Save data with php-script and hold post-variables on error - php

I have already searched an answer here and with google, but I don't found something. Because I'm having trouble ask the right question to find something.
What is the best way for this problem:
My Page: edit_data.php
I have a form (method="post" action="save.php"). On submit I store the data in a MySQL table.
In save.php:
MySQL insert (return the new id of dataset)
if success I call edit_data.php?id=<new_id>
if error I call error.php?msg=<error message>
The problem is that I lose the data on error.
This is what I want:
- go back to edit_data.php
- show the error directly there
- and I want that all fields contains their original data
I cannot take $_GET, because the data are too big.
Does anyone have an easy solution for me?
Thank you

Is there any reason you can't use $_SESSION? That way, all your data will be saved for the duration of the session, or until you delete it.
Make sure that every PHP document contains session_start(); before any headers are output, this also goes for any blank space before your <?php tag.
To put all your $_POST data in a $_SESSION['POST'] you could do something like,
<?php
session_start();
foreach($_POST as $key=>$val) {
$_SESSION['POST'][$key] = $val;
} ?>
Then you can access your previous POST variables by accessing $_SESSION['POST']['KEYNAMEHERE']
PS: $_GET and $_POST are interchangeable here

If $_GET is to big, you can edit your php.ini file.
Please note that PHP setups with the suhosin patch installed will have
a default limit of 512 characters for get parameters. Although bad
practice, most browsers (including IE) supports URLs up to around 2000
characters, while Apache has a default of 8000.
To add support for long parameters with suhosin, add
suhosin.get.max_value_length = in php.ini
http://www.php.net/manual/en/reserved.variables.get.php#101469
Max size of URL parameters in _GET

Related

How do you use XMLHttpRequest with POST method?

I have a central PHP script I use for handling many requests from my page, using XMLHttpRequest() calls from JavaScript, using the GET method. My server PHP is currently 5.6, and yes, I'm avoiding synchronous calls.
It all works well, however there are cases where I'd prefer NOT to have the request remain in browser history, or even be displayed in the URL. So based on the MDN reference on this call, I thought I could simply switch to the POST method, keeping my existing requests (such as "http://myscript.php?cmd=dothis&data=somedata"). then all I'd have to do is add some code to my PHP script, so I could gather the passed data either way...
if ($_SERVER['REQUEST_METHOD'] === 'GET') {
if(isset($_GET['cmd'])) $cmd = $_GET['cmd'];
if(isset($_GET['data'])) $data = $_GET['data'];
}
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
if(isset($_POST['cmd'])) $cmd = $_POST['cmd'];
if(isset($_POST['data'])) $data = $_POST['data'];
}
Well obviously i was dead wrong. What I found was...
Neither of the variables shown in this example are seen by the script within the $_POST array, when I switch to the POST method.
Switching from the $_POST array to the $_REQUEST array works fine (eg: "if(isset($_REQUEST['cmd'])) $cmd = $_REQUEST['cmd']);" ), BUT....
Just the act of issuing my XMLHttpRequest() calls with the POST method, results in errors like this in my log:
PHP Deprecated: Automatically populating $HTTP_RAW_POST_DATA is
deprecated and will be removed in a future version. To avoid this
warning set 'always_populate_raw_post_data' to '-1' in php.ini and use
the php://input stream instead. in Unknown on line 0
So obviously This is a dead end. Doing my best to research what is going on here, in the PHP manual reference to POST I read this right on top...
$_POST $HTTP_POST_VARS [deprecated]
So if I'm understanding this right, the reason I can only obtain the POST variables using the $_REQUEST array is because my requests are still formatted as if I were still using GET, which (apparently?) is a deprecated method. Therefore, "coaxing" it to work is just moving the problem to the future.
Incidentally, I can see by calling the phpinfo.php on my server that despite the ERROR I see in my logs, "always_populate_raw_post_data" is indeed already set to "-1". So all the "solutions" I've found recommending I "JUST" make this setting in my PHP.INI file do not help.
And even if it DID "hide" the error, doing so seems irrelevant to me. Am I wrong in saying that even if I simply gather my passed PHP vars from the $_REQUEST array when using the POST method, AND figure out a way to suppressing the "deprecated" warnings in my LOG, the whole scheme would still fall apart (and make my POST requests fail), the day I finally migrate to PHP 7.x.?
I apologize for asking here, but I have really tried to search every reference I could find for both doing XMLHttpRequests using POST method, AND the deprecated error messages I get in my logs. There is so much obsolete info out there, I can't find any clear discussion on how to PROPERLY alter or re-format my XMLHttpRequests so that I can use the POST method. In fact, I can't even positively determine whether doing so will be possible beyond PHP.5.6. Any help will be very much appreciated.
PHP made a mistake of naming $_GET and $_POST after the default place that a web browser will put data in an HTML form where the method attribute is set to GET or POST.
$_GET gets data from the query string, even if the request method was POST.
The request body is determined by the argument you pass to send. Data you put in the query string remains in the query string.
const url = 'http://myscript.php'
const form_data = new FormData();
form_data.append("cmd", "dothis");
form_data.append("data", "somedata");
cost xhr = new XMLHttpRequest;
xhr.open("POST", url);
xhr.addEventListener('load', function () { console.log(this.response); });
xhr.send(form_data);

