X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FWeb%2FSimple.pm;h=a334187e76928d961ecf1833a10ee4e380dbf8bd;hb=20645c5fa990200aa5e75011113659c4513c4c50;hp=33b23b3380811c5a924d0a7c950ab58c4804ce70;hpb=5c33dda5c048a8351784cfea7d6e04a24f110bb0;p=catagits%2FWeb-Simple.git diff --git a/lib/Web/Simple.pm b/lib/Web/Simple.pm index 33b23b3..a334187 100644 --- a/lib/Web/Simple.pm +++ b/lib/Web/Simple.pm @@ -1,38 +1,873 @@ 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 $VERSION = '0.020'; sub import { - strict->import; - warnings->import(FATAL => 'all'); - warnings->unimport('syntax'); - warnings->import(FATAL => qw( - ambiguous bareword digit parenthesis precedence printf - prototype qw reserved semicolon - )); my ($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]); - }; - *{"${app_package}::default_config"} = sub { - my @defaults = @_; - *{"${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'; } 1; + +=head1 NAME + +Web::Simple - A quick and easy way to build simple web applications + + +=head1 SYNOPSIS + + #!/usr/bin/env perl + + package HelloWorld; + use Web::Simple; + + 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 and then visit: + + http://my.server.name/cgi-bin/hello-world.cgi/ + +you'll get the "Hello world!" string output to your browser. At the same time +this file will also act as a class module, so you can save it as HelloWorld.pm +and use it as-is in test scripts or other deployment mechanisms. + +Note that you should retain the ->run_if_script even if your app is a +module, since this additionally makes it valid as a .psgi file, which can +be extremely useful during development. + +For more complex examples and non-CGI deployment, see +L. To get help with L, please connect to +the irc.perl.org IRC network and join #web-simple. + +=head1 DESCRIPTION + +The philosophy of L is to keep to an absolute bare minimum for +everything. It is not designed to be used for large scale applications; +the L 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 +might be just the thing for you. + +The only public interface the L module itself provides is an +C based one: + + use Web::Simple 'NameOfApplication'; + +This sets up your package (in this case "NameOfApplication" is your package) +so that it inherits from L and imports L, +as well as installs a C constant for convenience, as well as some +other subroutines. + +Importing L will automatically make your code use the C and +C 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 we also use L, which is +the the equivalent of: + + { + package NameOfApplication; + use Moo; + extends 'Web::Simple::Application'; + } + +So you can use L features in your application, such as creating attributes +using the C subroutine, etc. Please see the documentation for L for +more information. + +It also exports the following subroutines for use in dispatchers: + + response_filter { ... }; + + redispatch_to '/somewhere'; + +Finally, import sets + + $INC{"NameOfApplication.pm"} = 'Set by "use Web::Simple;" invocation'; + +so that perl will not attempt to load the application again even if + + require NameOfApplication; + +is encountered in other code. + +One important thing to remember when using + + NameOfApplication->run_if_script; + +At the end of your app is that this call will create an instance of your app +for you automatically, regardless of context. An easier way to think of this +would be if the method were more verbosely named + + NameOfApplication->run_request_if_script_else_turn_coderef_for_psgi; + +=head1 DISPATCH STRATEGY + +L despite being straightforward to use, has a powerful system +for matching all sorts of incoming URLs to one or more subroutines. These +subroutines can be simple actions to take for a given URL, or something +more complicated, including entire L applications, L +and nested subdispatchers. + +=head2 Examples + + sub dispatch_request { + # matches: GET /user/1.htm?show_details=1 + # GET /user/1.htm + sub (GET + /user/* + ?show_details~ + .htm|.html|.xhtml) { + my ($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]) }, + ... + } + +Well, a sub is a valid PSGI response too (for ultimate streaming and async +cleverness). If you want to return a PSGI sub you have to wrap it into an +array ref. + + sub dispatch_request { + [ sub { + my $respond = shift; + # This is pure PSGI here, so read perldoc PSGI + } ] + } + +If you return a subroutine with a prototype, the prototype is treated +as a match specification - and if the test is passed, the body of the +sub is called as a method and passed any matched arguments (see below for more details). + +You can also return a plain subroutine which will be called with just C<$env> +- remember that in this case if you need C<$self> you B close over it. + +If you return a normal object, L will simply return it