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From paulmer...@apache.org
Subject svn commit: r1689843 [47/48] - in /zest/site: content/java/develop/ content/java/develop/images/ content/java/develop/javadocs/ content/java/develop/javadocs/org/qi4j/api/ content/java/develop/javadocs/org/qi4j/api/activation/ content/java/develop/java...
Date Wed, 08 Jul 2015 11:08:57 GMT
Modified: zest/site/content/java/develop/what-is-cop.html
URL: http://svn.apache.org/viewvc/zest/site/content/java/develop/what-is-cop.html?rev=1689843&r1=1689842&r2=1689843&view=diff
==============================================================================
--- zest/site/content/java/develop/what-is-cop.html (original)
+++ zest/site/content/java/develop/what-is-cop.html Wed Jul  8 11:08:41 2015
@@ -66,20 +66,20 @@
   })();
  </script>
 
-  </head><body><div xmlns="" xmlns:exsl="http://exslt.org/common" class="logo"><a
href="index.html"><img src="images/logo-standard.png" /></a></div><div
xmlns="" xmlns:exsl="http://exslt.org/common" class="top-nav"><div xmlns="http://www.w3.org/1999/xhtml"
class="toc"><dl><dt><span class="section"><a href="index.html#home">Qi4j</a></span></dt><dt><span
class="section"><span xmlns="" href="intro.html">Introduction</span></span></dt><dt><span
class="section"><a href="tutorials.html">Tutorials</a></span></dt><dt><span
class="section"><a href="javadocs.html">Javadoc</a></span></dt><dt><span
class="section"><a href="samples.html">Samples</a></span></dt><dt><span
class="section"><a href="core.html">Core</a></span></dt><dt><span
class="section"><a href="libraries.html">Libraries</a></span></dt><dt><span
class="section"><a href="extensions.html">Extensions</a></span></dt><dt><span
class="section"><a href="tools.html">Tools</a></span></dt><dt><span
class="section"><a href="glossary.html">Glo
 ssary </a></span></dt></dl></div></div><div xmlns=""
xmlns:exsl="http://exslt.org/common" class="sub-nav"><div xmlns="http://www.w3.org/1999/xhtml"
class="toc"><dl><dt><span class="section"><a href="intro.html#highlights">Highligts</a></span></dt><dt><span
class="section"><a href="introduction-background.html">Background</a></span></dt><dt><span
class="section"><span xmlns="" href="what-is-cop.html">What is COP?</span></span></dt><dt><span
class="section"><a href="what-s-an-object-anyway.html">What’s an Object anyway?</a></span></dt><dt><span
class="section"><a href="state-modeling.html">Qi4j and state modeling</a></span></dt><dt><span
class="section"><a href="related.html">Related publications &amp; projects</a></span></dt></dl></div></div><div
class="section" title="What is COP?"><div class="titlepage"><div><div><h3
class="title"><a id="what-is-cop"></a>What is COP?</h3></div></div></div><p>We
found this very well written blog entry on the Internet, which very well describ
 es what Composite Oriented
+  </head><body><div xmlns="" xmlns:exsl="http://exslt.org/common" class="logo"><a
href="index.html"><img src="images/logo-standard.png" /></a></div><div
xmlns="" xmlns:exsl="http://exslt.org/common" class="top-nav"><div xmlns="http://www.w3.org/1999/xhtml"
class="toc"><dl><dt><span class="section"><a href="index.html#home">Zest™</a></span></dt><dt><span
class="section"><span xmlns="" href="intro.html">Introduction</span></span></dt><dt><span
class="section"><a href="tutorials.html">Tutorials</a></span></dt><dt><span
class="section"><a href="javadocs.html">Javadoc</a></span></dt><dt><span
class="section"><a href="samples.html">Samples</a></span></dt><dt><span
class="section"><a href="core.html">Core</a></span></dt><dt><span
class="section"><a href="libraries.html">Libraries</a></span></dt><dt><span
class="section"><a href="extensions.html">Extensions</a></span></dt><dt><span
class="section"><a href="tools.html">Tools</a></span></dt><dt><span
class="section"><a href="glossary.htm
 l">Glossary </a></span></dt></dl></div></div><div
xmlns="" xmlns:exsl="http://exslt.org/common" class="sub-nav"><div xmlns="http://www.w3.org/1999/xhtml"
class="toc"><dl><dt><span class="section"><a href="intro.html#highlights">Highligts</a></span></dt><dt><span
class="section"><a href="introduction-background.html">Background</a></span></dt><dt><span
class="section"><span xmlns="" href="what-is-cop.html">What is COP?</span></span></dt><dt><span