How to overwrite a stored variable in php

So I have 2 different .ini files that stores different languages and I'm trying to choose which one I will read data from via a form.
Is there an easy way to do this, or should I use MySQL to switch between the files? With this I mean storing the filename and then changing the filename value in the database via the form.
Or as I'm trying to accomplish, store a $filename variable in PHP that holds either file 'a.ini' or file 'b.ini', depending on my choice.
It should also be possible to switch back and forth between the choices.
Right now I'm stuck and have no idea what to do.
I have this and I know I have to put it in a function, but from there I have no clue..
$ini_array = parse_ini_file("languages/EN.ini");
I'm trying to change the "EN" to a different value, but to no success so far.
My code right now, after som modifications: https://pastebin.com/a077jFE1
Right now I either have to refresh the page after submitting or submit again for the changes to take effect. Why is this occuring?
I would try something like this:
if (isset($_POST["your_form_field"])){
$ini_string = "languages/" . $_POST["your_form_field"] . "ini";
$ini_array = parse_ini_file($ini_string);
} else {
# Default
$ini_array = parse_ini_file("languages/EN.ini");
}
mmdts has a good answer too, store the posted value and use it on all your pages :)
Have you tried looking up storing data in a session?
A good guide on how to do this is available at:
How to set session in php according to the language selected?
You can follow the first answer to the letter in the php script present in the action of the form which allows the user to select the language.
And in all your other pages, you'd just check for
session_start(); // You have to call this at the start of each page to make sure that the $_SESSION variable works.
if ($_SESSION['lang'] == 'en')
$ini_array = parse_ini_file("languages/EN.ini");
etc.
And the full session documentation is available at http://php.net/manual/en/reserved.variables.session.php

$_POST request in PHP how can i apply?

I want to know how to use POST request in PHP. I used $_REQUEST['text'] for getting data from url like http://localhost/data.php?text=ABCDEFGH but If i pass very long text than ERROR : Request-URI Too Long.
if(isset($_REQUEST['text'])){
$parsetext=$_REQUEST['text']; //get data here data > ABCDEFGH
}else{
echo "not valid";
}
Please any one tell me how to support long TEXT using POST request. I know that $_REQUEST is for both request GET & POST.
Regarding the error, you can check these links (I assume you've already seen this):
How do I resolve a HTTP 414 “Request URI too long” error?
Request-URI Too Large
And for your question: I want to know how to use POST request in PHP.
Create a form.
(I assume that the textbox from this form will get the long data that you want to POST).
<form method="POST" action="http://localhost/data.php">
<input type="text" name="input_text" />
<button type="submit">Submit</button>
</form>
Receive the data from the from input using the defined method on your form. In this case the method is POST and the url/file that will receive the submitted data is http://localhost/data.php.
if (isset($_POST['input_text'])) {
// Where input_text is the name of your textbox.
$text = $_POST['input_text'];
echo $text;
}
ERROR : Request-URI Too Long.
$_REQUEST, as you say, handles $_POST and $_GET methods is correct.
Regarding your question, even though you use $_REQUEST to get the data, in the background it use the $_GET method to catch the query string you pass with the url.
$_GET method has limit on size and this is the main reason why you encounter that error. Whereas $_POST method don't have limit: Is there a maximum size for content of an HTTP POST?.
Conclusion: Better not use $_REQUEST, use $_GET or $_POST specifically :D
First of all, read this Question/Answer, this will probably clear some things for you on the differences between POST and GET and what method you should use for your project.
Then, you should forget about the $_REQUEST and use either $_GET or $_POST. This will prevent some security issues that you'll probably run into if you keep using $_REQUEST. More on that in the PHP Manual
Next up, you should definitely switch to POST, instead of GET if you're passing large sets of data. Otherwise you have to modify your apache config and that is not recommended if you plan on releasing you code to the public.
-EDIT START-
You can even use POST within AJAX, if everything is on the same server.
-EDIT END-

