在发布功能中替换文档的属性 [英] Replace attributes of a document in publish function

问题描述

我正在使用meteor，我对发布功能（服务器端）有疑问

I'm using meteor and I have a question about the publish function (server side)

Meteor.publish('users', function () { .... }

我现在正在向浏览器发送文档具有其他集合的id。例如，任务文档属于项目

I'm sending now documents to the browser which have id's of other collections. For example the Task document belongs to a project

{ 
    title: '....',
    projectId: 'KjbJHvJCHTCJGVY234',
    ...
}

我想要的是在此文档中添加一个属性 projectTitle 所以我不必在客户端上查找项目。但是，当我在发布函数中添加此属性，它不会发送到客户端。这是我尝试过的：

What I want is to add a property to the this document projectTitle so I don't have to look up the project on the client. However, when I add this property in the publish function it is not send to the client. This is what I've tried:

Meteor.publish('tasks', function () {
    var tasks = Tasks.find();

    tasks.forEach(function (task) {
       var project = Projects.findOne({_id: task.projectId});
       task.projectTitle = project.title;
    });

    return tasks;
}

如何修改发布函数中的文档（非持久性）？ / p>

Any suggestions how to modify documents (not persistent) inside the publish function?

推荐答案

你可以这样做：

Meteor.publish("tasks", function() {

    var transform = function(task) {
        var project = Projects.findOne({_id: task.projectId});
        task.projectTitle = project.title;
        return task;
    }

    var self = this;

    var tasks = Tasks.find().observe({
        added: function (document) {
            self.added('tasks', document._id, transform(document));
        },
        changed: function (newDocument, oldDocument) {
            self.changed('tasks', document._id, transform(newDocument));
        },
        removed: function (oldDocument) {
            self.removed('tasks', oldDocument._id);
        }
    });

    self.ready();

    self.onStop(function () {
        tasks.stop();
    });

});

那里有很多自定义逻辑，但'transform'基本上添加了属性。

There's a lot of custom logic there, but the 'transform' basically adds the attributes in.

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