In-memory Data Management Utilities

This JavaScript module provides a suite of utility functions to manage in-memory data storage, specifically designed for demonstrative purposes or mock backend functionality. Utilizing the browser's localStorage, these methods simulate CRUD operations (Create, Read, Update, Delete) on a list of items and a dictionary, useful for front-end development testing and prototyping.

Functions Overview

getList(params)

Fetches a paginated list of items from local storage based on provided parameters such as pageSize and pageNum. Supports additional filter conditions through params.

getDict(key)

Retrieves a single value from a dictionary stored in local storage, identified by key.

getDicts(keys)

Retrieves multiple values from the dictionary based on an array or comma-separated string of keys.

getItem(id)

Retrieves a specific item from the list by its id.

updateItem(obj)

Updates an existing item within the list based on the provided obj object.

addItem(obj)

Adds a new item to the list. If the item lacks an id, one is automatically generated.

deleteItem(id)

Deletes an item from the list using its id.

batchDelete(ids)

Deletes multiple items from the list by their ids.

setList(data)

Overwrites the current list in local storage with the provided data array.

setDict(data)

Replaces the dictionary in local storage with the new data object.

Usage

Each function returns a promise that resolves after a simulated delay of 300ms with a status code (200 for success) and, where applicable, the requested data. These utilities can be used in a front-end application to mimic server responses without requiring an actual backend server setup.

To start using these functions:

1. Include this script in your project.
2. Call the desired methods with appropriate parameters to interact with the simulated data storage.

Note: Remember that localStorage is limited to strings; hence, objects are stringified before storage and parsed upon retrieval.

Example Usage

// Fetch the first page of items with default settings
getList({}).then(response => console.log(response));

// Get a value from the dictionary
getDict('exampleKey').then(response => console.log(response));

// Add a new item
addItem({ name: 'New Item', description: 'A newly added item' }).then(() => console.log('Item added'));

These utilities are particularly handy for rapid prototyping, UI testing, or for developers who want to simulate backend responses during front-end development.

TypeScript Support

If you are using ts, you can add the path to your tsconfig.json.

{
  "compilerOptions": {

    "types": ["demo-curd/types/index.d.ts"],

  }
}