Book detail page
needs to display the information for a specific
Book
(identified using its automatically generated
_id
field value), along with information about each associated copy in the library (
BookInstance
). Wherever we display an author, genre, or book instance, these should be linked to the associated detail page for that item.
打开
/controllers/bookController.js
. Find the exported
book_detail()
controller method and replace it with the following code.
// Display detail page for a specific book.
exports.book_detail = function(req, res, next) {
async.parallel({
book: function(callback) {
Book.findById(req.params.id)
.populate('author')
.populate('genre')
.exec(callback);
},
book_instance: function(callback) {
BookInstance.find({ 'book': req.params.id })
.exec(callback);
},
}, function(err, results) {
if (err) { return next(err); }
if (results.book==null) { // No results.
var err = new Error('Book not found');
err.status = 404;
return next(err);
}
// Successful, so render.
res.render('book_detail', { title: results.book.title, book: results.book, book_instances: results.book_instance } );
});
};
注意： We don't need to require async and BookInstance in this step, as we already imported those modules when we implemented the home page controller.
The method uses
async.parallel()
to find the
Book
and its associated copies (
BookInstances
) in parallel. The approach is exactly the same as described for the
Genre detail page
. Since the key 'title' is used to give name to the webpage (as defined in the header in 'layout.pug'), this time we are passing
results.book.title
while rendering the webpage.
创建 /views/book_detail.pug and add the text below.
extends layout
block content
h1 Title: #{book.title}
p #[strong Author:]
a(href=book.author.url) #{book.author.name}
p #[strong Summary:] #{book.summary}
p #[strong ISBN:] #{book.isbn}
p #[strong Genre:]
each val, index in book.genre
a(href=val.url) #{val.name}
if index < book.genre.length - 1
|,
div(style='margin-left:20px;margin-top:20px')
h4 Copies
each val in book_instances
hr
if val.status=='Available'
p.text-success #{val.status}
else if val.status=='Maintenance'
p.text-danger #{val.status}
else
p.text-warning #{val.status}
p #[strong Imprint:] #{val.imprint}
if val.status!='Available'
p #[strong Due back:] #{val.due_back}
p #[strong Id:]
a(href=val.url) #{val._id}
else
p There are no copies of this book in the library.
Almost everything in this template has been demonstrated in previous sections.
注意： The list of genres associated with the book is implemented in the template as below. This adds a comma after every genre associated with the book except for the last one.
p #[strong Genre:]
each val, index in book.genre
a(href=val.url) #{val.name}
if index < book.genre.length - 1
|,
Run the application and open your browser to
http://localhost:3000/
. Select the
All books
link, then select one of the books. If everything is set up correctly, your page should look something like the following screenshot.
最后修改： , 由 MDN 贡献者