class="section"><a href="what-s-an-object-anyway.html">What’s an Object anyway?</a></span></dt><dt><span
class="section"><a href="state-modeling.html">Zest™ and state modeling</a></span></dt><dt><span
class="section"><a href="related.html">Related publications &amp; projects</a></span></dt></dl></div></div><div
class="section" title="What is COP?"><div class="titlepage"><div><div><h3
class="title"><a id="what-is-cop"></a>What is COP?</h3></div></div></div><p>We
found this very well written blog entry on the Internet, which very 
 well describes what Composite Oriented
 Programming really is.</p><p>The article uses C# and a "show by example" approach
to explaining COP, and this shows clearly that COP is not
-Java specific, and although Qi4j was (to our knowledge) first to introduce the name, it applies
across languages and
+Java specific, and although Zest™ was (to our knowledge) first to introduce the name,
it applies across languages and
 potentially deserves one or more languages on its own.</p><p>The article is re-published
here, as allowed by the
 <a class="ulink" href="http://msdn.microsoft.com/en-us/windowsmobile/bb264332.aspx" target="_top">Microsoft
Permissive License</a>
 , more recently known as
 <a class="ulink" href="http://www.opensource.org/licenses/MS-PL" target="_top">Microsoft
Public License</a>. The content below
 is NOT under the usual <a class="ulink" href="http://www.opensource.org/licenses/Apache-2.0"
target="_top">Apache License</a>.</p><p>We would like to thank Fredrik
Kalseth for his explicit approval as well.</p><div class="section" title="Composite
Oriented Programming"><div class="titlepage"><div><div><h4 class="title"><a
id="_ulink_url_http_iridescence_no_post_composite_oriented_programming_aspx_composite_oriented_programming_ulink"></a><a
class="ulink" href="http://iridescence.no/post/composite-oriented-programming.aspx" target="_top">Composite
Oriented Programming</a></h4></div></div></div><p>I’ve
written a series of post on AOP lately (here, here and here), and in the last part I promised
to tackle mixins
 and introductions in a future post. When I was doing my research for just that, I came cross
a Java framework (just
-humor me :p) called Qi4j (that’s <span class="emphasis"><em>chee for jay</em></span>),
written by Swedish Richard Öberg, pioneering the idea of Composite
+humor me :p) called Zest™ (that’s <span class="emphasis"><em>chee for
jay</em></span>), written by Swedish Richard Öberg, pioneering the idea of
Composite
 Oriented Programming, which instantly put a spell on me. Essentially, it takes the concepts
from Aspect Oriented
 Programming to the extreme, and for the past week I’ve dug into it with a passion. This
post is the first fruits of
 my labor.</p><div class="section" title="OOP is Not Object Oriented!"><div
class="titlepage"><div><div><h5 class="title"><a id="_oop_is_not_object_oriented"></a>OOP
is Not Object Oriented!</h5></div></div></div><p>One of the
things that Richard Öberg argues, is that OOP is not really object oriented at all, but
rather class
-oriented. As the Qi4j website proclaims, "class is the first class citizen that objects are
derived from. Not objects
+oriented. As the Zest™ website proclaims, "class is the first class citizen that objects
are derived from. Not objects
 being the first-class citizen to which one or many classes are assigned". Composite oriented
programming (COP) then,
 tries to work around this limitation by building on a set of core principles; that behavior
depends on context, that
 decoupling is a virtue, and that business rules matter more. For a short and abstract explanation
of COP,
@@ -257,7 +257,7 @@ public interface ISubtraction : ICalcula
 posts. I’ve already implemented a prototype framework that supports the above examples,
which builds on my
 <a class="ulink" href="http://www.iridescence.no/Posts/Implementing-an-AOP-Framework-Part-2.aspx"
target="_top">previously posted AOP framework</a>, and I’ll
 post the source code for that soon. If you want to dig deeper right now (and don’t mind
-a bit of Java), then I suggest you head over to the Qi4j website and poke about there.
+a bit of Java), then I suggest you head over to the Zest™ website and poke about there.