upwards on +the assumption that a response_filter (or some arbitrary L) +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]) }, + } + +An alternative to using prototypes to declare a match specification for a given +route is to provide a Dancer like key-value list: + + sub dispatch_request { + my $self = shift; + ( + '.html' => sub { response_filter { $self->render_zoom($_[0]) } }, + '/user/*' => sub { $self->users->get($_[1]) }< + ) + } + +This can be useful in situations where you are generating a dispatch table +programmatically, where setting a subroutines protoype is difficult. + +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, which adds a C (basically a specialized routine +that follows the L specification), and then later we also +match C 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 we defined, after which the return is converted to a +true html response. + +However, two types of object are treated specially - a C object +will have its C method called and be used as a dispatcher: + + sub dispatch_request { + my $self = shift; + sub (/static/...) { Plack::App::File->new(...) }, + ... + } + +A L 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 B 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. + +=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/ where 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, $user) = @_; + +and so on. To match an arbitrary number of parts, use C<**>: + + sub (/page/**) { + my ($self, $match) = @_; + +This will result in a single element for the entire match. Note that you can do + + sub (/page/**/edit) { + +to match an arbitrary number of parts up to but not including some final +part. + +Note: Since Web::Simple handles a concept of file extensions, C<*> and C<**> +matchers will not by default match things after a final dot, and this +can be modified by using C<*.*> and C<**.*> in the final position, e.g.: + + /one/* matches /one/two.three and captures "two" + /one/*.* matches /one/two.three and captures "two.three" + /** matches /one/two.three and captures "one/two" + /**.* matches /one/two.three and captures "one/two.three" + +Finally, + + sub (/foo/...) { + +Will match C on the beginning of the path B 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' + +Almost the same, + + sub (/foo...) { + +Will match on C, but also include C. Otherwise it +operates the same way as C. + + /foo # match and strip path to '' + /foo/ # match and strip path to '/' + /foo/bar/baz # match and strip path to '/bar/baz' + +Please note the difference between C and C. In +the first case, this is expecting to find something after C (and fails to +match if nothing is found), while in the second case we can match both C +and C. The following are roughly the same: + + sub (/foo) { 'I match /foo' }, + sub (/foo/...) { + sub (/bar) { 'I match /foo/bar' }, + sub (/*) { 'I match /foo/{id}' }, + } + +Versus + + sub (/foo...) { + sub (~) { 'I match /foo' }, + sub (/bar) { 'I match /foo/bar' }, + sub (/*) { 'I match /foo/{id}' }, + } + +You may prefer the latter example should you wish to take advantage of +subdispatchers to scope common activities. For example: + + sub (/user...) { + my $user_rs = $schema->resultset('User'); + sub (~) { $user_rs }, + sub (/*) { $user_rs->find($_[1]) }, + } + +You should note the special case path match C which is only meaningful +when it is contained in this type of path match. It matches to an empty path. + +=head4 Naming your patch matches + +Any C<*>, C<**>, C<*.*>, or C<**.*> match can be followed with C<:name> to make it into a named +match, so: + + sub (/*:one/*:two/*:three/*:four) { + "I match /1/2/3/4 capturing { one => 1, two => 2, three => 3, four => 4 }" + } + + sub (/**.*:allofit) { + "I match anything capturing { allofit => \$whole_path }" + } + +In the specific case of a simple single-* match, the * may be omitted, to +allow you to write: + + sub (/:one/:two/:three/:four) { + "I match /1/2/3/4 capturing { one => 1, two => 2, three => 3, four => 4 }" + } + +=head4 C and C are different specs + +As you may have noticed with the difference between C and +C, trailing slashes in path specs are significant. This is +intentional and necessary to retain the ability to use relative links on +websites. Let's demonstrate on this link: + + bar + +If the user loads the url C and clicks on this link, they will be +sent to C. However when they are on the url C and click this +link, then they will be sent to C. + +This makes it necessary to be explicit about the trailing slash. + +=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 (?) { # match URI query + sub (%) { # match body params + +The body spec will match if the request content is either +application/x-www-form-urlencoded or multipart/form-data - the latter +of which is required for uploads - see below. + +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 C<&> character. The arguments added to the request are +one per non-C<:>/C<*> parameter (scalar for normal, arrayref for multiple), +plus if any C<:>/C<*> 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 C parameter with an optional C parameter one +would write: + + sub (?page=&order_by~) { + my ($self, $page, $order_by) = @_; + return unless $page =~ /^\d+$/; + $page ||= 'id'; + response_filter { + $_[1]->search_rs({}, $p); + } + } + +to implement paging and ordering against a L object. + +Another Example: To get all parameters as a hashref of arrayrefs, write: + + sub(?