exercise.js

exercise.js

var app = {
    uid: (function() {
        var seed = 0;
        return function() {
            return seed++;
        };
    })(),
    create: function(model, opts) {
        var instance = new app.model[model](opts);
        
        instance.id = app.uid();
        
        app.merge(instance, opts);
        
        return instance;
    },
    merge: function(target) {
        var merge = [].slice.call(arguments, 1);

        merge.forEach(function(current) {
            for(var p in current) {
                if(current.hasOwnProperty(p)) {
                    target[p] = current[p];
                }
            }
        });
    },
    xetterize: function(o, fields) {
        fields.forEach(function(current) {
            var name = current.replace(/./, function(c) { return c.toUpperCase() });

            o['set' + name] = function(value) {
                this[current] = value;
                return this;
            };
            o['get' + name] = function() {
                return this[current];
            };
        });
    },
    extend: function(f, parent) {
        var p = new parent;
        f.prototype = p;
        f.prototype.constructor = f;
        f.prototype.super = p;
    },
    model: function(name, opts) {
        var C = function() {
            if(this.super && this.super.init) {
                this.super.init.apply(this, arguments);
            }
            if(this.init) {
                this.init.apply(this, arguments);
            }
        };

        if(opts.extend) {
            app.extend(C, opts.extend);
        }
        
        opts.fields = opts.fields || [];
        
        opts.fields.push('id');
        app.xetterize(C.prototype, opts.fields);
        
        app.merge(C.prototype, opts.body || {});
        app.merge(C, opts.static || {});

        app.model[name] = C;

        return this;
    }
};


app.model('Company', {
    fields: ['name', 'employees'],
    body: {
        init: function(opts) {
            this.employees = [];
        },
        addEmployee: function(employee) {
            if(!(employee instanceof app.model.Employee)) {
                throw new Error('Invalid employee: ' + employee);
            }

            this.employees.push(employee);

            return this;
        },
        setEmployees: null,
        getEmployees: function() {
            return this.employees.concat();
        },
        findEmployees: function(fn) {
            return this.getEmployees().reduce(function(memo, current) {
                if(fn(current)) {
                    memo.push(current);
                }

                return memo;
            }, []);
        },
        getEmployeeById: function(id) {
            return this.findEmployees(function(current) {
                return current.getId() == id;
            })[0] || null;
        }
    }
});

app.model('Employee', {
    fields: ['name', 'lastName', 'age', 'type'],
    body: {
        setType: function(type) {
            if(!this.constructor.TYPE[type]) {
                throw new Error('Invalid type: ' + type);
            }

            this.type = type;

            return this;
        }
    }
});

app.model('Developer', {
    extend: app.model.Employee,
    static: {
        TYPE: {
            PHP: 'PHP',
            PYTHON: 'PYTHON',
            JAVASCRIPT: 'JAVASCRIPT'
        }
    }
});

app.model('Designer', {
    extend: app.model.Employee,
    static: {
        TYPE: {
            WEB: 'WEB',
            GRAPHIC: 'GRAPHIC'
        }
    }
});
//--------------------------------------------

var summa = app.create('Company', {
    name: 'Summa'
});


// Add employees
summa
  .addEmployee(
    app.create('Developer', {
      name: 'Agustin',
      lastName: 'Didiego',
      age: 38,
      type: app.model.Developer.TYPE.PHP
    })
  )
  .addEmployee(
    app.create('Developer', {
      name: 'Valentin',
      lastName: 'Starck',
      age: 25,
      type: app.model.Developer.TYPE.JAVASCRIPT
    })
  )
  .addEmployee(
    app.create('Developer', {
      name: 'Jose',
      lastName: 'De los Palotes',
      age: 21,
      type: app.model.Developer.TYPE.PYTHON
    })
  );
  
  
var aDesigner = app.create('Designer');

aDesigner.setName('Brenda');
aDesigner.setLastName('Herrada');
aDesigner.setAge(26);

try {
    aDesigner.setType(1);
} catch(e) {} //Error: Invalid type: 1

aDesigner.setType(app.model.Designer.TYPE.WEB);

summa.addEmployee(aDesigner);

summa.getEmployees().length // 4

// Find employees
summa.findEmployees(function(employee) {
    return employee.getAge() < 30;
}).length; // 3

summa.getEmployeeById(2).getName(); // "Valentin"