PHP $_GET and $_POST are returning empty arrays--trying to paginate SQL data

I have set up the following:
Database class ($db)
Pagination class ($paginator)
I am attempting to write a basic system to let me administrate pages. I have a page "page_manager.php" in which I include both my database class (database.php) and my pagination class (paginate.php).
In my pagination class I have a function which echoes my SQL data. I've come up with a way to echo an HTML < select > element with the necessary IDs, which allows me to successfully echo the corresponding results (10 per page), based on the value of the < select > element. So, "1" will echo the first 10 results in the database, "2" will echo from 11-20, "3" will echo from 21-30, etc., etc..
I have added an onChange event to the < select > element which will copy its value (using "this.value") to a hidden form field. I then submit this form using document.getElementById().submit();
This will then add the $_GET variable to the URL, so the URL becomes ".../?pagenumber_form=X". However, when I try to grab this value back from the URL, the $_GET['pagenumber_form'] is empty.
Some code:
<span style='font-family: tahoma; font-size: 10pt;'>Page #</span>
<select id="page_number_selection"
onchange='javascript: document.getElementById("pagenumber_form").value = this.value;
document.getElementById("pagenumber").submit();'>
<?php
for($i = 1; $i <= $this->num_pages; $i++)
echo"<option id='" . $i . "'>" . $i . "</option>";
?>
</select>
<form name="pagenumber" id="pagenumber" action="" method="get">
<input type="text" name="pagenumber_form" id="pagenumber_form" />
</form>
So, I've tried using $_POST as well, but the same thing happens. I want to use $_GET, for a couple of reasons: it's easier to see what is happening with my values and the data I'm using doesn't need to be secure.
To recap: the $_GET variable is being added to the URL when I change the < select > element, and the corresponding value gets added to the URL as: ".../?pagenumber_form=X", but when I try to use the value in PHP, for example...
$page_number = $_GET['pagenumber_form'];
... I get a NULL value. :-(
Can anybody help me out please? Thank you.
EDIT:
I've just made a discovery. If I move my print_r($_GET) to my main index page, then the superglobals are returning as expected. My site structure is like this:
index.php
- JavaScript buttons use AJAX HTTP requests to include the "responseText" as the .innerHTML of my main < div >. The "responseText" is the contents of the page itself, in this case page_manager.php, which in turn includes pagination.php.
So in other words, my site is built from PHP includes, which doesn't seem to be compatible with HTTP superglobals.
Any idea how I can get around this problem? Thank you :-).
+------------------------------------------------------------------+
I can't answer my own posts, so:
The problem is not solved, but has been worked around.
I am certainly not very knowledgeable when it comes to PHP, but I am of the impression that using AJAX requests to include a PHP file in a document, which itself includes other PHP files, is not a good idea. The problem, I believe, was being caused because PHP is executed before the document is loaded in to the browser. Therefore, dynamically including a PHP file in a document will result in the improper working of said file due to the fact that PHP must be executed by the server before the page is rendered, and not after.
As such, I have stopped using AJAX for my site and am simply using good old PHP instead. I don't know enough to carry on using the AJAX requests, so that's an end to that problem.
Thanks to those who replied.
You need to re-pass the superglobals to the AJAX calls. So where you would make a request to pagination.php you need to make it to pagination.php?pagenumber_form=<?php echo $_GET['pagenumber_form']; ?>.
the corresponding value gets added to the URL as: ".../pagenumber_form=X
You might wanna try
.../?pagenumber_form=X
Included files can access superglobals just fine (which is what makes them super). What can't be done is to access variables from one request in another. It isn't that clear what your code is doing (since the question doesn't include a proper minimal test case–a complete, concise, representative sample), but it sounds like loading a single page involves multiple requests, and only the first of these is given the form data. Each AJAX request involves a separate HTTP request, and (because HTTP is supposed to be stateless) has different request data, so any request that isn't explicitly given the data won't have access to it. After a request is handled, all data the script has access to is discarded. This is why if you need data to exist across requests, you need some form of persistence, such as sessions (which you should be careful of, in order not to break the HTTP stateless model) or databases.
Some of the difficulty may lie in a confusion over exactly what happens server-side, what happens client-side, what happens between the two and in what order it all happens. Before you go further, read up on HTTP (a web search should reveal countless documents on the topic). You can use debuggers (e.g. Firebug, XDebug+a client, Wireshark, Live HTTP Headers) to peer at what's happening as it happens.

How to store search result?

