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1.3.2 • Public • Published


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A versatile and efficient package for managing and calculating formula fields in a store.


🧮 formula-store is a TypeScript library designed to provide a flexible solution for handling formula fields. It enables you to manage dependencies, calculate values, and receive updates seamlessly. This package is well-suited for scenarios where dynamic formula-based computations are crucial and performance and robust api design matters.


yarn add formula-store
npm install formula-store


1. Create Formula Store

Initialize a FormulaStore to manage and update formula fields.

import { createFormulaStore } from "formula-store";

// Example Usage:
const store = createFormulaStore({
  onChange: updates => {
    // Handle updates when formula fields change.

2. Define Formula Fields

Create instances of FormulaField representing the formula fields you want to manage in your store.

import { FormulaField, FormulaStore } from "formula-store";

// Example Usage:
const myFormulaField: FormulaField<number> = {
  id: "uniqueId",
  value: 42,
  dependencies: ["dependencyA", "dependencyB"],
  calculate: (dependencyA, dependencyB) => dependencyA + dependencyB

3. Use Formula Store

Utilize the store to manage formula fields and receive updates.

// Example Usage:
// Add fields for dependencies.
  dependencies: [],
  id: "a",
  value: 1

  dependencies: [],
  id: "b",
  value: 3

  dependencies: ["a", "b"],
  id: "c",
  value: 0,
  calculate: (a, b) => a + b

// Update the values of formula fields in the store.
  { id: "a", value: 2 }
  // Add more updates as needed.

// Remove a formula field from the store.
const affectedFields = store.removeField("a");
console.log("Affected Fields: ", affectedFields);

// Edit a store field.
  dependencies: ["a", "b"],
  id: "c",
  value: 0,
  calculate: (a, b) => a + b

// Get previously added field.
const fieldA = store.getFieldById("a");
console.log("Field a: ", fieldA);

API Reference


Represents a field that is either a direct formula or a field that will be used inside another formula.

  • id: Unique identifier for the formula field.
  • value: The current value of the formula field.
  • dependencies: An array of other formula field ids representing the dependencies of the formula field.
  • calculate: A function that calculates the new value based on the provided dependencies. (Optional)


Represents an update for a formula field in the store.

  • id: Unique identifier for the formula field to be updated.
  • value: The new value for the formula field.


Represents the input configuration for the FormulaStore.

  • onChange: A callback function to be called when formula fields are updated.


Represents a store for managing formula fields.

  • addField: Adds a new formula field to the store.
  • editField: Edits a formula previously added to the store.
  • removeField: Removes a formula field from the store based on its identifier.
  • updateFieldsValue: Updates the values of multiple formula fields in the store.
  • getFieldById: Gets a field from the store by id.


Contributions are welcome! Please submit a pull request with any improvements or bug fixes. Make sure to add tests for any new features and bug fixes, and ensure that the existing tests pass.


This project is licensed under the MIT License.


If you need help or have questions, feel free to open an issue in the GitHub repository.

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