console.log) you then need to do something with jQuery/javascript. Instead of returning rowid write a javascript function like :
function printRowId(rowid) {
$('#your html div id here').text('Row id is ' + rowid);
}
and then call it in your response:
$.ajax({
url:'a.php',
type: 'POST',
async: false,
data: {labid: vallab},
success: function(data){
// console.log(data);
rowid = data;
}
});
printRowId(rowid);
return rowid;
You can use Ajax to update your data, update your database and then reflect the changes on the current page, but you cannot use it to pass directly to the php that has already finished executing
I'm using this jQuery AJAX function and I'm trying to figure out how to use the 'data:' part of it. According to this page (http://api.jquery.com/jQuery.ajax/) I can use 'data:' to send the number 22 to 'process_stage.php' so I can use it.
Can anyone tell me what I need to type in my process_stage.php page to access the number 22?
function myAJAX(){
$.ajax({
url: 'process_stage.php',
data: '22',
dataType: 'json',
success: function(data) {
var videoid = data[0];
var currentID = data[1];
$('#youtube').html("<iframe width='400' height='225' src='http://www.youtube.com/embed/"+videoid+"?rel=0&autohide=1&showinfo=0&autoplay=1' frameborder='0' allowfullscreen></iframe>");
setTimeout(function (){
timedCount(currentID);
},1000);
}
});
}
As you're making a HTTP GET request, data needs to be key-value pairs, as that's how a GET request is constructed (e.g. /get.php?var1=a&var2=b&var3=c).
jQuery.ajax() accepts this key-value pairs as either an object map, or a string, as described in the documentation:
Data to be sent to the server. It is converted to a query string, if not already a string. It's appended to the url for GET-requests. See processData option to prevent this automatic processing. Object must be Key/Value pairs. If value is an Array, jQuery serializes multiple values with same key based on the value of the traditional setting (described below).
So you should use either;
data: "value=22"
or
data: {
value: 22
}
Then in PHP you can use $_GET['value'] to retrieve it.
Your value needs a field name to go with it. To do this, make data an object e.g. {my_value: 22}. Then in your PHP script look for the field called my_value.
Is there a way to set a session variable from withing my JS function?
I have the following JS code:
$.ajax({
url: "ajax.php",
type: "POST",
data: {
tid: '.$testID.',
do:"'.$do.'"
},
success: function( html ) {
$("#partBox").html( html );
// add PHP here?
}
});
I would like to set the following var in the session, on SUCCESS:
$_SESSION['hgt'] = 'Math.ceil($("#partBox").height() / 2)';
I have no idea if this is even possible... Alternatively I could probably use cookies...
You can't set any PHP variables in JavaScript. Once the Page has finished loading PHP has done its job and is out of the picture. If you want to set a session variable using JavaScript you can do it one of two ways:
Use Ajax to send the value to a PHP script to set the session variable
Store it in a cookie and on the next page load have PHP use the value of that cookie to create the session varibale
Could someone point me in the right direction here?
Basically, I've got this jQuery code snippet:
$('.bggallery_images').click(function () {
var newBG = "url('" + $(this).attr('src');
var fullpath = $(this).attr('src');
var filename = fullpath.replace('img/Bakgrunner/', '');
$('#wrapper').css('background-image', newBG);
// Lagre til SQL
$.ajax({
url: "save_to_db.php",
// The url to your function to handle saving to the db
data: filename,
dataType: 'Text',
type: 'POST',
// Could also use GET if you prefer
success: function (data) {
// Just for testing purposes.
alert('Background changed to: ' + data);
}
});
});
This is being run when I click a certain button. So it's actually within a click handler.
If I understand this correctly, this snippet takes the source if the image I just clicked and strips it so I end up with only the filename. If I do an alert(filename), I get the filename only. So this is working ok.
But then, it does an ajax call to a php file called "save_to_db.php" and sends data: filename. This is correct right? Then, it does a callback which does an alert + data.
Does this seem correct so far?
Cause my php file looks like this:
<?php
require("dbconnect2.php");
$uploadstring = $_POST['filename'];
$sessionid = $_SESSION['id'];
echo ($sessionid);
mysql_query("UPDATE brukere SET brukerBakgrunn = '$uploadstring' WHERE brukerID=" .$_SESSION['id']);
mysql_close();
?>
When I click the image, the jQuery snippet fires and I get the results of this php file as output for the alert box. I think that the variables somehow are empty.
Because notice the echo($sessionid); which is a variable I've created just to test what the session ID is. And it returns nothing. What could be the issue here?
Edit: I just tried to echo out the $uploadstring variable as well and it also returns nothing. It's like the jQuery snippet doesn't even pass the variable on to the php file?
You're trying to send just the filename, but you're retrieving a named form field in your PHP code. So you need to send a named form field:
Change your ajax call like this:
$.ajax({
url: "save_to_db.php",
// The url to your function to handle saving to the db
data: {filename: filename}, // <= Change #1 (give jQuery a simple object)
dataType: 'text', // <= Change #2 ('text', not 'Text')
type: 'POST',
// Could also use GET if you prefer
success: function (data) {
// Just for testing purposes.
alert('Background changed to: ' + data);
}
});
Your PHP script will now receive a POST varible called filename whose value comes from your filename Javascript variable. (You can also use $.post to do this, but it's just a wrapper for ajax anyway...)
Passing a simple object into the ajax call is the easiest way to send fields to the server. jQuery will take the object and create the URL-encoded form data (doing all of the escaping for you) by using the object's keys and field names. So for instance, if you give it this object:
data: {a: 1, b: "testing one two three", c: 3}
...it sends this URL-encoded data:
a=1&b=testing+one+two+three&c=3
(Note how it encodes it for us.) More in the ajax docs (but beware, at present what the docs say about array handling is wrong; see this bug report for details).