 <a class="ulink" href="http://rickardoberg.wordpress.com/" target="_top">Richard Öbergs
blog</a> also provides great insight.</p></div></div></div><div
xmlns="" xmlns:exsl="http://exslt.org/common" class="footer"><p>
         Copyright © 2015 The Apache Software Foundation, Licensed under the <a href="http://www.apache.org/licenses/"
target="_blank">Apache License, Version 2.0</a>.
         <br /><small>

Modified: zest/site/content/java/develop/what-s-an-object-anyway.html
URL: http://svn.apache.org/viewvc/zest/site/content/java/develop/what-s-an-object-anyway.html?rev=1689843&r1=1689842&r2=1689843&view=diff
==============================================================================
--- zest/site/content/java/develop/what-s-an-object-anyway.html (original)
+++ zest/site/content/java/develop/what-s-an-object-anyway.html Wed Jul  8 11:08:41 2015
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html
xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html;
charset=UTF-8" /><title>What’s an Object anyway?</title><link rel="stylesheet"
type="text/css" href="css/style.css" /><meta name="generator" content="DocBook XSL Stylesheets
V1.76.1" /><link rel="home" href="index.html" title="" /><link rel="up" href="intro.html"
title="Introduction" /><link rel="prev" href="what-is-cop.html" title="What is COP?"
/><link rel="next" href="state-modeling.html" title="Qi4j and state modeling" />
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html
xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html;
charset=UTF-8" /><title>What’s an Object anyway?</title><link rel="stylesheet"
type="text/css" href="css/style.css" /><meta name="generator" content="DocBook XSL Stylesheets
V1.76.1" /><link rel="home" href="index.html" title="" /><link rel="up" href="intro.html"
title="Introduction" /><link rel="prev" href="what-is-cop.html" title="What is COP?"
/><link rel="next" href="state-modeling.html" title="Zest™ and state modeling"
/>
 
 
 <!-- favicon -->
@@ -66,7 +66,7 @@
   })();
  </script>
 
-  </head><body><div xmlns="" xmlns:exsl="http://exslt.org/common" class="logo"><a
href="index.html"><img src="images/logo-standard.png" /></a></div><div
xmlns="" xmlns:exsl="http://exslt.org/common" class="top-nav"><div xmlns="http://www.w3.org/1999/xhtml"
class="toc"><dl><dt><span class="section"><a href="index.html#home">Qi4j</a></span></dt><dt><span
class="section"><span xmlns="" href="intro.html">Introduction</span></span></dt><dt><span
class="section"><a href="tutorials.html">Tutorials</a></span></dt><dt><span
class="section"><a href="javadocs.html">Javadoc</a></span></dt><dt><span
class="section"><a href="samples.html">Samples</a></span></dt><dt><span
class="section"><a href="core.html">Core</a></span></dt><dt><span
class="section"><a href="libraries.html">Libraries</a></span></dt><dt><span
class="section"><a href="extensions.html">Extensions</a></span></dt><dt><span
class="section"><a href="tools.html">Tools</a></span></dt><dt><span
class="section"><a href="glossary.html">Glo
 ssary </a></span></dt></dl></div></div><div xmlns=""
xmlns:exsl="http://exslt.org/common" class="sub-nav"><div xmlns="http://www.w3.org/1999/xhtml"
class="toc"><dl><dt><span class="section"><a href="intro.html#highlights">Highligts</a></span></dt><dt><span
class="section"><a href="introduction-background.html">Background</a></span></dt><dt><span
class="section"><a href="what-is-cop.html">What is COP?</a></span></dt><dt><span
class="section"><span xmlns="" href="what-s-an-object-anyway.html">What’s an
Object anyway?</span></span></dt><dt><span class="section"><a
href="state-modeling.html">Qi4j and state modeling</a></span></dt><dt><span
class="section"><a href="related.html">Related publications &amp; projects</a></span></dt></dl></div></div><div
class="section" title="What’s an Object anyway?"><div class="titlepage"><div><div><h3
class="title"><a id="what-s-an-object-anyway"></a>What’s an Object anyway?</h3></div></div></div><p>In
OOP the main idea is that we shoul
 d model our reality by creating Objects. Objects have state, and they have methods.
+  </head><body><div xmlns="" xmlns:exsl="http://exslt.org/common" class="logo"><a
href="index.html"><img src="images/logo-standard.png" /></a></div><div
xmlns="" xmlns:exsl="http://exslt.org/common" class="top-nav"><div xmlns="http://www.w3.org/1999/xhtml"
class="toc"><dl><dt><span class="section"><a href="index.html#home">Zest™</a></span></dt><dt><span
class="section"><span xmlns="" href="intro.html">Introduction</span></span></dt><dt><span
class="section"><a href="tutorials.html">Tutorials</a></span></dt><dt><span
class="section"><a href="javadocs.html">Javadoc</a></span></dt><dt><span
class="section"><a href="samples.html">Samples</a></span></dt><dt><span
class="section"><a href="core.html">Core</a></span></dt><dt><span
class="section"><a href="libraries.html">Libraries</a></span></dt><dt><span
class="section"><a href="extensions.html">Extensions</a></span></dt><dt><span
class="section"><a href="tools.html">Tools</a></span></dt><dt><span
class="section"><a href="glossary.htm
 l">Glossary </a></span></dt></dl></div></div><div
xmlns="" xmlns:exsl="http://exslt.org/common" class="sub-nav"><div xmlns="http://www.w3.org/1999/xhtml"
class="toc"><dl><dt><span class="section"><a href="intro.html#highlights">Highligts</a></span></dt><dt><span
class="section"><a href="introduction-background.html">Background</a></span></dt><dt><span
class="section"><a href="what-is-cop.html">What is COP?</a></span></dt><dt><span
class="section"><span xmlns="" href="what-s-an-object-anyway.html">What’s an
Object anyway?</span></span></dt><dt><span class="section"><a
href="state-modeling.html">Zest™ and state modeling</a></span></dt><dt><span
class="section"><a href="related.html">Related publications &amp; projects</a></span></dt></dl></div></div><div
class="section" title="What’s an Object anyway?"><div class="titlepage"><div><div><h3
class="title"><a id="what-s-an-object-anyway"></a>What’s an Object anyway?</h3></div></div></div><p>In
OOP the main idea is t
 hat we should model our reality by creating Objects. Objects have state, and they have methods.
 Methods in an object are used to operate on the internal state and understands the domain
that is being modeled.</p><p>By contrast, in procedural programming the focus
is on algorithms, which can use several data structures to perform some
 task. The focus is on what is going on, rather than the "objects" involved.</p><p>With
OOP it becomes more difficult to "read" algorithms, as they are spread out in many objects
that interact. With
 procedural programming it becomes difficult to encapsulate and reuse functionality. Both
represent extremes, neither of
@@ -84,7 +84,7 @@ there will be an interface, and for each
 This mixin can be specific for that composite implementation, or it can be generic and reused.
The key point is that it
 is the OBSERVER of the object, meaning, the algorithm, that gets to decide what the object
should be able to do.</p><p>This is the same in real life. I don’t get to
decide how I communicate with you. I have to use english, and I have to
 use email, and I have to send it to a specific mailing list. It is the algorithm of the interaction
between us, the
-Qi4j dev mailing list, that has set these rules, not <span class="strong"><strong>I</strong></span>
as a participant in this interaction. The same should,
+Zest™ dev mailing list, that has set these rules, not <span class="strong"><strong>I</strong></span>
as a participant in this interaction. The same should,
 obviously, be the case for objects.</p><p>So, with the understanding that algorithms
should define roles for collaborating objects, and objects should then
 implement these in order to participate in these algorithms, it should be trivial to realize
that what has passed for
 OOP so far, in terms of "class oriented programming", where this role-focus of objects is
difficult to achieve, if not
@@ -92,7 +92,7 @@ even impossible, is just plain wrong. I
 designated as "coordinator", which then delegates to a number of other objects in order to
implement the various roles.
