package Web::Simple;
-use strict;
-use warnings FATAL => 'all';
+use strictures 1;
+use 5.008;
+use warnings::illegalproto ();
+use Moo ();
+use Web::Dispatch::Wrapper ();
+
+our $VERSION = '0.007';
sub import {
- strict->import;
- warnings->import(FATAL => 'all');
- warnings->unimport('syntax');
- warnings->import(FATAL => qw(
- ambiguous bareword digit parenthesis precedence printf
- prototype qw reserved semicolon
- ));
my ($class, $app_package) = @_;
+ $app_package ||= caller;
$class->_export_into($app_package);
+ eval "package $app_package; use Web::Dispatch::Wrapper; use Moo; 1"
+ or die "Failed to setup app package: $@";
+ strictures->import;
+ warnings::illegalproto->unimport;
}
sub _export_into {
my ($class, $app_package) = @_;
{
no strict 'refs';
- *{"${app_package}::dispatch"} = sub {
- $app_package->_setup_dispatchables(@_);
- };
- *{"${app_package}::filter_response"} = sub (&) {
- $app_package->_construct_response_filter($_[0]);
- };
- *{"${app_package}::redispatch_to"} = sub {
- $app_package->_construct_redispatch($_[0]);
- };
- *{"${app_package}::default_config"} = sub {
- my @defaults = @_;
- *{"${app_package}::_default_config"} = sub { @defaults };
- };
- *{"${app_package}::self"} = \${"${app_package}::self"};
+ *{"${app_package}::PSGI_ENV"} = sub () { -1 };
require Web::Simple::Application;
unshift(@{"${app_package}::ISA"}, 'Web::Simple::Application');
}
+ (my $name = $app_package) =~ s/::/\//g;
+ $INC{"${name}.pm"} = 'Set by "use Web::Simple;" invocation';
}
+=head1 NAME
+
+Web::Simple - A quick and easy way to build simple web applications
+
+=head1 WARNING
+
+This is really quite new. If you're reading this on CPAN, it means the stuff
+that's here we're probably happy with. But only probably. So we may have to
+change stuff. And if you're reading this from git, come check with irc.perl.org
+#web-simple that we're actually sure we're going to keep anything that's
+different from the CPAN version.
+
+If we do find we have to change stuff we'll add to the
+L<CHANGES BETWEEN RELEASES> section explaining how to switch your code across
+to the new version, and we'll do our best to make it as painless as possible
+because we've got Web::Simple applications too. But we can't promise not to
+change things at all. Not yet. Sorry.
+
+=head1 SYNOPSIS
+
+ #!/usr/bin/env perl
+
+ use Web::Simple 'HelloWorld';
+
+ {
+ package HelloWorld;
+
+ sub dispatch_request {
+ sub (GET) {
+ [ 200, [ 'Content-type', 'text/plain' ], [ 'Hello world!' ] ]
+ },
+ sub () {
+ [ 405, [ 'Content-type', 'text/plain' ], [ 'Method not allowed' ] ]
+ }
+ }
+ }
+
+ HelloWorld->run_if_script;
+
+If you save this file into your cgi-bin as C<hello-world.cgi> and then visit:
+
+ http://my.server.name/cgi-bin/hello-world.cgi/
+
+you'll get the "Hello world!" string output to your browser. For more complex
+examples and non-CGI deployment, see below. To get help with L<Web::Simple>,
+please connect to the irc.perl.org IRC network and join #web-simple.
+
+=head1 DESCRIPTION
+
+The philosophy of L<Web::Simple> is to keep to an absolute bare minimum for
+everything. It is not designed to be used for large scale applications;
+the L<Catalyst> web framework already works very nicely for that and is
+a far more mature, well supported piece of software.
+
+However, if you have an application that only does a couple of things, and
+want to not have to think about complexities of deployment, then L<Web::Simple>
+might be just the thing for you.
+
+The only public interface the L<Web::Simple> module itself provides is an
+C<import> based one:
+
+ use Web::Simple 'NameOfApplication';
+
+This sets up your package (in this case "NameOfApplication" is your package)
+so that it inherits from L<Web::Simple::Application> and imports L<strictures>,
+as well as installs a C<PSGI_ENV> constant for convenience, as well as some
+other subroutines.
