Add support for Generic class definitions

Added support in parser to translate characters surrounded by `~` into generic type definition ie: `Class01~T~` would turn into `Class01<T>`

cypress/integration/rendering/classDiagram.spec.js

@@ -163,4 +163,45 @@ describe('Class diagram', () => {
     );
     cy.get('svg');
   });
+
+  it('5: should render a simple class diagram with Generic class', () => {
+    imgSnapshotTest(
+      `
+    classDiagram
+    class Class01~T~
+      Class01 : size()
+      Class01 : int chimp
+      Class01 : int gorilla
+      Class08 <--> C2: Cool label
+      class Class10~T~ {
+        &lt;&lt;service&gt;&gt;
+        int id
+        test()
+      }
+      `,
+      {}
+    );
+    cy.get('svg');
+  });
+
+  it('6: should render a simple class diagram with Generic class and relations', () => {
+    imgSnapshotTest(
+      `
+    classDiagram
+    Class01~T~ <|-- AveryLongClass : Cool
+    Class03~T~ *-- Class04~T~
+      Class01 : size()
+      Class01 : int chimp
+      Class01 : int gorilla
+      Class08 <--> C2: Cool label
+      class Class10~T~ {
+        &lt;&lt;service&gt;&gt;
+        int id
+        test()
+      }
+      `,
+      {}
+    );
+    cy.get('svg');
+  });
 });

dist/index.html

@@ -418,6 +418,43 @@ class Class10 {
   size()
 }
   </div>
+
+  <div class="mermaid">
+    classDiagram
+    class Class01~T~
+    Class01 : #size()
+    Class01 : -int chimp
+    Class01 : +int gorilla
+    class Class10~T~ {
+      &lt;&lt;service&gt;&gt;
+      int id
+      size()
+    }
+      </div>
+
+      <div class="mermaid">
+        classDiagram
+        Class01~T~ <|-- AveryLongClass : Cool
+        &lt;&lt;interface&gt;&gt; Class01
+        Class03~T~ "0" *-- "0..n" Class04
+        Class05 "1" o-- "many" Class06
+        Class07~T~ .. Class08
+        Class09 "many" --> "1" C2  : Where am i?
+        Class09 "0" --* "1..n" C3
+        Class09 --|> Class07
+        Class07 : equals()
+        Class07 : Object[] elementData
+        Class01 : #size()
+        Class01 : -int chimp
+        Class01 : +int gorilla
+        Class08 <--> C2: Cool label
+        class Class10 {
+          &lt;&lt;service&gt;&gt;
+          int id
+          size()
+        }
+          </div>
+
   <div class="mermaid">
     stateDiagram
       State1

src/diagrams/class/classDb.js

@@ -3,17 +3,32 @@ import { logger } from '../../logger';
 let relations = [];
 let classes = {};
 
+const splitClassNameAndType = function(id){
+  let genericType = '';
+  let className = id;
+  
+  if(id.indexOf('~') > 0){
+    let split = id.split('~');
+    className = split[0];
+    genericType = split[1];
+  }
+
+  return {className: className, type: genericType};
+}
+
 /**
  * Function called by parser when a node definition has been found.
  * @param id
  * @public
  */
 export const addClass = function(id) {
+  let classId = splitClassNameAndType(id);
   // Only add class if not exists
-  if (typeof classes[id] !== 'undefined') return;
+  if (typeof classes[classId.className] !== 'undefined') return;
 
-  classes[id] = {
-    id: id,
+  classes[classId.className] = {
+    id: classId.className,
+    type: classId.type,
     methods: [],
     members: [],
     annotations: []
@@ -40,6 +55,10 @@ export const addRelation = function(relation) {
   logger.debug('Adding relation: ' + JSON.stringify(relation));
   addClass(relation.id1);
   addClass(relation.id2);
+
+  relation.id1 = splitClassNameAndType(relation.id1).className;
+  relation.id2 = splitClassNameAndType(relation.id2).className;
+
   relations.push(relation);
 };
 
@@ -51,7 +70,8 @@ export const addRelation = function(relation) {
  * @public
  */
 export const addAnnotation = function(className, annotation) {
-  classes[className].annotations.push(annotation);
+  const validatedClassName = splitClassNameAndType(className).className;
+  classes[validatedClassName].annotations.push(annotation);
 };
 
