Node.js 使用 q 框架递归调用多个 GET 请求

Question

在搜索 Whosebug 和 Q 文档后，不幸的是我仍然不理解 q.ninvoke 函数。我想知道是否有人可以向我解释它如何适用于我的场景：

我正在获取最多 returns 5000 个条目的 fetchXml 请求的结果。我想实现一个调用自身（通过链）的方法，直到服务器不再响应 pagingcookie。

最后，所有结果都应该通过递归连接到递归的顶部...

var tryReexecuteForNext5000Entries = function(entitySetName, fetchXml, args){
    var deferred = q.defer();
    var response = args[0];    
    var jsonBody = args[1];
    var fetchXmlPagingCookieResponse = jsonBody["@Microsoft.Dynamics.CRM.fetchxmlpagingcookie"];

    if(!fetchXmlPagingCookieResponse){        
        deferred.resolve(args);
        return deferred.promise;
    }

    var pagingArgs = getPagingArgs(fetchXmlPagingCookieResponse);
    var pageNumber = pagingArgs[0];
    var pagingCookie = transformCookieForFetch(pagingArgs[1]);
    fetchXml = injectPagingArgsIntoFetchXml(fetchXml, pageNumber, pagingCookie);


    getWithFetchXml(entitySetName, fetchXml)        //recursion!
         .done(function(bodyValue){
             args[1].value = args[1].value.concat(jsonBody.value).concat(bodyValue);
             deferred.resolve(args);
        }
        .fail(function(error){
            deferred.reject(error);
        }));

    return deferred.promise;
}

function getWithFetchXml(entitySetName, fetchXml){
    return AuthProvider.retrieveToken()
        .then(createFetchOptions.bind(this, entitySetName, fetchXml))
        .then(addProxyToOptions)
        .then(executeRequest)
        .then(checkResponse)
        .then(tryReexecuteForNext5000Entries.bind(this, entitySetName, fetchXml))
        .then(onRequestSucceeded.bind(this, "successfully GET fetchXml against CRM"))
        .fail(onFail.bind(this, "webApiRequest.getWithFetchXml: failed to GET with fetchXml: \r\n"+fetchXml));
}

使用此设置 Q 会抛出我 "TypeError: Cannot read property 'apply' of undefined"

应该如下工作：

调用 getWithFetchXml
检索 JsonObject List1 和 pagingtoken AND
===调用 getWithFechXml²
===检索 JsonObject List2 和 pagingToken AND
======调用 getWithFetchXml³
======检索 JsonObject List3 没有 pagingToken
======returns 列表
===将 List3 附加到 List2 并且 returns 它
将 List2 附加到 List1 并且 returns 它

Answer 1

这是一个愚蠢的语法错误...对此感到抱歉，我在开发 javascript 时没有设置 VisualStuidoCode 以获得良好的反馈。

问题是：

getWithFetchXml(entitySetName, fetchXml)        //recursion!
        .done(function(bodyValue){
             args[1].value = jsonBody.value.concat(bodyValue);
             deferred.resolve(args);
        }
        .fail(function(error){
            deferred.reject(error);
        }));

错误的括号！应该是：

getWithFetchXml(entitySetName, fetchXml)        //recursion!
            .then(function(bodyValue){
                 args[1].value = jsonBody.value.concat(bodyValue);
                 deferred.resolve(args);
            })
            .fail(function(error){
                deferred.reject(error);
            });

这是我在 Node.js 中的运行递归 JavaScript 代码：

function getWithFetchXml(entitySetName, fetchXml){
    return getWithFetchXmlRecursive(entitySetName, fetchXml, null);
}

var getWithFetchXmlRecursive = function(entitySetName, fetchXml, page){
    return AuthProvider.retrieveToken()
        (...)
        .then(tryReexecuteForNext5000Entries.bind(this, entitySetName, fetchXml, page))
        .then(onRequestSucceeded.bind(this, "successfully GET fetchXml against CRM"))
        .fail(onFail.bind(this, "webApiRequest.getWithFetchXml: failed to GET with fetchXml: \r\n"+fetchXml));
}

var tryReexecuteForNext5000Entries = function(entitySetName, fetchXml, page, args){
    (...)
    var fetchXmlPagingCookieResponse = jsonBody["@Microsoft.Dynamics.CRM.fetchxmlpagingcookie"];        
    var onRecursionSucceeded = function(bodyValue){
        args[1].value = jsonBody.value.concat(bodyValue);
        deferred.resolve(args);
    }
    var onRecursionFailed = function(error){deferred.reject(error);};

    if(!fetchXmlPagingCookieResponse){        
        deferred.resolve(args);
        return deferred.promise;
    }
    (...)
    console.log("webApiRequest.tryReexecuteForNext5000Entries: there is more! starting recursive request with depth: " + (page-1));
    getWithFetchXmlRecursive(entitySetName, fetchXml, ++page)        //recursion!
        .then(onRecursionSucceeded)
        .fail(onRecursionFailed);

    return deferred.promise;
}

Node.js 使用 q 框架递归调用多个 GET 请求

Node.js recursive calls with q framework for multiple GET requests

javascript

recursion

node.js

deferred

q