Changes between Version 3 and Version 4 of code/doc/Iterator

Timestamp:

Sep 27, 2008, 4:19:36 AM (16 years ago)

Author:

landauf

Comment:

—

code/doc/Iterator

@@ -2 +2 @@
 [[TracNav(TracNav/TOC_Development)]]
 
-== Description ==
+The Iterator allows you to iteratate through any [wiki:ObjectList] you like. It's possible to iterate through all objects of class '''B''' with an Iterator of class '''A''', under condition that '''B''' is a child of '''A'''. Iterator does a dynamic_cast to the requested class. Because this is not really performant, you should always use [wiki:ObjectListIterator] instead in case that '''A''' == '''B'''.
 
-The [wiki:Iterator] allows you to easily iterate through all objects in an [wiki:ObjectList]. An [wiki:ObjectList] stores all objects of a given class (and all derivatives). To start iterating, you need the first element in the [wiki:ObjectList]. This gets returned by !ObjectList<!ClassName>::begin().
+'''Important''': Always use [wiki:ObjectListIterator] if you know at compiletime through which class you want to iterate.
+
+Iterator is made to iterate through a list of objects which gets determined at runtime. For this reason you can create an Iterator not only by calling !ObjectList<T>::begin() but also through anyidentifier->getObjects()->begin(). Of course end(), rbegin() and rend() work too.
 
 == Example ==
+{{{
+Identifier* identifier = someFunctionReturningAnIdentifier();
 
-The following example uses the class-tree below.
+for (Iterator<BaseObject> it = identifier->getObjects()->begin();
+                          it != identifier->getObjects()->end(); ++it)
+{
+    it->callSomeFunction(...);
+    BaseObject* storeTheObject = (*it);
+}
+}}}
 
 {{{
-#!cpp
-new A1();
-new A1();
-new A1();
+for (Iterator<BaseClass> it = ObjectList<ChildClass>::begin();
+                          it != ObjectList<ChildClass>::end(); ++it)
+{
+    it->callSomeFunction(...);
+    BaseObject* storeTheObject = (*it);
+}
 
-new A3();
-new A3B1();
-new A3B1C1();
-
-int count = 0;
-for (Iterator<BaseObject> it = ObjectList<BaseObject>::begin(); it; ++it)
-  count++;
-std::cout << "BaseObject: " << count << std::endl;
-
-count = 0;
-for (Iterator<A1> it = ObjectList<A1>::begin(); it; ++it)
-  count++;
-std::cout << "A1:         " << count << std::endl;
-
-count = 0;
-for (Iterator<A3B1> it = ObjectList<A3B1>::begin(); it; ++it)
-  count++;
-std::cout << "A3B1:       " << count << std::endl;
-
-/*
-return:
-BaseObject: 6
-A1:         3
-A3B1:       2
-*/
+// Note:
+// In this case you should better use ObjectListIterator<ChildClass>
+// to avoid a dynamic_cast
 }}}
-
-[[Image(Core:testclass_tree.gif)]]