File: class/Extras/Code/pp3e/cgi-bin/peoplecgi.py

#!/usr/bin/python
import cgi, shelve                         # cgi.test() dumps inputs
form = cgi.FieldStorage()                  # parse form data
print "Content-type: text/html"            # hdr, blank line in string
shelvename = 'class-shelve'
fieldnames = ('name', 'age', 'job', 'pay')

# main html template
replyhtml = """
<html><body>
<title>People Input Form</title>
<form method=POST action="peoplecgi.py">
    <table>
    <tr><th>key<td><input type=text name=key value="%(key)s">
    $ROWS$
    </table>
    <p>
    <input type=submit value="Fetch",  name=action>
    <input type=submit value="Update", name=action>   
</form>
</body></html>
"""

# insert html for data rows at $ROWS$
rowhtml  = '<tr><th>%s<td><input type=text name=%s value="%%(%s)s">\n'
rowshtml = ''
for fieldname in fieldnames:
    rowshtml += (rowhtml % ((fieldname,) * 3))
replyhtml = replyhtml.replace('$ROWS$', rowshtml)

def htmlize(adict):
    new = adict.copy()
    for field in fieldnames:                      # values may have &, >, etc.
        value = new[field]                        # display as code: quoted
        new[field] = cgi.escape(repr(value))      # html-escape special chars
    return new
    
def fetchRecord(db, form):
    try:
        key = form['key'].value
        record = db[key]
        fields = record.__dict__                  # use attribute dict
        fields['key'] = key                       # to fill reply string
    except:
        fields = dict.fromkeys(fieldnames, '?')
        fields['key'] = 'Missing or invalid key!'
    return fields

def updateRecord(db, form):
    if not form.has_key('key'):
        fields = dict.fromkeys(fieldnames, '?')
        fields['key'] = 'Missing key input!'
    else:
        key = form['key'].value
        if key in db.keys():
            record = db[key]                      # update existing record
        else:
            from person import Person             # make/store new one for key
            record = Person(name='?', age='?')    # eval: strings must be quoted
        for field in fieldnames:
            setattr(record, field, eval(form[field].value))
        db[key] = record
        fields = record.__dict__
        fields['key'] = key
    return fields

db = shelve.open(shelvename)
action = form.has_key('action') and form['action'].value
if action == 'Fetch':
    fields = fetchRecord(db, form)        
elif action == 'Update':
    fields = updateRecord(db, form)
else:
    fields = dict.fromkeys(fieldnames, '?')       # bad submit button value
    fields['key'] = 'Missing or invalid action!'
db.close()
print replyhtml % htmlize(fields)                 # fill reply from dict