What is the best way to refresh the content of a var that is included? For example, I have this code:
<marquee>
<?php
include('note.php');
?>
</marquee>
This is great, as I can show on the page the contents of note.php. Say I change note.php but I don't want users refreshing to see the changes...is there any way to refresh the included file every 3 minutes for example?
To refresh only a portion of a page, you'll have to use some kind of Ajax Request : once the page has been sent to the browser, the server has done it's job, and cannot modify is anymore : the request of fetching a new portion of the page as to come from the browser.
You could do some Ajax requesting "by hand", it's not that hard ; but I'd rather suggest that you take a look at some of the great javascript frameworks that exists out there -- that might be helpful in the future, when adding more functionnalities to your application.
For instance :
With prototype, you can use Ajax.PeriodicalUpdater
Or, with jQuery, you could use something based on $.load
Only by using an ajax like call.. take a look at prototype or jquery for decent JS libraries to help with this..
Unless you just want to put some javascript in to refresh the page every three minutes, you'll need to look into another technology, namely AJAX. As far as I know, PHP can not do this alone.
Related
I don't have the means to test this right now but I am curious. Using AJAX, can you open the same file that the AJAX call was on? My goal is to pretty much reload the page, with a new POST parameter, without refreshing and using only one file.
Yes you can.
I just ask you, why don't, instead of reloading the page, you reload/rebuild/destroy and create the elements you need based on the response to that ajax call ? depending on your desired outcome you might want to do it better like that. More work in the user side, but a nicer 'web 2.0' experience.
I want to put Thumbs up/Thumbs down buttons on my website.
There will be quite a few of them displayed at once, so I don't want to have to do a POST and reload the page every time the user clicks on one.
I thought of using re-skinned radio buttons to choose Thumbs up/Thumbs down, but that would require the user to click a submit button.
So how do I do this? I am open to using JavaScript or some other form of Client-Side scripting, so long as it is built in to most/all web browsers.
Thanks!
YM
I would take a look at using jQuery, http://jquery.com/ It is a WIDELY used library and there is tons of support for it both here and # jQuery's website.
You could easily assign all those thumbs to do an ajax post to a save page with the correct id and the user would not know the difference
You're definitely going to need to use JavaScript on this. Well, there are other client-side languages that could technically do the job (ActionScript, for example), but JavaScript is definitely the best way to go.
Look into AJAX (Asynchronous JavaScript And XML). This is just a buzzwordy way of saying use the XMLHttpRequest() object to make page requests with JavaScript without reloading the page. Here's a good tutorial: http://www.w3schools.com/ajax/default.asp . Note that, despite the word "XML" being in the title, you don't have to use XML at all, and in many cases you won't.
What you'll basically do is this:
Have your thumbs-up and thumbs-down buttons linked to a JavaScript function (passing in whether it's a like or dislike via a function argument).
In that function, send a request to another page you create (a PHP script) which records the like/dislike. Optionally, you can have the PHP script echo out the new vote totals.
(optional) If you decided to have your PHP script output the new results, you can read that into JavaScript. You'll get the exact text of the PHP script's page output, so plan ahead according to that -- you can have the PHP script output the new vote totals in a user-friendly way and then just have your JavaScript replace a particular div with that output, for example.
I am working on a social network website similar to facebook. But, I am facing a rather confusing stage in the programming.
I am done with the register/login/logout pages/scripts, and you can view profiles with the www.mywebsite.com/profile.php.
Now, I want to do what facebook does and allow users to click links while on their profile page (info, notes, photos) but never actually leave www.mywebsite.com/profile.php — just the appropriate content is printed to the screen.
How is this done? I am not asking anyone to code this for me, just point me in the right direction!
You can use Ajax for this purpose.
Put the content that you want to replace in a div and using ajax replace that div and only send that content.
Are you trying to do something like this?
http://www.99points.info/2010/05/how-to-create-dynamic-content-loading-using-ajax-jquery/
That will have to be done via Javascript and Ajax.
A javascript function will fire when the link is clicked. An ajax request is sent to the corresponding php script which sends back a response to your javascript function. You then parse this response and place it on the screen.
If you go that way, have a fallback option that does not rely on javascript as well in case a user has JS turned off.
You Can use this reference...
function showdiv(id)
{
if(id)
{
var selected_offer="yourpagename.php"
HTML_AJAX.replace('divname',selected_offer);
}
}
call showdiv on onChange() function of your link..