+
+Importing L<strictures> will automatically make your code use the C<strict> and
+C<warnings> pragma, so you can skip the usual:
+
+ use strict;
+ use warnings FATAL => 'aa';
+
+provided you 'use Web::Simple' at the top of the file. Note that we turn
+on *fatal* warnings so if you have any warnings at any point from the file
+that you did 'use Web::Simple' in, then your application will die. This is,
+so far, considered a feature.
+
+When we inherit from L<Web::Simple::Application> we also use <Moo>, which is
+the the equivalent of:
+
+ {
+ package NameOfApplication;
+ use Moo;
+ extends 'Web::Simple::Application';
+ }
+
+So you can use L<Moo> features in your application, such as creating attributes
+using the C<has> subroutine, etc. Please see the documentation for L<Moo> for
+more information.
+
+It also exports the following subroutines for use in dispatchers:
+
+ response_filter { ... };
+
+ redispatch_to '/somewhere';
+
+Finally, import sets
+
+ $INC{"NameOfApplication.pm"} = 'Set by "use Web::Simple;" invocation';
+
+so that perl will not attempt to load the application again even if
+
+ require NameOfApplication;
+
+is encountered in other code.
+
+=head1 DISPATCH STRATEGY
+
+L<Web::Simple> despite being straightforward to use, has a powerful system
+for matching all sorts of incoming URLs to one or more subroutines. These
+subroutines can be simple actions to take for a given URL, or something
+more complicated, including entire L<Plack> applications, L<Plack::Middleware>
+and nested subdispatchers.
+
+=head2 Examples
+
+ sub dispatch_request {
+ # matches: GET /user/1.htm?show_details=1
+ # GET /user/1.htm
+ sub (GET + /user/* + ?show_details~ + .htm|.html|.xhtml) {
+ my ($self, $user_id, $show_details) = @_;
+ ...
+ },
+ # matches: POST /user?username=frew
+ # POST /user?username=mst&first_name=matt&last_name=trout
+ sub (POST + /user + ?username=&*) {
+ my ($self, $username, $misc_params) = @_;
+ ...
+ },
+ # matches: DELETE /user/1/friend/2
+ sub (DELETE + /user/*/friend/*) {
+ my ($self, $user_id, $friend_id) = @_;
+ ...
+ },
+ # matches: PUT /user/1?first_name=Matt&last_name=Trout
+ sub (PUT + /user/* + ?first_name~&last_name~) {
+ my ($self, $user_id, $first_name, $last_name) = @_;
+ ...
+ },
+ sub (/user/*/...) {
+ my $user_id = $_[1];
+ # matches: PUT /user/1/role/1
+ sub (PUT + /role/*) {
+ my $role_id = $_[1];
+ ...
+ },
+ # matches: DELETE /user/1/role/1
+ sub (DELETE + /role/*) {
+ my $role_id = $_[1];
+ ...
+ },
+ },
+ }
+
+=head2 The dispatch cycle
+
+At the beginning of a request, your app's dispatch_request method is called
+with the PSGI $env as an argument. You can handle the request entirely in
+here and return a PSGI response arrayref if you want:
+
+ sub dispatch_request {
+ my ($self, $env) = @_;
+ [ 404, [ 'Content-type' => 'text/plain' ], [ 'Amnesia == fail' ] ]
+ }
+
+However, generally, instead of that, you return a set of dispatch subs:
+
+ sub dispatch_request {
+ my $self = shift;
+ sub (/) { redispatch_to '/index.html' },
+ sub (/user/*) { $self->show_user($_[1]) },
+ ...
+ }
+
+If you return a subroutine with a prototype, the prototype is treated
+as a match specification - and if the test is passed, the body of the
+sub is called as a method any matched arguments (see below for more details).
+
+You can also return a plain subroutine which will be called with just $env
+- remember that in this case if you need $self you -must- close over it.
+
+If you return a normal object, L<Web::Simple> will simply return it upwards on
+the assumption that a response_filter (or some arbitrary L<Plack::Middleware>)
+somewhere will convert it to something useful. This allows:
+
+ sub dispatch_request {
+ my $self = shift;
+ sub (.html) { response_filter { $self->render_zoom($_[0]) } },
+ sub (/user/*) { $self->users->get($_[1]) },
+ }
+
+to render a user object to HTML, if there is an incoming URL such as:
+
+ http://myweb.org/user/111.html
+
+This works because as we descend down the dispachers, we first match
+C<sub (.html)>, which adds a C<response_filter> (basically a specialized routine
+that follows the L<Plack::Middleware> specification), and then later we also
+match C<sub (/user/*)> which gets a user and returns that as the response.
