PHP and AJAX Web Content - php

I am thinking of developing a website in PHP and I was thinking of using AJAX in order to send data to, and retrieve data from a server asynchronously (in the background) without interfering with the display and behavior of the existing page.
So my question: would it be better to use AJAX to GET or POST to php pages or any other options are possible?

There are not that many options when it comes to submiting data, either you use AJAX or use the normal http message like GET or POST. If you would like to determin witch is better i would say: it depends.
Ajax seems to me like a great way of making more dynamic a part of your site, but i dont think its always practical to use in all your site. Ajax is generally used when you need to show some context change on one page, like posting a commner, faving a question, or things like that. Another great thing about it is not to bound user to a form (you can save info with a link like when you vote a question here)
Using GET or POST its usefull to let the user now here's moving along a process or when things that happen after or before are different, or context change a lot when submitting.

Rule of thumb (regardless of AJAX).
If you're going to send large amounts of data, or sensitive data... POST.
Otherwise, GET works just as fine.

I recommend use JQuery.
with $.ajax of Jquery, you can use it with multiple options depending that you need.
So you can work with POST, GET, receive data like text, json...
Here you can get more info:
http://api.jquery.com/jQuery.ajax/

I always use $_POST. I wish I could give a reason why I think it's better, but I can't. I guess it's because I've always preferred sending data via POST rather than GET so the user doesn't see it, and it just carried over to my ajax.

I would use $_POST just for the fact that it can store more data.

Related

HTTP request via AJAX or form-submit. Which one should I choose and why?

I have a PHP page with a simple form. One input text field & a button. Input text field accepts user queries & on button click an HTTP GET request is made to the server & the result has to be shown back in the same page containing the form. That's too simple to do. I can do this in two ways. One is AJAX & other one is the good old sodding form-submit method.
My question is simple- Which method should I use? Since both of the roads lead us to the same place, which one should I choose to travel?
First of all, let me talk about form submit method. I can use <?php echo $_SERVER['PHP_SELF'] ; ?> as the action of the form for submitting the values of my form to the same page. Once I store those values into some random variables, I can make a GET request & obtain the result & show it to the world. This method is easy to use. Happy Down Voting to all of you.
Or I can make a GET request using AJAX and jQuery or JavaScript or whatever you wish to use & obtain the same result as in the previous case. Output is same. Only the mode of execution is different.
So which one is better? Which one fetches result faster? And why should I use that? Is there any difference? GET, POST, PUT or whatever- it doesn't really matter. AJAX or form-submit?
There shouldn't be any significant, genuine speed difference between them.
The Ajax approach will load a smaller amount of data (since you aren't loading an entire HTML document), but by the time you take into account HTTP compression and the fact that (if your system is sensibly configured) your dependancies (images, scripts, stylesheets, etc) will be cached, it won't be significantly smaller.
By using JavaScript to create a loading indicator and not refreshing the entire window in front of the user, you can create the illusion of a faster load time though. So if feeling faster was the only concern, then Ajax is the way forward.
Using JavaScript, however, is more complicated and slightly more prone to failure. The consequences of failure states are more severe because, unless your code detects and does something with them, the user will (not) see it fail silently. For example, if a normal page load times out because the user is on a train and went through a tunnel, they'll see an error page provided by their browser suggesting that they refresh and try again. With Ajax, you need to write the error handling code yourself. This does give you more flexibility (such as allowing you to simply try again a few times) but the work isn't done for you.
The other consequence of using Ajax is that the address bar will not update automatically. This means that the results won't be bookmarkable or sharable unless you do something explicit the make that possible. The usual way to do that is pushState and friends, but again, it is more work.
You should also make the site work without JavaScript so that if the JS doesn't run for any reason then the site won't break completely. If you use pushState then you have to do this for the URLs you are setting the address bar to point to to be useful.
The short answer: Use a regular form submission, then consider layering JavaScript over the top if you think it will give your visitors a worthwhile benefit.
I Should stick to an Ajax request when possible.
This because you then don't really have to load every single item on the page again ( like all the images, menu and so on ). You can just give the relevant HTML back and JQuery can place it inside the relevant holder.
But that is just my humble opinion...
If you have to retrive simple data from server without reload the page my advice is use jquery .get o .post
also it provides you a very large API that allows you to reduce your programming time.
http://api.jquery.com/
obviously the execution time increase but in my experience the user cant fell the differce with a simple ajax request.
so in my opinion if jquery allow you to obtain the results, this is the best solution because halves your work time!
See the edited one it may help you.
I think that AJAX should be used for displays updates and form submissions should be done via a page reload. Reasoning?
When submitting forms, you are telling the application to do something. Users tend to want to feel that it was done. When a page doesn't reload, users are often left wondering "Did that work?". Then they have to check to make sure what they did was right.
but when you are displaying a table or something, and the user says to "display x data....now x1 data" for instance, they aren't "doing" something (creating new entities, sending emails, etc). So AJAX can provide a nice user interface in this case. Page reloads would be annoying here.
In conclusion, I think form submission should be done via page reloads (let the user see it working), whereas display updates should use AJAX (prevent annoying page reloads).
Of course, this is a preference thing. Some of my company's applications use AJAX all over. But those are the applications that are the most difficult to maintain and debug. ;)``

