Question

当我从POST保存新作者时，我想返回一条消息，表明新作者已被保存。（如果作者已经存在，我也最终会想要返回一些内容）我遇到的问题是，虽然作者在数据库中保存，但我无法从内部写入res.locals.messages author.save（）的回调参数。（另请注意，createAuthor是一个调用数组 - 我不确定这是否会使result的值变得更加困难。）

如何将result的值传递给路由器？

路线：

router.post('/', authorController.createAuthor, (req, res) => {
    res.json({ messages: res.locals.messages})
})

控制器：

exports.createAuthor = [

check('firstName', 'First name must be specified').isLength({min: 1}).trim(),
check('lastName', 'Last name must be specified').isLength({min: 1}).trim(),
sanitizeBody('firstName').trim().escape(),
sanitizeBody('lastName').trim().escape(),


(req, res, next) => {

    const errors = validationResult(req);
    var author = new Author({
        firstName: req.query.firstName,
        lastName: req.query.lastName
    });

    if (errors.isEmpty()) {

       //Edit: added find before save function:
        const query = {$or:[{firstName:{$regex: req.query.firstName, $options: 'i'}},
                {lastName:{$regex: req.query.lastName, $options: 'i'}}]} //TODO this regex fails if a parameter is missing.

        Author.findOne(query).sort([['lastName', 'ascending']]).exec((err, author) => {
            if (err) {
                return next(err)
            }

            if(!(author ==null)){
                var result = {status: "Author already exists: ", author_id: String(author.id)}
                res.locals.messages = result;
                next();
            }

        });


        author.save(function (err, newAuthor) {
            if (err) {
                return next(err)
            }

            var result = {status: "New author saved", author_id: String(newAuthor.id)}
            res.locals.messages = result;

        });
    }
    next();

}
];

Answer 1

您需要在处理保存后调用next 并设置res.locals值：

exports.createAuthor = [ check('firstName', 'First name must be specified').isLength({min: 1}).trim(), check('lastName', 'Last name must be specified').isLength({min: 1}).trim(), sanitizeBody('firstName').trim().escape(), sanitizeBody('lastName').trim().escape(), (req, res, next) => { const errors = validationResult(req); var author = new Author({ firstName: req.query.firstName, lastName: req.query.lastName }); if (errors.isEmpty()) { author.save(function (err, newAuthor) { if (err) { return next(err) } var result = {status: "New author saved", author_id: String(newAuthor.id)} res.locals.messages = result; next(); }); } else { // Remember to do something about these non-empty errors! next(new Error('Got more than 0 errors')); } } ];

另外，不要忘记处理验证错误数非零的情况：）

Answer 2

使用克里斯福斯特的评论，我能够做到这一点：

exports.createAuthor = [

check('firstName', 'First name must be specified').isLength({min: 1}).trim(),
check('lastName', 'Last name must be specified').isLength({min: 1}).trim(),
sanitizeBody('firstName').trim().escape(),
sanitizeBody('lastName').trim().escape(),


(req, res, next) => {

    const errors = validationResult(req);
    var author = new Author({
        firstName: req.query.firstName,
        lastName: req.query.lastName
    });

    if (errors.isEmpty()) {
        //TODO - Fix this query.
        const query = {
            $or: [{firstName: {$regex: req.query.firstName, $options: 'i'}},
                {lastName: {$regex: req.query.lastName, $options: 'i'}}]
        } 

        Author.findOne(query).sort([['lastName', 'ascending']]).exec((err, existingAuthor) => {
            if (err) {
                return next(err)
            }

            if (!(existingAuthor == null)) {
                var result = {status: "Author already exists: ", author_id: String(existingAuthor.id)}

                res.locals.messages = result;
                next();
            } else if (existingAuthor == null) {

                author.save(function (err, newAuthor) {
                    if (err) {
                        return next(err)
                    }

                    var result = {status: "New author saved", author_id: String(newAuthor.id)}
                    res.locals.messages = result;
                    next();
                });

            }
        });
    }
}
];

从回调函数内部发送值以表示路由器

2 个答案: