阿賈克斯承諾不工作

Question

我試圖使用承諾返回當前登錄的用戶和SharePoint中的列表中的字段的比較。

function compareCurrentUserWithListObject() { 
    var userProp = this._userProfileProperties; 
    var userName = userProp.get_userProfileProperties()['UserName']; 

    return this._list.filter(function (element, index, array) { 
    var promise = jQuery.ajax({ 
     url: _spPageContextInfo.webAbsoluteUrl + "/_api/web/GetUserById(" + element.user.get_lookupId() + ")", 
     type: "GET", 
     headers: { "Accept": "application/json;odata=verbose" } 
    }); 
    promise.done(function(data) { 
     return (data.d.Email.indexOf(userName) > -1); 
    }); 
    }); 
} 

function init() { 
    var userArray = this.compareCurrentUserWithListObject(); 
    userArray.done(function(res) { 
    if (res.length > 0) { 
     //Do some stuff after compare... 
    } 
    }); 
} 

我不知道我在這裏使用.done正確。有人能幫我嗎？

編輯：

工作代碼：

function compareCurrentUserWithListObject() { 
    var userProp = this._userProfileProperties; 
    var userName = userProp.get_userProfileProperties()['UserName']; 

    return this._list.filter(function (element, index, array) { 
    var promise = jQuery.ajax({ 
     url: _spPageContextInfo.webAbsoluteUrl + "/_api/web/GetUserById(" + element.user.get_lookupId() + ")", 
     type: "GET", 
     headers: { "Accept": "application/json;odata=verbose" } 
    }); 
    promise.done(function(data) { 
     return (data.d.Email.indexOf(userName) > -1); 
    }); 
    return promise; 
    }); 
} 

function init() { 
    var userArray = this.compareCurrentUserWithListObject(); 
    if (userArray.length > 0) { 
     //Do some stuff after compare... 
    } 
} 

Answer 1

你需要返回的承諾

function compareCurrentUserWithListObject() { 
    var userProp = this._userProfileProperties; 
    var userName = userProp.get_userProfileProperties()['UserName']; 

    return this._list.filter(function (element, index, array) { 
    var promise = jQuery.ajax({ 
     url: _spPageContextInfo.webAbsoluteUrl + "/_api/web/GetUserById(" + element.user.get_lookupId() + ")", 
     type: "GET", 
     headers: { "Accept": "application/json;odata=verbose" } 
    }); 
    promise.done(function(data) { 
     return (data.d.Email.indexOf(userName) > -1); 
    }); 
    // return promise here 
    return promise; 
    }); 
} 

或本（這是清潔IMO）：

function compareCurrentUserWithListObject() { 
    var userProp = this._userProfileProperties; 
    var userName = userProp.get_userProfileProperties()['UserName']; 


    return jQuery.ajax({ 
     url: _spPageContextInfo.webAbsoluteUrl + "/_api/web/GetUserById(" + element.user.get_lookupId() + ")", 
     type: "GET", 
     headers: { "Accept": "application/json;odata=verbose" } 
    }); 

} 


function init() { 
    this.compareCurrentUserWithListObject() 
    .done(function(data) { 
    var res = data.d.Email.indexOf(userName) > -1; 
    if (res.length > 0) { 
     //Do some stuff after compare... 
    } 
    }); 

} 

它看起來像你想修改水庫請在init之前使用它。有一種方法可以做到這一點，但我會在使用.done時回調。

我沒有測試這個代碼，所以可能會有錯誤。但一般的答案是：你需要回報承諾。

Answer 2

使用承諾來做到這一點的慣用方法是使用Promise.all()。 （我將以Q promise爲例，但Promise.all內置於JS6承諾API和其他幾個承諾庫中）：

function getUserInfo(listItem) { 
    var promise = jQuery.ajax({ 
     url: _spPageContextInfo.webAbsoluteUrl + 
      "/_api/web/GetUserById(" + listItem.user.get_lookupId() + ")", 
     type: "GET", 
     headers: { "Accept": "application/json;odata=verbose" } 
    }); 
    return Q.Promise.when(promise); 
} 

function filterUsers(users) { 
    var userProp = this._userProfileProperties; 
    var userName = userProp.get_userProfileProperties()['UserName']; 

    return users.filter(function (user) { 
     return user.d.Email.indexOf(userName) > -1; 
    }); 
} 

function init() { 
    Q.Promise.all(this._list.map(getUserInfo)) 
    .then(filterUsers.bind(this)) 
    .then(function (matchedUsers) { 
     // matchedUsers is an array of all the users you want. 
     // use it as needed 
    }); 
}