NAME Perinci::Sub::Wrapper - A multi-purpose subroutine wrapping framework VERSION version 0.25 SYNOPSIS use Perinci::Sub::Wrapper qw(wrap_sub); my $res = wrap_sub(sub => sub {die "test\n"}, meta=>{...}); my ($wrapped, $meta) = ($res->[2]{sub}, $res->[2]{meta}); $wrapped->(); # call the wrapped function DESCRIPTION Perinci::Sub::Wrapper is an extensible subroutine wrapping framework. It works by creating a single "large" wrapper function from a composite bits of code, instead of using multiple small wrappers (a la Python's decorator). The single-wrapper approach has the benefit of smaller function call overhead. You can still wrap multiple times if needed. This module is used to enforce Rinci properties, e.g. "args" (by performing schema validation before calling the function), "timeout" (by doing function call inside an "eval()" and using "alarm()" to limit the execution), or "retry" (by wrapping function call inside a simple retry loop). It can also be used to convert argument passing style, e.g. from "args_as" "array" to "args_as" "hash", so you can call function using named arguments even though the function accepts positional arguments. There are many other possible uses. This module uses Log::Any for logging. EXTENDING The framework is simple and extensible. Please delve directly into the source code for now. Some notes: The internal uses OO. The main wrapper building mechanism is in the "wrap()" method. For each Rinci property, it will call "handle_NAME()" wrapper handler method. The "handlemeta_NAME()" methods are called first, to determine order of processing. You can supply these methods either by subclassing the class or, more simply, monkeypatching the method in the "Perinci::Sub::Wrapper" package. The wrapper handler method will be called with a hash argument, containing these keys: value (property value), new (this key will exist if "convert" argument of "wrap()" exists, to convert a property to a new value). For properties that have name in the form of "NAME1.NAME2.NAME3" (i.e., dotted) only the first part of the name will be used (i.e., "handle_NAME1()"). METHODS The OO interface is only used internally or when you want to extend the wrapper. SEE ALSO Perinci DESCRIPTION This module has Rinci metadata. FUNCTIONS None are exported by default, but they are exportable. wrap_sub(%args) -> [status, msg, result, meta] Wrap subroutine to do various things, like enforcing Rinci properties. Will wrap subroutine and bless the generated wrapped subroutine (by default into 'Perinci::Sub::Wrapped') as a way of marking that the subroutine is a wrapped one. Arguments ('*' denotes required arguments): * compile => *bool* (default: 1) Whether to compile the generated wrapper. Can be set to 0 to not actually wrap but just return the generated wrapper source code. * convert => *hash* Properties to convert to new value. Not all properties can be converted, but these are a partial list of those that can: v (usually do not need to be specified when converting from 1.0 to 1.1, will be done automatically), args*as, result*naked, default_lang. * debug => *bool* (default: 0) Generate code with debugging. If turned on, will produce various debugging in the generated code. Currently what this does: * add more comments (e.g. for each property handler) * forbid_tags => *array* Forbid properties which have certain wrapping tags. Some property wrapper, like dies*on*error (see Perinci::Sub::property::dies*on*error) has tags 'die', to signify that it can cause wrapping code to die. Sometimes such properties are not desirable, e.g. in daemon environment. The use of such properties can be forbidden using this setting. * meta* => *hash* The function metadata. * normalize_schema => *bool* (default: 1) Whether to normalize schemas in metadata. By default, wrapper normalize Sah schemas in metadata, like in 'args' or 'result' property, for convenience so that it does not need to be normalized again prior to use. If you want to turn off this behaviour, set to false. * remove_internal_properties => *bool* (default: 1) Whether to remove properties prefixed with _. By default, wrapper removes internal properties (properties which start with underscore) in the new metadata. Set this to false to keep them. * sub* => *code* The code to wrap. * sub_name => *str* The name of the code, e.g. Foo::func. It is a good idea to supply this so that wrapper code can display this information when they need to (e.g. see Perinci::Sub::property::dies*on*error). * trap => *bool* (default: 1) Whether to trap exception using an eval block. If set to true, will wrap call using an eval {} block and return 500 /undef if function dies. Note that if some other properties requires an eval block (like 'timeout') an eval block will be added regardless of this parameter. Return value: Returns an enveloped result (an array). First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information. AUTHOR Steven Haryanto COPYRIGHT AND LICENSE This software is copyright (c) 2012 by Steven Haryanto. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. CHANGES Version 0.25 (2012-07-31) * [ENHANCEMENTS] Add argument: sub_name (also so that 'dies_on_error' property can display proper die message showing subroutine name). * [ENHANCEMENTS] Add argument: forbid_tags. * [FIXES] Change handling of 'result_naked' property so that 'dies_on_error' property can get result status + message properly. Version 0.24 (2012-07-31) * [ENHANCEMENTS] Introduce section: 'before_return_res'. * [INCOMPATIBLE CHANGES] Introduce protocol version which must be specified by all property handlers (assumed to be 1 if unspecified). This is bumped whenever an incompatible change at the basic structure of wrapper code is introduced. Bumping the protocol version will force all existing property handlers to be updated. * [INCOMPATIBLE CHANGES] Bump protocol version from 1 to 2: to return result immediately, handler must now say 'goto RETURN_RES' instead of 'return $res' directly. This is so that some handlers get the last chance to do something to $res before it is returned. Version 0.23 (2012-07-29) * [ENHANCEMENTS] When encountering an unknown property, automatically try to require Perinci::Sub::property::PROP first. So you don't have to manually use() the property modules. * [ENHANCEMENTS] Add wrap_sub() argument 'debug' to show debugging in generated code. Currently show the handler from which each line comes from. * [ENHANCEMENTS] Check known arg spec key. Version 0.22 (2012-06-21) * features: Require transaction ('-tx_manager' argument) if features->{tx}{req} is 1. Version 0.21 (2012-06-07) * [FIXES] deps: '-undo_trash_dir' argument is not needed when '-tx_manager' argument is given. Version 0.20 (2012-06-07) * Update to Rinci 1.1.18 (some new deps introduced: 'tmp_dir', * 'trash_dir', 'undo_trash_dir'; some removed: 'undo_storage'). Version 0.19 (2012-03-22) * [ENHANCEMENTS] 'default_lang' also converts language properties in tag metadata in 'tags'. Version 0.18 (2012-03-21) * No functional changes. Rebuild with Perinci PodWeaver plugin enabled. Version 0.17 (2012-03-21) * [ENHANCEMENTS] Convert 'default_lang' property. * [ENHANCEMENTS] 'remove_internal_properties' now also removes internal properties in 'result', 'examples', and 'links'. Version 0.16 (2012-03-16) * [ENHANCEMENTS] Convert 1.0 - 1.1: Set argument spec's summary from argument schema. Version 0.15 (2012-02-28) * [NEW FEATURES] Handle 'cmdline_aliases' (Rinci 1.1.8+) * [NEW FEATURES] Convert 1.0 'arg_aliases' to 'cmdline_aliases' * [NEW FEATURES] Add 'remove_internal_properties' wrap option. Version 0.14 (2012-02-23) * [NEW FEATURES] Automatically convert metadata v1.0 to v1.1. Finally all the old Sub::Spec specs are now usable again. Version 0.13 (2012-02-22) * [NEW FEATURES] Sah schemas in 'args' and 'result' are now normalized in the new metadata, this is to make it simpler for other code to use the schema (e.g. Perinci-Access when completing args). New metadata is now a deep clone of the old (instead of just a shallow copy), this might increase memory usage. Version 0.12 (2012-02-15) * [REMOVED FEATURES] Remove 'force' argument. wrap_sub() still mark wrapping by blessing the generated wrapper, but will gladly double wrap. I believe caching should be done in the upper layers. Version 0.11 (2012-02-13) * [ETC] Add tweak to work better with 'retry' property wrapper. Version 0.10 (2012-02-13) * [NEW FEATURES] Add wrap option 'compile'. Version 0.09 (2012-02-13) * [BUG FIXES] Fix indenting in generated code. Version 0.08 (2012-02-12) * [BUG FIXES] Convert keys are now respected even though meta does not have that key. Version 0.07 (2012-02-12) * Add (or re-enable) unshift_lines() * Extract test routine to Test::Perinci::Sub::Wrapper to make it usable from other Perinci-Sub-property-* distributions. Version 0.06 (2012-02-12) * Rename distribution from Sub-Spec-Wrapper to Perinci-Sub-Wrapper. Version 0.05 (2012-01-21) * No functional changes. Mark Sub-Spec-Wrapper deprecated. Version 0.04 (2011-10-19) * No functional changes. Add missing dependency to * Sub::Spec::ConvertArgs::Array [thanks cpant & Andreas]. Version 0.03 (2011-09-22) * [ENHANCEMENTS] Support 'args_as' spec clause (hash/hashref/array/arrayref supported, but object not yet). Version 0.02 (2011-08-31) * Build and POD fixes. Version 0.01 (2011-08-31) * First release.