I'm currently only using PHP to take user submissions, put them in a database, and echo them out on a page using SQL to select from a table, such as comments. I need a system that will automatically update comments without refreshing the page like on YouTube. The less the user has to manually update, the better.
I want it to work pretty much exactly how YouTube and Twitter function, where it'll say "x NEW COMMENT(s)" and clicking that updates everything.
My teacher recommended a JQuery function, but I don't have any background in that language so I don't know where to begin looking.
I'm at a complete impasse. I will update this if you guys need additional information to aid in my search.
You are looking for AJAX
You will need a HTML page with jQuery/AJAX that calls another PHP page. In that PHP page you do the DB request and then ideally return the data as JSON so that your frontend part can display it to the user.
As every one says, AJAX is the way. You can find a simple blog I did on it here.
Related
I want to create a page where people can insert some text, hit enter, and the text be stored in a MySQL database. I can do this, but I want to be able to load a page, enter a password, and see a list of all the info in said database, then whenever something is added to the database, it's added to the list on the page, without me needing to refresh the page or setup some javascript code to refresh the page every five seconds.
I believe Satya has it correct in suggesting that you use Ajax in order to refresh the data without refreshing the page. You can have it request updated information from a php script which queries your database for the data you wish to display, and then sets the elements on your page accordingly.
this is probably the best way for you to implement ajax calls using javascript
http://api.jquery.com/jQuery.ajax/
Or you an simly do it with the help of setInterval() function. You can call an html code in a div using
$('#id').html("<htmlcode></htmlcode>");
Example : http://jsfiddle.net/ipsjolly/995PJ/6/
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.
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.
I am not sure the correct terminology for the process that I am trying to describe. I don't even know which platform is underlying the technique. If you understand my description, please give the link to the site(s) and or the keyword name of the process. I think it is done by AJAX, but I am not certain. I use php as the backend code, I just need to find a way to dynamically display the results. Please give suggestions. I forgot the name of the sites that use this, and my link history expired.
TIA
Description:
The page would have a search form and options. After the user submits, the search is initiated, and the results appear inside the dedicated result area. The page does not refresh, just the info inside the result area.
The display area will show 20 (or whatever) results (lines). There will be next, and previous buttons. If you hit next, the next set of results will display.
I am writing a code that generates 20 results for each display. There is no set number of results, so the results might have a start/first page, but do not have an end page.
Each time the user hits 'next', the program would generate/load new results. It would also store previous results, so that when a user hits 'prev', the previous results can instantly come up.
What techniques/program are theses?
Having recently handled pagination with Code Igniter (php framework), the following links might help you and anyone else out:
http://tympanus.net/jPaginate/
http://codeigniter.com/forums/viewthread/93045/
Usability is important and AJAX pagination introduces some important questions that need addressing regarding pagination, the following article will give some usability guidelines for displaying results in a table:
http://thedesignvanguard.com/crud-r-for-read
Code Igniter Prototype Framework Ajax Pagination:
http://codeigniter.com/wiki/AJAX_Pagination_with_CI_Pagination_Library/
Since we're using jQuery, we chose the following, Codeigniter jQuery framework for AJAX pagination
http://tohin.wordpress.com/2008/08/12/codeigniter-ajax-pagination/
http://tohin.wordpress.com/2008/10/07/codeigniter-ajax-pagination-exampleguideline/
It is not AJAX for sure.
Nobody uses AJAX for the pagination.
And there are about zillion pagination examples over internet
The only thing is never described in articles is how to persist search options for the other pages.
But it's simple enough: http_build_query() can help you
You need to have a GET/POST form submitted via AJAX which contains the fields in the search term and page number.
If you are going to set the page size to 20 results, page_num=4 will show results from 61-80 results.
Usually search results are GET instead of POST (Ex: See Google search results ) along with the page_number as another attribute and value.
#IVAN .. good to know that the library came helpful..
About that searching option; check the recent commit in github
http://github.com/neotohin/CodeIgniter-Ajax-pagination-Library there is an additional parameter added for searching.
I think the simple code in readme is enough for understanding the mechanism.
You could use datatables
https://datatables.net/
https://datatables.net/examples/data_sources/server_side.html
With this plugin using jquery also you could use server sided page request , you just have to handle the plugin post using Ajax.
post automatically sends row , page offset column, search criteria you just have to provide the json encode return
and the plugin automatically has library in featuring pagination, search sort number of rows per page and the table formatting.
Needed are jquery, and the plugin css and js for this to work
let me know if you understood my explanation.
thanks (=