Next we'll implement our list of all book copies (
BookInstance
) in the library. This page needs to include the title of the
Book
associated with each
BookInstance
(linked to its detail page) along with other information in the
BookInstance
model, including the status, imprint, and unique id of each copy. The unique id text should be linked to the
BookInstance
detail page.
BookInstance
list controller function needs to get a list of all book instances, populate the associated book information, and then pass the list to the template for rendering.
打开
/controllers/bookinstanceController.js
.
Find the exported
bookinstance_list()
controller method and replace it with the following code.
// Display list of all BookInstances.
exports.bookinstance_list = function(req, res, next) {
BookInstance.find()
.populate('book')
.exec(function (err, list_bookinstances) {
if (err) { return next(err); }
// Successful, so render
res.render('bookinstance_list', { title: 'Book Instance List', bookinstance_list: list_bookinstances });
});
};
The method uses the model's
find()
function to return all
BookInstance
objects. It then daisy-chains a call to
populate()
采用
book
field—this will replace the book id stored for each
BookInstance
with a full
Book
文档。
On success, the callback passed to the query renders the
bookinstance_list
(.pug) template, passing the
title
and
bookinstance_list
as variables.
创建 /views/bookinstance_list.pug and copy in the text below.
extends layout
block content
h1= title
ul
each val in bookinstance_list
li
a(href=val.url) #{val.book.title} : #{val.imprint} -
if val.status=='Available'
span.text-success #{val.status}
else if val.status=='Maintenance'
span.text-danger #{val.status}
else
span.text-warning #{val.status}
if val.status!='Available'
span (Due: #{val.due_back} )
else
li There are no book copies in this library.
This view is much the same as all the others. It extends the layout, replacing the
content
block, displays the
title
passed in from the controller, and iterates through all the book copies in
bookinstance_list
. For each copy we display its status (color coded) and if the book is not available, its expected return date. One new feature is introduced—we can use dot notation after a tag to assign a class. So
span.text-success
will be compiled to
<span class="text-success">
(and might also be written in Pug as
span(class="text-success")
.
Run the application, open your browser to
http://localhost:3000/
, then select the
All book-instances
link. If everything is set up correctly, your site should look something like the following screenshot.
最后修改： , 由 MDN 贡献者