I am trying to write a plug-in for firefox which would fetch all the domains from the links of the current site and display their IP addresses.
for that I have written js code containing "domians". And simple php script:
<?php
$ip = gethostbyname('www.example.com');
echo $ip;
?>
now i have to pass this "domains" array to php and return the ip values to js code in order to display the domains with ip(s).how can i do this?
I heard that ajax, json can do this. Is there is any other possible solution?
From what I understand, PHP is executed server side. This means that when the user load the plug-in/page/content, the PHP is executed and done with. This being said, JavaScript is executed Client side, meaning it can be executed during the page load, before the page load and after the page load. Unfortunately this means that you cannot pass JavaScript variables to PHP without using AJAX or going to another page.
The way you would pass information from JS to PHP would be by receiving the data you need, then making an Ajax request to a PHP script that would perform some action and then return some value. If that's what you want to do, then there are tutorials/many questions that will help you in doing that.
To pass from PHP to JS, you can do something like:
<script>
var JavascriptVariable = <?php echo $PHPVariable ?>;
</script>
But this might be bad practice, I am unsure.
Related
I want the value of JavaScript variable which i could access using PHP.
I am using the code below but it doesn't return value of that variable in PHP.
// set global variable in javascript
profile_viewer_uid = 1;
// php code
$profile_viewer_uid=$_POST['profile_viewer_uid'];
this gives me the following error :-
A PHP Error was encountered
Severity: Notice
Message: Undefined index: profile_viewer_uid
Another php code i used which give empty value
$profile_viewer_uid = "<script language=javascript>document.write(profile_viewer_uid);</script>
When I echo it shows nothing.
Add a cookie with the javascript variable you want to access.
document.cookie="profile_viewer_uid=1";
Then acces it in php via
$profile_viewer_uid = $_COOKIE['profile_viewer_uid'];
You will need to use JS to send the URL back with a variable in it such as:
http://www.site.com/index.php?uid=1
by using something like this in JS:
window.location.href=”index.php?uid=1";
Then in the PHP code use $_GET:
$somevar = $_GET["uid"]; //puts the uid varialbe into $somevar
Here is the Working example: Get javascript variable value on the same page.
<script>
var p1 = "success";
</script>
<?php
echo "<script>document.writeln(p1);</script>";
?>
You might want to start by learning what Javascript and php are. Javascript is a client side script language running in the browser of the machine of the client connected to the webserver on which php runs. These languages can not communicate directly.
Depending on your goal you'll need to issue an AJAX get or post request to the server and return a json/xml/html/whatever response you need and inject the result back in the DOM structure of the site. I suggest Jquery, BackboneJS or any other JS framework for this. See the Jquery documentation for examples.
If you have to pass php data to JS on the same site you can echo the data as JS and turn your php data using json_encode() into JS.
<script type="text/javascript>
var foo = <?php echo json_encode($somePhpVar); ?>
</script>
If you want to use a js variable in a php script you MUST pass it within a HTTP request.
There are basically two ways:
Submitting or reloading the page (as per Chris answer).
Using AJAX, which is made exactly for communicating between a web page (js) and the server(php) without reloading/changing the page.
A basic example can be:
var profile_viewer_uid = 1;
$.ajax({
url: "serverScript.php",
method: "POST",
data: { "profile_viewer_uid": profile_viewer_uid }
})
And in the serverScript.php file, you can do:
$profile_viewer_uid = $_POST['profile_viewer_uid'];
echo($profile_viewer_uid);
// prints 1
Note: in this example I used jQuery AJAX, which is quicker to implement. You can do it in pure js as well.
PHP runs on the server. It outputs some text. Then it stops running.
The text is sent to the client (a browser). The browser then interprets the text as HTML and JavaScript.
If you want to get data from JavaScript to PHP then you need to make a new HTTP request and run a new (or the same) PHP script.
You can make an HTTP request from JavaScript by using a form or Ajax.
These are two different languages, that run at different time - you cannot interact with them like that.
PHP is executed on the server while the page loads. Once loaded, the JavaScript will execute on the clients machine in the browser.
In your html form make a hidden field
<input type="hidden" id="scanCode" name="SCANCODE"></input>
Then in your javascript update the field value by adding;
document.getElementById("scanCode").setAttribute('value', scanCode);
This could be a little tricky thing but the secure way is to set a javascript cookie, then picking it up by php cookie variable.Then Assign this php variable to an php session that will hold the data more securely than cookie.Then delete the cookie using javascript and redirect the page to itself.
