流星forEach（）無法解釋的改變傳遞的變量

Question

我花了好一個半小時試圖弄清楚這裏有什麼問題，而且我沒有任何運氣。真的很感謝一些幫助，提前致謝！

我的問題似乎是在下面的sendMailing（）meteor方法的「Roles.getUsersInRole（mailingAttributes.role）.forEach」循環中，由客戶端調用傳遞的變量「mailingAttributes」以某種方式被覆蓋，等通過foreach（）循環第二輪，沒有什麼的.replace（）的替換

1 -這裏是一個被髮送到sendMailing對象的實例（）流星法，以及forEach（）循環首次運行時如何出現

{ 
    role:  "admin", //Which user group to send the email to 
    subject:  "Hello [[firstName]]!", //Email subject 
    html:  "<h1>Hello [[firstName]] [[lastName]], how do you do?</h1>", //HTML Email 
    text:  "Hello [[firstName]] [[lastName]], how do you do?" //Plain Text Email 
} 

2 -現在在foreach（）將用戶對象和替換與用戶屬性的佔位符（第一&姓）

3 -鑑於用戶鮑勃·瓊斯，這裏是如何同一個對象的示例出現第二次foreach（）循環中運行，其中該物體應該是儲存

{ 
    role:  "admin", //Which user group to send the email to 
    subject:  "Hello Bob!", //Email subject 
    html:  "<h1>Hello Bob Jones, how do you do?</h1>", //HTML Email 
    text:  "Hello Bob Jones, how do you do?" //Plain Text Email 
} 

所以沒有什麼的.replaces（）來改變......但我永遠不會改變的變量（mailingAttributes）...所以例1和2之間應該沒有區別

這裏是我的實際代碼：

function sendMailingEmail(mailingAttributes) { 
    //Send email 
    Email.send({ 
     from: 'no-reply@test.com', 
     to: mailingAttributes.to, 
     subject: mailingAttributes.subject, 
     html: mailingAttributes.html, 
     text: mailingAttributes.text, 
    }); 
} 

//Set up rate limiting on the email send function 
var sendMail = rateLimit(sendMailingEmail, 75); // wait at least 75 milliseconds between calls (1 second/14 emails) 

Meteor.methods({ 
    sendMailing: function(mailingAttributes) { 

     //Check incoming attributes 
     check(mailingAttributes, { 
      role:  String, 
      subject:  String, 
      html:  String, 
      text:  String 
     }); 

     // Confirm the user is logged in 
     if (this.userId === null || !Roles.userIsInRole(this.userId, 'admin')) 
      throw new Meteor.Error(401, 'You must be logged in and authorized'); 

     Roles.getUsersInRole(mailingAttributes.role).forEach(function(userObject) { 
      //Create a temporary copy of the passed attributes 
      var userMailingAttributes = mailingAttributes; 

      //Make sure the user is subscribed to mailings 
      if (userObject.profile.subscribed === true) { 
       //Replace placeholders in text with user profile information 
       userMailingAttributes.subject = userMailingAttributes.subject.replace("[[firstName]]", userObject.profile.firstName).replace("[[lastName]]", userObject.profile.lastName); 
       userMailingAttributes.text = userMailingAttributes.text.replace("[[firstName]]", userObject.profile.firstName).replace("[[lastName]]", userObject.profile.lastName); 
       userMailingAttributes.html = userMailingAttributes.html.replace("[[firstName]]", userObject.profile.firstName).replace("[[lastName]]", userObject.profile.lastName); 
       userMailingAttributes.to = userObject.emails[0].address; 

       //Call the rate limited function, passing along the temporary copy of passed attributes (edited above) 
       sendMail(userMailingAttributes); 
      } 
     }); 
    } 
}); 

我使用的alanning：角色& dandv：限速包

Answer 1

的問題是這樣的：

//Create a temporary copy of the passed attributes 
var userMailingAttributes = mailingAttributes; 

不創建傳遞的屬性的臨時副本 - 它創建一個新的引用指向內存中的相同位置。如果你改變了那個，你正在改變另一個。

你想要做的是clone the object並使用克隆的對象而不是對同一對象的引用。