Embeer.js Ember.NativeArray mapBy()用法及代碼示例

Ember.js 是一個開源 JavaScript 框架，用於開發基於 Model-View-Controller (MVC) 架構的大型客戶端 Web 應用程序。 Ember.js是使用最廣泛的前端應用框架之一。它的目的是加速開發並提高生產力。目前，它被大量網站使用，包括 Square、Discourse、Groupon、Linked In、Live Nation、Twitch 和 Chipotle。

mapBy() 方法用於獲取枚舉中所有項目的指定屬性的值。與map方法類似。

用法:

mapBy( key );

參數：

key: 它是我們想要其值的屬性的名稱。

返回值：映射數組。

第 1 步：要運行以下示例，您需要有一個 ember 項目。要創建一個，您需要先安裝ember-cli。在終端中寫入以下代碼：

npm install ember-cli

第 2 步：現在您可以通過輸入以下代碼來創建項目：

ember new <project-name> --lang en

要啟動服務器，請鍵入：

ember serve

示例 1：鍵入以下代碼以生成本示例的路由：

ember generate route mapBy1

應用程序/路線/mapBy1.js

Javascript


import Route from "@ember/routing/route";
class employee {
    name = null;
    mobile = null;
    city = null;
    country = null;
    gender = null;
    zipCode = null;
    constructor(name, mobile, city, country, gender, zipCode) {
        this.name = name;
        this.mobile = mobile;
        this.city = city;
        this.country = country;
        this.gender = gender;
        this.zipCode = zipCode;
    }
    get_add() {
        return `${this.name} is Employee from ${this.city}`;
    }
}
export default class DetailsRoute extends Route {
    details = [
        new employee("Anubhav", "1298119967", 
            "Patna", "India", "M", "800020",),
        new employee("Yogesh", "1234567890", 
            "Raipur", "India", "M", "402001"),
        new employee("Satyam", "2222222222", 
            "Delhi", "India", "M", "110012"),
        new employee("Shivam", "1122113322", 
            "Patna", "India", "M", "530068"),
        new employee("Ayushi", "2244668800", 
            "Jaipur", "India", "F", "302001")
    ];
    city;
    start;
    end;
    model() {
        return this.details;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set("details", this.details);
        controller.set("city", this.city);
        controller.set("start", this.start);
        controller.set("end", this.end);
    }
}

應用程序/控製器/mapBy1.js

Javascript


import Ember from "ember";
import { isAny }
    from "@ember/array";
export default Ember.Controller.extend({
    actions: {
        getNames() {
            let ans = this.details.mapBy('name');
            alert(ans.join('\n'));
        },
        showAdd() {
            let res = this.details.invoke('get_add');
            alert(res.join('\n'));
        },
        checkFemale() {
            let res = this.details.isAny('gender', 'F');
            alert(res ? `Female employee present in List` : 
                `No Female present`);
        },
    },
});

應用程序/模板/mapBy1.hbs

Javascript


import Ember from "ember";
import { isAny }
    from "@ember/array";
export default Ember.Controller.extend({
    actions: {
        getNames() {
            let ans = this.details.mapBy('name');
            alert(ans.join('\n'));
        },
        showAdd() {
            let res = this.details.invoke('get_add');
            alert(res.join('\n'));
        },
        checkFemale() {
            let res = this.details.isAny('gender', 'F');
            alert(res ? `Female employee present in List` : 
                `No Female present`);
        },
    },
});

輸出：訪問 localhost:4200/mapBy1 查看輸出

Ember.js Ember.NativeArray mapBy 方法

示例 2：鍵入以下代碼以生成本示例的路由：

ember generate route mapBy2

應用程序/路線/mapBy2.js

Javascript


import Route from '@ember/routing/route';
import { } from '@ember/array';
class fruit {
    name = null;
    isFruit = null;
    color = null;
    constructor(name, isFruit, color) {
        this.name = name;
        this.isFruit = isFruit;
        this.color = color;
    }
    show_item() {
        return `${this.name} is 
            ${this.isFruit ? '' : 'not'} fruit`;
    }
}
export default class FruitsRoute extends Route {
    fruits = [
        new fruit('Lady Finger', false, 'green'),
        new fruit('Brinjal', false, 'purple'),
        new fruit('Apple', true, 'red'),
        new fruit('Grapes', true, 'green'),
        new fruit('Mango', true, 'yellow'),
        new fruit('Watermelon', true, 'red'),
        new fruit('Orange', true, 'orange')
    ];
    model() {
        return this.fruits;
    }
    setupController(controller, model) {
        super.setupController(controller, model);
        controller.set('fruits', this.fruits);
    }
}

應用程序/控製器/mapBy2.js

Javascript


import Ember from "ember";
import { isAny, isEvery } from "@ember/array";
export default Ember.Controller.extend({
    actions: {
        showFruit() {
            let ans = this.fruits.invoke("show_item")
            alert(ans.join('\n'));
        },
        alertFruit() {
            let ans = this.fruits.mapBy("name");
            alert(ans.join('\n'));
        },
        checkFruits() {
            let ans = this.fruits.isAny('isFruit', true);
            alert(ans ? "Fruits present in list" : 
                "Fruits not present in list")
        },
        checkvegy() {
            let ans = this.fruits.isAny('isFruit', false);
            alert(!ans ? "Vegetables present in list" : 
                "Vegetables not present in list")
        },
    },
});

應用程序/模板/mapBy2.hbs

Javascript


{{page-title "mapBy"}}
<h3>Here is a list of eatables: </h3>
<ul>
    {{#each @model as |eatable|}}
        <li>
              {{eatable.name}}
        </li>
      {{/each}}
</ul>
<br />
<input
    type="button"
      id="fruit-show"
      value="Check Fruits"
      {{action "showFruit"}}
/>
<br /><br />
<input
    type="button"
      id="fruit-all"
      value="Alert all Item names"
      {{action "alertFruit"}}
/>
<br /><br />
<input
    type="button"
      id="check-Fruits"
      value="Check any Fruit"
      {{action "checkFruits"}}
/>
<br /><br />
<input
    type="button"
      id="check-NonFruits"
      value="Check any Vegetables"
      {{action "checkvegy"}}
/>
{{outlet}}

輸出：訪問 localhost:4200/mapBy2 查看輸出

Ember.js Ember.NativeArray mapBy 方法

參考： https://api.emberjs.com/ember/4.4/classes/Ember.NativeArray/methods/mapBy?anchor=mapBy

相關用法

注：本文由純淨天空篩選整理自jeemains0neet大神的英文原創作品 Ember.js Ember.NativeArray mapBy() Method。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。