I have 2 methods:
private static async Task<T> GetInfoAsync<T>(MyClient service, Func<Task<T>> funcAsync, string resultText)
{
var result = default(T);
if (service != null) {
try {
service.Open();
result = await funcAsync();
service.Close();
Console.WriteLine(resultText);
} catch (Exception ex) {
service.Abort();
}
}
return result;
}
private static async Task<T> GetInfoAsync<T>(MyClient service, Func<string,Task<T>> funcAsync, string resultText, string param)
{
var result=default(T);
if (service != null) {
try {
service.Open();
result = await funcAsync(param);
service.Close();
Console.WriteLine(resultText);
} catch (Exception ex) {
service.Abort();
}
}
return result;
}
Is is possible to create 1 method for 2 functions?
Something like
"private static async Task GetInfoAsync(MyClient service, Something??, string resultText, string param)"
No, but in general you can do a partial function (see for example http://blogs.msdn.com/b/wesdyer/archive/2007/01/29/currying-and-partial-function-application.aspx) that, given a function with a parameter, calls it with a fixed value for that parameter.
// The original function
Func<string, Task<T>> fullFunction = x => ...;
// The partial function
string param = "...";
Func<Task<T>> partialFunction = () => fullFunction(param);
So it would be the caller of GetInfoAsync that would need to create this partialFunction and pass it to GetInfoAsync.
Related
I have the following API call to retrieve page data
List<VillageNewsItem> newsList = pageRetriever.RetrieveAsync<VillageNewsItem>(
query => query
.Path("/Home/Village-News", PathTypeEnum.Children)
.Published(true)
.OnSite(SiteContext.CurrentSiteName)
.OrderByDescending(x => x.DocumentCreatedWhen)
)?.Result?.ToList();
It works fine and return 2 records if I run the query on page load. Inside Index action of the controller.
public VillageNewsListController(IPageDataContextRetriever dataRetriever, VillageNewsListRepository villageNewsListRepository,
IPageRetriever pagesRetriever, IPageDataContextRetriever pageDataContextRetriever, IPageUrlRetriever pageUrlRetriever)
{
this._dataRetriever = dataRetriever;
this._villageNewsListRepository = villageNewsListRepository;
this._pagesRetriever = pagesRetriever;
this.pageDataContextRetriever = pageDataContextRetriever;
this.pageUrlRetriever = pageUrlRetriever;
}
public async Task<ActionResult> Index(CancellationToken cancellationToken)
{
try
{
List<VillageNewsItem> newsList = pagesRetriever.RetrieveAsync<VillageNewsItem>(
query => query
.Path("/Home/Village-News", PathTypeEnum.Children)
.Published(true)
.OnSite(SiteContext.CurrentSiteName)
.OrderByDescending(x => x.DocumentCreatedWhen)
)?.Result?.ToList();
newsItems.VillageNewsItems = newsList;
return View(newsItems);
}
catch (Exception ex)
{
ErrorHandler.EventLog.LogError(ex.Source, ex.Message, ex.StackTrace);
return RedirectToAction("ErrorPage", "Error");
}
}
However, if I try to make the same API call via a client side AJAX call, it doesn't work and return 0 records. Why it's not working with Ajax calls?
Ajax call
function loadMoreNews() {
$.ajax({
url: '/VillageNewsList/VillageNewsItemList',
//data: { "term": request.term },
type: "POST",
success: function (data) {
response($.map(data,
function (item) {
console.log(data);
}));
},
error: function (response) {
//alert(response.responseText);
},
failure: function (response) {
// alert(response.responseText);
}
});
}
Server side method.
[HttpPost]
[Route("VillageNewsList/VillageNewsItemList")]
public VillageNewsListViewModel VillageNewsItemList(string NodeAliasPath = "", int villageId = 0, string state = "", int page = 1, int pageSize = 4)
{
try
{
List<VillageNewsItem> newsList = pagesRetriever.RetrieveAsync<VillageNewsItem>(
query => query
.Path("/Home/Village-News", PathTypeEnum.Children)
.Published(true)
.OnSite(SiteContext.CurrentSiteName)
.OrderByDescending(x => x.DocumentCreatedWhen)
)?.Result?.ToList();
var model = new VillageNewsListViewModel
{
VillageNewsItems = newsList, // returns 0 records
};
return model;
}
catch (Exception ex)
{
ErrorHandler.EventLog.LogError(ex.Source, ex.Message, ex.StackTrace);
//return RedirectToAction("ErrorPage", "Error");
}
return null;
}
Couple things I see.
You're calling IPageRetriever.RetrieveAsync, but you aren't putting an await before it. There may be some odd behavior due to this. Get rid of the ?.Result?.ToList() and instead just put await before it, it will return an IEnumerable of the specified type.
You don't need ".Published" nor "OnSite" with IPageRetriever, this API automatically uses the Current Site Context, the current culture, and either Published or not / Latest Version or not based on if it's in edit/preview mode or not.
