After searching stack overflow and the Q documentation I do unfortunately still not understand the q.ninvoke function. I wonder if someone could explain me how it works with my scenario:
I am GET-ing a result of a fetchXml request which returns at most 5000 entries. I wanted to implement a method which calls itself (over a chain) until no pagingcookie is responded by the server anymore.
In the end all results should get concatenated over the recursion to the top of the recursion...
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));
}
with this setup Q throws me
"TypeError: Cannot read property 'apply' of undefined"
Should work as follows:
it was a stupid syntactical mistake... sorry for that, I have not setup my VisualStuidoCode for good feedback when developing javascript.
the problem was:
getWithFetchXml(entitySetName, fetchXml) //recursion!
.done(function(bodyValue){
args[1].value = jsonBody.value.concat(bodyValue);
deferred.resolve(args);
}
.fail(function(error){
deferred.reject(error);
}));
WRONG BRACKETS! should be:
getWithFetchXml(entitySetName, fetchXml) //recursion!
.then(function(bodyValue){
args[1].value = jsonBody.value.concat(bodyValue);
deferred.resolve(args);
})
.fail(function(error){
deferred.reject(error);
});
Here is my running code for recursive JavaScripts in Node.js:
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;
}