Class: Constraint::NilConstraint

Inherits:
Object
  • Object
show all
Defined in:
lib/constraint.rb

Overview

The base constraint class. Always evaluates to true.

Direct Known Subclasses

AndConstraint, OrConstraint

Instance Method Summary collapse

Constructor Details

#initialize(shell, name, description = nil, &block) ⇒ NilConstraint

shell

The Shell class containing this constraint

name

This constraint’s name

description

Optional constraint description

block

The constraint that must evaluate to true in order for this constraint to succeed



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# File 'lib/constraint.rb', line 27

def initialize(shell, name, description=nil, &block)
    @shell       = shell
    @other       = shell.constraints
    @name        = name
    @description = description
    @this        = block
end

Instance Method Details

#evaluate(object) ⇒ Object

Return true if args complies with @this constraint.



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# File 'lib/constraint.rb', line 36

def evaluate(object)
    begin
        rv = @this.call(object)
    rescue Exception => e
        @shell.log_constraint_exception(e)
    end
    begin
        if @other
            return evaluate_control(rv, object)
        elsif rv
            return object
        else
            return evaluate(handle_violation(object))
        end
    rescue ConstraintViolation => e
        raise e
    end
end

#handle_violation(object) ⇒ Object

Delegate to Shell#handle_constraint_violation.



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# File 'lib/constraint.rb', line 56

def handle_violation(object)
    return @shell.handle_constraint_violation(@name, object)
end