conditions.md

Conditions

Simplest condition specification

{
  operator: "equal",
  lhs: 1,
  rhs: 1
}

1. Conditions can include sets of any or all
2. A condition may specify an operator
3. If an operator is specified, the lhs and rhs properties must exist

Operators

1. An operator specification can be a string representing an operator name
2. An operator specification can be an object with a single property of not. The value of the not property is the actual operator.
3. Operators can include a property on the condition named info which can contain extra info about the evaluation of the operator.

Example of not operator specification

{
  operator: {
    not : "equal"
  },
  lhs: 1,
  rhs: 1
}

Built-In Operators

• equal
• greatherThan
• lessThan
• in - Tests if a single value or a sebset of values in the lhs exist in the rhs
• regex - Tests if the regex pattern in lhs matches the value of rhs. Remember to double escape \\ special characters in the double quoted string. The regex operator will also output any strings captured from the evaluation in the info property

Values (lhs and rhs)

All condition operations use values to evaluate the condition. The lhs and rhs value specifications are those values.

1. A value can be a constant
2. A value can have a path specification. path specifications use the lodash library for path resolution using _.get.
3. A value can be an exists specification. exists specifications use the lodash library for path resolution using _.has.

Example of path specification

{
  operator: {
    not : "equal"
  },
  lhs: {
    path: "prop1.prop2"
  },
  rhs: 1
}

Example of exists specification

{
  operator: "equal",
  lhs: {
    exists: "prop1.prop2"
  },
  rhs: true
}

Depedencies

A condition can include an optional depends attribute which must either be a single string or an array of strings. A dependent string value will be evaluated against any other conditions who included an optional id property in the condition statement.