發送調用結果的異常：TypeError：不是流星中的一個函數

Question

當我在onSuccessCreateClass中添加到meteor.call回調中，並且出現此錯誤。不知道這裏有什麼問題嗎？

Exception in delivering result of invoking 'createClass': TypeError: this.onSuccessCreateClass is not a function at http://localhost:3000/app/client/components/MyClasses.jsx?044c7b228d4b33fcea4b9f3c05da6d82e5e6c8b7:37:11 at null._callback (http://localhost:3000/packages/meteor.js?9730f4ff059088b3f7f14c0672d155218a1802d4:999:22) at _.extend._maybeInvokeCallback (http://localhost:3000/packages/ddp-client.js?250b63e6c919c5383a0511ee4efbf42bb70a650f:3500:12) at .extend.dataVisible (http://localhost:3000/packages/ddp-client.js?250b63e6c919c5383a0511ee4efbf42bb70a650f:3529:10) at http://localhost:3000/packages/ddp-client.js?250b63e6c919c5383a0511ee4efbf42bb70a650f:4365:7 at Array.forEach (native) at Function..each._.forEach (http://localhost:3000/packages/underscore.js?46eaedbdeb6e71c82af1b16f51c7da4127d6f285:149:11) at _.extend._runAfterUpdateCallbacks (http://localhost:3000/packages/ddp-client.js?250b63e6c919c5383a0511ee4efbf42bb70a650f:4364:7) at _.extend._livedata_data (http://localhost:3000/packages/ddp-client.js?250b63e6c919c5383a0511ee4efbf42bb70a650f:4354:10) at onMessage (http://localhost:3000/packages/ddp-client.js?250b63e6c919c5383a0511ee4efbf42bb70a650f:3361:12)

onSuccessCreateClass() { 
    console.log("Successfully created New Class") 
    $("#createClassModal").modal('hide') 
    $('#createClassModal').on('hidden.bs.modal', function() { 
     $(this).find('form').trigger('reset') 
    }) 
}, 

onPressSubmit(e) { 
    e.preventDefault() 
    const className = e.target.cname.value 
    console.log(this.props.courseId) 
    console.log(className) 
    if (Meteor.user().classes.length !== 0) 
    { 
     console.log("Got Class") 
     Meteor.call("createClass", this.props.courseId, className, function(error) { 
      if (error) 
      { 
       console.log(error.reason) 
      } 
      else 
      { 
       this.onSuccessCreateClass() 
      } 
     }) 
    } 
    else 
    { 
     console.log("No Class") 
     Meteor.call("createNewClass", this.props.courseId, className, function(error) { 
      if (error) 
      { 
       console.log(error.reason) 
      } 
      else 
      { 
       this.onSuccessCreateClass() 
      } 
     }) 
    } 
}, 

Answer 1

應設置this在Meteor.call回調，因爲現在this是指全球範圍或undefined如果您正在使用strict mode。在JavaScript中有方法.bind允許一套this的方法

Meteor.call("createClass", this.props.courseId, className, function(error) { 
    if (error) { 
    console.log(error.reason) 
    } else { 
    this.onSuccessCreateClass() 
    } 
}.bind(this)) 

-

Meteor.call("createNewClass", this.props.courseId, className, function(error) { 
    if (error) { 
    console.log(error.reason) 
    } else { 
    this.onSuccessCreateClass() 
    } 
}.bind(this))