Question

我需要在loopback应用程序中访问一些数据。为此，我刚刚在accessToken中附加了数据。并且可以很方便。

但是有一段时间我的linux服务器被关闭了。在查看永远日志时，我发现了一些错误，即超出最大通话大小。

module.exports = function (options) {
        return function storeCurrentUser(req, res, next) {
            if (!req.accessToken) {
                next();
            }else{
                app.models.User.findById(req.accessToken.userId, function (err, user) {
                    if (err) {
                        next(err);
                    }
                    if (!user) {
                        next(new Error('No user with this access token was found.'));
                    }else{                   
                        var PM = app.registry.getModel("PersistedModel");
                        PM.observe("access", function (ctx, next) {
                            ctx.options.data = req.accessToken.data; // each error showing this line
                            next();
                        });
                        next();
                    }
                });      
            } 
        };
    };

记录错误：

有请求GET / API / ACL可以使用未处理的= {误差％二条％22：{％22principalId％22：％22admin％22}}＆安培; =的access_token 4N8gnOrgGUpjVDohYsNj9pWBruUFhif8NCjg95RoITxU1xDGwvcgFwTGjxNbqs9C：？的RangeError：最大调用堆栈大小超过在补充（/home/ubuntu/hms/node_modules/loopback-datasource-juggler/node_modules/async/dist/async.js:870：27）在iterateeCallback（/home/ubuntu/hms/node_modules/loopback-datasource-juggler/node_modules/async/dist/async.js:866:17） at /home/ubuntu/hms/node_modules/loopback-datasource-juggler/node_modules/async/dist/async.js:843:16 在/home/ubuntu/hms/server/middleware/store-current-user.js:62:25 在notifySingleObserver（/home/ubuntu/hms/node_modules/loopback-datasource-juggler/lib/observer.js:160:22） at /home/ubuntu/hms/node_modules/loopback-datasource-juggler/node_modules/async/dist/async.js:3025:16 在补充（/home/ubuntu/hms/node_modules/loopback-datasource-juggler/node_modules/async/dist/async.js:881:17）在iterateeCallback（/home/ubuntu/hms/node_modules/loopback-datasource-juggler/node_modules/async/dist/async.js:866:17） at /home/ubuntu/hms/node_modules/loopback-datasource-juggler/node_modules/async/dist/async.js:843:16 在/home/ubuntu/hms/server/middleware/store-current-user.js:62:25 在notifySingleObserver（/home/ubuntu/hms/node_modules/loopback-datasource-juggler/lib/observer.js:160:22） at /home/ubuntu/hms/node_modules/loopback-datasource-juggler/node_modules/async/dist/async.js:3025:16 在补充（/home/ubuntu/hms/node_modules/loopback-datasource-juggler/node_modules/async/dist/async.js:881:17）在iterateeCallback（/home/ubuntu/hms/node_modules/loopback-datasource-juggler/node_modules/async/dist/async.js:866:17） at /home/ubuntu/hms/node_modules/loopback-datasource-juggler/node_modules/async/dist/async.js:843:16 at /home/ubuntu/hms/server/middleware/store-current-user.js:62:25

由于我有多个模型，因此不同文件的最大大小超出错误。

我用过

mongodb v3.6

loopback v3

angular 4

请有人帮忙或指导，可能的原因是什么？

Answer 1

显然PM.observe的问题就像我理解的那样在每次请求时被调用，因此对于每个请求你都有一个+1的监听器模型。

最好将上下文用于此类目的 https://loopback.io/doc/en/lb3/Using-current-context.html

例如： server.js或中间件

app.remotes().phases.addBefore('invoke', 'options-from-request').use(function(ctx, next) {
        ctx.shared = {};
        let promise;
        let accessToken = ctx.req.accessToken;
        if (accessToken) {
            promise = app.models.OrmUser.findOne({
                where: {
                    id: accessToken.userId
                }
            });
            promise.then(function(result) {
                if (!result) {
                    return next(new Error('No user with this access token was found.')) || null;
                }
                ctx.shared.currentUser = result;
                return Promise.resolve(result);
            }).catch(function(err) {
                return next(err);
            });
        } else {
            promise = Promise.resolve(null);
        }
        promise.then(function(result) {
            let options = ctx.args.options || {};
            options.remoteCtx = ctx;
            ctx.args.options = options;
            return next() || null;
        }).catch(function(err) {
            return next(err) || null;
        });
    });

你的模特：

Model.process = function(data, options, cb) {
            if (typeof options == 'function') {
                cb = options;
                options = {};
            }
            cb = cb || utils.createPromiseCallback();

            // from context
            let remoteCtx = options && options.remoteCtx;
            let shared = remoteCtx && remoteCtx.shared;
            let currentUser = shared && shared.currentUser;

            cb(new Error('no impl'));
            return cb.promise;
        };

        Model.remoteMethod('process', {
            accessType: 'WRITE',
            accepts: [{
                arg: 'data',
                type: 'object',
                required: true,
                http: {
                    source: 'body'
                }
            }, {
                arg: 'options',
                type: 'object',
                http: 'optionsFromRequest'
            }],
            http: {
                path: '/process',
                verb: 'post'
            },
            returns: {
                type: Model.modelName,
                root: true
            }
        });

Loopback如何处理RangeError：超出最大调用堆栈大小？

记录错误：

1 个答案: