I've got a simple website using plain HTML/CSS to display and PHP/MySQL for data storage.
Now I'd like to add a toggle button similar to facebooks "like" button.
How can I act on the user pressing the button (add database record for this item, change button text) without leaving the page?
I thought this question would have been asked and diskussied to no end, but all solutions I found require some other frameworks than plain PHP as background.
You'll need to do it with javascript. Read up on "AJAX form posting".
A high level view:
user clicks on button
you capture the click via an onclick handler in javascript, and use it to call a javascript function
said function does a remote url request via XmlHttpRequest to a target page
that target page takes in the parameters passed via POST or GET and performs actions with them (eg add database record), and prints out any response required
the javascript function reads the response and acts accordingly (eg change button text)
and all this happens without refreshing the page.
You can do all this with pure low level javascript code, but plenty of libraries already abstract it while solving various issues with browser compatibilities. I'd suggest the jQuery javascript library. It provides an easy way to do exactly what you require, and good documentation.
Related
i have a website that uses a number of containers (div's). In this scenario, we have three boxes down the left side and one bigger box on the right of these boxes. The bigger box on the right is the only thing that changes when a link is pressed, this is done with Javascript.
SO i have the index which is the main layout of the website and i also have the "pages" of the site, so when a link is pressed the main box (on the right) loads the new data.
On one of my pages i want to collect data and then run it through a PHP script that is in the head of the file, but when i click the button i realise it refreshes the whole page and it doesn't run the script on the page with the form.
Anyone had a problem like this, or know of something i could do to work around it?
I'm not really sure what code would be useful for helping me but if you need something just ask.
Thanks for the help
Since you are loading all your content via JS already, you could just POST the form data via AJAX to a PHP script to process, then read the output and either provide an error message or remove the form from the page and show your success message.
How to approach your AJAX call is dependant on what you've used as a basis for the rest of your JS.
Personally I like to use the JQuery library, as it makes AJAX calls (and much more) very simple.
How about you make the page design able to do it. Have the backend be able to spit out the state of the page when it posted.
Or use Ajax to post the data back and set the new state like you do already.
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.
Hello guys I newbie question :) - I am currently using PHP/Zend and now I need to display a form and other content in one of my pages. I do not want the page to reload and I cant use a pop-up window so the best option is to sort of dynamic display a "square" in the middle of the current page with this form being load on the go... this way i could have my pages (forms, text, whatever) being pulled in this square.
In order to keep compatibility with older/new and different browsers, what would be the best choice? DOJO - that is already in Zend, JQuery, or just HTML5/CSS3? Besides, if anyone could point me to some references of where can I find this info it would be great!
AJAX is the most common means (Asynchronous Javascript And Xml) to do this- which uses Javascript to poll other scripts (can be .php pages) which then return predefined output based on the request- this output can be content to inject into a page, or data which can then be interpreted by your page for another action (i.e. the output from another page etc..).
In this instance, your .php page could include JS (javascript) in the head, whether linked or inline, which would contain details for launching an AJAX request- namely, how often or on what trigger (button press etc), by what means (POST or GET), what is sent (any other variables you wish), what the target script is (the script which will handle the request and output your required content/data), and what to do when the response is recieved (i.e. which element on the page should be updated with the response).
A little about AJAX:
http://webdesign.about.com/od/ajax/a/aa101705.htm
http://webtrends.about.com/od/web20/a/what-is-ajax.htm
Likely the simplest way to begin is to use a pre-existing Javascript library like the ubiquitous jQuery (jquery.com), there are thousands of tutorials out there for it, and though you will need to do some Javascript programming, the library has meant that you can rely on fairly simple syntax to do so (as simple as $('#myelement').load('mypage.php')):
http://net.tutsplus.com/tutorials/javascript-ajax/5-ways-to-make-ajax-calls-with-jquery/
http://www.devirtuoso.com/2009/07/beginners-guide-to-using-ajax-with-jquery/
http://www.sitepoint.com/ajax-jquery/
http://yensdesign.com/2008/12/how-to-load-content-via-ajax-in-jquery/
In simple terms:
You have your php page with the element (area) that needs updating (page A)
Build another php script which outputs the content you want 'refreshing', e.g. the latest news stories, each time it is run (page B)
Link to the jQuery library in your header section (page A)
Write a simple jquery function in the header section of page A, which says every X seconds/minutes (or on demand), run an AJAX request to fetch the content of page B and insert into an element (DIV) within page A
---updated---
If you wish to use DOJO as opposed to jQuery, there is also a wealth of resources available:
http://dojotoolkit.org/documentation/tutorials/1.6/ajax/
http://www.infernodevelopment.com/dojo-ajax-tutorial
http://startdojo.com/2010/01/02/simple-ajax-form-tutorial/
http://today.java.net/pub/a/today/2006/04/27/building-ajax-with-dojo-and-json.html
http://www.ibm.com/developerworks/web/tutorials/wa-dojotoolkit/index.html
http://www.roseindia.net/dojo/
Why use AJAX for dynamic web pages when you can do it only with php?
The main reason to bother with AJAX is User Experience (UX).
Now AJAX won't necessarily improve UX in every single instance so in a lot of places sticking with pure PHP is perfectly okay.