Way to send POST data to a PHP file from another PHP file?

Alright, so I've looked at a ton of questions, but I only found 1 that resembled what I am trying to do. Here is the link to it: Passing POST data from one web page to another with PHP
I want to pass data from one PHP file(we'll call it editData.php) to another PHP file(we'll call it submitData.php). Neither file has any HTML elements (pure PHP code I mean). The first file(editData.php) receives $_POST data, edits it, and needs to send it to the second file. The second file(submitData.php) needs to be able to read in the data using $_POST. No sessions nor cookies can be used I'm afraid.
In the linked question above, the answer accepted was to create hidden fields inside a form and POST the data from there. This worked for the OP because he had user interaction on his "editData.php", so when the user wanted to go to "submitData.php", he would POST the data then.
I can't use this solution(at least, I don't think I can), because I am accessing (and sending $_POST data to) editData.php from a javascript AJAX call and there will be no user interaction on this page. I need the modified data to be POSTed by code, or some other way that does the transfer 'automatically'(or 'behinid-the-scenes' or whatever you want to call it). submitData.php will be called right after editData.php.
I don't know if I can rewrite submitData.php to accept GET data, so count that out as well (it's a matter of being able to access the file). I really don't want to echo stuff back to my original JavaScript function(and then AJAX again). I am encrypting info in editData.php, and (while it sounds silly to say it) I don't want to make it easy for someone to develop a cipher for my encryption. Returning values after being encrypted(viewable with Inspect Element) would make it too easy to decipher if you ask me.
I feel like this issue could come up a lot, so I'd expect that there is something obvious I'm missing. If so, please tell me.
tl;dr? How can I send data to a PHP file via the POST method while only using code in another PHP file?
Well you might consider just streamlining your approach and including the submitData logic at the end of the editData file. But assuming that this is not possible for some reason (files live on different systems, or whatver), your best bet might be to use cURL functionality to post the data to the second script.
If the files are on the same server though I would highly recommend not posting the data to the second script as this will basically just double the amount of requests your web server needs to handle related to this script.

How to check availability of an ID in same page?

To be specific, I want to make code like Yahoo's Registration (Yahoo ID - Check Availability) checking the availability. The problem here is I need to use PHP to connect, get, and search/verify if the entered value in the textbox is unique.
I tried passing a JavaScript value to a PHP variable, but based on my research, doing this isn't possible, so I need another possible solution to get the value of the textbox and set it to a PHP variable.
Thank you in advance.
The only way to get data from JavaScript to PHP (in a typical environment) is to deliver it over HTTP. Doing this without leaving the page is known as Ajax, and usually done using XMLHttpRequest.
There are no shortage of tutorials describing how to do this, nor any shortage of libraries that will help (plus, of course, all the large libraries such as YUI and jQuery).
You can use Ajax for manipulating this situation.. Have a look at following link.
http://www.digimantra.com/technology/javascript/check-username-availability-validation-ajaxphp/
You need to use AJAX for that.
AJAX is used to send and receive data from the server. So, on the server side, you can create a URL that checks whether a username (can be passed using get/post) is available or not & accordingly send a response. At the client side, depending on the response you receive from the server, you can alert the user.