+This user object 'bubbles up' through all the wrapping middleware until it hits
+the C<response_filter> we defined, after which the return is converted to a
+true html response.
+
+However, two types of object are treated specially - a Plack::App object
+will have its C<->to_app> method called and be used as a dispatcher:
+
+ sub dispatch_request {
+ my $self = shift;
+ sub (/static/...) { Plack::App::File->new(...) },
+ ...
+ }
+
+A Plack::Middleware object will be used as a filter for the rest of the
+dispatch being returned into:
+
+ ## responds to /admin/track_usage AND /admin/delete_accounts
+
+ sub dispatch_request {
+ my $self = shift;
+ sub (/admin/**) {
+ Plack::Middleware::Session->new(%opts);
+ },
+ sub (/admin/track_usage) {
+ ## something that needs a session
+ },
+ sub (/admin/delete_accounts) {
+ ## something else that needs a session
+ },
+ }
+
+Note that this is for the dispatch being -returned- to, so if you want to
+provide it inline you need to do:
+
+ ## ALSO responds to /admin/track_usage AND /admin/delete_accounts
+
+ sub dispatch_request {
+ my $self = shift;
+ sub (/admin/...) {
+ sub {
+ Plack::Middleware::Session->new(%opts);
+ },
+ sub (/track_usage) {
+ ## something that needs a session
+ },
+ sub (/delete_accounts) {
+ ## something else that needs a session
+ },
+ }
+ }
+
+And that's it - but remember that all this happens recursively - it's
+dispatchers all the way down. A URL incoming pattern will run all matching
+dispatchers and then hit all added filters or L<Plack::Middleware>.
+
+=head2 Web::Simple match specifications
+
+=head3 Method matches
+
+ sub (GET) {
+
+A match specification beginning with a capital letter matches HTTP requests
+with that request method.
+
+=head3 Path matches
+
+ sub (/login) {
+
+A match specification beginning with a / is a path match. In the simplest
+case it matches a specific path. To match a path with a wildcard part, you
+can do:
+
+ sub (/user/*) {
+ $self->handle_user($_[1])
+
+This will match /user/<anything> where <anything> does not include a literal
+/ character. The matched part becomes part of the match arguments. You can
+also match more than one part:
+
+ sub (/user/*/*) {
+ my ($self, $user_1, $user_2) = @_;
+
+ sub (/domain/*/user/*) {
+ my ($self, $domain, $user) = @_;
+
+and so on. To match an arbitrary number of parts, use -
+
+ sub (/page/**) {
+
+This will result in an element per /-separated part so matched. Note that
+you can do
+
+ sub (/page/**/edit) {
+
+to match an arbitrary number of parts up to but not including some final
+part.
+
+Finally,
+
+ sub (/foo/...) {
+
+Will match /foo/ on the beginning of the path -and- strip it. This is designed
+to be used to construct nested dispatch structures, but can also prove useful
+for having e.g. an optional language specification at the start of a path.
+
+Note that the '...' is a "maybe something here, maybe not" so the above
+specification will match like this:
+
+ /foo # no match
+ /foo/ # match and strip path to '/'
+ /foo/bar/baz # match and strip path to '/bar/baz'
+
+=head3 Extension matches
+
+ sub (.html) {
+
+will match .html from the path (assuming the subroutine itself returns
+something, of course). This is normally used for rendering - e.g.
+
+ sub (.html) {
+ response_filter { $self->render_html($_[1]) }
+ }
+
+Additionally,
+
+ sub (.*) {
+
+will match any extension and supplies the extension as a match argument.
+
+=head3 Query and body parameter matches
+
+Query and body parameters can be match via
+
+ sub (?<param spec>) { # match URI query
+ sub (%<param spec>) { # match body params
+
+The body is only matched if the content type is
+application/x-www-form-urlencoded (note this means that Web::Simple does
+not yet handle uploads; this will be addressed in a later release).
