how can you be constantly sending data through an ajax request (POST) to a script, and constantly retrieving the results? Id prefer a jquery method but plain ajax is fine too.
I need to send a javascript variable with the height of the page, but obviously theres no windowReSize event, so how can it be set up so that data is constantly being posted and retrieved? Thanks, sorry for the lame question
As Ozair Kafray stated, you'd better use the setInterval method.
By the way, the window resize event does exist.
Also, if you don't mind supporting new browsers only, this "constant ajax stuff" is what WebSockets have been invented for.
You can use setinterval method to do anything after a certain interval.
I am not sure why you want it so, I thought that one of the following thread(s) might be helpful for you.
https://stackoverflow.com/search?q=hash+change+event
you could do this by doing a recursive call in javascript try this code:
<script>
function infinite()
{
setTimeout('infinite()', 50000);
//put any statement here...
jQuery.post(<parameters>);
}
infinite();
</script>
hope this helps. :)
Related
Can i get the content or value of the tag with php?
I know i can get it with javascript:
$(function() {
$('class or id').text();
});
But i would like to get it with php, so i can send it back in another query to my sql table.
function changeContentToId(id) {
$("#spanContent").html(id); }
<?php echo "<span onclick='changeContentToId($ob->ID)'>...</span>"; ?>
<span id="spanContent"></span>
This is my code right now, any tips on how to write the top code in php?
thanks. :)
No way : PHP is server-side, and your data is on the client.
Then you have 2 alternatives : getting the information before sending it to the browser (output buffering is a good way), or after, via an AJAX call.
Hope this helps !
Why don't you send it in a 'normal' way ? Like putting the content inside a form then submit it to PHP.
Or get it using Javascript then submit it using AJAX.
PHP won't access client-side information(HTML) once it is in your client(after the content is delivered) you can use client-side manipulation(Javascript) or send it back to server then use it there.
Regards
The simple answer is you cannot do that. PHP is executed on the server before the page is rendered. JavaScript, which updates the content, is executed in the browser after the page is rendered. Hence by the time your content is ready to be read, there is no PHP any more.
The way around it would be to use AJAX to read the info with JavaScript and then send it to another PHP script.
get it with javascript and send it uing ajax to the server.
Just if you really need to, because i don't see any reason since it's generated with php the first time. so you should use the word you want before rendring the html page.
For instance I have a php function
<?php
function SayHi($msg){
return $msg;
}
?>
The following part triggers the onclick event
Click
How can I merge the two such that when I click on Click, the php function is invoked..?
You can not. PHP is executed serverside, while javascript is executed clientside.
THe generic solution for this is to use asynchronous Javascript (ajax) to call on your webserver, which in turn can invoke PHP code to do various things.
jQuery is a very nice library to handle this, and much more.
There are many ways to do this, most are complicated.
One easier way is:
<?php
function myFunc() { die('yay'); }
if (isset($_REQUEST['myButton'])) myFunc();
?>
<form><button name="myButton">Click Me</button></form>
Whaaat? PHP is server-side you cannot invoke a php function from javascript. However you can do this with ajax.
AJAX
You'll want to use AJAX. You need to call a server-side resource from the JavaScript code, and jQuery has a very handy function for making the call to the server. But making the call from the JavaScript is only half the story, you'll also need something on the server listening for that call. It would essentially be another PHP script which acts as a page in and of itself, but would return data in the form of (most likely) JSON instead of HTML. It's not meant to be human-readable, but rather to be a sort of web service for your JavaScript code to use.
You can find a simple example here.
please get involved with the basics of PHP: http://tut.php-quake.net/en/
how can i pass a variable from javascript to php using same file
in this example page keeps refreshing and i don't get to see the result
it works only if i separate the scripts... but i need it somehow like on ajax..
<SCRIPT language="JavaScript">
var carname="Volvo";
location.href="http://localhost/put.php?Result=" + carname;
</SCRIPT>
and this is the seccond part of the script ( they are both in same file )
<?php
Id = $_GET[Result];
echo $dbId;
?>
As Brian said you should put it in a conditional statement.. also your PHP is bad. Try the following
<?php if(isset($_GET["Result"])) : ?>
// do work with set variable
<?php $dbID = $_GET["Result"];
echo($dbID); ?>
<?php else : ?>
// "Result" not set
<SCRIPT language="JavaScript">
var carname="Volvo";
location.href="http://localhost/put.php?Result=" + carname;
</SCRIPT>
<? endif; ?>
I think this is a good exercise if you're trying to learn the Ajax method, in the real world I recommend using a framework like jQuery. Of course understanding how this works will help you build better applications in the end.
