When is $_POST set and unset?

I have a script that submits form data via a "post" method to another
script. I have an href link in the destination script that links back
to itself for processing form data on that page with some "get" data
appended to the URL. I noticed that after clicking on that link and
sending the action back to itself, a check of isset($_POST) returns
true while displaying the content of $_POST displays an empty array.
I had expected isset($_POST) to return false, thinking the script
would unset the $_POST array when the <a> link sent it back to
itself. Instead, it leaves $_POST set but empty.

What is the convention here?

--Kenoli

On May 15, 7:38 pm, kenoli <kenol...@gmail.com> wrote:
> I have a script that submits form data via a "post" method to another
> script. I have an href link in the destination script that links back
> to itself for processing form data on that page with some "get" data
> appended to the URL. I noticed that after clicking on that link and
> sending the action back to itself, a check of isset($_POST) returns
> true while displaying the content of $_POST displays an empty array.
> I had expected isset($_POST) to return false, thinking the script
> would unset the $_POST array when the <a> link sent it back to
> itself. Instead, it leaves $_POST set but empty.
>
> What is the convention here?
>
> --Kenoli

You should check if some variable from the posting form is set instead
of the entire $_POST. The submit button or something like that. If the
variables are the same for some reason, you can add a hidden field in
the posting form and check if that is set.

-Mike PII

On May 16, 1:24 am, Mike P2 <sumguyovrt...@gmail.com> wrote:
> On May 15, 7:38 pm, kenoli <kenol...@gmail.com> wrote:
>
> > I have a script that submits form data via a "post" method to another
> > script. I have an href link in the destination script that links back
> > to itself for processing form data on that page with some "get" data
> > appended to the URL. I noticed that after clicking on that link and
> > sending the action back to itself, a check of isset($_POST) returns
> > true while displaying the content of $_POST displays an empty array.
> > I had expected isset($_POST) to return false, thinking the script
> > would unset the $_POST array when the <a> link sent it back to
> > itself. Instead, it leaves $_POST set but empty.
>
> > What is the convention here?
>
> > --Kenoli
>
> You should check if some variable from the posting form is set instead
> of the entire $_POST. The submit button or something like that. If the
> variables are the same for some reason, you can add a hidden field in
> the posting form and check if that is set.
>
> -Mike PII

you could use
if( !isset($_POST) || empty($_POST) )
since if the form is posted without being filled $_POST still wont be
empty

There is a form on the page with a post method and some submit
buttons, however, none of them are triggered here. The script is
called using an <a>tag with this kind of thing:

<a href = "<? echo 'http://' . $_SERVER['PHP_SELF'] . '?pid=' .
$row[id]; ?>" >Delete</a>

It just leaves the page and starts again at the top of the script. It
works fine. What caused me to catch it is that I was using:

if (!isset($_POST))

to set a switch variable in the case that the data had not been sent
via a post submit. It wasn't working so I checked and found the
$_POST variable was sure enough set, but empty.

What would be setting the $_POST variable if the form wasn't
triggered.

--Kenoli

On May 15, 5:24 pm, Mike P2 <sumguyovrt...@gmail.com> wrote:
> On May 15, 7:38 pm, kenoli <kenol...@gmail.com> wrote:
>
> > I have a script that submits form data via a "post" method to another
> > script. I have an href link in the destination script that links back
> > to itself for processing form data on that page with some "get" data
> > appended to the URL. I noticed that after clicking on that link and
> > sending the action back to itself, a check of isset($_POST) returns
> > true while displaying the content of $_POST displays an empty array.
> > I had expected isset($_POST) to return false, thinking the script
> > would unset the $_POST array when the <a> link sent it back to
> > itself. Instead, it leaves $_POST set but empty.
>
> > What is the convention here?
>
> > --Kenoli
>
> You should check if some variable from the posting form is set instead
> of the entire $_POST. The submit button or something like that. If the
> variables are the same for some reason, you can add a hidden field in
> the posting form and check if that is set.
>
> -Mike PII

On May 16, 6:05 am, kenoli <kenol...@gmail.com> wrote:
> There is a form on the page with a post method and some submit
> buttons, however, none of them are triggered here. The script is
> called using an <a>tag with this kind of thing:
>
> <a href = "<? echo 'http://' . $_SERVER['PHP_SELF'] . '?pid=' .
> $row[id]; ?>" >Delete</a>
>
> It just leaves the page and starts again at the top of the script. It
> works fine. What caused me to catch it is that I was using:
>
> if (!isset($_POST))
>
> to set a switch variable in the case that the data had not been sent
> via a post submit. It wasn't working so I checked and found the
> $_POST variable was sure enough set, but empty.
>
> What would be setting the $_POST variable if the form wasn't
> triggered.
>
> --Kenoli
>
> On May 15, 5:24 pm, Mike P2 <sumguyovrt...@gmail.com> wrote:
>
> > On May 15, 7:38 pm, kenoli <kenol...@gmail.com> wrote:
>
> > > I have a script that submits form data via a "post" method to another
> > > script. I have an href link in the destination script that links back
> > > to itself for processing form data on that page with some "get" data
> > > appended to the URL. I noticed that after clicking on that link and
> > > sending the action back to itself, a check of isset($_POST) returns
> > > true while displaying the content of $_POST displays an empty array.
> > > I had expected isset($_POST) to return false, thinking the script
> > > would unset the $_POST array when the <a> link sent it back to
> > > itself. Instead, it leaves $_POST set but empty.
>
> > > What is the convention here?
>
> > > --Kenoli
>
> > You should check if some variable from the posting form is set instead
> > of the entire $_POST. The submit button or something like that. If the
> > variables are the same for some reason, you can add a hidden field in
> > the posting form and check if that is set.
>
> > -Mike PII

try it with GET, COOKIE, REQUEST, FILES, SESSION, all will be set but
empty (if you arent populating them).
they are superglobals, always set in the current scope.