+
+The param spec is elements of one of the following forms -
+
+ param~ # optional parameter
+ param= # required parameter
+ @param~ # optional multiple parameter
+ @param= # required multiple parameter
+ :param~ # optional parameter in hashref
+ :param= # required parameter in hashref
+ :@param~ # optional multiple in hashref
+ :@param= # required multiple in hashref
+ * # include all other parameters in hashref
+ @* # include all other parameters as multiple in hashref
+
+separated by the & character. The arguments added to the request are
+one per non-:/* parameter (scalar for normal, arrayref for multiple),
+plus if any :/* specs exist a hashref containing those values.
+
+Please note that if you specify a multiple type parameter match, you are
+ensured of getting an arrayref for the value, EVEN if the current incoming
+request has only one value. However if a parameter is specified as single
+and multiple values are found, the last one will be used.
+
+For example to match a page parameter with an optional order_by parameter one
+would write:
+
+ sub (?page=&order_by~) {
+ my ($self, $page, $order_by) = @_;
+ return unless $page =~ /^\d+$/;
+ $page ||= 'id';
+ response_filter {
+ $_[1]->search_rs({}, $p);
+ }
+ }
+
+to implement paging and ordering against a L<DBIx::Class::ResultSet> object.
+
+Another Example: To get all parameters as a hashref of arrayrefs, write:
+
+ sub(?@*) {
+ my ($self, $params) = @_;
+ ...
+
+To get two parameters as a hashref, write:
+
+ sub(?:user~&:domain~) {
+ my ($self, $params) = @_; # params contains only 'user' and 'domain' keys
+
+You can also mix these, so:
+
+ sub (?foo=&@bar~&:coffee=&@*) {
+ my ($self, $foo, $bar, $params);
+
+where $bar is an arrayref (possibly an empty one), and $params contains
+arrayref values for all parameters -not- mentioned and a scalar value for
+the 'coffee' parameter.
+
+Note, in the case where you combine arrayref, single parameter and named
+hashref style, the arrayref and single parameters will appear in C<@_> in the
+order you defined them in the protoype, but all hashrefs will merge into a
+single C<$params>, as in the example above.
+
+=head3 Combining matches
+
+Matches may be combined with the + character - e.g.
+
+ sub (GET + /user/*) {
+
+to create an AND match. They may also be combined withe the | character - e.g.
+
+ sub (GET|POST) {
+
+to create an OR match. Matches can be nested with () - e.g.
+
+ sub ((GET|POST) + /user/*) {
+
+and negated with ! - e.g.
+
+ sub (!/user/foo + /user/*) {
+
+! binds to the immediate rightmost match specification, so if you want
+to negate a combination you will need to use
+
+ sub ( !(POST|PUT|DELETE) ) {
+
+and | binds tighter than +, so
+
+ sub ((GET|POST) + /user/*) {
+
+and
+
+ sub (GET|POST + /user/*) {
+
+are equivalent, but
+
+ sub ((GET + /admin/...) | (POST + /admin/...)) {
+
+and
+
+ sub (GET + /admin/... | POST + /admin/...) {
+
+are not - the latter is equivalent to
+
+ sub (GET + (/admin/...|POST) + /admin/...) {
+
+which will never match!
+
+=head3 Whitespace
+
+Note that for legibility you are permitted to use whitespace -
+
+ sub (GET + /user/*) {
+
+but it will be ignored. This is because the perl parser strips whitespace
+from subroutine prototypes, so this is equivalent to
+
+ sub (GET+/user/*) {
+
+=head3 Accessing the PSGI env hash
+
+In some cases you may wish to get the raw PSGI env hash - to do this,
+you can either use a plain sub -
+
+ sub {
+ my ($env) = @_;
+ ...
+ }
+
+or use the PSGI_ENV constant exported to retrieve it:
+
+ sub (GET + /foo + ?some_param=) {
+ my $param = $_[1];
+ my $env = $_[PSGI_ENV];
+ }
+
+but note that if you're trying to add a middleware, you should simply use
+Web::Simple's direct support for doing so.
