=head1 NAME
-Apache::MVC - Web front end to a data source
+Apache::MVC - Apache front-end to Maypole
=head1 SYNOPSIS
package BeerDB;
use base 'Apache::MVC';
- sub handler { Apache::MVC::handler("BeerDB", @_) }
- BeerDB->set_database("dbi:mysql:beerdb");
+ BeerDB->setup("dbi:mysql:beerdb");
BeerDB->config->{uri_base} = "http://your.site/";
BeerDB->config->{display_tables} = [qw[beer brewery pub style]];
# Now set up your database:
=head1 DESCRIPTION
-A large number of web programming tasks follow the same sort of pattern:
-we have some data in a datasource, typically a relational database. We
-have a bunch of templates provided by web designers. We have a number of
-things we want to be able to do with the database - create, add, edit,
-delete records, view records, run searches, and so on. We have a web
-server which provides input from the user about what to do. Something in
-the middle takes the input, grabs the relevant rows from the database,
-performs the action, constructs a page, and spits it out.
-
-This module aims to be the most generic and extensible "something in the
-middle".
-
-An example would help explain this best. You need to add a product
-catalogue to a company's web site. Users need to list the products in
-various categories, view a page on each product with its photo and
-pricing information and so on, and there needs to be a back-end where
-sales staff can add new lines, change prices, and delete out of date
-records. So, you set up the database, provide some default templates
-for the designers to customize, and then write an Apache handler like
-this:
-
- package ProductDatabase;
- use base 'Apache::MVC';
- __PACKAGE__->set_database("dbi:mysql:products");
- BeerDB->config->{uri_base} = "http://your.site/catalogue/";
- ProductDatabase::Product->has_a("category" => ProductDatabase::Category);
- # ...
-
- sub authenticate {
- my ($self, $request) = @_;
- return OK if $request->{ar}->get_remote_host() eq "sales.yourcorp.com";
- return OK if $request->{action} =~ /^(view|list)$/;
- return DECLINED;
- }
- 1;
+Maypole is a Perl web application framework to Java's struts. It is
+essentially completely abstracted, and so doesn't know anything about
+how to talk to the outside world. C<Apache::MVC> is a mod_perl based
+subclass of Maypole.
-You then put the following in your Apache config:
+To use it, you need to create a package which represents your entire
+application. In our example above, this is the C<BeerDB> package.
- <Location /catalogue>
- SetHandler perl-script
- PerlHandler ProductDatabase
- </Location>
+This needs to first inherit from C<Apache::MVC>, and then call setup.
+This will give your package an Apache-compatible C<handler> subroutine,
+and then pass any parameters onto the C<setup_database> method of the
+model class. The default model class for Maypole uses L<Class::DBI> to
+map a database to classes, but this can be changed by messing with the
+configuration. (B<Before> calling setup.)
-And copy the templates found in F<templates/factory> into the
-F<catalogue/factory> directory off the web root. When the designers get
-back to you with custom templates, they are to go in
-F<catalogue/custom>. If you need to do override templates on a
-database-table-by-table basis, put the new template in
-F<catalogue/I<table>>.
+Next, you should configure your application through the C<config>
+method. Configuration parameters at present are:
-This will automatically give you C<add>, C<edit>, C<list>, C<view> and
-C<delete> commands; for instance, a product list, go to
+=over
- http://your.site/catalogue/product/list
+=item uri_base
-For a full example, see the included "beer database" application.
+You B<must> specify this; it is the base URI of the application, which
+will be used to construct links.
-=head1 HOW IT WORKS
+=item display_tables
-There's some documentation for the workflow in L<Apache::MVC::Workflow>,
-but the basic idea is that a URL part like C<product/list> gets
-translated into a call to C<ProductDatabase::Product-E<gt>list>. This
-propagates the request with a set of objects from the database, and then
-calls the C<list> template; first, a C<product/list> template if it
-exists, then the C<custom/list> and finally C<factory/list>.
+If you do not want all of the tables in the database to be accessible,
+then set this to a list of only the ones you want to display
-If there's another action you want the system to do, you need to either
-subclass the model class, and configure your class slightly differently:
+=item rows_per_page
- package ProductDatabase::Model;
- use base 'Apache::MVC::Model::CDBI';
+List output is paged if you set this to a positive number of rows.
- sub supersearch :Exported {
- my ($self, $request) = @_;
- # Do stuff, get a bunch of objects back
- $r->objects(\@objects);
- $r->template("template_name");
- }
+=back
- ProductDatabase->config->{model_class} = "ProductDatabase::Model";
+You should also set up relationships between your classes, such that,
+for instance, calling C<brewery> on a C<BeerDB::Beer> object returns an
+object representing its associated brewery.
+
+For a full example, see the included "beer database" application.
-(The C<:Exported> attribute means that the method can be called via the
-URL C</I<table>/supersearch/...>.)
+=head1 INSTALLATION
-Alternatively, you can put the method directly into the specific model
-class for the table:
+Create a driver module like the one above.
+
+Put the following in your Apache config:
+
+ <Location /beer>
+ SetHandler perl-script
+ PerlHandler BeerDB
+ </Location>
+
+Copy the templates found in F<templates/factory> into the
+F<beer/factory> directory off the web root. When the designers get
+back to you with custom templates, they are to go in
+F<beer/custom>. If you need to do override templates on a
+database-table-by-table basis, put the new template in
+F<beer/I<table>>.
+
+This will automatically give you C<add>, C<edit>, C<list>, C<view> and
+C<delete> commands; for instance, a list of breweries, go to
- sub ProductDatabase::Product::supersearch :Exported { ... }
+ http://your.site/beer/brewery/list
-By default, the view class uses Template Toolkit as the template
-processor, and the model class uses C<Class::DBI>; it may help you to be
-familiar with these modules before going much further with this,
-although I expect there to be other subclasses for other templating
-systems and database abstraction layers as time goes on. The article at
-C<http://www.perl.com/pub/a/2003/07/15/nocode.html> is a great
-introduction to the process we're trying to automate.
+For more information about how the system works and how to extend it,
+see L<Maypole>.
=head1 AUTHOR
projects / maypole.git / blobdiff