Thanks. Yeah, I tried it in a new script with nothing except:

if (isset($_POST)) { echo "Is set!"; } else { echo "Is not set."; }

Output: Is set!

It is definitely set. Learn something everyday. Super globals are
always set. Got it.

--Kenoli


On May 16, 2:30 am, shimmyshack <matt.fa...@gmail.com> wrote:
> On May 16, 6:05 am, kenoli <kenol...@gmail.com> wrote:
>
>
>
> > There is a form on the page with a post method and some submit
> > buttons, however, none of them are triggered here. The script is
> > called using an <a>tag with this kind of thing:
>
> > <a href = "<? echo 'http://' . $_SERVER['PHP_SELF'] . '?pid=' .
> > $row[id]; ?>" >Delete</a>
>
> > It just leaves the page and starts again at the top of the script. It
> > works fine. What caused me to catch it is that I was using:
>
> > if (!isset($_POST))
>
> > to set a switch variable in the case that the data had not been sent
> > via a post submit. It wasn't working so I checked and found the
> > $_POST variable was sure enough set, but empty.
>
> > What would be setting the $_POST variable if the form wasn't
> > triggered.
>
> > --Kenoli
>
> > On May 15, 5:24 pm, Mike P2 <sumguyovrt...@gmail.com> wrote:
>
> > > On May 15, 7:38 pm, kenoli <kenol...@gmail.com> wrote:
>
> > > > I have a script that submits form data via a "post" method to another
> > > > script. I have an href link in the destination script that links back
> > > > to itself for processing form data on that page with some "get" data
> > > > appended to the URL. I noticed that after clicking on that link and
> > > > sending the action back to itself, a check of isset($_POST) returns
> > > > true while displaying the content of $_POST displays an empty array.
> > > > I had expected isset($_POST) to return false, thinking the script
> > > > would unset the $_POST array when the <a> link sent it back to
> > > > itself. Instead, it leaves $_POST set but empty.
>
> > > > What is the convention here?
>
> > > > --Kenoli
>
> > > You should check if some variable from the posting form is set instead
> > > of the entire $_POST. The submit button or something like that. If the
> > > variables are the same for some reason, you can add a hidden field in
> > > the posting form and check if that is set.
>
> > > -Mike PII
>
> try it with GET, COOKIE, REQUEST, FILES, SESSION, all will be set but
> empty (if you arent populating them).
> they are superglobals, always set in the current scope.

"kenoli" <kenoli.p@gmail.com> wrote in message
news:1179272305.382461.25810@p77g2000hsh.googlegro ups.com...
> I have a script that submits form data via a "post" method to another
> script. I have an href link in the destination script that links back
> to itself for processing form data on that page with some "get" data
> appended to the URL. I noticed that after clicking on that link and
> sending the action back to itself, a check of isset($_POST) returns
> true while displaying the content of $_POST displays an empty array.
> I had expected isset($_POST) to return false, thinking the script
> would unset the $_POST array when the <a> link sent it back to
> itself. Instead, it leaves $_POST set but empty.
>
> What is the convention here?
>
> --Kenoli
>

Rather than testing for $_POST, I'd add a hidden form field so you can test
if that was specifically submitted.

Tom
--
Newsguy.com - Express Accounts - 30 GB $9.95 / month

kenoli wrote:
> I have a script that submits form data via a "post" method to another
> script. I have an href link in the destination script that links back
> to itself for processing form data on that page with some "get" data
> appended to the URL. I noticed that after clicking on that link and
> sending the action back to itself, a check of isset($_POST) returns
> true while displaying the content of $_POST displays an empty array.
> I had expected isset($_POST) to return false, thinking the script
> would unset the $_POST array when the <a> link sent it back to
> itself. Instead, it leaves $_POST set but empty.


if you have a <input type="text" name="something" value=""> then test against
the something cell in the $_POST: isset($_POST['something'])

--

//Aho

Thanks. What triggered all of this was the need to pass various
values between scripts to various variables in the receiving script,
some connected naturally to a form field and some not. Sometimes they
are the result of a database query or sometimes the result of an
operator like a switch statement. There are obviously various ways to
do this, e.g. "get" pairs in a URL, session variables, name value
pairs in a hidden field, And then the receiving script needs a
trigger to know which value to use. I'm seeing the significant
variety of ways php provides to accomplish both these functions.

As I'm coding, things seem to start out by getting complicated fast
and then collapsing into more simplified structures as I start to see
the patterns. One thing that seems particularly valuable is being
able to see the symetries that can be collapsed into triggered
choices.

--Kenoli


On May 16, 11:20 am, "J.O. Aho" <u...@example.net> wrote:
> kenoli wrote:
> > I have a script that submits form data via a "post" method to another
> > script. I have an href link in the destination script that links back
> > to itself for processing form data on that page with some "get" data
> > appended to the URL. I noticed that after clicking on that link and
> > sending the action back to itself, a check of isset($_POST) returns
> > true while displaying the content of $_POST displays an empty array.
> > I had expected isset($_POST) to return false, thinking the script
> > would unset the $_POST array when the <a> link sent it back to
> > itself. Instead, it leaves $_POST set but empty.
>
> if you have a <input type="text" name="something" value=""> then test against
> the something cell in the $_POST: isset($_POST['something'])
>
> --
>
> //Aho