So you could do something like this in the PHP script:
if (!isset($_GET['Result']))
{
// include the javascript portion with the redirect
}
I'm with the others, though--I'm not seeing the value in a page load followed by an immediate redirect to the same page.
What you are trying to do cannot be done. Your script runs on the client in real time but the php will run on the server during the request. You will need to make an AJAX request.
First you will want to use Firefox with firebug and the web developer toolbar. Firebug gives a great view of ajax traffic and the web developer toolbar helps you see what's going on in the page.
Use jQuery make an ajax request to "send" the value to another php file. Don't be afraid to separate out files, in fact it's encouraged and considered good programming. If you find your sending a lot if information to a php script you will want to use JSON instead of as part of the url.
Man, you should follow a client-server pattern.. So the Client page can use some ajax to make a request to a Server page. This will response to the Client and you can make with the data what you want.
of course it will keep refreshing:)) Because as soon as the browser gets the js code, it will load that page you specify, which will send your browser the same page... you get the idea. It's like writing for(;;){}
Your question is difficult to understand (for me at least.) My guess is that you are wanting to use AJAX to send data to the server and receive a response without leaving the page.
Probably the easiest way to accomplish this is to use a library such as jQuery. (see jQuery.ajax())
PHP only runs on the server and the javascript only runs on the client. By the time your client is running the javascript, no more PHP can be executed on that request.
Another question by a newbie. I have a php variable that queries the database for a value. It is stored in the variable $publish and its value will change (in the database) when a user clicks on a hyperlink.
if ($publish == '') {
Link to publish.html
} else {
Link to edit.html
}
What is happening in the background is i am querying a database table for some data that i stored in the $publish variable. If the $publish is empty, it will add a link for publish.html in a popup. The popup will process a form and will add the data to the database and which means that the $publish is no more empty. What i would like to achieve is that as soon as the form is processed in the popup and a data has been added to the database, the link should change to edit.html. This can happen when the page will re-query the database but it should happen without page refresh.
How can it be donw using javascript, jquery or ajax?? Please assist.
Javascript by itself cannot be used to deal with database. That is done using php (Or the server side language of your choice). Ajax is used to send a request to your php script using javascript which will in turn communicate with the db. And it doesn't require a page refresh.
So what you are trying to do can be easily achieved using ajax. Since you mentioned jquery, you can check out the $.ajax or $.post methods in jquery which make the process even more simple.
You need to process the form using ajax. The ajax request is sent to a php script which will make the necessary changes in the database and send the new link (link to edit.html) in the response. Upon getting the response, just replace the current anchor element with the new one ..
for eg..
$.post(url, formdataobject , function (resp) {
$("a.youra").text('edit').attr('href', resp);
});
url - where the php script is located
formdataobject - a javascript object that will have the form data as key value pairs
the third parameter is an anonymous function also known as callback function since it will be invoked only when the response is received from the server. This is because ajax requests are asynchronous.
Inside the callback function, jquery is used to change the text inside the anchor element to edit and the href attribute is changed to value that came in the response.
$.post means we are using the post method. so the parameters can be accessed as elements of $_POST array in php.
After updating the db, you can simply echo out the new link and it will be received in the response.
Also, there are other formats in which you can get the response for eg. xml, json.
I'll try to leave the technical jargon aside and give a more generic response since I think you might be confused with client-side and server-side scripting.
Think of javascript as a language that can only instruct your WEB BROWSER how to act. Javascript executes after the server has already finished processing your web page.
PHP on the other hand runs on your web server and has the ability to communicate with your database. If you want to get information from your database using javascript, you'll need to have javascript ask PHP to query the database through an AJAX call to a PHP script.
For example, you could have javascript call a script like:
http://www.myserver.com/ajax_function.php?do=queryTheDatabase
In summary: Javascript can't connect to the database but it can ask PHP to do so. I hope that helps.
