(This is the third part. Part 1. Part 2.)
Time For Some Code
Save the Google Docs Form page (viewform) to a local file on c:\wamp\www\viewform.php .
Changed the form action to point to a local page. viewpost.php:
<form action="viewpost.php?assignmentId=dog" method="POST" id="ss-form">
When I browse to http://localhost/viewform.php , I get a page looking exactly like my Google Docs Form, thanks to the fact that the CSS files was saved with the page. I created a page viewpost.php with the following code:
<?php
print("<pre>");
print_r($_POST);
print_r($_GET);
print("</pre>");
?>
Finally, I entered the form on localhost and submitted it. Here is the output:
Array
(
[entry_68_single_yodawg] =>
[entry_63_single] =>
[pageNumber] => 0
[backupCache] =>
[submit] => Submit
)
Array
(
[assignmentId] => dog
)
What can we learn from this?
- PHP makes accessing POST or GET (URL) parameters very easy. As easy as $_POST['param-name'].
- For every input element in the original form, it's name attribute is used as the parameter name.
- For radio button groups in which no selection was made, the matching parameter does not appear in the $_POST variable.
- And after some validations against the code - dots are not allowed in the parameter names, so they are converted to underscores in the $_POST array. "entry_63_single" in $_POST is originally "entry.63.single" in the HTML.
So what now?
First, we need to define a
protocol for describing a questionnaire. In Google Docs, you get a WYSIWYG editor and things are very easy. In this project's case, I am not interested in creating such an editor. My employers did not allocate such amounts of money for this project - and something simpler would suffice. I am thinking about an Excel spreadsheet which they'd write according to my guidelines. I will convert the spreadsheet into a TSV file which Python will handle.
We'll use this protocol to generate the questionnaire. Again, that means two php pages:
One just for
displaying the form. That's not so hard, we've sort of got it done.
The second is for
validating the form, insert the data into the SQL server if it's good or display it with error boxes if necessary. Both should have their HTML elements tagged in accordance with Google Docs' CSS file so they would look good. (The distances I'd walk to avoid styling on my own are immense, I assure you.)
Another thing we'll need to generate is
SQL code for defining the table properly. Creating the database could also be nice but that's less important for me right now. Defining the table, though, is crucial.
The
display,
validation ,
insertion and
table definition are all dependant on the
protocol. Therefore, my solution is to iterate over the protocol-based input file (probably a TSV adapted from excel) and for each row, parse it and generate PHP code for each of these targets.
On that note, creating an
interface for vieweing or downloading the results can be nice. wamp server comes with phpmyadmin installed, but something more friendly for the researchers is always a pleasure.
Viewing
The viewer was the easiest part to make and you can find it here: https://gist.github.com/3049801
It's mostly based on this post:
http://www.anyexample.com/programming/php/php_mysql_example__display_table_as_html.xml
This php script
- Pulls the table data as a TSV, independantly of the table's schema.
- Makes your browser automatically download it.
- Can get dbname and table as GET parameters (in the URL).
It works when the connection details (server address, username, password) are correctly set; and when the mysql server itself has permissions for that user over the requested table.
Since it's already 02:25, I think I'll go to sleep now... Later this week I'll be working on creating prepared SQL statements and binding them with the incoming POST parameters.
Happy hacking!
