I have a PHP Function that I would like to integrate into my (existing) web page. Further, I would like it to execute when the user clicks a link on the page. The function needs to accept the text of the link as an input argument.
Everything I've researched for sending data to a PHP script seems to involve using forms to obtain user input. The page needs to accept no user input, just send the link-text to the function and execute that function.
So I guess the question is two-part. First, how to execute a PHP script on link click. And second, how to pass page information to this function without the use of forms. I am open to the use of other technologies such as AJAX or JavaScript if necessary.
EDIT:: Specifically what I am trying to do. I have an HTML output representing documentation of some source code. On this output is a series of links (referring to code constructs in the source code) that, upon being clicked, will call some python function installed on the web server (which leads me to think it needs called via PHP). The python function, however, needs the name present on the link as an input argument.
Is there some sort of interaction I could achieve by having JavaScript gather the input and call the PHP function?
Sorry for the vagueness, I am INCREDIBLY new to web development. If anything is unclear let me know.
You'll need to have a JS function which is triggered by an onclick event which then sends an AJAX request and returns false (so it won't be redirected to a new page in the browser). You can do the following in jQuery:
jQuery:
<script type="text/javascript" src="jquery.min.js"></script>
<script type="text/javascript">
function doSomething() {
$.get("myfile.php");
return false;
}
</script>
And in your page body:
Click Me!
In myfile.php:
You can add whatever function you want to execute when the visitor clicks the link. Example:
<?php
echo "Hey, this is some text!";
?>
That's a basic example. I hope this helps.
You will need to use AJAX to accomplish this without leaving the page. Here is an example using jQuery and AJAX (this assumes you have already included the jQuery library):
First File:
<script language="javascript">
$(function(){
$('#mylink').click(function(){
$.get('/ajax/someurl', {linkText: $(this).text()}, function(resp){
// handle response here
}, 'json');
});
});
</script>
This text will be passed along
PHP File:
$text = $_REQUEST['linkText'];
// do something with $text here
If you are familiar with jQuery, you could do the following, if you don't want the site to redirect but execute your function:
in your html head:
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
the link:
Execute function
in ajax.php you put in your function to be executed.
Maybe something like this:
....
<script>
function sendText(e)
{
$.ajax({
url: '/your/url/',
data: {text: $(e).html()},
type: 'POST'
});
}
</script>
You can use query strings for this. For example if you link to this page:
example.php?text=hello
(Instead of putting a direct link, you can also send a ajax GET request to that URL)
Inside example.php, you can get the value 'hello' like this:
<?php
$text = $_GET['hello'];
Then call your function:
myfunction($text);
Please make sure you sanitize and validate the value before passing it to the function. Depending on what you're doing inside that function, the outcome could be fatal!
This links might help:
http://net.tutsplus.com/tutorials/php/sanitize-and-validate-data-with-php-filters/
http://phpmaster.com/input-validation-using-filter-functions/
Here's an overly simplistic example of what you're trying to do..
Your link:
Some Action
Your PHP file:
<?php
if (isset($_GET['action']))
{
// make sure to validate your input here!
some_function($_GET['action']);
}
PHP is a server side language i.e. it doesn't run in the web browser.
If you want a function in the browser to operate on clicking a link you are probably talking about doing some Javascript.
You can use the Javascript to find the text value contained in the link node and send that to the server, then have your PHP script process it.
Related
If I want to do some PHP on an event(e.g. onchange) should I use jQuery ajax like:
$("#elm").on("change", function(){
//ajax code
}
, should I use the PHP in the HTML attribute like:
<element onchange="<?php //stuff to do ?>"></element>
You seem to be conflating two different issues.
JS bound events vs intrinsic event attributes.
Bind your event handlers with JS.
Follow the principles of Progressive Enhancement and Unobtrusive JavaScript.
Ajax vs Putting PHP in a JS function
If you put PHP in a JS function then it will run when the PHP outputs the JS function to the browser, not when the JS function is called.
If you want to run PHP in response to an event, then you have to make an HTTP request to the server to run the PHP.
If you want to insert content from the load of page and leave it static, you should use only PHP.
If you want to insert content dynamically (changing with users interactions) you should use AJAX.
I can't found out what are you trying to achieve with your example, so not very sure what you should do there.
taking your code it would give this :
$("#elm").on("change", function(){
//ajax code
$.get('url', {data:'tosend'}, function(data){
// here you have the response of the php script in the data object
// it can be json for exemple
});
}
You must realise two things, your php code will be render when the page is loaded in the
browser so the second code you gave us
means that your "onchange" event is already present in your page.
If you want to request something (data, html, etc) to server from a loaded page, then do an ajax.
In that case below code is correct.
$("#elm").on("change", function(){
//ajax code
}
You cannot execute a piece of php code from client side. But you can assign values from php to javascript and then do operations on client side.
I have a javascript code that I wanna put a php on it.Then in middle of php code , put a javascript variable.
like this :
<script>
function getuserid(id,shop){
...
var htmlString="<?php $_SESSION['SELECTED_CID']= {I want to put 'id' variable here}?>";
}
</script>
PHP code was compiled and run once when you done loading your page. But javascript function can be used many time! So, some function like this does not exist.
You can use Ajax to accomplish what you want, whenever you wanna retrieve UserID, you can call an ajax, then ajax do a request to server and return you what you need!
Have a try :)
On my page I have a search result that contains a list with users where each is followed by an "addfriend" button. Each row contains a username and userID. Meanwhile the ID of the user that requested the searchresult is stored in a Session variable.
When the addfriend-botton is clicked the following 2 things should happen:
Store the userID and $_SESSION['userID'] is a MySQL table which describes the relationship.
Do NOT refresh the page (this the core of my problem) but stay focussed and change the state of the button to e.g. "friend request send". I'm thinking of GetElementByID().style method.
I was thinking of this:
<a href="#" onClick="addFriend('<? echo $_SESSION['userID'];?>','<? echo $rij['userID']; ?>')">
which calls the javascript function addfriend
I was hoping to catch the two ID's like this:
<script>
function addfriend(id1, id2)
{
//server side php code where I use value of
//the client-side javascript variables: +id1+ and +id2+ .
}
</script>
Is this at all possible or I'm I thinking the wrong way? Any suggetions on how to accomplish this?
You are in the right way, inside your addFriend() function, you can call one php file (via AJAX) and send the IDS without refresh the page. I think better you work with Jquery in this case, something like this:
<script>
function addfriend(id1, id2)
{
$.ajax({
type: 'POST',
url: 'yourPHPfile.php',
data: { your_id_1:id1, your_id_2:id2 },
success: function(data){
if(data){
alert('Done!');
}
},
dataType: 'text'
});
}
</script>
And in your PHP File you can do this:
<?php
//receive Ids
$id1 = $_POST['your_id_1'];
$id2 = $_POST['your_id_2'];
//do something here
echo "OK!";
<?
to do this work you need download and add the jQuery plugin in your page, rather into head tag
<head>
<script type="text/javascript" src="jquery.js"></script>
</head>
Good work and don't give up! (:
You can do this using AJAX (asynchronous JavaScript and XML), which is really just a fancy term for "sending stuff to a server with JavaScript and getting a response back, without reloading the page". There's nothing special about AJAX; it just involves using plain old JavaScript to send an HTTP request.
Check out jQuery, a JavaScript library that handles most of the technical stuff for you. Specifically, look at its post() function, which allows you to send data to a PHP script using the $_POST system variable. There are lots of clear examples on that page.
Note that you don't need jQuery to use AJAX; jQuery is just a library that makes things easier. If you really want to learn how the JavaScript side of AJAX works, try following one of the many tutorials out there, such as Mozilla's or this one.
AJAX is the answer you're looking for.
It sounds like you already have a basic understanding of this, but to clarify, Javascript executes on the client side, and PHP executes on the server side. So you would have to make a call back to your server in order to interact with PHP/MySQL.
The purpose of AJAX is to do this without requiring a page refresh.
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
For example, I have a php function:
function DeleteItem($item_id)
{
db_query("DELETE FROM {items} WHERE id=$item_id");
}
Then, I have something like the following:
<html>
<head>
<script type="text/javascript">
function DeleteItem($item_id)
{
alert("You have deleted item #"+$item_id);
}
</script>
</head>
<body>
<form>
Item 1
<input type="button" value="Delete" onclick="DeleteItem(1)" />
</form>
</body>
</html>
I want to be able to call the PHP function DeleteItem() from the javascript function DeleteItem() so that I can use Drupal's db_query() function, so I don't have to try to establish a connection to the database from javascript.
Does anyone have any suggestions on how this might be done? P.S. I understand that PHP processes on the server-side and javascript processes on the client-side, so please no responses saying that. There has got to be some kind of trick one can do in order to have this work out. Or maybe there is a better way of doing what I am trying to accomplish.
Since you are aware that PHP processes on the server-side and javascript processes on the client-side, you must also realize you can't call a PHP "function" from javascript. Your client side code can redirect to a PHP page, or invoke a PHP program using AJAX. That page or program must be on the server and it should do a lot more than just the one line you have in your function. It should also check for authentication, authorization, etc. You don't want just any client side script anywhere to call your PHP.
You need to write a PHP script which will execute the function. To call it, either:
use XMLHttpRequest (aka Ajax) to send the request
change the page's location.href and return HTTP status code 204 No Content from PHP
You will want to use ajax for that.
Also, database connection from within javascript is something you should not even consider as an option - terribly insecure.
A very simple example:
//in javascript
function DeleteItem($item_id) {
$.post("delete.php", { id: $item_id}, function(data) {
alert("You have deleted item #"+$item_id);
});
}
//in php file
db_query("DELETE FROM {items} WHERE id=" . $_REQUEST["id"]);
you can't actually call PHP functions within JavaScript per se. As #Christoph writes you need to call a PHP script via a normal HTTP request from within JavaScript using the magic that is known as AJAX (silly acronym, basically means JS can load external HTTP requests on the fly).
Take a look at jQuery's AJAX functionality on how to reliably make a HTTP request via JS, see http://docs.jquery.com/Ajax
All the normal security rules apply, i.e. make sure you filter incoming data and ensure it's what you're expecting (the $item_id in your example). Bear in mind there's nothing to stop someone manually accessing the URL requested by your JS.
First, use jQuery.
Then, your code will have to be something like:
<input ... id="item_id_1" />
<script>
$(document).ready(function() {
$('input').click(function(){
var item_id = $(this).attr('id');
item_id = item_id.split('_id_');
item_id = item_id[1];
$.get('/your_delete_url/' + item_id);
});
});
</script>