如何避免Uncaught TypeError：無法讀取Meteor的屬性'appendChild'爲null？

Question

當使用第三方庫如UserVoice和Meteor時，如何根據加載順序避免Uncaught TypeError: Cannot read property 'appendChild' of null錯誤？

我把這個文件client/uservoice.js

// Include the UserVoice JavaScript SDK (only needed once on a page) 
UserVoice=window.UserVoice||[];(function(){var uv=document.createElement('script');uv.type='text/javascript';uv.async=true;uv.src='//widget.uservoice.com/GSl7xKyRNrN4iiGY3j53hA.js';var s=document.getElementsByTagName('script')[0];s.parentNode.insertBefore(uv,s)})(); 

// 
// UserVoice Javascript SDK developer documentation: 
// https://www.uservoice.com/o/javascript-sdk 
// 

// Set colors 
UserVoice.push(['set', { 
    accent_color: '#448dd6', 
    trigger_color: 'white', 
    trigger_background_color: 'rgba(46, 49, 51, 0.6)' 
}]); 

// Identify the user and pass traits 
// To enable, replace sample data with actual user traits and uncomment the line 
UserVoice.push(['identify', { 
    //email:  'john.doe@example.com', // User’s email address 
    //name:  'John Doe', // User’s real name 
    //created_at: 1364406966, // Unix timestamp for the date the user signed up 
    //id:   123, // Optional: Unique id of the user (if set, this should not change) 
    //type:  'Owner', // Optional: segment your users by type 
    //account: { 
    // id:   123, // Optional: associate multiple users with a single account 
    // name:   'Acme, Co.', // Account name 
    // created_at: 1364406966, // Unix timestamp for the date the account was created 
    // monthly_rate: 9.99, // Decimal; monthly rate of the account 
    // ltv:   1495.00, // Decimal; lifetime value of the account 
    // plan:   'Enhanced' // Plan name for the account 
    //} 
}]); 

// Add default trigger to the bottom-right corner of the window: 
UserVoice.push(['addTrigger', { mode: 'contact', trigger_position: 'bottom-right' }]); 

// Or, use your own custom trigger: 
//UserVoice.push(['addTrigger', '#id', { mode: 'contact' }]); 

// Autoprompt for Satisfaction and SmartVote (only displayed under certain conditions) 
UserVoice.push(['autoprompt', {}]); 

Answer 1

感謝@hubert的小費。

在Meteor.startup包裝它伎倆。

Meteor.startup(function() { 
// Include the UserVoice JavaScript SDK (only needed once on a page) 
    UserVoice=window.UserVoice||[];(function(){var uv=document.createElement('script');uv.type='text/javascript';uv.async=true;uv.src='//widget.uservoice.com/GSl7xKyRNrN4iiGY3j53hA.js';var s=document.getElementsByTagName('script')[0];s.parentNode.insertBefore(uv,s)})(); 

    // 
    // UserVoice Javascript SDK developer documentation: 
    // https://www.uservoice.com/o/javascript-sdk 
    // 

    // Set colors 
    UserVoice.push(['set', { 
    accent_color: '#448dd6', 
    trigger_color: 'white', 
    trigger_background_color: 'rgba(46, 49, 51, 0.6)' 
    }]); 

    // Identify the user and pass traits 
    // To enable, replace sample data with actual user traits and uncomment the line 
    UserVoice.push(['identify', { 
    //email:  'john.doe@example.com', // User’s email address 
    //name:  'John Doe', // User’s real name 
    //created_at: 1364406966, // Unix timestamp for the date the user signed up 
    //id:   123, // Optional: Unique id of the user (if set, this should not change) 
    //type:  'Owner', // Optional: segment your users by type 
    //account: { 
    // id:   123, // Optional: associate multiple users with a single account 
    // name:   'Acme, Co.', // Account name 
    // created_at: 1364406966, // Unix timestamp for the date the account was created 
    // monthly_rate: 9.99, // Decimal; monthly rate of the account 
    // ltv:   1495.00, // Decimal; lifetime value of the account 
    // plan:   'Enhanced' // Plan name for the account 
    //} 
    }]); 

    // Add default trigger to the bottom-right corner of the window: 
    UserVoice.push(['addTrigger', { mode: 'contact', trigger_position: 'bottom-right' }]); 

    // Or, use your own custom trigger: 
    //UserVoice.push(['addTrigger', '#id', { mode: 'contact' }]); 

    // Autoprompt for Satisfaction and SmartVote (only displayed under certain conditions) 
    UserVoice.push(['autoprompt', {}]); 

});