I'm working on a company intranet system and have a function to load a form via include while passing an url encoded array in GET format
$draftcook = urlencode(serialize($draft));
include(FORM_PATH .'newrangesubtypeform.php?draft=yes&type='.$value.'&draftcook='.$draftcook);
Unfortunately my array has gotten too long to be able to be passed via a url, I have tried many other alternatives, including setting the array into a session variable and then pulling it through in the included form but that for some reason is unable to see the session variable.
Could someone please suggest a work around for this situation, the array itself is likely to have upward of 1000 fields in it by the time the whole page is completed if that effects the solution.
Thanks
You can write into db or file a threat (id, draftcook) and pass the PK of the threat vía URL and then get the draftcook
Included code runs in the same scope as wherever you called include. I'm not even sure why you're passing this stuff info the new file; any variable that exists can be used in the include.
So you can access $draft as a regular variable already.
Related
This is a pretty long question in words, but it all adds up to one function.
For some time, I have tried figuring out how to increment a variable, save it and then display it. Only problem is I figured out that to save the variable and allow all users on the website to see the same updated variable, it has to be saved server side, so now I have a big question as I have tried to figure out one thing, and now has to do it another way.
To store a variable server side, is it enough to save the variable in a .php script because if so, I think what I am looking for is a way to have a variable in a .php script, then when a specific function is called I want to increment this variable by one, and then last I want to save this variable server side, to always be able to have the exact same variable on all users screens. The .php script is called by a form from the html script, so there is no problem there, the problem is as mentioned above, how to make a variable in .php script, increment that variable when a function is called, save that variable and then pass it back to the html page to display.
At first one may think of a Session variable, But as you pointed out it should be shared among all users, you need to save it into a database, file or use a cache server.
Are you using a database? You can create a single table containing a key and value columns. Then you keep the row with the specified key up-to-date with the variable value you want to keep track of.
If you don't have access to a database server, you can serialize the variable or simply store it as a text file and read from it. Only problem here is concurrency, if you have too many users at the same time, you won't be able to update it at once.
Cache server is a bit more complicated to explain, but you could look for further documentation about that.
Good luck!
I'm trying to save all my session data in the Database and have this class that should handle all that and have used session_set_save_handler to set that up. Now, I don't know if it's because I don't fully understand the whole idea behind that function but the problem I'm running into is that the read() function of my Session handler class is called BEFORE the write() function is. And the reason why that is not good is because read() is trying to look for information in the database that has yet to be written into the database and of course it gets empty results.
So I decided to read the documentation behind session_set_save_handler and it looks like the only time write() is called is when the session is terminated or when PHP is closed. From my perspective this seems pretty useless... why would anyone write() or store this information at the END before they could ever get a chance to retrieve it?
What I'm trying to do is when someone creates a use session, this information is written into the database and whenever I want to check for authentication or lookup user values I want to retrieve said information.
Am I going about this all wrong?? I appreciate any clarification. If anyone needs any code to demonstrate what I'm trying to do I'll update this.
From my perspective this seems pretty useless... why would anyone write() or store this information at the END before they could ever get a chance to retrieve it?
What do you mean before they got a chance to retrieve it?
To retrieve it, the read method is called – and it is called before, so that you already have the info. But somehow this is what you are complaining about …?
Am I right in assuming that you don’t have much understanding of how PHP’s session mechanism works at all?
You call session_start on top of every script. If PHP finds a session id in the parameters passed to the script, it looks for an existing session with that id, and if it finds one, it reads the data from it. From that point on, you can work with that data – PHP has put it into the super-global array $_SESSION for you. You can access it from there, and you can put new data into it or alter the existing data.
And then, when the script ends, or session_write_close is called, the data is written back.
So of course the read function is called before the write function.
I've never understood this, and on my own projects I have never needed it. But I've been contributing to WordPress a little, and they use it heavily.
Somehow they are able to redirect the user to a different page with some sort of GET variable in the URL (which is what I understand to be the advantage of using GET over POST). How do they do this? Is it as simple as making a header like header('site.com/page.php?foo=true');? This can't be useful since you have to hard code everything in (unless you want to create a string based on other variables which is kind of annoying, even still). I thought there would be a built-in function like send_get('page.php', $foo);.
I understand how to use information by using $foo = $_GET['foo'];, but I don't know how to send it with PHP.
An explanation would be appreciated - thanks!
There isn't exactly a "customary" way of using it. It is one of nine superglobals. The way you use them is at your discretion. As Greg P already mentioned, they are passed through the URL.
I know how to set up a HTML form that sends variables this way, but how can I do the same thing with PHP?
If you're talking about sending GET variables with PHP solely, the answer is no. You needn't even have PHP to send a GET variable. It is as simple as adding a question mark followed by a variable name = something. Separate several of them using an ampersand (&)
Setting up a GET variable is as easy as creating an anchor link.
<a href='somepage.php?getVar1=foo&anotherVariable=2&thirdVar=3
You can use PHP to dynamically place certain information in there instead of writing it manually, which is the entire purpose of the language to begin with. It is a preprocessor
So, something like this should get you started
<?php
$someID = // An id pulled from a mysql_query
echo "<a href='somepage.php?someID=" . $someID . "'>GET LINK</a>";
I thought there would be a built-in function like send_get('page.php', $foo);
Again, PHP is a preprocessor. It doesn't send information, it only outputs it. What you're talking about is Javascript.. moreover, AJAX. AJAX is the only method that will allow you to send GET variables "behind-the-scenes". And, like was mentioned in another post, jQuery has an awesome codebase for this.