 /**
@@ -64,7 +84,9 @@ export const addAnnotation = function(className, annotation) {
  * @public
  */
 export const addMember = function(className, member) {
-  const theClass = classes[className];
+  const validatedClassName = splitClassNameAndType(className).className;
+  const theClass = classes[validatedClassName];
+
   if (typeof member === 'string') {
     // Member can contain white spaces, we trim them out
     const memberString = member.trim();

src/diagrams/class/classDiagram.spec.js

@@ -56,6 +56,33 @@ describe('class diagram, ', function () {
       parser.parse(str);
     });
 
+    it('should handle generic class', function() {
+      const str =
+        'classDiagram\n' +
+        'class Car~T~\n' +
+        'Driver -- Car : drives >\n' +
+        'Car *-- Wheel : have 4 >\n' +
+        'Car -- Person : < owns';
+
+      parser.parse(str);
+    });
+
+    it('should handle generic class with brackets', function() {
+      const str =
+        'classDiagram\n' +
+        'class Dummy_Class~T~ {\n' +
+        'String data\n' +
+        '  void methods()\n' +
+        '}\n' +
+        '\n' +
+        'class Flight {\n' +
+        '   flightNumber : Integer\n' +
+        '   departureTime : Date\n' +
+        '}';
+
+      parser.parse(str);
+    });
+
     it('should handle class definitions', function() {
       const str =
         'classDiagram\n' +
@@ -326,6 +353,21 @@ describe('class diagram, ', function () {
       expect(relations[3].relation.lineType).toBe(classDb.lineType.DOTTED_LINE);
     });
 
+    it('should handle generic class with relation definitions', function () {
+      const str = 'classDiagram\n' + 'Class01~T~ <|-- Class02';
+
+      parser.parse(str);
+
+      const relations = parser.yy.getRelations();
+
+      expect(parser.yy.getClass('Class01').id).toBe('Class01');
+      expect(parser.yy.getClass('Class01').genericType).toBe('T');
+      expect(parser.yy.getClass('Class02').id).toBe('Class02');
+      expect(relations[0].relation.type1).toBe(classDb.relationType.EXTENSION);
+      expect(relations[0].relation.type2).toBe('none');
+      expect(relations[0].relation.lineType).toBe(classDb.lineType.LINE);
+    });
+
     it('should handle class annotations', function () {
       const str = 'classDiagram\n' + 'class Class1\n' + '<<interface>> Class1';
       parser.parse(str);

src/diagrams/class/classRenderer.js

@@ -318,10 +318,16 @@ const drawClass = function(elem, classDef) {
     isFirst = false;
   });
 
+  let classTitleString = classDef.id;
+
+  if(classDef.genericType !== undefined && classDef.genericType !== ''){
+    classTitleString += '<' + classDef.genericType + '>';
+  }
+
   // add class title
   const classTitle = title
     .append('tspan')
-    .text(classDef.id)
+    .text(classTitleString)
     .attr('class', 'title');
 
   // If class has annotations the title needs to have an offset of the text height

src/diagrams/class/parser/classDiagram.jison

@@ -6,7 +6,7 @@
 
 /* lexical grammar */
 %lex
-%x string struct
+%x string generic struct
 
 %%
 \%\%[^\n]*\n*           /* do nothing */
@@ -23,6 +23,9 @@
 "class"               return 'CLASS';
 "<<"                  return 'ANNOTATION_START';
 ">>"                  return 'ANNOTATION_END';
+[~]                   this.begin("generic");
+<generic>[~]          this.popState();
+<generic>[^~]*        return "GENERICTYPE";
 ["]                   this.begin("string");
 <string>["]           this.popState();
 <string>[^"]*         return "STR";
@@ -136,6 +139,8 @@ statements
 className
     : alphaNumToken className { $$=$1+$2; }
     | alphaNumToken { $$=$1; }
+    | alphaNumToken GENERICTYPE className { $$=$1+'~'+$2+$3; }
+    | alphaNumToken GENERICTYPE { $$=$1+'~'+$2; }
     ;
 
 statement