From: Justin Guenther Date: Fri, 24 Mar 2006 06:04:16 +0000 (+0000) Subject: expanded/clarified documentation X-Git-Tag: v0.06000~19 X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=82b01c38eb0b505543a829a5a171a26cca030c91;p=dbsrgits%2FDBIx-Class.git expanded/clarified documentation --- diff --git a/lib/DBIx/Class/Schema.pm b/lib/DBIx/Class/Schema.pm index 3d63657..17c1602 100644 --- a/lib/DBIx/Class/Schema.pm +++ b/lib/DBIx/Class/Schema.pm @@ -57,9 +57,10 @@ particular which module inherits off which. =head2 register_class -=head3 Arguments: +=head3 Arguments: ($moniker, $component_class) -Registers a class which isa ResultSourceProxy; equivalent to calling +Registers a class which isa L. Equivalent to +calling $schema->register_source($moniker, $component_class->result_source_instance); @@ -72,9 +73,10 @@ sub register_class { =head2 register_source -=head3 Arguments: +=head3 Arguments: ($moniker, $result_source) -Registers the result source in the schema with the given moniker +Registers the L in the schema with the given +moniker. =cut @@ -93,9 +95,15 @@ sub register_source { =head2 class - my $class = $schema->class('CD'); +=head3 Arguments: ($moniker) + +=head3 Returns: $classname + +Retrieves the result class name for the given moniker. -Retrieves the result class name for a given result source +e.g., + + my $class = $schema->class('CD'); =cut @@ -106,9 +114,13 @@ sub class { =head2 source +=head3 Arguments: ($moniker) + +=head3 Returns: $result_source + my $source = $schema->source('Book'); -Returns the result source object for the registered name +Returns the L object for the registered moniker. =cut @@ -126,9 +138,13 @@ sub source { =head2 sources - my @source_monikers = $schema->sources; +=head3 Returns: @source_monikers + +Returns the source monikers of all source registrations on this schema. -Returns the source monikers of all source registrations on this schema +e.g., + + my @source_monikers = $schema->sources; =cut @@ -136,9 +152,13 @@ sub sources { return keys %{shift->source_registrations}; } =head2 resultset +=head3 Arguments: ($moniker) + +=head3 Returns: $result_set + my $rs = $schema->resultset('DVD'); -Returns the resultset for the registered moniker +Returns the L object for the registered moniker. =cut @@ -149,16 +169,27 @@ sub resultset { =head2 load_classes -=head3 Arguments: @classes?, { $namespace => [ $class+ ] }+ +=head3 Arguments: @classes?, { $namespace => [ @classes ] }+ -Uses L to find all classes under the database class' namespace, -or uses the classes you select. Then it loads the component (using L), -and registers them (using B); +With no arguments, this method uses L to find all classes under +the schema's namespace. Otherwise, this method loads the classes you specify +(using L), and registers them (using L). It is possible to comment out classes with a leading '#', but note that perl will think it's a mistake (trying to use a comment in a qw list) so you'll need to add "no warnings 'qw';" before your load_classes call. +e.g., + + My::Schema->load_classes(); # loads My::Schema::CD, My::Schema::Artist, + # etc. (anything under the My::Schema namespace) + + # loads My::Schema::CD, My::Schema::Artist, Other::Namespace::Producer but + # not Other::Namespace::LinerNotes nor My::Schema::Track + My::Schema->load_classes(qw/ CD Artist #Track /, { + Other::Namespace => [qw/ Producer #LinerNotes /], + }); + =cut sub load_classes { @@ -225,16 +256,21 @@ sub load_classes { =head2 compose_connection -=head3 Arguments: $target_ns, @db_info +=head3 Arguments: ($target_namespace, @db_info) -=head3 Return value: $new_schema +=head3 Returns: $new_schema -Calls compose_namespace to the $target_ns, calls ->connection(@db_info) on -the new schema, then injects the ResultSetProxy component and a -resultset_instance classdata entry on all the new classes in order to support -$target_ns::Class->search(...) method calls. Primarily useful when you have -a specific need for classmethod access to a connection - in normal usage -->connect is preferred. +Calls L to the target namespace, +calls L(@db_info) on the new schema, then +injects the L component and a resultset_instance +classdata entry on all the new classes in order to support +$target_namespaces::$class->search(...) method calls. + +This is primarily useful when you have a specific need for class method access +to a connection. In normal usage it is preferred to call +L and use the resulting schema object to operate +on L objects with L for +more information. =cut @@ -279,16 +315,30 @@ sub compose_connection { =head2 compose_namespace -=head3 Arguments: $target_ns, $additional_base_class? +=head3 Arguments: $target_namespace, $additional_base_class? + +=head3 Returns: $new_schema -=head3 Return value: $new_schema +For each L in the schema, this method creates a +class in the target namespace (e.g. $target_namespace::CD, +$target_namespace::Artist) that inherits from the corresponding classes +attached to the current schema. -For each result source in the schema, creates a class in the target -namespace (e.g. $target_ns::CD, $target_ns::Artist) inheriting from the -corresponding classes attached to the current schema and a result source -to match attached to the new $schema object. If an additional base class is -given, injects this immediately behind the corresponding classes from the -current schema in the created classes' @ISA. +It also attaches a corresponding L object to the +new $schema object. If C<$additional_base_class> is given, the new composed +classes will inherit from first the corresponding classe from the current +schema then the base class. + +e.g. (for a schema with My::Schema::CD and My::Schema::Artist classes), + + $schema->compose_namespace('My::DB', 'Base::Class'); + print join (', ', @My::DB::CD::ISA) . "\n"; + print join (', ', @My::DB::Artist::ISA) ."