jQuery posting variables within the same file

I have some variables set in Javascript. Further down the script I want to use these values in PHP. I realise I need to POST/GET them with jQuery, but I don't understand either function fully, even after looking at the manuals.
Could somebody break it down and explain the parameters?
Would I be better off using GET or POST in the instance?
Can the URL specified be the same as the current page e.g. index.php?
Thanks very much for your help.
You can not do this unless PHP is writing the javascript. PHP is on the server side and will be parsed before Javascript is ever seen by the client. Any variables set by JS will NOT be seen by PHP on the same request.
It's really just a question of style, really.
GET places all key/value-pairs in the URL field, whereas POST puts it in the HTTP body. Since URLs are limited in length, POST is preferred for longer, larger sets of data or data needing to benefit from TLS/SSL encryption.
So let's say we have a key: articleID. You want to pass 1 to articleID, so that the backend can contact the database and retrieve the article in question.
If you make a GET request, you'd invoke the following URL:
index.php?articleID=1
If you use POST, you'll put the data in the request body itself, so you wouldn't be able to tell what value you sent to the server without opening the packet in question and examining the request.
You'll find more information on how to perform these requests back at jQuery's reference site. More information about GET and POST.
You are the architect of the application, so you would know best what method to use. As for contacting the view itself, it's certainly possible albeit questionable from an architectural point of view.

Passing variable over to a new HTTP Request

As the title says, is there another way to pass a variable from "current" page over to "next" (new HTTP request) page without using sessions/cookies/$_GET?
Well, I guess $_POST could be an option too, but the thing here is, that I want to pass this variable from already executed $_POST back to off-the-post environment page, but inbetween I'm having a redirect, to disallow reposting the same form.
In other words, basicly, I'm trying to "make" a seamless PRG, but sessions/cookies/$_GET is not an option.
And yes, I'm working with classes (hence the oop tag). Therefore maybe some kind of magic functions, or output control?
This has to work within PHP environment, no JavaScript or other non server side language.
I also have a bad feeling that it's impossible, but hopefully I'm wrong, and there is a solution.
Thanks in advance!
update no. 1
Basicly, I want to create a PRG with response.
Inside this $_POST I'm adding data to database. I want this response to hold information whether this database query has been successful or not. Kind of make this $_POST process almost invisible to the user. And yes, display a response with the result later on.
All of this happens in one method:
if($_POST){
// insertion
}else{
// display no-post environment, if response exists (therefore posted) display response too
}
Something like that...
Sessions is not an option because this is meant to be some kind of API.
update no. 2
Huh, let me rephrase the question a little. Well, it seems that I don't actually need to pass the variable over. What I want to do, is to have 2 different results after POST so on next page load I could know whether the actions in POST has been successful or not. So, what other options are out there without using sessions/cookies/$_GET to get this result?
Currently there is:
temporary database usage: a good option, but I'd like to see different options;
Since you're already using a database it seems like the easiest way to handle this would be to update some kind of temporary table with the information you want based on the post call, then on the page you're doing a header redirect to, read the information in that table. With the constraints you've placed on this (no GET, SESSION, Cookie or Javascript) you're not going to be able to maintain a variable when you redirect from one page to the next.
So leverage that database and take the work off of PHP. Initially I was going to suggest utilizing cURL but I don't think that will help here (though you may want to look it up if you're unfamiliar with it, as it might be what you're looking for)
HTTP is a stateless protocol; thus, there's not going to be an easy, built-in way to add state. That said, I think sessions are the best way to accomplish what you want to do. If what you're doing isn't in the browser, maybe try some sort of session key setup (like the Facebook platform uses).

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