Class slides

two/03_dart_classes.md

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+!SLIDE
+# Dart Classes
+
+## B'more on Rails
+## Chris Strom
+## @eee_c
+
+!SLIDE
+
+# Quick Review
+
+ * Familiar syntax
+ * Can be compiled to JS
+ * Can serve both JS and Dart depending on browser
+
+!SLIDE
+
+    @@@ Javascript
+    class Hipster {
+      // describe class operations here...
+    }
+
+
+!SLIDE
+# Instance Variables
+
+    @@@ Javascript
+    class Hipster {
+      bool glasses;
+      bool flannel;
+      List other;
+    }
+
+
+!SLIDE
+# Instance Getters
+
+    @@@ Javascript
+    class Hipster {
+      bool glasses;
+      bool flannel;
+      List other;
+    }
+
+    var chris = new Hipster();
+    chris.glasses = true;
+    chris.flannel = false;
+    chris.other = ['Toe shoes'];
+
+!SLIDE
+# Private Instance Variables
+
+    @@@ Javascript
+    class Hipster {
+      bool _lovesMadonna;
+    }
+
+    var chris = new Hipster();
+    chris._lovesMadonna = true;
+    // => No such method!
+
+!SLIDE
+# Instance Methods
+
+    @@@ Javascript
+    class Hipster {
+      String sayHi(friend) {
+        return "Howdy $friend!";
+      }
+    }
+
+    var chris = new Hipster();
+    chris.sayHi("Bob");
+    // => "Howdy Bob!"
+
+!SLIDE
+# Instance Methods
+
+    @@@ Javascript
+    class Hipster {
+      String sayHi(friend) =>
+        "Howdy $friend!";
+    }
+
+    var chris = new Hipster();
+    chris.sayHi("Bob");
+    // => "Howdy Bob!"
+
+!SLIDE
+# Getters and Setters
+
+
+!SLIDE
+# Getters and Setters
+
+    @@@ Javascript
+    class Hipster {
+      List other;
+    }
+
+    var chris = new Hipster();
+    chris.other = ['Toe shoes'];
+
+!SLIDE
+# Getters
+
+    @@@ Javascript
+    class Hipster {
+      bool glasses;
+      bool flannel;
+
+      bool get isPoser() =>
+        !(glasses && flannel);
+    }
+
+    var chris = new Hipster();
+    chris.glasses = true;
+    chris.flannel = false;
+    chris.isPoser;
+    // => true
+
+!SLIDE
+# Setters
+
+    @@@ Javascript
+    class Hipster {
+      // ...
+      void set poser(bool am_i) {
+        _poser = bool;
+      }
+
+      bool get isPoser() {
+        if (_poser != null) return _poser;
+        return !(glasses && flannel);
+      }
+    }
+
+!SLIDE
+# Setters
+
+    @@@ Javascript
+    class Hipster {
+      // ...
+      void set poser(bool am_i) { /* ... */ }
+      bool get isPoser() { /* ... */ }
+    }
+
+    var chris = new Hipster();
+    chris.poser = false;
+    chris.isPoser;
+    // => false
+
+!SLIDE
+# Operator Methods
+
+`==`, `<`, `>`, `<=`, `>=`, `-`, `+`, `/`, `~/`,  `*`, `%`, `|`, `^`, `&`, `<<`, `>>`, `[]=`, `[]`, `~` and `!`
+
+    @@@ Javascript
+    class Hipster {
+      List other;
+      operator [](index) =>
+        other[index];
+    }
+
+    var chris = new Hipster();
+    chris.other = ['Toe shoes'];
+    chris[0];
+    // => 'Toe shoes'
+
+!SLIDE
+# Class Methods
+
+Use the "static" keyword
+
+    @@@ Javascript
+    class Hipster {
+      static List traits() =>
+        ['glasses', 'flannel'];
+    }
+
+    Hipster.traits();
+    // => ['glasses', 'flannel']
+
+!SLIDE
+# Interfaces
+
+    @@@ Javascript
+    class Hipster implements HashMap {
+      var _traits = {};
+
+      // expected to quack
+      operator [](attr) =>
+        _traits[attr];
+    }
+
+
+!SLIDE
+# Sub-classes
+
+    @@@ Javascript
+    class Hipster {
+      String sayHi(name) =>
+        "Howdy, $name";
+    }
+
+    class BmoreHipster extends Hipster {
+      String sayHi(name) =>
+        "Hi, hon";
+    }
+
+    var chris = new BmoreHipster();
+    chris.sayHi();
+    // => "Hi, hon"
+
+!SLIDE
+# Constructors
+
+    @@@ Javascript
+    class Hipster {
+      bool glasses;
+      bool flannel;
+
+      Hipster(glasses, flannel) {
+        this.glasses = glasses;
+        this.flannel = flannel;
+      }
+    }
+
+    var chris = new Hipster(true, false);
+    chris.flannel;
+    // => false;
+
+!SLIDE
+# Constructor Shortcut!
+
+    @@@ Javascript
+    class Hipster {
+      bool glasses;
+      bool flannel;
+
+      Hipster(this.glasses, this.flannel);
+    }
+
+    var chris = new Hipster(true, false);
+    chris.flannel;
+    // => false;
+
+!SLIDE
+# Advanced Topics
+
+ * Optional parameters
+ * Named Constructors
+ * Factory Constructors
+
+!SLIDE
+# Optional Parameters
+
+    @@@ Javascript
+    class Hipster {
+      bool glasses;
+      bool flannel;
+
+      Hipster([this.glasses, this.flannel]);
+    }
+
+    var chris = new Hipster(glasses: true);
+    chris.glasses;
+    // => true;
+
+!SLIDE
+# Named Constructors
+
+    @@@ Javascript
+    class Hipster {
+      bool glasses, flannel;
+
+      Hipster.booleans([
+        this.glasses, this.flannel
+      ]);
+    }
+
+    var chris = new Hipster.booleans(
+      glasses: true,
+      flannel: false
+    );
+    chris.glasses;
+    // => true;
+
+!SLIDE
+# Named Constructors
+
+    @@@ Javascript
+    class Hipster {
+      bool glasses, flannel;
+
+      Hipster.booleans([
+        this.glasses, this.flannel
+      ]);
+    }
+
+    var chris = new Hipster();
+    chris.glasses;
+    // => null;
+
+!SLIDE
+# Factory Constructors
+
+Use the `factory` keyword.
+
+    @@@ Javascript
+    class PrettyName {
+      factory PrettyName(name) {
+        return "Pretty $name";
+      }
+    }
+
+    new PrettyName("Chris");
+    // => "Pretty Chris"
+
+!SLIDE
+# More Info
+
+## http://dart4hipsters.com
+## http://japhr.blogspot.com
+## @eee_c