Given that you have added an php command to catch the variable, you will get it.
You need to add this value to the form data that is submitted to the server. You can use
<input type="hidden" value="1" name="profile_viewer_uid" id="profile_viewer_uid">
inside your form tag.
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.
For example:
$(document).ready(function(){
$('.selector').click(function(){
<?php
// php code goes here
?>
});
});
Will this cause issues or slow down the page? Is this bad practice? Is there anything important that I should know related to this?
Thanks!
If you are trying to bound some PHP code with the click event then this is impossible in the way you are trying and PHP code will be executed as soon as page load without waiting for a click event.
If you are trying to generate final javascript or jquery code using PHP then this is okay.
It won't slow down the page; the PHP runs on the server and emits text which is sent to the browser, as on any PHP page. Is it bad practice? I wouldn't say "bad" necessarily, but not great. It makes for messy code - in the event where I need to do something like this, I usually try to break it up, as in:
<script>
var stuff = <?php print $stuff; ?>;
var blah = "<?php print $blah; ?>";
// Do things in JS with stuff and blah here, no more PHP mixed in
</script>
PHP is executed on the server, and then the javascript will be executed on the client. So what you'd be doing here is using php to generate javascript that will become the function body. If that's what you were trying to do then there's nothing wrong with doing it.
If you thought you were going to invoke some PHP code from javascript, then you're on the wrong track. You'd need to put the PHP code in a separate page and use an ajax request to get the result.
Sure, as long as you keep in mind that PHP code will be executed by the server before the page is sent out. Other than that, have fun.
PHP is a "backend" language and javascript is a "frontend" language. In short, as long as the PHP code is loaded through a web server that understands PHP - the downside is that you have to inline the JS, losing caching ability (there are workarounds to parse php in .js files but you shouldn't really do this). To the user it will just look like javascript and HTML. Here's the server order:
User requests page.
Apache (or equivalent) notices this
is a php file. It then renders all
the php that are between php tags.
Apache sends the page to the user.
User's browser sees the JavaScript
and executes it.
Just be sure the PHP is outputting valid JavaScript.
you have a better choice to use ajax that runs the php script when you are handling a click event
$(document).ready(function(){
$('.selector').click(function(){
$.ajax({url:"phpfile.php",type:"POST",
data:"datastring="+value+"&datastring2="othervalue,
,success:function(data){
//get the result from the php file after it's executed on server
}
});
});
});
No it's not. Just as long as you know that the JS is executed after the PHP page is parsed.
I was wondering how i could achieve using <?php?> in javascript for url's? There's a certain route you have to go, Anyone know?
the normal way for example:
$fetchContent = $('#div').load('website/members #content');
What i'm trying to do:
$fetchContent = $('#grav').load('<?php?> #poppu');
Yep, thats wrong as hell lol, but i'm sure someone knows
I would also like to know how to tie php with javascript, but thats probably a whole new topic
You said it right :)
Yep, thats wrong as hell lol, but i'm
sure someone knows
Anyway, from your php script, output the url as a javascript code anywhere in the script before the javascript used for ajax call, e.g.
<?php
echo '<script language="javascript"> var g_ajax_url = "'. $the_url . '";</script>';
?>
and in your javascript, use it this way
$fetchContent = $('#grav').load(g_ajax_url + ' #poppu');
What it simply does is define g_ajax_url as a global variable with the proper php value, and you can use that variable in your js as you use other variables.
To tie php with js directly, try looking into xmlrpc topic.
If javascript is in .php file you can use <?php echo $url ?> and if the file is .js you can't use <?php ?>
It is not clear to me what you are trying to achieve. I assume you are using the jQuery load() function, if yes, you should state so.
You can't load php during javascript execution because the php has already been processes and rendered as HTML and sent back to the client. As PHP is processes on the server it is logical that you cannot run it on the client side.
You could of course send an AJAX request to the server that runs a certain php page and you will be able to use the response as you please.
you can't necessarily "tie" them together because they operate in two different spectrums of processing, php being processed on the server, and javascript being processed in the browser.
You can however render javascript within a php file.
if your javascript is included within a <script> tag within your php page your example should work should actually work. The php would render the urls into the script before it is sent to the browser.
if you are wanting to load external javascript files with php inlcuded urls, you will need to set the proper headers and include the php file just as you would a normal .js file.
good article on this topic HERE
You cannot execute <?php ?> inside JavaScript, but inside PHP you can declare a global variable as:
var x = '<?php echo x;?>';
or, if it's an array, store it as JSON:
var x = <?php json_encode(x); ?>
then access the JavaScript variables inside the external JavaScript.
