Hi Rasmus
Thanks, I think I got it now.
Seems my problem with understanding was with the actual setting of the
variables.
The logic dictated that the session variables should stay the same
throughout the session unless "changed" via a form selection, so I
simply added a
session_register("session_var");
if ($_POST["my_var"]) {
$session_var = $_POST["my_var"];
}
to my code and it works like a charm as the $_POST var will be empty if
it comes from one of my "back" links to the page...
Rasmus Lerdorf wrote:
>Yup, get rid of both ini_set() calls and take out the $sid=...
>and <?=$sid?> stuff and it should simply work.
>
>On Tue, 30 Jul 2002, Petre wrote:
>
>>Thanks, will work through this immediately.
>>Just to be clear.
>>If I DO stick with your suggestion of letting PHP do the url mangling,
>>and taking your code below, I can simply remove the
>>
>>ini_set('session.use_trans_sid',false); and <?=$sid?> from your code to make it work
>exactly as is?
>>
>>Thanks
>>
>>
>>
>>Rasmus Lerdorf wrote:
>>
>>>The trick is to not name your form vars the same as your session vars.
>>>Keep them separate so you have full control of what ends up where. Also,
>>>note that if you are not relying on trans_sid or cookies then don't use
>>>SID. Call session_id() explicitly to get the session id. So, a quick
>>>little mockup to illustrate this.
>>>
>>>login.php:
>>><?
>>>ini_set('session.use_cookies',false);
>>>ini_set('session.use_trans_sid',false);
>>>session_start();
>>>$sid = session_name().'='.session_id();
>>>session_register('username');
>>>$username = 'petre';
>>>?>
>>><a href="page1.php?<?=$sid?>">Next Page</a>
>>>
>>>page1.php:
>>><?
>>>ini_set('session.use_cookies',false);
>>>ini_set('session.use_trans_sid',false);
>>>session_start();
>>>$sid = session_name().'='.session_id();
>>>?>
>>><form action="page2.php?<?=$sid?>" method="POST">
>>><input type="text" name="form_foo" value="<?=$_SESSION['foo']?>">
>>></form>
>>>
>>>page2.php:
>>><?
>>>ini_set('session.use_cookies',false);
>>>ini_set('session.use_trans_sid',false);
>>>session_start();
>>>$sid = session_name().'='.session_id();
>>>session_register('foo');
>>>$foo = $_POST['form_foo'];
>>>echo "You entered $foo<br />\n";
>>>?>
>>><a href="page1.php?<?=$sid?>">Back</a>
>>>
>>>
>>>I am ini_setting on each page to force PHP to not do trans-sid/cookies.
>>>Would be easier to simply turn these off in the php.ini file.
>>>
>>>When you hit the back link, $_SESSION['foo'] will exist on page1.php and
>>>the form will get filled in with the previous value. You can then change
>>>it, hit enter again and the session value will take on the new submitted
>>>value because I have decoupled the form data from the session data and I
>>>set the session var in page2.php.
>>>
>>>There are other ways to do this, but this is probably the easiest method
>>>to understand. Play with this simple example until you understand how it
>>>works.
>>>
>>>But again, I'd suggest letting PHP do session id handling for you by
>>>letting it default to cookies and fall back to url mangling in the few
>>>cases where cookies are turned off.
>>>
>>>-Rasmus
>>>
>>>On Tue, 30 Jul 2002, Petre wrote:
>>>
>>>>Yes, it is a forward link to the page, but as mentioned, that page
>>>>contains a form with the selection options, and on that form's action
>>>>page is where I don't see the values change, so the question should
>>>>probably be something like "how do I change the value in the session_var
>>>>with the newly selected value?
>>>>And oh, I almost forgot:
>>>>Due to that fact that this type of app doesn't really have a logical end
>>>>page, I cannot issue a session_destroy() anywhere logically ( except
>>>>using a logout button), but that's not going to ensure that people use it...
>>>>I would ideally like to have this "app" run on an intranet, where people
>>>>will most probably have this app open indefinately, and thus I also
>>>>battle with my logic of keeping a session alive.
>>>>
>>>>Thanks
>>>>.
>>>>
>>>>Rasmus Lerdorf wrote:
>>>>
>>>>>Well, how exactly do you implement the back button? If it is a normal
>>>>>client-side back, then of course the previous value will be shown. If it
>>>>>is actually a forward-link to the previous page, then your logic on that
>>>>>target page is bogus.
>>>>>
>>>>>By the way, trans-sid is compiled in by default in PHP so should always be
>>>>>available. And it will fallback to sid mangling only if cookies are
>>>>>disabled. You would probably be better off just letting php manage this
>>>>>for you.
