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【前端必會】使用indexedDB,降低環(huán)境搭建成本

背景

  1. 學(xué)習(xí)前端新框架、新技術(shù)。如果需要做一些數(shù)據(jù)庫的操作來增加demo的體驗(CURD流程可以讓演示的體驗根據(jù)絲滑)
  2. 最開始的時候一個演示程序我們會調(diào)用后臺,這樣其實(shí)有一點(diǎn)弊端,就是增加了開發(fā)和維護(hù)成本,簡單的一個demo不應(yīng)該勞師動眾
  3. 后來我會在demo中使用一些websql,奈何,websql也真的是沒前景了。代碼寫起來也不是特別好
  4. 下面來介紹下今天的主角indexedDB和jsStore

介紹

站在用戶的角度思考問題,與客戶深入溝通,找到龍州網(wǎng)站設(shè)計與龍州網(wǎng)站推廣的解決方案,憑借多年的經(jīng)驗,讓設(shè)計與互聯(lián)網(wǎng)技術(shù)結(jié)合,創(chuàng)造個性化、用戶體驗好的作品,建站類型包括:成都網(wǎng)站制作、做網(wǎng)站、企業(yè)官網(wǎng)、英文網(wǎng)站、手機(jī)端網(wǎng)站、網(wǎng)站推廣、域名申請、虛擬空間、企業(yè)郵箱。業(yè)務(wù)覆蓋龍州地區(qū)。

  1. indexedDB可以給瀏覽器本地存儲的能力,并且容量還比較大。
  2. jsStore只是眾多封裝的indexedDB庫中的一個??梢杂靡环N類似SQL的感覺操作數(shù)據(jù)

開始
package.json

{
  "name": "npm1",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "lint": "eslint scripts/**",
    "fix": "eslint scripts/** --fix",
    "serve": "webpack serve"
  },
  "dependencies": {
    "jsstore": "^4.4.4",
    "lodash": "^4.17.21"
  },
  "devDependencies": {
    "css-loader": "^6.7.1",
    "eslint": "^8.23.1",
    "eslint-config-google": "^0.14.0",
    "eslint-config-prettier": "^8.5.0",
    "eslint-plugin-prettier": "^4.2.1",
    "file-loader": "^6.2.0",
    "html-webpack-plugin": "^5.5.0",
    "prettier": "2.7.1",
    "style-loader": "^3.3.1",
    "webpack": "^5.74.0",
    "webpack-cli": "^4.10.0",
    "webpack-dev-server": "^4.11.1"
  },
  "author": "",
  "license": "ISC"
}

webpack配置,添加了devServer配置

//webpack.config.js
 const path = require("path");
const HtmlWebpackPlugin = require("html-webpack-plugin");

module.exports = {
  context: path.resolve(__dirname),
  devServer: {
    static: {
      directory: path.join(__dirname, "dist"),
    },
    compress: true,
    port: 9000,
  },
  mode: "production",
  optimization: {
    minimize: false,
  },
  entry: "./src/main.js",
  target: ["web", "es5"],
  output: {
    clean: true,
    filename: "bundle.js",
    path: path.resolve(__dirname, "dist"),
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: "index.html",
    }),
  ],
  module: {
    rules: [
      {
        test: /\.css$/i,
        use: ["style-loader", "css-loader"],
      },
    ],
  },
};

jsStore鏈接幫助類,結(jié)合webpack+webworker。安裝了file-loader

//store-connection.js
 import { Connection } from "jsstore";
const getWorkerPath = () => {
  // return dev build when env is development
  if (process.env.NODE_ENV === "development") {
    return require("file-loader?name=scripts/[name].[hash].js!jsstore/dist/jsstore.worker.js");
  } else {
    // return prod build when env is production

    return require("file-loader?name=scripts/[name].[hash].js!jsstore/dist/jsstore.worker.min.js");
  }
};

const workerPath = getWorkerPath().default;
export const connection = new Connection(new Worker(workerPath));

主邏輯

//main.js
 import { connection } from "./store-connection";

async function init() {
  var dbName = "JsStore_Demo";
  var tblProduct = {
    name: "Product",
    columns: {
      // Here "Id" is name of column
      id: { primaryKey: true, autoIncrement: true },
      itemName: { notNull: true, dataType: "string" },
      price: { notNull: true, dataType: "number" },
      quantity: { notNull: true, dataType: "number" },
    },
  };
  var database = {
    name: dbName,
    tables: [tblProduct],
  };

  const isDbCreated = await connection.initDb(database);
  if (isDbCreated === true) {
    console.log("db created");
    // here you can prefill database with some data
  } else {
    console.log("db opened");
  }

  var value = {
    itemName: "Blue Jeans",
    price: 2000,
    quantity: 1000,
  };

  var insertCount = await connection.insert({
    into: "Product",
    values: [value],
  });

  console.log(`${insertCount} rows inserted`);

  // results will be array of objects
  var results = await connection.select({
    from: "Product",
  });

  results.forEach((item) => {
    console.log(item);
  });
}

window.addEventListener("load", function () {
  console.log(connection);
  init();
});

數(shù)據(jù)已經(jīng)存進(jìn)去了

API插入、查詢也沒什么問題

總結(jié)

  1. 使用indexDB強(qiáng)化自己的demo體驗,避免搭建后端環(huán)境,增加復(fù)雜度
  2. jsStore 的API多了解下,并且涉及的indexedDB的API都是異步的
  3. API沒有啥,主要就是打開鏈接,事務(wù),CRUD。語法參考下官網(wǎng)的例子即可

https://jsstore.net/tutorial/get-started/


網(wǎng)頁標(biāo)題:【前端必會】使用indexedDB,降低環(huán)境搭建成本
文章起源:http://fisionsoft.com.cn/article/dsojgoh.html