interface.ts

Overview

This file defines TypeScript type aliases that model filter-related data structures and a callback type used in filtering functionality. It provides the foundational type definitions for representing filter options, collections of filters, the current state of filter selections, and the handler signature for filter change events.

These types are typically used in a UI or data-processing context where users can select filters to narrow down datasets or views, enabling type-safe handling of filter metadata and interactions.

Type Definitions

FilterType

Represents an individual filter option.

• Properties:

  • id: string
    A unique identifier for the filter option.

  • label: string
    The human-readable name displayed for the filter.

  • count: number
    The number of items or entities that match this filter option.

Usage Example:

const filterOption: FilterType = {
  id: "color_red",
  label: "Red",
  count: 42,
};

FilterCollection

Represents a collection or group of related filter options for a specific field.

• Properties:

  • field: string
    The key or name of the field this filter collection applies to (e.g., "color", "size").

  • label: string
    The display label for the filter group.

  • list: FilterType[]
    An array of FilterType objects representing the available filter options within this collection.

Usage Example:

const colorFilters: FilterCollection = {
  field: "color",
  label: "Color",
  list: [
    { id: "color_red", label: "Red", count: 42 },
    { id: "color_blue", label: "Blue", count: 30 },
  ],
};

FilterValue

Represents the current filter state, mapping filter fields to an array of selected filter option IDs.

• Type: Record<string, Array<string>>
  An object where each key is the filter field and the value is an array of selected filter option ids.

Example:

const currentFilters: FilterValue = {
  color: ["color_red", "color_blue"],
  size: ["size_large"],
};

This structure facilitates easy retrieval and update of selected filters per field.

FilterChange

Defines the signature of a callback function that handles changes to the filter state.

• Type: (value: FilterValue) => void
  A function that takes the updated FilterValue object and returns nothing.

Usage Example:

const onFilterChange: FilterChange = (newFilters) => {
  console.log("Filters updated:", newFilters);
  // Update UI or fetch new data based on newFilters
};

Implementation Details

• The file exclusively uses TypeScript type aliases (type) to define data shapes and function signatures.

• There are no classes, functions, or runtime logic implemented here; it serves as a pure interface/type declaration module.

• The types are designed to be composable and scalable for any number of filter fields and options.

• Using Record<string, Array<string>> for FilterValue allows flexible dynamic keys reflecting different filter categories.

Interaction with Other System Components

• These types are likely imported and used in UI components responsible for rendering filter controls (checkboxes, dropdowns, etc.).

• The FilterChange type is used to type-check event handlers that respond to user interactions with filters.

• Components or services that fetch or process filtered data will use FilterValue to represent the current filter selections.

• FilterCollection and FilterType dictate how filter options are structured and displayed.

In a typical React or Angular application, these types would be utilized across:

• Filter panel components (displaying filter options)

• State management or context providers (maintaining filter state)

• API services (constructing queries based on selected filters)

• Analytics or logging modules (tracking filter usage)

Mermaid Diagram

classDiagram
    class FilterType {
        +id: string
        +label: string
        +count: number
    }

    class FilterCollection {
        +field: string
        +label: string
        +list: FilterType[]
    }

    class FilterValue {
        <<type>>
        +Record<string, Array<string>>
    }

    class FilterChange {
        <<function>>
        +(value: FilterValue) => void
    }

    FilterCollection "1" *-- "*" FilterType : contains
    FilterChange ..> FilterValue : uses

Summary

This file interface.ts defines the essential TypeScript types for representing filter options and their collections, the current filter selection state, and the callback function to handle filter changes. It is a critical part of the filtering system's type safety and consistency across UI components and business logic layers.