For this, you need the technique known as Ajax, which is short for asynchronous JavaScript and XML. The basic idea is that when the user does something - in your case clicks on a link or button - instead of loading a page, a script runs that calls on a server side script to send back some data. This is sometime XML, but you can get other types of data back as well. The asynchronous part is that the user and the page can go on doing other things while waiting on your script to return the data you asked for.
There's a good book for beginners in Ajax that I read myself: Head First Ajax. Looks like you can pick up a used copy for about $10. It's a nice intro, has a quirky style that appeals to some, and the authors do whatever they can to keep your attention. Hardcore programmers probably won't like this one, but I sense you're a little newer to the game and this may be a good read. Otherwise, Google "learning Ajax" and there are a bajillion resources.
Good luck!
To respond to your comment, you can set up a "router" script that takes input and runs a specific function in response. This "router" function looks at the $_GET[] superglobal for a parameter like "action" and then calls a corresponding function. If not action parameter is sent over, the router calls a default function.
Now for a little more detail. Your page script would have 3 basic parts: The router, the various action functions, and the page template function. The router just calls the appropriate function from the action functions and passes the output into the template function. Here are a few examples.
The user arrives on the page, index.php. No action is specified, so the router finds $_GET['action'] == '' and it calls default_action(). This returns a welcome message, status, whatever, and the router passes this output to the function that displays your page, output included.
Now the user clicks a link/button for updates and arrives at index.php?action=update. $_GET['action'] == 'update', so the router calls update_action(). The output goes on to the template function for display.
Does this help you envision how you might accomplish this?
refreshing a top bar just like facebook where the no of messages are getting updated when the new messages comes just like facebook or gmail without refreshing the whole page . i can do this if that top bar is located externally i can refresh that bar with either meta tag set timeout or with refresh tag , but not getting how to refresh when it is part of main page.how to do this without reloading whole page and without any external file as the full code of the inbox and alert is located in main.php so i cant take it out and call these function externally.
maybe you can try to set a timer to pick new messages with ajax method and use js to change dom element's performance.
You need to use a partial page refresh using an AJAX callback. A good place to start learning AJAX is the Google Code University and the jQuery JavaScript framework.
Not sure what you want, but try this one: http://www.brightcherry.co.uk/scribbles/2009/02/26/jquery-auto-refresh-div-every-x-seconds/
Sujit, you definetly need to use AJAX. I think you have not explained yourself very clearly, but you are saying you want all the code on the same page, that's a bad programming practice. You need to use AJAX and have "code separation" (separate HTML from JS from PHP).
Maybe you are afraid of using AJAX, I recommend and easy library for managing AJAX, it's called SACK. You can see a nice an easy tutorial here.
Hope that works for you.
What about this then
setInterval(function(){
SomeAjaxFunction();
}, 1000);
Let's say we have a page written in PHP. This page loads by it self a template with header, body and footer and print this out. Now let's say that in the body of this page we would like to start a loop and load some posts (messages taken from a database).
We also need the page to load new posts every 10 seconds, if any, without refreshing the page (classic AJAX). This ajax call will use JSON and AJAX and micro templates.
Now i'm just wondering:
Do we really need PHP to load posts the first time the page is loaded? Can't we just start that Ajax call and load posts with Ajax instead? (Notice that the existing ajax call would be kept as it is, since it loads posts starting from the latest loaded (in case of no posts, that would mean all posts).
If you did not understand my question don't hesitate to let me know.
In this situation I think the simpler approach is the let AJAX handle it, if you do let php load the initial messages, you'll have two places in code, that you'll need to maintain to perform identical jobs.
I think you are asking how you should load the posts the first time the page is accessed. If so: When the page firsts loads, have some PHP that prints out the existing posts. Then, add some JavaScript to update the page with new posts every 10 seconds. This is a matter of preference. You might want there to be no posts when the page first loads, and then use Ajax to get the existing posts once your page has loaded.
Edit:
I agree with jondavidjohn that you might be better off using pure Ajax. However, you could always isolate the code that fetches the pages into a separate function. That way, the script that generates the page calls the same function as the script that is called via Ajax.
The drawback with that technique is that it doesn't downgrade gracefully. So people with javascript disabled will not see any posts.
I'd recommend outputting some data with php - AJAX requires JavaScript which many people don't have activated.
Why not, instead of having the browser poll the server for new posts, have the browser push new content to the browser when it is available using the likes of node.js?
I designed my site with AJAX exclusively, and it works perfectly except for one rather major issue: Using AJAX requires JS to be enabled. Of course, if users trust your site, this is not a problem, but if they don't, then an AJAX solution won't work unless you put the entire page in a noscript tag.