Time Is Money (part 2) - Getting Creative (
Page 2 of 11 )
If you look at
the main menu, you'll see that the third menu item allows the user to view
entries for a specified date. When you analyze this a little, though, you'll see
that this menu item has broader implications - it must allow the user
to:
view a list of timesheet entries for the specified date;
add
new entries for the specified date;
delete existing entries from the
list.
In order to perform these functions, the script - I've called it
"view.php" - must necessarily receive a valid datestamp (created from the
variables $d, $m and $y). These three variables are generated from the drop-down
boxes in "menu.php" - you may remember this from last time's article (if not,
I'd strongly suggest you review the source code for "menu.php" and then come
back here). Once "view.php" receives these values, it generates a datestamp,
checks to ensure that the date is a valid one, and then queries the "log" table
for all relevant data.
So that takes care of displaying existing entries.
But what about adding new ones, or deleting existing ones?
Well, after
much thought and a couple of conversations with our resident interface designer,
I've come up with a clever way to combine both these functions into "view.php".
Here's a rough sketch of what I have in mind:
Essentially, I plan to split the page into two main
sections. The left side of the page will contain a list of entries retrieved
from the database, with a checkbox next to each; the user can select an entry
for deletion by checking the corresponding box. The right side of the page will
hold a form, which can be used to add new entries to the timesheet. Entries
added from the form on the right side will immediately appear in the list on the
left side.
This sounds complicated, but it's actually not all that
difficult to implement. The important thing here is to take the pieces one at a
time and deal with them separately. And so, the first thing I need to do is set
up a page template.
<?
// view.php - view/add/delete entries for a specific date
// includes
// check for valid user session
session_start();
if(!session_is_registered("SESSION_UID"))
{
header("Location: error.php?ec=1");
exit;
}
// check for valid date
if (!checkdate($m, $d, $y))
{
header("Location: error.php?ec=2");
exit;
}
<html>
<head>
</head>
<body bgcolor="white">
<?
// display page header
?>
<!-- table (1r, 3c) -->
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td valign="top" align="left" width="60%">
<!-- table for existing timesheet records goes here - snip -->
</td>
<!-- spacer -->
<td width="10%">
</td>
<td valign="top" align="left" width="30%">
<!-- table for new timesheet records goes here - snip -->
</td>
</tr>
</table>
<?
// display page footer
?>
</body>
</html>
The script begins with the usual checks and includes, and
generates an HTML page containing a (1r, 3c) table. The first and last of these
cells will be used for the existing and new timesheet data
respectively.
Note the checkdate() function at the top of the script -
I'm using this to validate the date value received by "view.php". This check is
necessary to catch incorrect date values - for example, 30 February or 31 April.
If the date selected by the user is invalid, the script will redirect to the
generic error handler, which should display a message indicating the
error.
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