javascript - 关于请求参数的命名/选择的困惑

Question

我很难理解请求参数的命名方式(例如 req.params.id、req.body.authorid 等)以及它们与其他变量的关系。

可以为它们分配任何随机名称吗？ (例如 req.params.x、req.body.y)

对于author_delete_get函数中的以下代码，似乎只接受req.params.id。将其更改为例如 req.params.x 将导致错误。

对于 author_delete_post 函数，将 req.body.authorid 更改为 req.body.authorids 似乎不会影响功能。

authorController.js

// Display Author delete form on GET
exports.author_delete_get = 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 }).exec(callback);
      },
  }, function(err, results) {
      if (err) { return next(err); }
      //Successful, so render
      res.render('author_delete', { title: 'Delete Author', author: results.author, author_books: results.authors_books } );
  });
};

// Handle Author delete on POST
exports.author_delete_post = function(req, res, next) {
  req.checkBody('authorid', 'Author id must exist').notEmpty();
  async.parallel({
      author: function(callback) {
          Author.findById(req.body.authorid).exec(callback);
      },
      authors_books: function(callback) {
        Book.find({ 'authors': req.body.authorid },'title summary').exec(callback);
      },
  }, function(err, results) {
      if (err) { return next(err); }
      //Success
      if (results.authors_books>0) {
          //Author has books. Render in same way as for GET route.
          res.render('author_delete', { title: 'Delete Author', author: results.author, author_books: results.authors_books } );
          return;
      }
      else {
        //Author has no books. Delete object and redirect to the list of authors.
          Author.findByIdAndRemove(req.body.authorid, function deleteAuthor(err) {
              if (err) { return next(err); }
              //Success - got to author list
              res.redirect('/catalog/authors');
          });
      }
  });
};

目录.js

/* GET request to delete Author. */
router.get('/author/:id/delete', author_controller.author_delete_get);

// POST request to delete Author
router.post('/author/:id/delete', author_controller.author_delete_post);

author_detail.pug

extends layout

block content

  h1 Author: #{author.name}
  p #{author.date_of_birth_formatted} - #{author.date_of_death_formatted}

  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}
      br
    else
      p This author has no books.
    br
    p
      a(href=author.url+'/delete') Delete author

author_delete.pug

extends layout

block content
  h1 #{title}: #{author.name}
  p= author.lifespan

  if author_books.length

    p #[strong Delete the following books before attempting to delete this author.]

    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 Do you really want to delete this Author?

    form(method='POST' action='')
      div.form-group
        input#authorid.form-control(name='authorid', required='true', value=author._id )

      button.btn.btn-primary(type='submit') Delete

Answer 1

在 req.params.id 中，.id 部分来自以下内容的 :id 部分:

router.get('/author/:id/delete', author_controller.author_delete_get);

从与此请求匹配的 URL 中解析。

<小时/>

在 req.body.authorid 中，.authorid 部分来自通过 POST 请求提交的表单数据，它可能来自表单的这一部分:

input#authorid.form-control(name='authorid', required='true', value=author._id )

如果您尝试使用此表单字段，更改它会产生影响。