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Posted by Ian Davies on 10/25/05 12:47
Colin
> I may be misunderstanding you - in which case I apologise for
> patronising you - but it seems to me that you are not understanding how
> the web works.
You right there. I am new to web programming. I have a VB project that need
to become web enabled and I am learning as I rewrite this project for the
web. Thank you for all your information, it has been saved and will be added
to my resources for future use.
Another question. It seems that a variable can only be passed on to the next
form. How can I pass it to a third form in the line? Would I have to 'leap
frog' it from one hidden field to the next via a form's POST action or
should I use sessions.
Also if you know of a good link to a tutorial on the above and also on
filtering values in a dropdown list based on the values in preceeding
dropdown list I would be v grateful as most of my searches for such things
lead usually to dead ends
Thanks
Ian
>
> Anything the user does is entirely on their client machine. They can
> fill in forms and pick links (and possibly completely change what's on
> the page they're looking at, if you've embedded suitable client-side
> scripting in it- typically Javascript). But nothing can happen on the
> server (such as changing the database) until they have requested a new
> page, either by picking a link or submitting a form.
> Of course, if it is to do anything other than simply sending HTML, that
> page must be a CGI script. But it will not have any data from the user's
> page unless the data has been sent back as CGI variables - either GET or
> POST. Alternatively, in PHP they can have been preserved (on the server)
> from when the previous page was processed, by using a _SESSION.
>
> If I understand correctly, what you really want is logically two
> separate pages:
>
> page1.php:
> // extract the data from SQL
> // display it to the user
> print "<a href='page2.php?arg1=$val1&arg2=$val2'>Confirm</a>";
>
> page2.php:
> $sql = "INSERT INTO ... (arg1, arg2 ... ) VALUES ($_GET['arg1'],
> $_GET['arg2'])";
>
> // display whatever you want the page to look like
>
> You can make them a single page if you want by (eg) making the link
>
> href='page1.php?confirm=yes&arg1=$val1&arg2=val2'
>
> and then starting your page with
>
> <?php
> if (array_key_exists('confirm', $_GET) && $_GET['confirm'] == 'yes') {
> // update database
> } else {
> // send request-confirmation page
> }
>
> but you must still pass the data back from the client.
>
>
> All the above assumes that it is practical and desirable to send the
> data by GET. If you prefer POST (because there's too much of it, or
> because you would rather it didn't appear in the URL, then you need to
> use a form, even if there is nothing on it but a submit button:
>
> <form method='POST' action = 'page2.php'>
> <input type='hidden' name='arg1' value='<?php echo $val1 ?>'>
> <input type='hidden' name='arg2' value='<?php echo $val2 ?>'>
> <submit name='confirm'>
> </form>
>
> Then the variables will be available in the $_POST array in the next page.
>
> Colin
>
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