+
+=head1 EXPORTED SUBROUTINES
+
+=head2 response_filter
+
+ response_filter {
+ # Hide errors from the user because we hates them, preciousss
+ if (ref($_[0]) eq 'ARRAY' && $_[0]->[0] == 500) {
+ $_[0] = [ 200, @{$_[0]}[1..$#{$_[0]}] ];
+ }
+ return $_[0];
+ };
+
+The response_filter subroutine is designed for use inside dispatch subroutines.
+
+It creates and returns a special dispatcher that always matches, and calls
+the block passed to it as a filter on the result of running the rest of the
+current dispatch chain.
+
+Thus the filter above runs further dispatch as normal, but if the result of
+dispatch is a 500 (Internal Server Error) response, changes this to a 200 (OK)
+response without altering the headers or body.
+
+=head2 redispatch_to
+
+ redispatch_to '/other/url';
+
+The redispatch_to subroutine is designed for use inside dispatch subroutines.
+
+It creates and returns a special dispatcher that always matches, and instead
+of continuing dispatch re-delegates it to the start of the dispatch process,
+but with the path of the request altered to the supplied URL.
+
+Thus if you receive a POST to '/some/url' and return a redispatch to
+'/other/url', the dispatch behaviour will be exactly as if the same POST
+request had been made to '/other/url' instead.
+
+Note, this is not the same as returning an HTTP 3xx redirect as a response;
+rather it is a much more efficient internal process.
+
+=head1 CHANGES BETWEEN RELEASES
+
+=head2 Changes between 0.004 and 0.005
+
+=over 4
+
+=item * dispatch {} replaced by declaring a dispatch_request method
+
+dispatch {} has gone away - instead, you write:
+
+ sub dispatch_request {
+ my $self = shift;
+ sub (GET /foo/) { ... },
+ ...
+ }
+
+Note that this method is still -returning- the dispatch code - just like
+dispatch did.
+
+Also note that you need the 'my $self = shift' since the magic $self
+variable went away.
+
+=item * the magic $self variable went away.
+
+Just add 'my $self = shift;' while writing your 'sub dispatch_request {'
+like a normal perl method.
+
+=item * subdispatch deleted - all dispatchers can now subdispatch
+
+In earlier releases you needed to write:
+
+ subdispatch sub (/foo/...) {
+ ...
+ [
+ sub (GET /bar/) { ... },
+ ...
+ ]
+ }
+
+As of 0.005, you can instead write simply:
+
+ sub (/foo/...) {
+ ...
+ (
+ sub (GET /bar/) { ... },
+ ...
+ )
+ }
+
+=head2 Changes since Antiquated Perl
+
+=over 4
+
+=item * filter_response renamed to response_filter
+
+This is a pure rename; a global search and replace should fix it.
+
+=item * dispatch [] changed to dispatch {}
+
+Simply changing
+
+ dispatch [ sub(...) { ... }, ... ];
+
+to
+
+ dispatch { sub(...) { ... }, ... };
+
+should work fine.
+
+=back
+
+=head1 DEVELOPMENT HISTORY
+
+Web::Simple was originally written to form part of my Antiquated Perl talk for
+Italian Perl Workshop 2009, but in writing the bloggery example I realised
+that having a bare minimum system for writing web applications that doesn't
+drive me insane was rather nice and decided to spend my attempt at nanowrimo
+for 2009 improving and documenting it to the point where others could use it.
+
+The Antiquated Perl talk can be found at L<http://www.shadowcat.co.uk/archive/conference-video/>.
+
+=head1 COMMUNITY AND SUPPORT
+
+=head2 IRC channel
+
+irc.perl.org #web-simple
+
+=head2 No mailing list yet
+
+Because mst's non-work email is a bombsite so he'd never read it anyway.
+
+=head2 Git repository
+
+Gitweb is on http://git.shadowcat.co.uk/ and the clone URL is:
+
+ git clone git://git.shadowcat.co.uk/catagits/Web-Simple.git
+
+=head1 AUTHOR
+
+Matt S. Trout <mst@shadowcat.co.uk>
+
+=head1 CONTRIBUTORS
+
+None required yet. Maybe this module is perfect (hahahahaha ...).
+
+=head1 COPYRIGHT
+
+Copyright (c) 2010 the Web::Simple L</AUTHOR> and L</CONTRIBUTORS>
+as listed above.
+
+=head1 LICENSE
+
+This library is free software and may be distributed under the same terms
+as perl itself.
+
+=cut
+
1;
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