Ember CLI中的承諾/ Ember.js

Question

我正在嘗試編寫一個ember-cli-deploy插件，並且可以真正使用一些有關promise的幫助。在我的index.js主插件，我有以下代碼 index.js：

prepare: function(context) { 
    ... 
    ... 
    var awsDeploymentOptions = {....}; 
    this._awsCodeDeployClient = new CodeDeployClient({awsDeploymentOptions: awsDeploymentOptions}); 

} 
upload: function() { 
    ... 
    ... 
    var uploadPromise = (awsDeploymentOptions.revision.revisionType === 'S3') ? this._awsS3Client.upload(filesToUpload, this.readConfig('s3UploadOptions')) : new Promise().resolve(); 
    return uploadPromise.then(function(result){return this._awsCodeDeployClient.createDeployment(result)}.bind(this)); 
} 

預期和承諾得到妥善解決上述作品。

如果我上面的代碼更改爲：

return uploadPromise.then(this._awsCodeDeployClient.createDeployment); 

，代碼失敗。然後，我嘗試以下，這也將失敗：

return uploadPromise.then(this._awsCodeDeployClient.createDeployment.bind(this)); 

在上述兩種情況下，它抱怨未定義的變量/ createDeployment方法，其被定義爲下面的內部屬性：

createDeployment: function(s3FileUploadOptions) { 
    return new Promise(function(resolve, reject) { 
     //This is where the problem lies. this is never resolved 
     //to this module's 'this' and I cannot access this.deploymentOptions 
     //Any reference to 'this' variable causes an error 
     var awsDeploymentOptions = this.awsDeploymentOptions; 
     this.codeDeploy.createDeployment(this.awsDeploymentOptions, function(error, data) { 
      if (error) 
       reject(error); // an error occurred 
      else resolve({awsDeploymentId:data.deploymentId}); // successful response. Return deployment Id 
     }.bind(this)); 
    }.bind(this)); 
} 

什麼我在上面的兩個場景中做錯了嗎？

Answer 1

這個怎麼樣？

return uploadPromise.then(result => this._awsCodeDeployClient.createDeployment(result)); 

Arrow functions保持作用域內的範圍。