roam/aweber/20210928155832-translating_the_search_dsl.org

Translating the search DSL

• Searches
  • A search is a collection of groupings
  • A grouping is a collection of conditions
  • A condition is a boolean expression applied to a field
  • A field refers to a specific database field somewhere in our system
  • Allowable conditions
• Decisions
  • Should the input type presented to the end-user be tied to the database field or the conditional operator?
• Code

Defining and translating the Search DSL for the Subscriber Search Service.

Searches

A search is a collection of groupings

  @dataclasses.dataclass
  class Search:
      conditions: typing.List[Group]

A grouping is a collection of conditions

  class GroupType(enum.Enum):
      AND = 1
      # TODO: OR = 2


  @dataclasses.dataclass
  class Group:
      group_type: GroupType
      conditions: typing.List[Condition]

A condition is a boolean expression applied to a field

  @dataclasses.dataclass
  class Condition:
      field: Field
      operator: str
      value: typing.Optional[str]

A field refers to a specific database field somewhere in our system

  class Database(enum.Enum):
      AppDB = 1
      Analytics = 2
  
  
  @dataclasses.dataclass
  class FieldType:
      name: str
  
  
  @dataclasses.dataclass
  class Field:
      name: str
      column: str
      table: str
      database: Database

Allowable conditions

Decisions

Should the input type presented to the end-user be tied to the database field or the conditional operator?

Seems it should be the operator, as an "equals" operator would match a single value, whereas an "in" operator would match against multiple. That said, it could be parameterized by the field's type (e.g. a tag has type str, its "equals" operator has type str, its "in" operator has type List[str]).

Code

  import dataclasses
  import enum
  import typing

  <<field>>


  <<condition>>


  <<group>>


  <<search>>