@*) { + my ($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 $params contains +arrayref values for all parameters B mentioned and a scalar value for +the 'coffee' parameter. + +Note, in the case where you combine arrayref, single parameter and named +hashref style, the arrayref and single parameters will appear in C<@_> in the +order you defined them in the protoype, but all hashrefs will merge into a +single C<$params>, as in the example above. + +=head3 Upload matches + + sub (*foo=) { # param specifier can be anything valid for query or body + +The upload match system functions exactly like a query/body match, except +that the values returned (if any) are C objects. + +Note that this match type will succeed in two circumstances where you might +not expect it to - first, when the field exists but is not an upload field +and second, when the field exists but the form is not an upload form (i.e. +content type "application/x-www-form-urlencoded" rather than +"multipart/form-data"). In either of these cases, what you'll get back is +a C object, which will C with an error +pointing out the problem if you try and use it. To be sure you have a real +upload object, call + + $upload->is_upload # returns 1 on a valid upload, 0 on a non-upload field + +and to get the reason why such an object is not an upload, call + + $upload->reason # returns a reason or '' on a valid upload. + +Other than these two methods, the upload object provides the same interface +as L with the addition of a stringify to the temporary +filename to make copying it somewhere else easier to handle. + +=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 parameters via C<%_> + +If your dispatch specification causes your dispatch subroutine to receive +a hash reference as its first argument, the contained named parameters +will be accessible via C<%_>. + +This can be used to access your path matches, if they are named: + + sub (GET + /foo/:path_part) { + [ 200, + ['Content-type' => 'text/plain'], + ["We are in $_{path_part}"], + ]; + } + +Or, if your first argument would be a hash reference containing named +query parameters: + + sub (GET + /foo + ?:some_param=) { + [ 200, + ['Content-type' => 'text/plain'], + ["We received $_{some_param} as parameter"], + ]; + } + +Of course this also works when all you are doing is slurping the whole set +of parameters by their name: + + sub (GET + /foo + ?*) { + [ 200, + ['Content-type' => 'text/plain'], + [exists($_{foo}) ? "Received a foo: $_{foo}" : "No foo!"], + ], + } + +Note that only the first hash reference will be available via C<%_>. If +you receive additional hash references, you will need to access them as +usual. + +=head3 Accessing the PSGI env hash + +In some cases you may wish to get the raw PSGI env hash - to do this, +you can either use a plain sub: + + sub { + my ($env) = @_; + ... + } + +or use the C constant exported to retrieve it from C<@_>: + + 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 C and return a redispatch to +C, the dispatch behaviour will be exactly as if the same POST +request had been made to C 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 B the dispatch code - just like +C did. + +Also note that you need the C<< my $self = shift >> since the magic $self +variable went away. + +=item * the magic $self variable went away. + +Just add C<< my $self = shift; >> while writing your C<< 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/) { ... }, + ... + ) + } + +=back + +=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 and the slides are reproduced in this distribution under +L. + +=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) + +=head1 CONTRIBUTORS + +Devin Austin (dhoss) + +Arthur Axel 'fREW' Schmidt + +gregor herrmann (gregoa) + +John Napiorkowski (jnap) + +Josh McMichael + +Justin Hunter (arcanez) + +Kjetil Kjernsmo + +markie + +Christian Walde (Mithaldu) + +nperez + +Robin Edwards + +Andrew Rodland (hobbs) + +Robert Sedlacek (phaylon) + +=head1 COPYRIGHT + +Copyright (c) 2011 the Web::Simple L and L +as listed above. + +=head1 LICENSE + +This library is free software and may be distributed under the same terms +as perl itself. + +=cut