When searching for information, as can be incorporated into
WordPress forms, the results repeatedly point to one theme: the integration of
contact forms. That was not sought, because I wanted to incorporate a
self-designed form in my WordPress blog and analyze the data entered in this
form in a PHP script to display a graphic.
First of all, I got gnuplot to mind, as well gnuplot for
generating a plurality of suitable diagrams. As far as I know, supported
gnuplot but unfortunately not the output of the graphics in a stream, as it is
desirable for the output as an image in a PHP script would be, but must always
be realized through the detour of an output file, which in a multi-user
environment, such as a website a few problems inevitable.
The second approach was to use the Google Chart API to a
corresponding graphic display. Have a short flight over the document gave
assurance that the venture with Google Chart API is possible; however, the
parameters of the graphics as URL parameters are transmitted. That
contradicted, however, my idea of how much you need to know about Google.
Google had when the corresponding side slightly different cookies that have
been placed on their side on your computer already, with your birth date
entered here can match.
So there was only his own generation of graphics. Gnuplot
output stream from a lack of difference to PHP. The PHP GD library module into
the foreground. Although the creation of a chart with the help of the GD
library is not just "dedicated optimized", but remains nevertheless
limited in terms of cost. Simple lines and grids can be realized to a very
reasonable cost. Especially since the GD library can be enabled as a module in
PHP and supports the direct stream output - so graphics can be printed directly
from a PHP script.
Realization
Shortcode
First of all, I've got a new short code defined that
implements a form to enter your birth date. To change the formatting of the
output I have not thought about, because the task is the installed WordPress
themes and this is the task perfectly mastered.
The entered data is stored by the form (after verification)
in the PHP global $ _SESSION array. A transfer to the graphic artist compelling
script by URL was not an option, because that would have modified the
parameters of a possible aggressor and to overload (by continuous multiple
views) can be abused. Likewise, there are plugins for every major browser,
which transmit the URL be surfed only once to a service (which may be well
meant) to check the safety of the respective links. Such transmission of your
date of birth I wanted to avoid at all costs. Therefore, only came to save the
entered data in the session variable in question. And for your protection is to
store the session data is limited to the duration of your browsing session.
Once you close your browser, the site no longer knows what data you have
entered into this form.
The issued by the Short Form Code has as its goal (when you
click the submit button) itself The following should be recognized:
the form was filled out (values submitted with the
appropriate name)?
correspond to the values transmitted to the default values
(they are valid)?
If so, then store the values in the PHP variable $ _SESSION
['...']
If so, then embedding a URL that will contain an image as
output
if (isset ($ _SESSION ['bio_day']) && isset ($
_SESSION ['bio_month']) && isset ($ _SESSION ['bio_year']))
{
$ Bday = $
_SESSION ['bio_day'];
Bmonth $ = $
_SESSION ['bio_month'];
Byear $ = $
_SESSION ['bio_year'];
}
if (isset ($ _POST ['bio_day']) && isset ($ _POST
['bio_month']) && isset ($ _POST ['bio_year']))
{
$ Tday =
intval ($ _POST ['bio_day']);
$ Tmonth =
intval ($ _POST ['bio_month']);
$ Tyear =
intval ($ _POST ['bio_year']);
if ($ tday>
= 1 && $ tday <= 31 && $ tmonth> = 1 && $ tmonth
<= 12 && $ tyear> = date ('Y') - 100 && $ tyear <=
date ('Y') && checkdate ($ tmonth, $ tday, $ tyear))
{
$ = $
Bday tday;
$ = $
Bmonth tmonth;
$ = $
Byear tyear;
$
_SESSION ['Bio_day'] = $ bday;
$
_SESSION ['Bio_month'] = $ bmonth;
$
_SESSION ['Bio_year'] = $ byear;
}
}
PHP Script
The embedded PHP script to generate the graphics then
verifies the existence of the first values. It must be given no parameters in
the URL, as has been previously stored after successful validation all the
required values in session variables. The PHP script is the source of an
image in the form <img source="myphpscript.php" /> indicated.
When calling the script myphpscript.php (from the same
domain!) then all $ _SESSION variables to read again and can be further
processed. With the help of the GD library can then generate corresponding
graphics.
The result of this work is available on the site biorhythms
are tested.