 This "solution", which is caused by this fundamental flaw in "class oriented programming",
is essentially a hack, and
 causes a number of other problems, such as the "self schizophrenia" problem, whereby there
is no way to tell where the
-object really is. There is no "this" pointer that has any relevant meaning.</p><p>The
Composite pattern, as implemented in COP and Qi4j, gets around this by simply saying that
the composite, as a
+object really is. There is no "this" pointer that has any relevant meaning.</p><p>The
Composite pattern, as implemented in COP and Zest™, gets around this by simply saying
that the composite, as a
 whole, is an object. Tada, we now have a "this" pointer, and a coherent way to deal with
the object graph as though it
 was a single object. We are now able to get back to the strengths of the procedural approach,
which allows the
 implementer of the algorithm to define the roles needed for the algorithm. The roles can
either be specific to an
@@ -100,7 +100,7 @@ algorithm, or they can be shared between
 algorithm is not too tightly encoded in the composites, thereby making the algorithms more
reusable, and making it less
 necessary to read composite code when trying to understand algorithms. The assumption here
is that we are going to write
 more algorithms than composites, therefore it has to be easy to ready algorithms, and only
when necessary dive down into
-composite code.</p><p>When talking about Composites as Objects in Qi4j it is
most relevant to look at Entities, since these represent physical
+composite code.</p><p>When talking about Composites as Objects in Zest™
it is most relevant to look at Entities, since these represent physical
 objects in a model, rather than algorithms or services, or other non-instance-oriented things.</p><p>If
Entities should implement roles, via mixins, in order to interact with each other through
algorithms, then the
 majority of their behaviour should be put into those role-mixins. These are exposed publically
for clients to use.
 However, the state that is required to implement these roles should not be exposed publically,
as they represent
@@ -132,7 +132,7 @@ general allow our role-oriented approach
 generally reusable, and the state interfaces are usually reusable. This minimizes the need
for us to go into the mixin
 code and read it. If we have read the mixin code once, and the same mixin is reused between
objects, then this makes
 it easier for us to understand it the next time we see it being used in another algorithm.</p><p>To
summarize thus far, we have looked at why OOP so far has not worked out, why this is the case,
and how COP deals
-with it, and how we can implement a better solution of Entities using Qi4j. All is well!</p><p>The
next step is to start using these Entities in algorithms. Algorithms are usually stateless,
or at least they don’t
+with it, and how we can implement a better solution of Entities using Zest™. All is
well!</p><p>The next step is to start using these Entities in algorithms. Algorithms
are usually stateless, or at least they don’t
 have any state that survives the execution of the algorithm. There is input, some calculation,
and then output. In
 other words, our notion of services fit perfectly here!</p><p>Algorithms, then,
should(/could?) be modeled using services. If an algorithm needs other algorithms to compute
 something, that is, if a service needs another service to do something, we can accomplish
this using dependency
@@ -162,14 +162,14 @@ would need to get the three objects invo
 selected item in a list, and "TaskExecutor to" could be a user designated from a popup dialog.
These three are then
 taken by the context and used to execute the "delegate" interaction, which performs all the
steps necessary.</p><p>The interaction method "delegate" is testable, both with
mocks of the input, and with specific instances of the various
 roles. The implementations are also testable, and if the same mixin is used over and over
for the implementation, then
-only one set of tests is needed for each role interface.</p><p>To summarize we
have in COP/Qi4j a way to get the best from procedural and object-oriented programming. As
we have seen
+only one set of tests is needed for each role interface.</p><p>To summarize we
have in COP/Zest™ a way to get the best from procedural and object-oriented programming.
As we have seen
 the functionality falls into three categories, the entities implementing objects, the services
implementing
 interactions, and the user interface implementing the context. This also maps well to the
ideas of ModelViewController,
 which in turn maps well to the new ideas from Mr Reenskaug (inventor of MVC) called DCI:
Data-Context-Interaction. As a
-side-effect of this discussion we have therefore also seen how COP/Qi4j can be used to implement
DCI, which is an
+side-effect of this discussion we have therefore also seen how COP/Zest™ can be used
to implement DCI, which is an
 important next step in understanding objects and their interactions, the fundamentals of
which (I believe) are captured
 on this page.</p><p>That’s it. Well done if you’ve read this far :-)</p><p>Comments
and thoughts to qi4j-dev forum at Google Groups on this are highly appreciated. This is very
very important topics,
-and crucial to understanding/explaining why COP/Qi4j is so great! :-)</p></div><div
xmlns="" xmlns:exsl="http://exslt.org/common" class="footer"><p>
+and crucial to understanding/explaining why COP/Zest™ is so great! :-)</p></div><div
xmlns="" xmlns:exsl="http://exslt.org/common" class="footer"><p>
         Copyright © 2015 The Apache Software Foundation, Licensed under the <a href="http://www.apache.org/licenses/"
target="_blank">Apache License, Version 2.0</a>.
         <br /><small>
             Apache Zest, Zest, Apache, the Apache feather logo, and the Apache Zest project
logo are trademarks of The Apache Software Foundation.<br />



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