I am working on my personal site, where I want to store my customers recent search result limited to that particular session.
I am using PHP platform and Javascripts.
Here is an example of what I am exactly looking at :
It stores your previously searched domain name for that particular session so that user can make decision by comparing those results.
Thanks.
EDIT- Well Thanks for all of your answers and suggestions.
But If you have noticed
above example
It looks like some kind of script loading a new content on the same page without refreshing it and keeping previous search content <div> as it is.
How to achieve this using javascripts or some sort of div layer ????
UPDATE START
This example uses page reload. If you want to do it without page reload, you can but you'll have to use AJAX to load new search results. But then, it's not a PHP question. I suggest looking at jquery library, as it makes it easy. Tutorials: http://docs.jquery.com/Tutorials and e.g. this one ( http://docs.jquery.com/Tutorials:Getting_Started_with_jQuery#Rate_me:_Using_Ajax ).
When loading data via AJAX, the page rendering result (in my example search.php) should return only HTML for results part, not whole HTML page. This is generally a first part of my tutorial (without session).
But I really think that AJAX in here is not really needed. Session is more reliable and allows access to your page from older / mobile browsers where not always JS works correctly.
UPDATE END
Ok then. Let's try the simple tutorial then. Sorry if too simple, but I don't know your exact level.
PHP has mechanism called sessions. In reality they are just bytes stored on server. Server knows which session is for each client by reading session cookie from client browser.
Not every page uses sessions (not every page needs it, and session uses server space, even if only temporarily), session is not enabled by default. To turn on session you use command
<?php session_start(); ?>
In most cases this is either run by PHP framework you use, or put near the top of your site. Session is definitely needed if you want to authenticate user somehow. Or in your case :)
To access session you can use superglobal $_SESSION variable (superglobal means that you can access it anywhere). It's an array, so session element will be e.g. $_SESSION['search'] etc.
As example, let's assume that your page looks like that
<html>
...
<form action="search.php" method="post">
Search: <input type="text" name="searchQuery" />
<input type="submit" value="Search" />
</form>
...
</html>
this very form will send user search to file named search.php. It can be the same file where the form resides - in simplest case when you put both your code and HTML in one file. Beginners often use this schema, although it's not advisable as result is a mess and hard to further change.
In search.php then, you'll use similar code:
<?php
if (!empty($_POST['searchQuery'])) //we have a new search
{
$result = do_search($_POST['searchQuery']);
}
?>
Then, somewhere below you'll display your search result ($result variable). do_search() function is your search mechanism, I guess you have it somewhere. You may have it not 'wrapped' in a function, then I advise to create it like that, it's much more useful.
function do_search($searchQuery)
{
...
return $result;
}
mind it, the above code doesn't use sessions yet. Let's add saving previous search results in session. The code may then look like that:
<?php
session_start(); //Starting session
//let's create session variable used to store results
if (!isset($_SESSION['searches']))
$_SESSION['searches'] = array();
if (!empty($_POST['searchQuery'])) //we have a new search
{
if (isset($_SESSION['searches'][$_POST['searchQuery']]) //User already searched on this value, delete previous result from sesion
{
unset($_SESSION['searches'][$_POST['searchQuery']]);
}
$result = do_search($_POST['searchQuery']);
//Let's add new search on the begining of session array to make iterations easier.
$result = array($_POST['searchQuery'] => $result); //convert result to same format as session table
$_SESSION['searches'] = array_merge($result, $_SESSION['searches']);
}
?>
In display you'll now not iterate on $result variable as before, but instead you will do something like
foreach ($_SESSION['searches'] as $query => $result)
{
...//display of single result
}
I haven't tested following code and it's not a full program. Parts to display result and to do actual search are not described but I guess you have them already prepared. Also, this is only one possible approach of countless possibilities. But I hope this helps :)
Possible modification - now I always perform search, even if user already searched on this term. You may want to receive the result from cache without second search. Then the code will look like
if (isset($_SESSION['searches'][$_POST['searchQuery']]) //User already searched on this value
{
$result = $_SESSION['searches'][$_POST['searchQuery']];
unset($_SESSION['searches'][$_POST['searchQuery']]);
}
else
{
$result = do_search($_POST['searchQuery']);
}
For more in-depth information about sessions and some other constructs used in my example I suggest PHP manual
http://pl.php.net/manual/en/book.session.php
and various tutorials over the network. Or you can add a comment here :)
Put this code near the beginning of your script(s):
if (!isset($_SESSION['previous_searches']) || !is_array($_SESSION['previous_searches'])) {
$_SESSION['previous_searches'] = array();
}
[edit]
This code snippet checks if if there is already an array with prevous searches and if not it will be created.
[/edit]
Then when the user hits the search page put this code in the receiving script of the search:
$_SESSION['previous_searches'][] = $_GET['what_ever_your_search_value_might_be'];
[edit]
This code snippet adds the current search value to the and of the array with previous search values
[/edit]
Now you have all previous search values in $_SESSION['previous_searches']
If your website is a web application where you never reload the page nor change the page, you can keep it JavaScript in a global store (declare at top level something like var StoredSearch = []; and use it). If not, then use $_SESSION to store this and AJAX to save/load searches from JavaScript to PHP.

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