User-defined Types

Sometimes, you might want to define your own types according to your business needs.
We provide two features to achieve this.

Class

class is used to group related fields together. For example, you might want to define an Employee class to group all information about an employee.

    def class Employee {
        def string name;
        def string dept;
        def real salary;
    }

In the above example you have created a class named Employee that has three different fields. Note that you still haven't created any variable of Employee type. You can do this via:

    Employee john;
    Employee jane;

In this way, we can create two Employee type variables john and jane. Now, you might be asking how do I put the Jane's salary in jane. There are many ways to achieve this:

Using JSON

  Employee john = {
      "name": "John Doe",
      "dept": "HR",
      "salary": 45000.0
  };
  Employee jane = {
      "name": "Jane Doe",
      "dept": "Engineering",
      "salary": 71000.0
  };

As seen above, using JSON syntax, you can directly assign values to variables;

Using new and dot notation.

Sometime you don't know all the values of variable and may want to provide them when you have them. You can use new and dot notation for that.

  Employee john = new Employee();
  john.name = "John Doe";
  john.dept = "HR";
  john.salary = 45000.0;
  Employee jane = new Employee();
  jane.name = "Jane Doe";
  jane.dept = "Engineering";
  jane.salary = 71000.0;

The above example achieves the same result as the example when using JSON.

As you can see, classes can be used to group all related data together. This can reduce clutter and helps with long term maintainability.

Alternative Syntax

You can use objectBlueprint instead of class.

Enum

enum (short for enumeration) is used when a variable can only have one of some possible values.
For example, in the class example we defined department field to be a string type. What if someone gives it the value Human Resources instead of HR. Now at every place where you check if the department is HR, you'll have to check for both Human Resources and HR values. As you can see, this can very quickly lead to all kinds of chaos and bugs. To avoid this, you can use enums.

    def enum Department {
        HR("HR"),
        Engineering("Engineering"),
        Accounting("Accounting"),
    }
    def Department myDepartment = Department.Engineering;
    def Department myFriendsDepartment = Department.Accounting;

In the above example
- You first defined an enum Department with three possible values
- Then you created two variables of Department type
  - myDepartment with value Department.Engineering
  - myFriendsDepartment with value Department.Accounting
As you can see, enums can be used to restrict the values that a variable can have.

Alternative Syntax

You can use categoryBlueprint instead of enum.

Class​

Enum​

Class

Enum