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ew-responsive-store Making Session Storage Data Reactive

If your project requires using session storage (either localStorage or sessionStorage) to persist data, and you want the data to be retained after a page refresh while also automatically updating the view when the data changes, I highly recommend using the ew-responsive-store library. It's under 1 KB in size and extremely easy to use. With just a single function call, you can make session storage data reactive, which can be applied to any framework-based project, even native JavaScript projects. The library also includes comprehensive unit tests and type inference.

Installation

First, you need to install the ew-responsive-store package. You can install it using the following command:

npm install ew-responsive-store --save-dev
# Or using pnpm
pnpm add ew-responsive-store
# Or using yarn
yarn add ew-responsive-store

Usage

1. Basic Usage

The core of the ew-responsive-store package exports two methods: parseStr and useStorage. The useStorage method is used to make session storage data reactive.

Basic Values

You can use useStorage to create reactive basic values. For example, let's say you have a counter stored in localStorage:

import { useStorage } from 'ew-responsive-store';

// Initialize the count with a default value of 0
const count = useStorage('count', 0);

// Modify the count value
count.value++;  // count value becomes 1

Vue Template Code:

<template>
  <p>{{ count }}</p>
  <button @click="count++">Click Me</button>
</template>

<script setup>
import { useStorage } from 'ew-responsive-store';

const count = useStorage('count', 0);
</script>

At this point, the value of count is stored in the browser's session storage, and it is reactive, meaning it will persist even after the page refreshes and the view will update automatically when the value changes.

Object Values

You can also store reactive objects in a similar way:

import { useStorage } from 'ew-responsive-store';

// Initialize the userInfo object
const userInfo = useStorage('user', { name: 'eveningwater' });

// Modify the userInfo object
userInfo.value.name = '夕水';  // userInfo's name property becomes '夕水'

Vue Template Code:

<template>
  <p>{{ userInfo.name }}</p>
  <button @click="userInfo.name = '小张'">Click Me</button>
</template>

<script setup>
import { useStorage } from 'ew-responsive-store';

const userInfo = useStorage('user', { name: 'eveningwater' });
</script>

When you change the name property of userInfo, the view will automatically update, and the data will be saved in session storage.

Array Values

You can also store arrays, and they will be reactive as well:

import { useStorage } from 'ew-responsive-store';

// Initialize an array
const countList = useStorage('countList', [1, 2, 3]);

// Modify the array
countList.value.push(4);  // The array becomes [1, 2, 3, 4]

Vue Template Code:

<template>
  <p v-for="item in countList" :key="item">{{ item }}</p>
  <button @click="countList.pop()">Click Me</button>
</template>

<script setup>
import { useStorage } from 'ew-responsive-store';

const countList = useStorage('countList', [1, 2, 3]);
</script>

2. Configuration and Optimization

Disable Deep Watch

By default, useStorage enables deep watching, which is useful for objects and arrays. If you're dealing with basic types and don't need deep watching, you can disable it by passing a third configuration parameter:

import { useStorage } from 'ew-responsive-store';

// Initialize count with deep watching disabled
const count = useStorage('count', 0, { deep: false });

// Modify count
count.value++;  // count value becomes 1

Change Session Storage Type

By default, useStorage uses localStorage for persistent storage. If you want to use sessionStorage instead, you can specify it in the configuration:

import { useStorage } from 'ew-responsive-store';
import { StoreType } from 'ew-responsive-store/typings/core/enum';

const count = useStorage('count', 0, { deep: false, storage: StoreType.SESSION });

// Modify count
count.value++;  // count value becomes 1, and the data is stored in sessionStorage

Control Initial Value Watching

By default, useStorage listens to changes in the initial value. If you don't want to watch the initial value changes, you can control it by passing the immediate parameter:

import { useStorage } from 'ew-responsive-store';
import { StoreType } from 'ew-responsive-store/typings/core/enum';

// Don't listen to changes in the initial value
const count = useStorage('count', 0, { deep: false, immediate: false });

// Only the next change will be watched
count.value++;  // count value becomes 1

3. parseStr Method

The parseStr method is used to parse string values. It provides two parsing modes:

• EVAL: Similar to the eval method, which executes JavaScript code within the string.
• JSON: Similar to JSON.parse, useful for parsing JSON-formatted strings.

Example Code:

import { parseStr } from 'ew-responsive-store';
import { parseStrType } from 'ew-responsive-store/typings/core/enum';

// Parse a JSON string
const testJSONData = parseStr('{"name":"eveningwater"}'); 
console.log(testJSONData);  // { name: "eveningwater" }

// Execute JavaScript code from a string
const testEvalData = parseStr('console.log("hello, eveningwater")', parseStrType.EVAL); 
// The console will log: hello, eveningwater

4. More Configuration and Usage

Since ew-responsive-store is built on Vue's reactive system, you can configure it in more advanced ways by passing different parameters for the underlying watch functionality. You can refer to the Vue Reactivity API documentation to learn more about the parameters and usage.