I want to call a PHP function when pressing on a button, sort of like:
<?php
function output(){
// do something
}
?>
<input type="button" value="Enter" onclick="output()"/>
I tried to make something like:
<input type="button" value="Enter" onclick="test.php?execute=1"/>
where test.php is current page and then by php
<? if(isset(&execute)){ echo "Hello"; } ?>
but it doesn't work.
Since PHP runs on the webserver, and buttons (and JavaScript in this case) appear on the client, you have to make an HTTP request to the server.
The easiest way to do this is to use a form. No JavaScript is required. You can add JavaScript (although it should be layered on top of a working non-JS version). Using JavaScript to make an HTTP request without leaving the page is known as Ajax, and generally achieved with the XMLHttpRequest object. There are various libraries such as YUI and jQuery that can do some of the heavy lifting for you.
I think using an AJAX call would do sort of what you are asking. I don't know PHP very well but you can use the following example, and add another variable with the data you are passing in to the server to indicate which function you want to call on the server. On the server you can add some "IF" statements that will call a certain function based on the name passed in and return the result.
Here is what you could use on in your javascript client using the jQuery library as a helper to do the AJAX call:
<input type="button" value="Enter" onclick="output()"/>
<script type="text/javascript">
function output(){
$.ajax({
type: "POST",
url: "submit_data.php",
data: "username=" + "SomeUser"
+ "&email=" + "someEmail#google.com"
+ "&functionName=" + "theFunction1",
success: function(html){
alert('sucess! Result is:' + html);
}
});
}
</script>
and you can use code such as this to catch the data your javascript is passing in. In this example you would want to call this file name as "submit_data.php" to match the javascript above:
<?php
// Variables
$Username = $_POST['username'];
$Email = $_POST['email'];
$FunctionName = $_POST['functionName'];
//Add code here to choose what function to call and echo the result
// If $FunctionName equals 'theFunction1' then execute theFunction1
// If $FunctionName equals 'theFunction2' then execute theFunction2
echo "You called A Page!";
?>
Here I am doing nothing with the "username" and "email" simply grabbing it and storing them into holding variables. But you can easily add extra functionality here, such as checking for a name of a function that you want to run.
PHP is server side and javascript is client side. So I'm not sure if that is really what you want to be doing??
Perhaps you could explain why you want to specifically call a php function?
I googled PHP function from button and found this question on webdeveloper.com
It doesn't use Javascript.
This is PHP you're talking about, not ASP.NET. In PHP, there is no such thing as a button click event. PHP runs entirely on the server and has absolutely no knowledge of client-side events.
Your first try won't work because the PHP code only runs when the page first loads. It does not run when you call a JavaScript function. Your second example won't work because JavaScript and PHP can't talk directly to eachother like that. Trying to directly call a PHP function from JavaScript just doens't make sense. Remember, PHP only runs on the server. By the time you get to the point where JavaScript can run, the PHP code has long since completed its work.
If you want to do something when a button is clicked, you have to explicitly make a request back to the server. You can do this by just POSTing the form as CTphpnwb suggested. Just be aware that this will reload the page and you will have to manually save and restore the page state, e.g. repopulate input boxes. There is no built-in magic that will do this for you.
Alternatively, you can get all AJAXy and do the POST in JavaScript. However, you will have to write the JavaScript to send the request and process the response, and write the server-side PHP code to handle the request. This gets a little awkward to do in a single page.
From : http://www.dreamincode.net/forums/showtopic72353.htm
You cannot directly invoke a PHP function from Javascript this way :
PHP code is executed on the server
HTML / Javascript are interpreted on the client-side.
One the HTML page has been generated and sent to the client (the browser), there is nothing more PHP can do.
One solution would be to use an Ajax request :
Your onclick event would call a Javascript function
This Javascript function would launch an Ajax request : a request sent to the server
The server would then execute some PHP code
And, then, return the result of that execution to the client
And you'd be able to get that result in your Javascript code, and act depending on what was returned by the server.
There are plenty of solutions to do an Ajax request :
You can re-invent the wheel ; not that complex, I should say -- but see the next point
If already using a Javascript framework, like jQuery, Prototype, ... Those provide classes/methods/functions to do Ajax requests
Googling a bit will get you lots of tutorials/examples, about that ;-)