But imagine the case where you have a text field on the site and a link to vote on something. Kinda like this site. When you add AJAX your users won't loose the text they entered in the textfield when they decide to vote on the link! How incredibly useful!
So if you care about your user's experience it is a good idea to use AJAX in situations like that.
PHP creates and outputs the Content to the Client Browser as it's a Server-Side Language and that's what it was built for, so on a request your code will access database, files etc. and then output the constructed html/text to the client.
Ajax just gives the User a more Desktop like feel. For example deleting a record and instead of the entire page reloading just letting the one element disappear from say a list and letting the server know that the record is to be deleted. But Remember to let the User know when you are busy sending data to the server (With a progress bar in .gif format for example). As lot's of user feel that if nothing happens on the screen to notify them, that the application is frozen which means they will either reload the page or just try to click the button again.
But you will need to provide some sort of compatibility with browsers that have Javascript disable and thus cannot use your AJAX functions, just something to keep in mind.
AJAX stands for Asynchronus Javascript and XML, meaning that a page can get new data, without having to reload a page.
PHP cannot send data without reloading the whole page. A user has to press a button, to send data.
An example of AJAX is for example google suggestions or the tag suggestions on this website.
Context
I'm working on a project that I'd like to make more dynamic with PHP + AJAX.
I'm using jQuery for the AJAX part because I totally suck in Javascript, and anyway it seems to be worth something.
I reached a point where my application needs to use a form to send a post, and I want to use an ajax call to perform this action. In the page I'd like to send the post, there is also a list of the most recent 15 posts submitted.
First question: Should I just forget about it and use just PHP?
The action
The user writes something in the <textarea></textarea> and clicks on a <a id="myPostSubmit">Submit</a> that is the handler that I'll manage on the jQuery script with something like $("#myPostSubmit").live('click', function() { /* here i make the ajax call */ });. If the post is successfully submitted we are going to do something (I'll talk about it in the next section), either we will alert the user using my showAlert(text) function, that shows a black box for 4 seconds with the text in it.
Second question: Should I manage the click event in any other ways? Should I create a function, such as sendpost(post) and attach it into the HTML onclick="" event?
If the post is successfully sent
I'd open a discussion about 2 options:
We refresh the page [not actually
loading the entire page but making
another ajax call that retrieves the
posts lists and makes disappear the
old one, load the PHP file to
retrieve the new posts (including
the one we just sent), and then make
the post list appear]. Pro: 1) We are sure that what the user is reading after the post list is loaded is the real post sent. So it actually double checks the action. 2) We load also some possible posts sent in the mean while. Cons: 1) We have to create a PHP file that gets the post list template, slicing the template of that page in 2 files. 2) It doesn't really seems that smooth to me.
We just use Javascript to get the post template, add it to the list. Pro: 1) We make it really smooth, without reloading the entire page. 2) We don't need of any PHP file to reload the page. We just use Javascript (jQuery). Cons: 1) How do we get the post html template to add it to the list? 2) How do we get the user (logged) informations without PHP?
Third question: Is it better the 1st or the 2nd solution? Would you provide a even better 3rd solution?
The PHP page
The PHP page that will receive this AJAX call is : ?p=action&a=sendpost. The page require $_POST['myMessage'] to be set and not empty and nothing else. The page itself will get all the user infos from the cookies and will manage to perform the needed query.
The application
It is divided in 3 parts: App, Template, Library. Basically each page of the application has its own .app.php and .tpl.php file.
The .app.php file manages the building
of the basis of the page, using classes
and other stuff from the library. In
our case it retrieves datas from the
database and put them into
variable.
The Template is called at the end of the .app.php file. The .app.php file send to the template the retrieved data and the .tpl.php file outputs them.
The library is used to contain the classes and functions we need in the application file.
Fourth question: Is this a good way of manage my web application?
Edit: What about returning the alert message to the user?
I read about an option, inside $.ajax() that will manage the response on success or in error. The documentation about it is very simple and I didn't get it.
Fifth question: How should I return (from the PHP file) the error
or the success?
First question: Should i just forget about it and use just PHP?
Well, you application will relay on JavaScript if you use ajax, this days i think it just fine ;)
Second question: Should i manage the click event in any other ways? Should i create a function, such as sendpost(post) and attach it into the HTML onclick="" event?
Create a function and bind onclick. Code will be more readable ;)
Third question: Is it better the 1st or the 2nd solution? Would you provide a even better 3rd solution?
My solution: ajax submit the form and on callback insert new comment in to the list or display error message if user can't comment.
Check jQuery serilize() for submitting forms data with ajax.
Fourth question: Is this a good way of manage my web application?
It's just fine ;) When you application get's bigger you will have to redesign it, but don't do it know, do it when current solution becomes to hard to work with.
Read some good book on building MVC framework. And on programming patterns in general.
You seem to be on the right track with everything. There are lot of opinions called "best practices" about how to exactly attach event handlers, how to reload the data on the page and how to organize your application, etc, but I personally would rather build more software instead of worrying about details like that. The details will come to you eventually.
I personally find that updating whole chunks of server-side-rendered HTML on the page is more robust solution, but I have seen people getting excellent results with templates.