I have a PHP page with a mysql connection, a select query and then i'm building a table using PHP. If i wanted to use jQuery AJAX to refresh the data on a setInterval, on the same page, how would i go about doing that? (by the way i can do it to another PHP page but i've never done it if the PHP stuff is on the same page)
If you want to keep making ajax calls i suggest you do long polling, which basically means you have a script that is requesting content via ajax every given time, and it will verify every time if the content has been modified, if not it will wait again and make another call.
I used jQuery Periodical updater for a chat box and it worked perfectly.
If you wnat to learn more about how jQuery and AJAX work, check out this Nettus article
You set the param in request, for instance file.php?ajax=1
The, depending on its value, you render full html or just the necessary elements for ajax
in php:
if($_GET['ajax']) renderAjax();
else renderFullHTML();
in js:
$.get('file.php?ajax=1', function(data) {
$('.result').html(data);
});
Related
Dear Firends I have large number of forms on a single web page all of them calls a single PHP function. However what I want is that the forms should call a jquery function and if there is a need then jquery should let it call the PHP function.
I do not want to use Ajax just want to create a PHP function call if the matter can not be solved by jquery.
Each of the form is associated with some data. how ever all the data that is displayed on the page is not available all the time. So what I want is
if (data == available) { call PHP}
elseif (data != available) { jquery alert('sory bro');}
if data can not be seen now just use jquery to say sorry (no need to check from server). When a page is loaded we know which all pieces of data can not bee seen and are given in different color.
The forms are generated using a PHP loop with each form showing different data but of same type (each form is assocaited with a sort of Article).
All the questions that I have seen are about Ajax. Where as my current PHP code is working fine. all I want it that before making a trip to server if the data is not available the jquery shoould say so. We already know which data is not avaiable so far.
I hope I have explained it
Thanks a lot
**I think I have not made my point clear.. When the page is loaded is already know which data is not available for display and it is marked in seperate color and the div has different arrtibute...*is there some way so that I do not call PHP function for those forms?
PHP executes on the server side. Javascript (jQuery) executes on the client-side. So PHP is completely done executing before Javascript starts executing.
That's why everyone is saying you need to use AJAX. AJAX is a way to make a call back to the server in order to execute PHP code. PHP code only executes on the server. So in order to execute PHP, you have to make a call back to the server.
According to your logic, the data is present on the server.
If you want to know if the data is available or not then you have to contact the server right.
If that's the case how can it be solved without sending an ajax request..
You need to make the request as jQuery is a client side code and cannot contact the server directly.. You need the server side script to execute it which is PHP in your case
The easiest solution:
if (data == available) { $("form").trigger('submit') }
elseif (data != available) { jquery alert('sory bro');}
Obviously you need to adapt the selector according to your specific form / requirements.
Just make sure your form does not get submitted accidentally when you press submit by adding something like event.preventDefault(); in your function.
I have a page which shows a list of items. Page coded with html, css, php and using mysql db.
On that page a user can request to add one of the items to their special list.
I want to do this within the page without having to do a complete page refresh. So user clicks button to add, item is added to their list and button changed so they can't add it again.
Do I use ajax calls to run code behind the page and then refresh the div?
Or is there a better more efficient way to do it.
I'd prefer a php option of possible in case user has js turned off, but don't know if it can be done with using js.
Any help appreciated.
If you want dynamic content (changing the page without refreshing) you are going to have to use Javascript. To do what you are asking, you could call a PHP script via Ajax that outputs the contents of the div with the new item, and then change the div based on that response.
Dagon is exactly right. Create a form which handles the request and set the action of the form to the PHP script you want to handle the request. Note that although this can be the same php script that you use to process your ajax request, it does not necessarily have to be.
Many times when I implement such functionality, I'll set the PHP to send variables as POST (in the event of JS disabled) and have my ajax request as a GET so I can use a single PHP page to handle the 'same' request. When using AJAX, I'll have the script echo a specific code then have the ajax response handle that return.
if(val == 'OK') {
//in event of success, perhaps you want to hide the original form and show a success message
} else {
//do something like unhide a hidden div to display an error
}
If JavaScript is turned off, the page has to be reloaded. In your case jQuery could be very handy and simply rewrite the element you need to rewrite. The server send's a simple json. Using a PHP Framework might also be a good idea, since the way you ask it seems (with respect, and not wanting to offend), that you are not using any framework and might run into falls making your script vulnerable (sql injections for example)
If your visitor doesn't have JavaScript enabled and you want to serve anyways, then you have to do a page reload. First check if that is worth to do, who is your client/visitor, what browser do they use, ... questions like that help you to design your page/app.
Is there a way to trigger a function when a $_POST is received?
I have a php page that finishes executing and calls another page. The other page performs certain actions and POST updates back to this page. I need to be able to update a div as and when a POST is received.
Making an ajax request and using "success" callback as a trigger doesn't work since this will update my div ONLY ONCE. The problem is that this page will receive POST multiple times at irregular intervals and I need a way to trigger an action whenever POST is received.
Use Ajax (I'd use jQuery) and set a time interval to check if there was a status change. The "other page" should not post back to the first page, but save data in a "requestable" area (might be an database, a file etc) where this new info/status will be stored and retrieved periodically by the Ajax request.
Use AJAX, because you can't trigger $_POST recieving in php,
As I understand you just need to update some <div> inner html after post is recieved, and you are able to do it with jQuery events
I would do this in the following way (below is the PHP code, just FYI):
if (!empty($_POST)) {
// do whatever you mean by 'updating the div'
}
However AJAX may be more appropriate and it is (believe or not) more flexible.
AJAX call will be smaller load on your server and can update the box single or multiple times (depending on how you write the JS code) - in such case I recommend using jQuery for simplicity (if you are not familiar with JS).
usually, I would do something like this...