\n"; + +Will produce the output + + My::Schema::CD, Base::Class + My::Schema::Artist, Base::Class =cut @@ -323,10 +373,10 @@ sub compose_namespace { =head2 setup_connection_class -=head3 Arguments: <$target> <@info> +=head3 Arguments: ($target, @info) -Sets up a database connection class to inject between the schema -and the subclasses the schema creates. +Sets up a database connection class to inject between the schema and the +subclasses that the schema creates. =cut @@ -341,9 +391,12 @@ sub setup_connection_class { =head3 Arguments: (@args) -Instantiates a new Storage object of type storage_type and passes the -arguments to $storage->connect_info. Sets the connection in-place on -the schema. +=head3 Returns: $new_schema + +Instantiates a new Storage object of type +L and passes the arguments to +$storage->connect_info. Sets the connection in-place on the schema. See +L for more information. =cut @@ -367,7 +420,11 @@ sub connection { =head3 Arguments: (@info) -Conveneience method, equivalent to $schema->clone->connection(@info) +=head3 Returns: $new_schema + +This is a convenience method. It is equivalent to calling +$schema->clone->connection(@info). See L and L for more +information. =cut @@ -375,7 +432,9 @@ sub connect { shift->clone->connection(@_) } =head2 txn_begin -Begins a transaction (does nothing if AutoCommit is off). +Begins a transaction (does nothing if AutoCommit is off). Equivalent to +calling $schema->storage->txn_begin. See +L for more information. =cut @@ -383,7 +442,9 @@ sub txn_begin { shift->storage->txn_begin } =head2 txn_commit -Commits the current transaction. +Commits the current transaction. Equivalent to calling +$schema->storage->txn_commit. See L +for more information. =cut @@ -391,7 +452,9 @@ sub txn_commit { shift->storage->txn_commit } =head2 txn_rollback -Rolls back the current transaction. +Rolls back the current transaction. Equivalent to calling +$schema->storage->txn_rollback. See +L for more information. =cut @@ -399,13 +462,15 @@ sub txn_rollback { shift->storage->txn_rollback } =head2 txn_do -=head3 Arguments: $coderef, @coderef_args? +=head3 Arguments: (C<$coderef>, @coderef_args?) + +=head3 Returns: (C<$return_value> | C<@return_values> | C) for scalar, +list and void contexts, respectively -Executes C<$coderef> with (optional) arguments C<@coderef_args> -transactionally, returning its result (if any). If an exception is -caught, a rollback is issued and the exception is rethrown. If the -rollback fails, (i.e. throws an exception) an exception is thrown that -includes a "Rollback failed" message. +Executes C<$coderef> with (optional) arguments C<@coderef_args> atomically, +returning its result (if any). If an exception is caught, a rollback is issued +and the exception is rethrown. If the rollback fails, (i.e. throws an +exception) an exception is thrown that includes a "Rollback failed" message. For example, @@ -436,10 +501,10 @@ For example, } } -Nested transactions work as expected (i.e. only the outermost -transaction will issue a txn_commit on the Schema's storage), and -txn_do() can be called in void, scalar and list context and it will -behave as expected. +In a nested transaction (calling txn_do() from within a txn_do() coderef) only +the outermost transaction will issue a L on +the Schema's storage, and txn_do() can be called in void, scalar and list +context and it will behave as expected. =cut @@ -458,11 +523,10 @@ sub txn_do { my $wantarray = wantarray; # Need to save this since the context # inside the eval{} block is independent # of the context that called txn_do() - eval { + # Need to differentiate between scalar/list context to allow for # returning a list in scalar context to get the size of the list - if ($wantarray) { # list context @return_values = $coderef->(@args); @@ -502,6 +566,8 @@ sub txn_do { =head2 clone +=head3 Returns: $new_schema + Clones the schema and its associated result_source objects and returns the copy. @@ -523,8 +589,10 @@ sub clone { =head3 Arguments: ($moniker, \@data); Populates the source registered with the given moniker with the supplied data. -@data should be a list of listrefs, the first containing column names, the -second matching values - i.e. +@data should be a list of listrefs -- the first containing column names, the +second matching values. + +i.e., $schema->populate('Artist', [ [ qw/artistid name/ ], @@ -550,7 +618,14 @@ sub populate { =head2 throw_exception -Defaults to using Carp::Clan to report errors from user perspective. +=over 4 + +=item Arguments: ($message) + +=back + +Throws an exception. Defaults to using L to report errors from +user's perspective. =cut @@ -561,7 +636,13 @@ sub throw_exception { =head2 deploy (EXPERIMENTAL) -Attempts to deploy the schema to the current storage using SQL::Translator. +=over 4 + +=item Arguments: ($sqlt_args) + +=back + +Attempts to deploy the schema to the current storage using L. Note that this feature is currently EXPERIMENTAL and may not work correctly across all databases, or fully handle complex relationships.