C<DBIx::HTML::PopupRadio> - Convert sql into a popup menu or radio group.

- NAME
- Synopsis
- Description
- Distributions
- Usage
- Options
- Methods
- Sample Code
- See Also
- Author
- Copyright

# NAME

`DBIx::HTML::PopupRadio` - Convert sql into a popup menu or radio group.

# Synopsis

            use DBIx::HTML::PopupRadio;

            my($popup_object) = DBIx::HTML::PopupRadio -> new
            (
                    dbh => $dbh,
                    sql => 'select campus_id, campus_name from campus order by campus_name',
            );

            $popup_object -> set(default => '1');

            my($popup_menu)  = $popup_object -> popup_menu();
            my($radio_group) = $popup_object -> radio_group();

            print $popup_menu;

# Description

This module takes a db handle and an SQL statement, and builds a hash.

Then you ask for that hash in HTML, as a popup menu or as a radio group.

The reading of the db table is delayed until you actually call one of the methods 'popup_menu' or 'radio_group'. Even then, it is delayed until any parameters passed in to these 2 methods are processed.

After a call to one of these 2 methods, you can call the 'size' method if you need to check how many rows were returned by the SQL you used.

Neither the module CGI.pm, nor any of that kidney, are used by this module. We simply output pure HTML.

# Distributions

This module is available both as a Unix-style distro (*.tgz) and an ActiveState-style distro (*.ppd). The latter is shipped in a *.zip file.

See http://savage.net.au/Perl-modules/html/installing-a-module.html for help on unpacking and installing each type of distro.

# Usage

You create an object of the class by calling the constructor, 'new'.

You then call 'set', if you wish, to set any options.

Now call 'popup_menu' or 'radio_group' to get the HTML.

Lastly, display the HTML as part of a form.

The method names 'popup_menu' and 'radio_group' (and 'param') were chosen to be reminiscent of methods with the same names in the CGI.pm module. But let me repeat, my module does not use CGI.

# Options

Here, in alphabetical order, are the options accepted by the constructor, together with their default values.

dbh => ''
  Pass in an open database handle.

  This option is mandatory, in the call to new, set, popup_menu or radio_group. Ie By the time you call one of the latter 2 methods, dbh must be set.

default => ''
  Pass in the string which is to be the default item on the popup menu or radio group. You supply here the visible menu item, not the value associated with that menu item.

  See the discussion of the sql option for details about the menu items.

  This option is not mandatory.

linebreak => 0
  Pass in 1 if you want each radio group item on a separate line, ie separated by <br />s.

  This option is not mandatory.

name => 'dbix_menu'
  Pass in the name of the form item to use for the popup menu or radio group.

  This option is not mandatory, since it has a default value. It could be unset and then reset, but must have a value by the time you call popup_menu or radio_group.

  The value of this parameter is what you will pass into a CGI object when you call its `param()` method to retrieve the user's selection.

  Hence you would do something like:

              my($name)         = 'fancy_menu';
              my($popup_object) = DBIx::HTML::PopupRadio -> new(name => $name, ...);
              my($q)            = CGI -> new();
              my($id)           = $q -> param($name) || '';

prompt => ''
  Pass in a prompt to use as the first entry in the popup menu.

  The string can contain a single quote but not a double quote.

  This string will be both a visible menu item and the value returned to yoru CGI script if the user selects this menu item.

  This option is not mandatory.

sql => ''
  Pass in the SQL used to select the popup menu or radio group items.

  This option is mandatory, in the call to new, set, popup_menu or radio_group. Ie By the time you call one of the latter 2 methods, sql must be set.

  The SQL must select 2 columns. The first will be used as the value returned by a CGI object, for example, when you call its `param()` method. The second value will be used as the visible selection offered to the user on the menu.

  Of course, the 2 columns selected could be the same:

              $obj -> set(sql => 'select campus_name, campus_name from campus order by campus_name');

  But normally you would do this:

              $obj -> set(sql => 'select campus_id, campus_name from campus order by campus_name');

  This means that the second column is used to construct visible menu items, and when an item is selected by the user, the first column is what is returned to your CGI script.

  The question remains: After you do something like this:

              my($q)     = CGI -> new();
              my($id)    = $q -> param('dbxi_menu') || '';

  how do you convert the value, eg campus_id, back into the visible menu item, eg campus_name.

  Simple: You call the param method of the DBIx::HTML::PopupRadio class:

              my($name) = $popup_object -> param($id);

  param returns the empty string if the value of $id is unknown.

# Methods

new(%arg): The constructor
  See the previous section for details.

param($id): Returns visible menu item corresponding to menu value
  Call this to convert the value returned to the CGI script when the user slected a menu item, into the visible menu item selected by the user.

  In other words, convert the first column of the SQL into the second column.

popup_menu(%arg): Return the HTML for a popup menu
  `popup_menu(%arg)` takes the same parameters as new().

radio_group(%arg): Return the HTML for a radio group
  `radio_group(%arg)` takes the same parameters as new().

set(%arg): Set class member options
  Call this to set options after calling new().

  `set(%arg)` takes the same parameters as new().

size(): Return the number of rows returned by your SQL
  Call this after callling 'popup_menu' or 'radio_group'.

  It will tell you whether or not your menu is empty.

# Sample Code

See examples/*.cgi for complete programs, both simple and complex.

You will need to run examples/bootstrap-menus.pl to load the 'test' database, 'campus' table, with sample data.

You'll have to patch these 2 programs vis-a-vis the db vendor, username and password.

The sample data in bootstrap-menus.pl is simple, but is used by several modules, so don't be too keen on changing it :-).

# See Also

            DBIx::HTML::LinkedMenus
            DBIx::CSS::TreeMenu
            DBIx::CSS::TabMenu

These modules will be released after the current one.

# Author

`DBIx::HTML::PopupRadio` was written by Ron Savage <ron@savage.net.au> in 2002.

Home page: http://savage.net.au/index.html

# Copyright

Austrlian copyright (c) 2002, Ron Savage. All rights reserved.

            All Programs of mine are 'OSI Certified Open Source Software';
            you can redistribute them and/or modify them under the terms of
            The Artistic License, a copy of which is available at:
            http://www.opensource.org/licenses/index.html