Get selected value and send that by ajax onclick - php

This is the second time I ask this question because in my first try I was totally misunderstood.
php, jQuery, Lightbox, Ajax GET and POST issue
What I am trying to achieve is simply to get the selected value from a dropdown list and send that by an ajax function to a php file that will run the necessary functions. So let's say I select Africa/Accra as timezone, onclick the ajax function is called and that will pass the data to the php file that will do the rest. No page refresh, nothing, just getting the data and send that with ajax. Is this possible? please to better understand me see my first try (link above).
I am not an experienced PHP programmer. I do not know about anything of Ajax, so propably I have just done everything wrong..so forgive me. Thanks

this is what you want:
$("#submitButton").click(function(){
var selectedValue = $("#IdOfDropdown").val();
$.get("test.php", { timezone: selectedValue } , function(data){
alert("Data Loaded: " + data);
});
return false;
});
You can also do a post instead of a get, here is a reference with a bunch of jquery ajax stuff
http://api.jquery.com/category/ajax/

To get the value you could use Javascript or Jquery.
In javascript you can say:
var selectedValue = document.getElementById("selectId");
selectedValue.options[selectedValue.selectedIndex].value;
Afterwards try and see how these guys do it:
AJAX TO PHP
This is one way to do it. The AJAX call could look different, but try and se if this solves your problem. :)
//Gerner

Related

Javascript not executing after Ajax call

I know this has been asked on SO a lot, but I have trawled through the posts for a few hours now and nothing works.
I'm working on a Wordpress blog where the prev/next buttons on a single post page have to load the prev/next post by Ajax. I have written the code (jQuery Ajax) all fine (I think - if you want to improve it, be my guest!), but in each post there a few bits of jQuery that need to work. However, after I click either of the prev/next buttons to move between posts, the jQuery won't work (it works absolutely perfectly when the page is first loaded). I know this is due to the content not being 'connected' to the JS anymore but I'm not sure what to do about it.
Here is my code:
$(".page-feed").on('click', '.post-nav>a', function() {
event.preventDefault ? event.preventDefault() : event.returnValue = false;
var link = $(this).attr('href'); // get the value of the href attribute on the links
$(".post-content").html("Loading...");
$.get(link, function(result) {
$result = $(result);
$content = $result.find(".post-content");
$(".post-content").replaceWith($content);
}, 'html');
});
I know that you're probably going to ask what I've already tried, but if I'm honest, not a lot that would be worth putting here.
The code above is located right at the top of a file called script.js, with all the other JS below it (which doesn't currently work after the Ajax call). The script is started by the standard $(document).ready(function() { statement.
Thanks for any help :)
First, you need to accept the event object as an argument.
$(".page-feed").on('click', '.post-nav>a', function(event) {
Next, by using the jQuery event object, you can simplify the next line because event is normalized by jQuery to work cross-browser.
event.preventDefault();
Now, as far as it working on the first click but not after, that's likely because .page-feed is a dynamic element. You'll need to instead select an element that is an ancestor of .post-content. document is a decent replacement, but it would be better if you picked one more local.
$(document).on('click', '.post-nav>a', function(event) {

AJAX/PHP – callback after finished loading data

(Not sure if I missed an already similar answered question…)
On click of a button, I'm loading various images from a database via PHP/MySQL and appending it to the body (the actual images are of course not stored in the database, the correct selection of the images is based on a posted variable).
My goal is to display a loading indicator after pressing the button and hiding the indicator after all the image data has completely loaded and displayed. This may be an easy to solve callback issue but I'm just getting started with AJAX. :)
The following is the code I currently managed to come up with. I'm guessing the load() function is not really the right one here?
Thanks for your help!
$("#somebutton").click(function(){
alert("fetching…");
$.post('loadmore.php', {
somevariable: somevariable
},
function(data){
$("body").append(data);
$(window).load(function(){
alert("finished loading…");
});
});
});
The function you have with the finished loading... alert is a success callback, so it gets executed once the AJAX call has finished. This means you don't need to use $(window).load.
Also, you can use the html method on an element to change its contents and display a message.
Something like this would work fine:
$("#somebutton").click(function(){
$('#divID').html('Loading...');
$.post('loadmore.php', {
somevariable: somevariable
},
function(data){
$("body").append(data);
$('#divID').html('');
});
});
Read the docs http://api.jquery.com/jQuery.ajax/
Use the success callback to append the body and then the complete and error callbacks to clear things up correctly.
$("#somebutton").click(function(){
alert("fetching…");
$.post('loadmore.php', {
somevariable: somevariable
})
.success(function(data){$("body").append(data)})
.error(function(){alert("oh dear")})
.complete(function(){alert("finished loading…")});
});
Remember to always have a fallback for removing the loader - nothing worse than just having a loader and no way to remove it from the page and continue using the application / web site.
I managed to solve my problem by reading and tweaking the code in the following article.
The function load() with the equation containing the self-explanatory variables [imagesLoaded >= imageCount] did the trick.
Know when images are done loading in AJAX response

PHP - Execute a specific php code when clicking a link

I'm currently working on a website and I would like to be able to do the following:
when clicking one of the links from the sideMenu the only thing I would like to change would be the content of my contentMain div and nothing else(page layout/design/etc)
Could anybody give me some general pointers on how I could achieve this in php?
Thank You in advance :D
This is a client-side change that cannot be accomplished using PHP. PHP is evaluated on the server-side, so once the page is loaded for the user, it has no control over what the user sees (unless you use client-side code to call PHP).
To accomplish this, you will need to use Javascript and/or jQuery.
Reference: https://developer.mozilla.org/en/JavaScript/
jQuery: http://jquery.org/
iFrame, frameset or AJAX all work for your case depending on what you are actually trying to achieve.
For AJAX calls (the most modern way out of the three that relies on Javascript) you can use a library such as jQuery.
http://api.jquery.com/category/ajax/
You can use ajax for this one. Using jQuery to detect the click on the link or use normal JavaScript onClick function. Then do the things like you want.
<a href="" id="my_link">My link<a>
<script type="text/javascript">
jQuery(document).ready(function(){
jQuery('#my_link').click(function(){
jQuery.ajax({
url: 'ajax page need to be called',
success: function(data) {
//do your operations on success
}
});
});
});
</script>
You can get more details on :
jQuery
jQuery Ajax
Hope this helps you

use php to get value of jquery div

I've a div <div id="single-home-container"></div> that displays a value from a jquery script. Can I use php to get that value so I can pass it into a mysql query?
Thanks
yes this is called AJAX. There are all kinds of AJAX functions in jQuery, in your case I think post would work great. This is the standard example from the jQuery doc:
$.post('ajax/test.php', $('#single-home-container').html(), function(data) {
$('.result').html(data);
});
Take a look here.
You should definitely take some time to learn the concept of AJAX before trying to use it.

Updating MySQL with textarea content without reloading

I'm building a page which loads the contents of our MySQL db for editing. Each row of the table is in a seperate, editable textarea on the page. I need the user to be able to update each row (ie send it's contents to the db) without reloading the whole page, with a click of a button that's responsible for that specific textarea.
I understand that such procedure would involve some JavaScript, but sadly I know none - I did all I could with php, so I need a pointing in that direction. Basically my question (I think) is how do I grab a text from an edited textarea and send it to MySQL without reloading the page. If I'm heading in the wrong direction I'd be more than willing to hear other suggestions.
Yes this will require javascript. Namely an async call to a PHP page you have. This is often called AJAX.
I hate to be the "use jquery" answer here but the hump of learning jQuery to use AJAX based calls is very low to the value you gain from calls like this.
The documentation has great examples and most of them are quite simple.
That's precisely what AJAX does: Asynchronous JavaScript and XML. It lets you send requests to the server without reloading the page.
I'd recommend starting with jQuery which you'll notice has a lot of support in the StackOverflow community, as well as elsewhere, and which makes cross-browser AJAX requests very easy.
With the jQuery script on your page, you can do something like this:
$("#id-of-the-button-the-user-will-click").click(function() {
$.post('/path/to/your/script.php', { field1: value1, field2: value2 }, function(data) {
// This function is called when the request is completed, so it's a good place
// to update your page accordingly.
});
});
Understanding the details will still require a thorough understanding of JavaScript, so really the best thing to do is dive in and start writing (and thus learning) a lot of JavaScript. AJAX is a fine place to start.
There is a good introduction to JavaScript at Opera. Jibbering covers the use of the XHR object, which is the usual way to send data to the server without leaving the page. Libraries such as YUI or jQuery can do some of the heavy lifting for you.
What you're looking for is AJAX. jQuery makes a lot of that easier; try starting here.
You can add JavaScript event to textarea:
onblur="sendUpdate(this.value)"
This event will happen when user has finished editing the text and leaves the input.
In example, "this" references current textarea component.
And then use Ajax, as previously mentioned. An example would be:
function sendUpdate (text) {
$.post('script.php', {textarea_value:text},function(){});
}
You need to make asynchronous calls to server from your script (javascript).Use ajax to achieve this.You need to have a look at using XMLhttp objects to communicate with the server /database from your client side script (javascript) . You need not submit the entire page using a button click,instead you can invoke the javscript code in a button click event or a onBlur event or a onTextChange event etc...
jQuery is a javascript framework library which helps you to reduce the number of lines of code to implement this. But its not necessary that you need to use jquery .You can do ajax calls without using jquery.Usage of jQuery will reduce the number of lines.
Check this
http://docs.jquery.com/Ajax/jQuery.ajax
You will definitely require JavaScript, and some method of sending a HTTP request to your PHP server without reloading the page. Generally, this is called AJAX.
It is probably best to use a JavaScript library, as AJAX is a bit complicated for beginning JavaScript developers. A good choice is JQuery, or MooTools
AJAX libraries usually use XMLHttpRequest or JSONP to implement the HTTP requests. Understanding those should make it a bit easier.
JQuery AJAX: http://docs.jquery.com/Ajax
MooTools AJAX: http://mootools.net/docs/core/Request/Request
Selecting the textarea element, updating it, would require use of the DOM (http://www.w3.org/DOM/). Most JavaScript frameworks now use an implementation of CSS or XSLT selectors to query the DOM.
JQuery Selectors: http://docs.jquery.com/Selectors
MooTools Selectors: http://mootools.net/docs/core/Utilities/Selectors
You can do this fine without JavaScript. Just have each textarea+button in its own <form>, then submit the form to a script that updates the database from the textarea value, and returns a:
204 No Content
status instead of 200 OK and a new page. The old page will stay put.
You can start by adding a jquery function to pick up any changes made ie:
$('#inputelement').on('input propertychange', function(){
alert("Alert to test jquery working");
});
You should then use AJAX to create a php script with the data (as php is how you update to the server) and send using either a GET or POST variable. Then use that script file to upload the changes to your server. e.g.
$('#yourElement').on('input propertychange', function(){
$.ajax({
method: "POST",
url: "updatedatabase.php",
data: {content: $("#yourElement").val()}
})
.done(function( msg ) {
alert( "Data Saved: " + msg );
});
});
Script upload:
session_start();
if(array_key_exists("content", $_POST)){
include("connection.php");//link to your server
$query = "UPDATE `users` SET `updateColumn`= '".mysqli_real_escape_string($link, $_POST['content'])."' WHERE id= ".mysqli_real_escape_string($link, $_SESSION['id'])." LIMIT 1";
if(mysqli_query($link, $query)){
echo "success";
}else {
echo "failed";
}
}
Try to read more about Ajax. There are a lot of libraries for it.

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