[//000000001]: # (oometa \- Data registry for TclOO frameworks) [//000000002]: # (Generated from file 'oometa\.man' by tcllib/doctools with format 'markdown') [//000000003]: # (Copyright © 2015 Sean Woods ) [//000000004]: # (oometa\(n\) 0\.7\.2 tcllib "Data registry for TclOO frameworks")
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# NAME oometa \- oo::meta A data registry for classess # Table Of Contents - [Table Of Contents](#toc) - [Synopsis](#synopsis) - [Description](#section1) - [Usage](#section2) - [Concept](#section3) - [COMMANDS](#section4) - [Bugs, Ideas, Feedback](#section5) - [Keywords](#keywords) - [Category](#category) - [Copyright](#copyright) # SYNOPSIS [__oo::meta::info__](#1) [__oo::meta::info branchget__ ?*key*? ?\.\.\.?](#2) [__oo::meta::info branchset__ ?*key\.\.\.*? *key* *value*](#3) [__oo::meta::info dump__ *class*](#4) [__oo::meta::info__ *class* __is__ *type* ?*args*?](#5) [__oo::meta::info__ *class* __[merge](\.\./\.\./\.\./\.\./index\.md\#merge)__ ?*dict*? ?*dict*? ?*\.\.\.*?](#6) [__oo::meta::info__ *class* __rebuild__](#7) [__oo::meta::metadata__ *class*](#8) [__oo::define meta__](#9) [__oo::class method meta__](#10) [__oo::object method meta__](#11) [__oo::object method meta cget__ ?*field*? ?*\.\.\.*? *field*](#12) # DESCRIPTION The __oo::meta__ package provides a data registry service for TclOO classes\. # Usage oo::class create animal { meta set biodata animal: 1 } oo::class create mammal { superclass animal meta set biodata mammal: 1 } oo::class create cat { superclass mammal meta set biodata diet: carnivore } cat create felix puts [felix meta dump biodata] > animal: 1 mammal: 1 diet: carnivore felix meta set biodata likes: {birds mice} puts [felix meta get biodata] > animal: 1 mammal: 1 diet: carnivore likes: {bird mice} # Modify a class mammal meta set biodata metabolism: warm-blooded puts [felix meta get biodata] > animal: 1 mammal: 1 metabolism: warm-blooded diet: carnivore likes: {birds mice} # Overwrite class info felix meta set biodata mammal: yes puts [felix meta get biodata] > animal: 1 mammal: yes metabolism: warm-blooded diet: carnivore likes: {birds mice} # Concept The concept behind __oo::meta__ is that each class contributes a snippet of *local* data\. When __oo::meta::metadata__ is called, the system walks through the linear ancestry produced by __oo::meta::ancestors__, and recursively combines all of that local data for all of a class' ancestors into a single dict\. Instances of oo::object can also combine class data with a local dict stored in the *meta* variable\. # COMMANDS - __oo::meta::info__ __oo::meta::info__ is intended to work on the metadata of a class in a manner similar to if the aggregate pieces where assembled into a single dict\. The system mimics all of the standard dict commands, and addes the following: - __oo::meta::info branchget__ ?*key*? ?\.\.\.? Returns a dict representation of the element at *args*, but with any trailing : removed from field names\. ::oo::meta::info $myclass set option color {default: green widget: colorselect} puts [::oo::meta::info $myclass get option color] > {default: green widget: color} puts [::oo::meta::info $myclass branchget option color] > {default green widget color} - __oo::meta::info branchset__ ?*key\.\.\.*? *key* *value* Merges *dict* with any other information contaned at node ?*key\.\.\.*?, and adding a trailing : to all field names\. ::oo::meta::info $myclass branchset option color {default green widget colorselect} puts [::oo::meta::info $myclass get option color] > {default: green widget: color} - __oo::meta::info dump__ *class* Returns the complete snapshot of a class metadata, as producted by __oo::meta::metadata__ - __oo::meta::info__ *class* __is__ *type* ?*args*? Returns a boolean true or false if the element ?*args*? would match __string is__ *type* *value* ::oo::meta::info $myclass set constant mammal 1 puts [::oo::meta::info $myclass is true constant mammal] > 1 - __oo::meta::info__ *class* __[merge](\.\./\.\./\.\./\.\./index\.md\#merge)__ ?*dict*? ?*dict*? ?*\.\.\.*? Combines all of the arguments into a single dict, which is then stored as the new local representation for this class\. - __oo::meta::info__ *class* __rebuild__ Forces the meta system to destroy any cached representation of a class' metadata before the next access to __oo::meta::metadata__ - __oo::meta::metadata__ *class* Returns an aggregate picture of the metadata for *class*, combining its *local* data with the *local* data from its ancestors\. - __oo::define meta__ The package injects a command __oo::define::meta__ which works to provide a class in the process of definition access to __oo::meta::info__, but without having to look the name up\. oo::define myclass { meta set foo bar: baz } - __oo::class method meta__ The package injects a new method __meta__ into __oo::class__ which works to provide a class instance access to __oo::meta::info__\. - __oo::object method meta__ The package injects a new method __meta__ into __oo::object__\. __oo::object__ combines the data for its class \(as provided by __oo::meta::metadata__\), with a local variable *meta* to produce a local picture of metadata\. This method provides the following additional commands: - __oo::object method meta cget__ ?*field*? ?*\.\.\.*? *field* Attempts to locate a singlar leaf, and return its value\. For single option lookups, this is faster than __my meta getnull__ ?*field*? ?*\.\.\.*? *field*\], because it performs a search instead directly instead of producing the recursive merge product between the class metadata, the local *meta* variable, and THEN performing the search\. # Bugs, Ideas, Feedback This document, and the package it describes, will undoubtedly contain bugs and other problems\. Please report such in the category *tcloo* of the [Tcllib Trackers](http://core\.tcl\.tk/tcllib/reportlist)\. Please also report any ideas for enhancements you may have for either package and/or documentation\. When proposing code changes, please provide *unified diffs*, i\.e the output of __diff \-u__\. Note further that *attachments* are strongly preferred over inlined patches\. Attachments can be made by going to the __Edit__ form of the ticket immediately after its creation, and then using the left\-most button in the secondary navigation bar\. # KEYWORDS [TOOL](\.\./\.\./\.\./\.\./index\.md\#tool), [TclOO](\.\./\.\./\.\./\.\./index\.md\#tcloo) # CATEGORY TclOO # COPYRIGHT Copyright © 2015 Sean Woods