Item14237: Started Foswiki v3 Essentials Category

Few more docs changes.

core/data/System/ClassMethod.txt

@@ -14,5 +14,5 @@ my $mobile = Telecoms->new();
 </verbatim>
 
 ---
-*Related Topics:* StaticMethod, ObjectMethod
+*Related Topics:* StaticMethod, ObjectMethod, ObjectAttribute
 <!-- %JQREQUIRE{"chili"}% -->

core/data/System/DeveloperDocumentationCategory.txt

@@ -52,6 +52,7 @@ Topics for normal users that want to develop Foswiki applications.
 Topics for programmers that which to design new skins and develop new extensions for Foswiki.
 
 ---+++ Reference
+   $ [[FoswikiV3Essentials]] : Topics related to main development concepts of Foswiki v3.
    $ [[ReferenceManual]] : Documentation for webmasters, system administrators, project managers, team leaders, and all other users of Foswiki 
    $ [[DevelopingPlugins]] : An introduction to developing Plugins
    $ [[Contribs]] : A short introduction to Contribs. Contribs are Extensions to Foswiki that are not plugins
@@ -64,6 +65,7 @@ Topics for programmers that which to design new skins and develop new extensions
    $ [[JavascriptFiles]] : Foswiki Javascript support comprises a number of base Javascript files, attached to this topic, that provide support for features in the basic screens, and are used by most skins. 
    $ [[SkinTemplates]] : Skin templates are used when composing the output from all actions, such as view, edit, and preview. This allows you to change the look and feel of all pages by editing just a few template files. This topic describes the special template directives. Both for Skin developers and for advanced wiki application development.
    $ [[MetaData]] : Additional data, Foswiki-generated or from [[DataForms][forms]], may be embedded in the topic text using =META:= macros
+   $ [[ObjectAttribute]] : An ObjectAttribute is a named data stored on an object
    $ [[ClassMethod]] : A ClassMethod is a method that must be called relative to the containing class object
    $ [[ObjectMethod]] : An ObjectMethod is a method that must be called relative to a previous constructed object of the class type
    $ [[StaticMethod]] : A StaticMethod is a method in a package that can be called without reference to an object of the package type

core/data/System/FoswikiV3Essentials.txt

@@ -0,0 +1,44 @@
+%META:TOPICINFO{author="ProjectContributor" date="1506995134" format="1.1" version="1"}%
+%META:TOPICPARENT{name="DeveloperDocumentationCategory"}%
+---+ Foswiki v3 Essentials
+
+This category is dedicated to development under Foswiki v3 core. 
+
+Basically, what makes v3 different from all previous versions are:
+
+   $ Full OO : New version is totally redesigned. Where all previous versions
+   were basically procedural code using some OO elements – v3 is OO from the
+   first call of =%PERLDOC{"Foswiki::App" method="run"}%= method.
+   $ Application centric : Everything in the new core is summoned and
+   manipulated by a single application object.
+   $ PSGI support : Yes, the new code is PSGI compliant. Basically, it is the
+   main and only mode of operation now. Any other environments like CGI, FastCGI,
+   etc. are now supported through corresponding CPAN:Plack::Handler adapters.
+   $ PSGI testing framework : It comes as an extension to the legacy testing
+   code and wraps around CPAN:Plack::Test.
+   $ OO-redesigned test framework : It's all said.
+   $ Manageable callbacks : Flexible and powerful, the new callback protocol
+   unifies the interface and provides more control.
+   $ Extensions : They're here to replace some day the old plugins framework.
+   Their power is probably limitless within Perl's limitations. Yet many tasks
+   are now easier to accomplish.
+   $ Perl-based Config specs : The legacy specs bundled with special language
+   are now just an additional data type of the new powerful specs format. There
+   is no more need to learn a new obscure language to declare your configuration
+   keys!
+   $ Structured exceptions : Together with switching to CPAN:Try::Tiny and
+   CPAN:Throwable exceptions are now forming an inheritance tree allowing
+   better granularity of error processing.
+   $ Macros as objects : A macro could now be defined as a class.
+   $ Feature sets : Foswiki core and any component can now define a set of
+   supported features as well as version range which defines a feature's life
+   span. Any component (extensions mostly) can now request what features it
+   needs to work correctly. This provides way more flexible control over
+   code compatibility matters than just version range tests.
+
+There are some under the hood changes in behaviour of some components like
+=%PERLDOC{"Foswiki::Request"}%= initialization procedures; or alike.
+
+
+   $ [[SpecFileFormat]] : Config Specs v2
+

core/data/System/ObjectAttribute.txt

@@ -0,0 +1,17 @@
+%META:TOPICINFO{author="BaseUserMapping_333" date="1506994530" format="1.1" version="1"}%
+%META:TOPICPARENT{name="DeveloperDocumentationCategory"}%
+An object attribute is a named data store on object. For example:
+
+---+ Class Foswiki::SampleClass
+---++ ATTRIBUTES
+---+++ ObjectAttribute lastError
+
+A hash containing two keys:
+
+   $ errNum : Integer error code
+   $ errStr : Text explanation of the error
+
+Lazy attribute.
+
+---
+*Related topics:* ClassMethod, ObjectMethod, StaticMethod

core/data/System/ObjectMethod.txt

@@ -18,4 +18,4 @@ Telecoms::phone( $mobile, "home" );
 </verbatim>
 
 ---
-*Related Topics:* ClassMethod, StaticMethod
+*Related Topics:* ClassMethod, StaticMethod, ObjectAttribute

core/data/System/SpecFileFormat.txt

@@ -1,4 +1,5 @@
 %META:TOPICINFO{author="ProjectContributor" date="1506731777" format="1.1" version="1"}%
+%META:TOPICPARENT{name="FoswikiV3Essentials"}%
 ---+!! Spec Files v2.0
 %TOC%
 

core/data/System/StaticMethod.txt

@@ -11,4 +11,4 @@ my $colour = Telecoms::defaultColour()
 
 </verbatim>
 
-*Related Topics:* ClassMethod, ObjectMethod
+*Related Topics:* ClassMethod, ObjectMethod, ObjectAttribute

core/lib/Foswiki/Config/Node.pm

@@ -25,7 +25,9 @@ and can be anything, even *undef*.
 
 In uninitialized state =has_value()= returns _false_. In this case =getValue()=
 method will return data defined in =default= option as returned by
-=Foswiki::Config::ItemRole= =getOpt()= method.
+%PERLDOC{"Foswiki::Config::ItemRole"  method="getOpt"}% method.
+
+See: %PERLDOC{"Foswiki::Config"}%
 
 =cut