建立書籍表單

const { body, validationResult } = require("express-validator");

// Display book create form on GET.
exports.book_create_get = asyncHandler(async (req, res, next) => {
  // Get all authors and genres, which we can use for adding to our book.
  const [allAuthors, allGenres] = await Promise.all([
    Author.find().sort({ family_name: 1 }).exec(),
    Genre.find().sort({ name: 1 }).exec(),
  ]);

  res.render("book_form", {
    title: "Create Book",
    authors: allAuthors,
    genres: allGenres,
  });
});

// Handle book create on POST.
exports.book_create_post = [
  // Convert the genre to an array.
  (req, res, next) => {
    if (!Array.isArray(req.body.genre)) {
      req.body.genre =
        typeof req.body.genre === "undefined" ? [] : [req.body.genre];
    }
    next();
  },

  // Validate and sanitize fields.
  body("title", "Title must not be empty.")
    .trim()
    .isLength({ min: 1 })
    .escape(),
  body("author", "Author must not be empty.")
    .trim()
    .isLength({ min: 1 })
    .escape(),
  body("summary", "Summary must not be empty.")
    .trim()
    .isLength({ min: 1 })
    .escape(),
  body("isbn", "ISBN must not be empty").trim().isLength({ min: 1 }).escape(),
  body("genre.*").escape(),
  // Process request after validation and sanitization.

  asyncHandler(async (req, res, next) => {
    // Extract the validation errors from a request.
    const errors = validationResult(req);

    // Create a Book object with escaped and trimmed data.
    const book = new Book({
      title: req.body.title,
      author: req.body.author,
      summary: req.body.summary,
      isbn: req.body.isbn,
      genre: req.body.genre,
    });

    if (!errors.isEmpty()) {
      // There are errors. Render form again with sanitized values/error messages.

      // Get all authors and genres for form.
      const [allAuthors, allGenres] = await Promise.all([
        Author.find().sort({ family_name: 1 }).exec(),
        Genre.find().sort({ name: 1 }).exec(),
      ]);

      // Mark our selected genres as checked.
      for (const genre of allGenres) {
        if (book.genre.includes(genre._id)) {
          genre.checked = "true";
        }
      }
      res.render("book_form", {
        title: "Create Book",
        authors: allAuthors,
        genres: allGenres,
        book: book,
        errors: errors.array(),
      });
    } else {
      // Data from form is valid. Save book.
      await book.save();
      res.redirect(book.url);
    }
  }),
];

[
  // Convert the genre to an array.
  (req, res, next) => {
    if (!Array.isArray(req.body.genre)) {
      req.body.genre =
        typeof req.body.genre === "undefined" ? [] : [req.body.genre];
    }
    next();
  },
  // …
];

[
  // …
  body("genre.*").escape(),
  // …
];

// Mark our selected genres as checked.
for (const genre of allGenres) {
  if (book.genre.includes(genre._id)) {
    genre.checked = "true";
  }
}

extends layout

block content
  h1= title

  form(method='POST')
    div.form-group
      label(for='title') Title:
      input#title.form-control(type='text', placeholder='Name of book' name='title' required value=(undefined===book ? '' : book.title) )
    div.form-group
      label(for='author') Author:
      select#author.form-control(name='author' required)
        option(value='') --Please select an author--
        for author in authors
          if book
            if author._id.toString()===book.author._id.toString()
              option(value=author._id selected) #{author.name}
            else
              option(value=author._id) #{author.name}
          else
            option(value=author._id) #{author.name}
    div.form-group
      label(for='summary') Summary:
      textarea#summary.form-control(placeholder='Summary' name='summary' required)= undefined===book ? '' : book.summary
    div.form-group
      label(for='isbn') ISBN:
      input#isbn.form-control(type='text', placeholder='ISBN13' name='isbn' value=(undefined===book ? '' : book.isbn) required)
    div.form-group
      label Genre:
      div
        for genre in genres
          div(style='display: inline; padding-right:10px;')
            if genre.checked
              input.checkbox-input(type='checkbox', name='genre', id=genre._id, value=genre._id, checked)
            else
              input.checkbox-input(type='checkbox', name='genre', id=genre._id, value=genre._id)
            label(for=genre._id)  #{genre.name}
    button.btn.btn-primary(type='submit') Submit

  if errors
    ul
      for error in errors
        li!= error.msg