Files
Shaun Hamilton c2a11ad00d feat: add 'back/front end' in curriculum (#42596)
* chore: rename APIs and Microservices to include "Backend" (#42515)

* fix typo

* fix typo

* undo change

* Corrected grammar mistake

Corrected a grammar mistake by removing a comma.

* change APIs and Microservices cert title

* update title

* Change APIs and Microservices certi title

* Update translations.json

* update title

* feat(curriculum): rename apis and microservices cert

* rename folder structure

* rename certificate

* rename learn Markdown

* apis-and-microservices -> back-end-development-and-apis

* update backend meta

* update i18n langs and cypress test

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>

* fix: add development to front-end libraries (#42512)

* fix: added-the-word-Development-to-front-end-libraries

* fix/added-the-word-Development-to-front-end-libraries

* fix/added-word-development-to-front-end-libraries-in-other-related-files

* fix/added-the-word-Development-to-front-end-and-all-related-files

* fix/removed-typos-from-last-commit-in-index.md

* fix/reverted-changes-that-i-made-to-dependecies

* fix/removed xvfg

* fix/reverted changes that i made to package.json

* remove unwanted changes

* front-end-development-libraries changes

* rename backend certSlug and README

* update i18n folder names and keys

* test: add legacy path redirect tests

This uses serve.json from the client-config repo, since we currently use
that in production

* fix: create public dir before moving serve.json

* fix: add missing script

* refactor: collect redirect tests

* test: convert to cy.location for stricter tests

* rename certificate folder to 00-certificates

* change crowdin config to recognise new certificates location

* allow translations to be used

Co-authored-by: Nicholas Carrigan (he/him) <nhcarrigan@gmail.com>

* add forwards slashes to path redirects

* fix cypress path tests again

* plese cypress

* fix: test different challenge

Okay so I literally have no idea why this one particular challenge
fails in Cypress Firefox ONLY. Tom and I paired and spun a full build
instance and confirmed in Firefox the page loads and redirects as
expected. Changing to another bootstrap challenge passes Cypress firefox
locally. Absolutely boggled by this.

AAAAAAAAAAAAAAA

* fix: separate the test

Okay apparently the test does not work unless we separate it into
a different `it` statement.

>:( >:( >:( >:(

Co-authored-by: Sujal Gupta <55016909+heysujal@users.noreply.github.com>
Co-authored-by: Noor Fakhry <65724923+NoorFakhry@users.noreply.github.com>
Co-authored-by: Oliver Eyton-Williams <ojeytonwilliams@gmail.com>
Co-authored-by: Nicholas Carrigan (he/him) <nhcarrigan@gmail.com>
2021-08-13 21:57:13 -05:00

3.6 KiB

id, title, challengeType, forumTopicId, dashedName
id title challengeType forumTopicId dashedName
5a24c314108439a4d403618b 給同級元素一個唯一的鍵屬性 6 301394 give-sibling-elements-a-unique-key-attribute

--description--

上一個挑戰展示瞭如何使用 map 方法根據用戶輸入動態渲染多個元素。 然而,這個例子中缺少一個重要的部分。 創建元素數組時,每個元素都需要一個設置爲唯一值的 key 屬性。 React 使用這些鍵來跟蹤哪些項目被添加、更改或刪除。 這有助於在以任何方式修改列表時提高重新渲染過程的效率。

注意: 鍵只需要在兄弟元素之間是唯一的,它們不需要在應用程序中是全局唯一的。

--instructions--

代碼編輯器有一個數組,它包含一些前端框架和一個名爲 Frameworks() 的無狀態函數組件。 Frameworks() 需要將數組映射到無序列表,就像上一個挑戰一樣。 完成 map 回調,爲 frontEndFrameworks 數組中的每個框架返回一個 li 元素。 這次,確保給每個 likey 屬性設置一個唯一的值。 li 元素還應該包含來自 frontEndFrameworks 的文本。

通常,希望使 key 能唯一標識要渲染的元素。 數組索引可以是最後的選擇,但通常你應該嘗試使用唯一標識。

--hints--

Frameworks 組件應該存在並渲染到頁面。

assert(
  Enzyme.mount(React.createElement(Frameworks)).find('Frameworks').length === 1
);

Frameworks 應該渲染一個 h1 元素。

assert(Enzyme.mount(React.createElement(Frameworks)).find('h1').length === 1);

Frameworks 應該渲染一個 ul 元素。

assert(Enzyme.mount(React.createElement(Frameworks)).find('ul').length === 1);

ul 標籤應該渲染 6 個子 li 元素。

assert(
  Enzyme.mount(React.createElement(Frameworks)).find('ul').children().length ===
    6 &&
    Enzyme.mount(React.createElement(Frameworks))
      .find('ul')
      .childAt(0)
      .name() === 'li' &&
    Enzyme.mount(React.createElement(Frameworks)).find('li').length === 6
);

每個列表項元素應該具有唯一的 key 屬性。

assert(
  (() => {
    const ul = Enzyme.mount(React.createElement(Frameworks)).find('ul');
    const keys = new Set([
      ul.childAt(0).key(),
      ul.childAt(1).key(),
      ul.childAt(2).key(),
      ul.childAt(3).key(),
      ul.childAt(4).key(),
      ul.childAt(5).key()
    ]);
    return keys.size === 6;
  })()
);

每個列表項元素應該包含來自 frontEndFrameworks 的文本。

assert(
  (() => {
    const li = Enzyme.mount(React.createElement(Frameworks))
      .find('ul')
      .children();
    return [...Array(5)].every((_, i) =>
      frontEndFrameworks.includes(li.at(i).text())
    );
  })()
);

--seed--

--after-user-code--

ReactDOM.render(<Frameworks />, document.getElementById('root'))

--seed-contents--

const frontEndFrameworks = [
  'React',
  'Angular',
  'Ember',
  'Knockout',
  'Backbone',
  'Vue'
];

function Frameworks() {
  const renderFrameworks = null; // Change this line
  return (
    <div>
      <h1>Popular Front End JavaScript Frameworks</h1>
      <ul>
        {renderFrameworks}
      </ul>
    </div>
  );
};

--solutions--

const frontEndFrameworks = [
  'React',
  'Angular',
  'Ember',
  'Knockout',
  'Backbone',
  'Vue'
];

function Frameworks() {
  const renderFrameworks = frontEndFrameworks.map((fw, i) => <li key={i}>{fw}</li>);
  return (
    <div>
      <h1>Popular Front End JavaScript Frameworks</h1>
      <ul>
        {renderFrameworks}
      </ul>
    </div>
  );
};