Modify Records Part 3

Back on course, our edit_three sub procedure.

    if (%result) { &build_record_page(%result); }

Since %result holds our freshly returned data, we look to see if it has a null value or not. If it has an actual value, we use that sub we saw at the start of the program, &build_record_page, and send with it the hash %result. This way, we now will have our values filled out for us in the form, instead of just empty values.

    else { print qq~Error --- Record Does Not Exist ~; }

If %result has a null value, we report the error.

    print qq~
    <CENTER>
    <INPUT TYPE="submit" value="Edit Record"></CENTER>
    <CENTER>
    </FORM></TD></TR></TABLE></CENTER>~;
    &footer;

Just closing up our form here, and printing the footer once again.

}

End of edit_three.

This is alot of work for just editing a freakin database entry, but here is our last step.

Since you guys already can guess the next sub is edit_four, I'll just go right to it.

sub edit_four {
    $form{$db_key} = $form{'key'};

Here we set the $form{$db_key} key in the hash to the value of $form{'key'}. This is for the next procedure, which we sent the contents of %form, and it will be processing $form{$db_key}. Therefore, we can't send it an empty key when its very important now can we?

    my ($line) = &make_data(%form);

The database line, which is now called $line, will become the value of what &make_data returns to it. Since this sub procedure was explained at the top of this tutorial, no need to cover it again,

    my ($found) = 0;
    my ($output) = "";

Both of these variables are set to my, and null values.

    open (DATABASE, $file);

The database file is opened, once again, in read-only mode. Its handle is DATABASE.

    while (<DATABASE>) {

You know what this means. It just loops as long as DATABASE has a value, so its not at the end of file.

        chomp($_);

That newline is cut off of the record.

        (/^\s*$/) and next;

Blank lines are skipped, and we just go to the next line.

        my (%dat) = &process_record(&grab_data($_));

This you should recognize. %dat has the results of &process_record sent to it. &process_record has sent to it the array created by &grab_data, which is working on the current line ($_).

        if ($dat{$db_key} eq $form{'key'}) {
            $output .= $line;
            $found = 1;
        }

If the current database entries key is equal to the key we just sent to it, then $output has appended to it the value of $line, which &make_data just sent to us a few lines back. Since we already have the newline attached, we don't need to include another one. $found is also now a non-null value, 1.

        else {
            $output .= "$_\n";
        }

Otherwise, $output just has appended to the end of it the current record ($_), plus a nice newline.     }

    close (DATABASE);

The read-only copy of DATABASE is now closed... as we need to open another copy.