著者詳細ページ

著者詳細ページには、指定された Author に関する情報を、その (自動的に生成された) _id フィールド値を使用して識別し、その Author に関連するすべての Book オブジェクトのリストを表示する必要があります。

Controller

Open /controllers/authorController.js.

Add the following lines to the top of the file to import the async and Book modules (these are needed for our author detail page).

js
var async = require("async");
var Book = require("../models/book");

Find the exported author_detail() controller method and replace it with the following code.

js
// Display detail page for a specific Author.
exports.author_detail = function (req, res, next) {
  async.parallel(
    {
      author: function (callback) {
        Author.findById(req.params.id).exec(callback);
      },
      authors_books: function (callback) {
        Book.find({ author: req.params.id }, "title summary").exec(callback);
      },
    },
    function (err, results) {
      if (err) {
        return next(err);
      } // Error in API usage.
      if (results.author == null) {
        // No results.
        var err = new Error("Author not found");
        err.status = 404;
        return next(err);
      }
      // Successful, so render.
      res.render("author_detail", {
        title: "Author Detail",
        author: results.author,
        author_books: results.authors_books,
      });
    },
  );
};

The method uses async.parallel() to query the Author and their associated Book instances in parallel, with the callback rendering the page when (if) both requests complete successfully. The approach is exactly the same as described for the Genre detail page above.

View

Create /views/author_detail.pug and copy in the following text.

js
extends layout

block content

  h1 Author: #{author.name}
  p #{author.date_of_birth} - #{author.date_of_death}

  div(style='margin-left:20px;margin-top:20px')

    h4 Books

    dl
      each book in author_books
        dt
          a(href=book.url) #{book.title}
        dd #{book.summary}

      else
        p This author has no books.

Everything in this template has been demonstrated in previous sections.

What does it look like?

Run the application and open your browser to http://localhost:3000/. Select the All Authors link, then select one of the authors. If everything is set up correctly, your site should look something like the following screenshot.

Author Detail Page - Express Local Library site

メモ: The appearance of the author lifespan dates is ugly! We'll address that in the final challenge in this article.

Next steps