从集合中获取数据会给出“无法读取属性”按钮1“未定义”

Question

我试图在文档准备就绪时从MongoDb集合中获取4个值，但它给出了“无法读取”按钮1“未定义”。

ButtonsList = new Meteor.Collection('list');

$(document).ready(function(){
    var obj = ButtonsList.findOne({_id:'ZcLkjSwNGTpgHkoeq'});

    //button1 - button4 are fields that have some values
    var b1 = obj.button1;
    var b2 = obj.button2;
    var b3 = obj.button3;
    var b4 = obj.button4;

    console.log(b1);
    console.log(b2);
    console.log(b3);
    console.log(b4);
});

顺便说一下，当我点击一个按钮时它会起作用，但我想在页面加载时这样做。单击按钮

时，这是工作代码

'click .getRec': function(){

    var num = ButtonsList.findOne({_id:'ZcLkjSwNGTpgHkoeq'});

    var b1 = num.button1;
    var b2 = num.button2;
    var b3 = num.button3;
    var b4 = num.button4;
    console.log("button number is: "+b1);
    console.log("button number is: "+b2);
    console.log("button number is: "+b3);
    console.log("button number is: "+b4);
}