$var_posted=0;
if($_POST['var']){$var_posted=1;}
then...
if($var_posted==1){some_function();}
Goal: I want to get the text from the selected element and then create a PHP variable from it.
I know how to do this using jQuery but can't wrap my mind around the idea of how to do it in PHP. Basically lets say I have a table with some data. When the user clicks on the data I would like to retrieve that text and then place it in a PHP variable. I could use .text(); from jQuery to create the variable but I could not pass that variable into PHP for further use.
I am very new to PHP (a front-end developer trying to learn back-end). So any explanation would be helpful also.
thanks!
***OK I now understand how to do it. Thanks for the input. I was not thinking. It makes perfect sense to create the variable using a _post and then returning the data via AJAX. Sorry for wasting your time. Thanks for replying.
There is no onclick event in the backend, at least not that works like in javascript
if you want to pass a variable to the server you can use a form and send the data through a GET or POST
Example:
<form action="index.php" method="get">
<input type="button" value="somevalue" name="action" />
</form>
when the user clicks you will see this in the url
www.example.com/index.php?action=somevalue
now you can retrieve this value in php using the $_GET global variable
$variable = $_GET['action'];
The same can be done using POST, this way the variable is not shown in the url
In order to have PHP gather any client side data you would have to pass that data back to the server.
To assign data from client action to a PHP variable, you would first have to capture that data using a front end solution (like your jQuery one above) then pass that information to your server application for processing using AJAX or form submission.
Your PHP data handler could then parse that information out from the data submission and push that info into a variable.
Your front end would look something like
$.ajax({
type: "POST",
url: 'your_file.php',
data: 'selected='+ captured_data,
});
and on your back end...
<?php
...some php code...
$var_to_hold_selected_thing = $_POST["selected"];
...more php code
?>
Specifics of how to do more than that would depend on your application...
You can do it with ajax:
$.ajax({
type: "POST",
url: 'your_file.php',
data: 'text='+ text,
success: function(data) {
alert(data);
}
});
After the .click() event you could have a dialog box appear, with Is this your text?. Then post it.
You could grab that text with jQuery using $(elem).text() as you've described and then pass the captured value to PHP using an AJAX request with jQuery (see $.ajax). The PHP script you pinged with AJAX (either via GET or POST) can then take the value you passed and push it into a $_SESSION variable.
session_start();
$_SESSION["text_clicked"] = $_GET["text_string"];
exit;
After you do this, any subsequent ajax calls made with jQuery (to any PHP script), can recall this variable, provide that you've properly initiated the session.
Stack 101's answer is the correct execution that you're looking for, however it sounds like you could use a little more background on the context first.
Basically, PHP is a server-side scripting language, which means that it gets executed before the page loads into your browser. Here it can look at a database, connect to other sites, or do a whole host of other stuff. Once it's in the browser, your HTML + CSS + jQuery is in charge of displaying + styling + and manipulating that information respectively.
AJAX is usually used to describe the act of posting data to a PHP script, and then re-loading it back into your page without the page refreshing. In other words, jQuery passes data to a PHP script that runs on the server, and then loads in whatever the PHP script outputted. Sometimes PHP can output an entire site (html tags, css, js, whatever). Other times it can simply access a few variables that it got from the POST array, and output a result. This is much more common with AJAX requests.
A quick search turned up this tutorial which might help (I haven't followed it)
http://www.php4every1.com/tutorials/jquery-ajax-tutorial/
Good luck!
I believe it could be done by sending all the required content through GET or POST, and then make PHP stuff it to a variable, however I'm not exactly sure.
PHP runs on the server. Variables come and go each request. Everytime you refresh a page (or send a request otherwise), a PHP script starts running, spits out a response, and stops again. So setting just a loose variable is not really an option.
The options you got are
- Use a cookie. You can set it from Javascript and it will automatically be sent with the next request. Your PHP script can read this cookie.
- Send the variable by doing an AJAX (asynchronous) request. You can send the value in the url or as posted data.
In either case, you can decide to use the variable only once, or store it in a session. I think the cookie will remain unless you explicitly clear it. So you could keep using that.
can any one please help how to get the values from the javascript to php other than while using submit button.
scenario:
i am searching for record, if the record found then, i need confrim alert asking to continue or not, if he click continue how can i say he selected continue
If you want to check without having a page reload, you probably want to execute an AJAX call, then depending on the result returned by the underlying PHP script, take the appropriate action. If you have no knowldege of how to implement this, take a look here
You can never use JavaScript to communicate with the page while it is loading, you can only send a new request to the web server from the JavaScript layer... although you can send that request to the same script that's already running, it will still be a new instance of the PHP script, just like when you open a new browser tab to the same page.
The only way for JavaScript to communicate with PHP at all, is by sending an HTTP request. But you don't have to refresh the page in order to do that if you use AJAX.
AJAX is basically a word to describe JavaScript exchanging information with web pages without refreshing the page. But note that it will still not be able to change variables in the PHP script which is running when the JavaScript code is executed.
In the case of PHP, I've used the open-source library SAJAX which is quite simple. You will find it at http://www.modernmethod.com/sajax/
Hope it helps and good luck!
You can use this as an example using jquery and PHP:
$.post('searchimage.php', { action: 'searchimage', imgreference: $(this).val() },
function(data) {imgsample.html(data);}
);
Basically apply the above function in a document ready function so its run when the page loads.
This can be triggered using $("#prodcode").click() or what ever event handler you want to use.
The php page in my example will get sent the value from imgreference as a post, you can do whatever you want in the php page then return the value which gets added to the imgsample (in this case a td)
hope this helps.