I think you're missing the forest for the trees...the $_GET/$_POST are just variables that are passed to the page processing them - what is DONE with them and how it is done, is up to the design of the application. For example, Joomla always puts the component_id and the item_id in the $_GET array, and has been designed with that in mind, so expects them to be there, and constructs the page, or redirects, or whatever with that in mind.
In your example, a send_get() function might be a good idea (I didn't design it), but the architects didn't see it that way for one reason or another. Joomla happens to have a redirect function that does have a certain dependancy on what was passed in the $_GET, but that is only by design of the applications authors.
Maybe redirect URL is kept in some of session variable. Properly $_GET variable, indicate for wordpress: "check session variable for redirect URL".
PHP.net says:
An associative array of variables passed to the current script via the URL parameters.
URL parameters: generally are variables passed to a script via the URL such as in your example site.com/page.php?foo=true. Everything after the ? is considered a paramter.
Quoted from a StackOverflow question:
The HTTP protocol defines GET type requests as being idempotent, while POST may have side effects. In pain English that means that GET is used for viewing something, without changing it, while POST is used for changing something. For example, a search page should use GET, while a form that changes your password should use POST.
Normally I try to format my question as a basic question and then explain my situation, but the solution I'm looking for might be the wrong one altogether, so here's the problem:
I'm building a catalog application for an auction website that has the ability to save individual lots. So far this has worked great by simply creating a cookie with a comma-separated list of IDs for those lots, via something like this:
$_COOKIE["MyLots_$AuctionId"] = implode(",",$arrayOfIds);
The problem I'm now hitting is that when I go to print the lots, I'm using wkhtmltopdf through the command-line to request the url of the printout I want, like this:
exec("wkhtmltopdf '$urlofmylots' filename.pdf");
The problem is that I can't pass a cookie to this call, because Apache sees an internal request, not the request of the user. I tried putting it in the get string, but once I have more than a pre-set limit for GET parameters, that value disappears from the $_GET array on the target url. I can't seem to find a way to send POST data between them. My next possible ideas are the following:
Maybe just pass the sessionID to the url, and see if there's a way that I can use PHP to dig through the cookies for that session and pull the right cookie, but that sounds like it'd be risky security-wise for a PHP server to allow (letting one session be aware of another). Example:
exec("wkhtmltopdf '$urlofmylots?sessionId=$sessionIdFromThisRequest' filename.pdf");
Possibly set a session variable and then pass that session Id, and see if I can use PHP to wade through that information instead (rather than using the cookie).
Would I be able to just create an array and somehow have that other script be aware of it, possibly by including it? That doesn't really solve the problem of wkhtmltopdf expecting a web-facing address as its first parameter.
(not really an idea, but some reasoning) In other instances of using this, I've just passed an ID to the script that generates the markup for wkhtmltopdf to parse, and the script uses that ID to get data from the database. I don't want to store this data in a file or the database for the simple purpose of transferring data from the caller to the callee in this case. Cookies and sessions seem cleaner since apache/php handle memory allocation for these sessions.
The ultimate problem here is that I'm trying to get my second script (referenced here by $urlofmylots) to be aware of data available to the calling script but it's being executed as if it were an external web request, not two php scripts being called from the web root.
Can anyone offer some insight here?
You might consider rendering whatever the output of $urlofmylots?lots=$lots_to_print would be to a temporary file and running wkhtmltopdf against that file.
I have a script that has PHP on it, and a link that goes to a new script that alters that PHP. When writing the query and containing variables on the second script, do I need to use the same variables or are the new ones I create completely seperate? or can will the variables from the first script carry over to the second script if used?
If by "link" you mean you use require or include, then any variables that are defined in the same scope as the "link" will already be defined within that file's "global" scope (under most conditions).
If you are linking to another page via a typical HTML anchor tag, then the answer is no. You can, however, pass along information using HTTP GET method or create sessions through manipulations of $_SESSION in php or by setting cookies in the browser. All of the various ways of maintaining informaion across multiple links really depend on your needs. In the case where you would want to use HTTP GET, you could setup the link in script A to link to script B like this:
Click here
Then in script B you would access that data like this:
<?php
$data1 = $_GET['var1'];
$data2 = $_GET['var2'];
And use it however you need. Of course, be sure to perform sanity checks against the data before accepting it as reliable.
You can try and use sessions
As mentioned by everyone else, HTTP is stateless and nothing is shared unless you explicitly store it. Most of the time you will want to store these in the $_SESSION[] super global, but you could also store them in files, cookies, or the database, although the file system and database introduce larger overhead and cookies can easily be manipulated.
PHP is basically "nothing shared". So, when you build your link, you control the state of the $_REQUEST variable using the query parameters (GET or POST) and the hidden parameters (cookies).
The session ($_SESSION) is a convenient cookie/file storage to migrate common data between pages, but it is typically best to keep session lean and free of non-critical state details.