>>>>>
>>>>>-Rasmus
>>>>>
>>>>>On Tue, 30 Jul 2002, Petre wrote:
>>>>>
>>>>>>Well, I have asked a couple of questions on this list, but they havn't
>>>>>>really helped alot. Maybe you can help?
>>>>>>
>>>>>>My situation background is as follow:
>>>>>>I have always written my apps in the following way: register_globals=on,
>>>>>>so I allowed PHP to "generate" my variables for me on the action page,
>>>>>>and if I cannot use a form to "send" variables to the next pages, I
>>>>>>added them manually to the url.
>>>>>>So, then I discovered sessions and thought my probelms were solved, only
>>>>>>to discover that it uses cookies by default, and has to have the
>>>>>>--trans-sid option compiled to have PHP handle the app if you don't want
>>>>>>cookies ( like me, don't want cookies at all, or for that matter,
>>>>>>anything that relies on the client's side). So, I couldn't just jump in
>>>>>>and use sessions as I would not be sure that my app would work on any
>>>>>>PHP4 system regardless of the options it was compiled with. ( Oh, I am
>>>>>>writing my apps to work with register_globals=off now, so that shouldn't
>>>>>>be a problem).
>>>>>>So I started to look for a way to code with sessions that will not
>>>>>>require cookies nor require any special compile features; the answer
>>>>>>came in adding <?=SID?> to all relative URL's in my app.
>>>>>>Alas, that is where I'm at, and it's still not working as I would have
>>>>>>expected.
>>>>>>My problem is with the way my proposed app works/should work.
>>>>>>
>>>>>>I am trying to write an app that allows the user to log in, then
>>>>>>add/remove projects to his list, then, when a project is selected, he
>>>>>>should have access to all the relevan documents in that project, again
>>>>>>allowing him to add/remove documents from the project here, and in the
>>>>>>last step, when a document is selected, allows hime to add/remove/edit
>>>>>>chapters to the document.
>>>>>>
>>>>>>My first attempt at using sessions with this failed miserably ( keeping
>>>>>>in mind my approach of adding SID at end of urls). I have a "back" link
>>>>>>on all the pages that takes the user to the previous step(s) and thus
>>>>>>on the last page ( the chpaters edit/remove/add page), there is a link
>>>>>>to go back one level, two and three levels. Yet, using these causes
>>>>>>unexpected results.
>>>>>>I think the problem comes in with overriding the value of the session
>>>>>>variable.
>>>>>>For instance, on the first page you have a login form, on the action
>>>>>>page I session_register("username","password"), and that works fine even
>>>>>>when using the back buttons as the values are never changed. But, on the
>>>>>>2nd page I have the drop down select containing all the project names (
>>>>>>gets built with a while that reads all the project names from the
>>>>>>project_table) and send over the project_id.
>>>>>>On that actio page, I session_register("project_id"); and it also works
>>>>>>fine for all pages "down stream", however, when I come back to that page
>>>>>>to select a new project, it keeps the old variable...
>>>>>>At first I did nothing special in the sence of assigning a value to the
>>>>>>session variables, as I let the register_globals=on do it's trick, but
>>>>>>later I explicitly said
>>>>>>$project_id = $HTTP_POST_VARS["project_id"];
>>>>>>
>>>>>>But that also did not overwrite the value of the session var. In the end
>>>>>>I was forced to again add all my variables to the end of the url,
>>>>>>keeping the session solely for the username and password.
>>>>>>
>>>>>>I don't know if you would like me to post my code ( it is quite a bit
>>>>>>already ) but I would really appreciate it if someone could look at it,
>>>>>>and then point out where I'm missing the picture, as then I would have
>>>>>>two pictures that I can compare and see where my reasoning failed.
>>>>>>
>>>>>>Thanks for your time.
>>>>>>
>>>>>>
>>>>>>Rasmus Lerdorf wrote:
>>>>>>
>>>>>>>What issues? Just ask.
>>>>>>>
>>>>>>>-Rasmus
>>>>>>>
>>>>>>>On Mon, 29 Jul 2002, Petre wrote:
>>>>>>>
>>>>>>>>What are good books/websites about sessions.
>>>>>>>>I'm looking for more advanced stuff, I have the Luke Welling/Laura
>>>>>>>>Tompson book, and have read the manual, but I still have issues that are
>>>>>>>>unresolved.
>>>>>>>>
>>>>>>>>Thanks
>>>>>>>>
>>>>>>>>
>>>>>>>>
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>>>>>>>>PHP General Mailing List (http://www.php.net/)
>>>>>>>>To unsubscribe, visit: http://www.php.net/unsub.php
>>>>>>>>
>>
>
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