Let me try, you want to change the link in a page from a pop-up that handles a form processing. Try to give your link a container:
<div id="publish_link">Publish</div>
As for the form submission use Ajax to submit data to the server to do an update and get a response back to change the link to edit or something:
$.post("submit.php", { some_field: "some_value"}, function(response) {
if(response.isPublished)
$('#publish_link', window.opener.document).html('Edit');
});
Basically your publish link is contained in a div with an ID publish_link so you change its content later after data processing without reloading the page. In the pop-up where you would do the form processing it is done using jQuery Ajax POST method to submit the data. Your script then accepts that data, update the database and if successful returns a response. jQuery POST function receives that response and there's a check there if isPublished is true, get the pop-up's opener window (your main window) and update the link to Edit. Just an idea, may not be the best out there.
It cannot be made with javascript, jquery or ajax. only server side script can query a database. with ajax request you can get the script output. ajax requests can be sent either with pure javascript or jquery.
Well, i think i understand your quaestion, but you have to get a starting point, try to understand this:
try to understand what are client variables and server variables.
javascript does not comunicate with database.
you can use javascript to retrieve data to a specific "Object variable".
Using ajax methods of jquery you can post that data do other page, that will execute the
proper actions
you can ;)
at first you must create php file to query database and return something like true or flase and then with file url check the function and get answer
function find_published(folder_id) {
var aj_url = "{{server_path}}/ajax/url"
var list;
$.getJSON(aj_url+"?callback=?&",
function(data) {
//here is your data... true false ... do every thing you want
}
);
};
this app for node.js does mysql queries https://github.com/felixge/node-mysql
You need to use AJAX for this, like .post() or .get() or JSON.
I understand there is a method send for xmlHttpRequest objects, but I've been working on this site all day and I'm unable to find any halfway decent tutorials on the subject and my brain feels like mush. Ajax is hard.
What I'm trying to do is send data from one Javascript file back to a PHP script on the server, where the data is simply a string and a small number. Is this possible? Why can't I find a good article on the subject?
tl;dr How do I use the send method to pass a string and a number from a javascript file to a php file?
Why don't you user jQuery or similar library?
Sending a variables with jQuery will be simple as that:
$.post("save.php", { name: "John", time: "2pm" } );
In your save.php file you can handle POST variables as you wish:
$name = $_POST["name"];
$time = $_POST["time"];
You can check it out: http://jquery.com/
I think you are wasting your time trying to make self made methods ...
It's definitely possible. This is a really nicely organized tutorial that walks you through the XmlHttpRequest object, how to set it up, and how to consume it on the server.
The server-side code is PHP, and I'm more of a C# guy, and it made total sense to me. (Maybe I should switch to PHP??).
I hope this helps! Good luck.
EDIT: In response to a previous SO question, I put this jsfiddle together to demo how to use XmlHttpRequest. Hope this also helps.
lots of good links here, so I'm not going to add to that. Just as a sidenote, you're dealing with a light case of ajaxness here :) - typically you'd want to send something back from the server that changes the state of the page in response to what was sent from the page in the first place (in fact one might argue why you need ajax in the first place and not simply post, if the page's not supposed to change - but I can see how there might be situations where you'd want ajax anyway). I'm just saying that because you're going to encounter a lot of content about how to deal with the stuff sent back from the server - just making sure you're aware that's not needed for what you're trying to do (I'm always glad when I know what I can leave out in the first pass ;)
step 1:
get jquery. all you have to do is download the latest file and include it on your page.
step 2:
make 2 files:
somepage.html:
<script type='text/javascript' src='jquery.js'></script>
<script type='text/javascript'>
$.get("someScript.php",
// data to send if you want
{
'someVar' : 'someValue'
},
// receive and do something with response
function(response){
alert(response);
} // function (response)
); // .get()
</script>
someScript.php
<?php
echo $_GET['someVar'] . " response!";
?>
step 3:
upload all your files to your server and go to somepage.html
That's all there is to it. Though, you would generally put that code inside some kind of onclick or whatever, depending on what you want to use ajax for. But the comments in there are pretty self explanatory. jquery is used to make the ajax request, with an example of sending data to the server-side script receiving the request (using GET method). You would do whatever in someScript.php but in this example, it simply echoes back the value you sent. Then jquery takes what someScript.php echoes out and just throws it in a popup.
Using jQuery, you can use the post method:
$.post("test.php", { name: "John", number: 2 } );
Behind the scenes, this uses xmlHttpRequest, have a look at the source to see how they do it.