See if those things fix the issue!
I also asume it is caused by async context here...
You can try to use a document query instead.
Would be something like this:
var items = new DocumentQuery<VillageNewsItem>(
.Path("/Home/Village-News", PathTypeEnum.Children)
.PublishedVersion()
.Published()
.OnCurrentSite()
.OrderByDescending(x => x.DocumentCreatedWhen))
?.Result
?.ToList();
If you have multiple cultures, add the culture to your query, too.
.Culture(LocalizationContext.CurrentCulture.CultureCode)
Let say we have an object:
#:checkDirty
class Test {
var a:Int;
var b(default, default):String;
var c(get, set):Array<Int>;
public function new() {
...
}
public function get_c() {
...
}
public function set_c(n) {
...
}
}
Could we write a macro checkDirty so that any change to field/properties would set property dirty to true. Macro would generate dirty field as Bool and clearDirty function to set it to false.
var test = new Test();
trace(test.dirty); // false
test.a = 12;
trace(test.dirty); // true
test.clearDirty();
trace(test.dirty); //false
test.b = "test"
trace(test.dirty); //true
test.clearDirty();
test.c = [1,2,3];
trace(test.dirty); //true
Just to note - whenever you consider proxying access to an object, in my experience, there are always hidden costs / added complexity. :)
That said, you have a few approaches:
First, if you want it to be pure Haxe, then either a macro or an abstract can get the job done. Either way, you're effectively transforming every property access into a function call that sets the value and also sets dirty.
For example, an abstract using the #:resolve getter and setter can be found in the NME source code, replicated here for convenience:
#:forward(decode,toString)
abstract URLVariables(URLVariablesBase)
{
public function new(?inEncoded:String)
{
this = new URLVariablesBase(inEncoded);
}
#:resolve
public function set(name:String, value:String) : String
{
return this.set(name,value);
}
#:resolve
public function get(name:String):String
{
return this.get(name);
}
}
This may be an older syntax, I'm not sure... also look at the operator overloading examples on the Haxe manual:
#:op(a.b) public function fieldRead(name:String)
return this.indexOf(name);
#:op(a.b) public function fieldWrite(name:String, value:String)
return this.split(name).join(value);
Second, I'd just point out that if the underlying language / runtime supports some kind of Proxy object (e.g. JavaScript Proxy), and macro / abstract isn't working as expected, then you could build your functionality on top of that.
I wrote a post (archive) about doing this kind of thing (except for emitting events) before - you can use a #:build macro to modify class members, be it appending an extra assignment into setter or replacing the field with a property.
So a modified version might look like so:
class Macro {
public static macro function build():Array<Field> {
var fields = Context.getBuildFields();
for (field in fields.copy()) { // (copy fields so that we don't go over freshly added ones)
switch (field.kind) {
case FVar(fieldType, fieldExpr), FProp("default", "default", fieldType, fieldExpr):
var fieldName = field.name;
if (fieldName == "dirty") continue;
var setterName = "set_" + fieldName;
var tmp_class = macro class {
public var $fieldName(default, set):$fieldType = $fieldExpr;
public function $setterName(v:$fieldType):$fieldType {
$i{fieldName} = v;
this.dirty = true;
return v;
}
};
for (mcf in tmp_class.fields) fields.push(mcf);
fields.remove(field);
case FProp(_, "set", t, e):
var setter = Lambda.find(fields, (f) -> f.name == "set_" + field.name);
if (setter == null) continue;
switch (setter.kind) {
case FFun(f):
f.expr = macro { dirty = true; ${f.expr}; };
default:
}
default:
}
}
if (Lambda.find(fields, (f) -> f.name == "dirty") == null) fields.push((macro class {
public var dirty:Bool = false;
}).fields[0]);
return fields;
}
}
which, if used as
#:build(Macro.build())
#:keep class Some {
public function new() {}
public var one:Int;
public var two(default, set):String;
function set_two(v:String):String {
two = v;
return v;
}
}
Would emit the following JS:
var Some = function() {
this.dirty = false;
};
Some.prototype = {
set_two: function(v) {
this.dirty = true;
this.two = v;
return v;
}
,set_one: function(v) {
this.one = v;
this.dirty = true;
return v;
}
};
When I am throwing exception my function to bubble it out and catch it in the task exception, rather then continuation it breaks the code- below is my code
public override void Run()
{
SendRenewalsEmail("ddd#xxx.com", " Email Body from test More", "Test Email from Service another Test");
}
private async void SendRenewalsEmail(string userEmail, string emailBody, string emailSubject)
{
string replyFromEmailAddress = "renewals#xxx.net";
string cc = "";
string bcc = "ccc#xxxx.com";
SMTPMailHelperAsync sMTPMailHelperAsync = new SMTPMailHelperAsync();
var x= await sMTPMailHelperAsync.SendEmailAsync(userEmail, cc, bcc, emailSubject, SMTPMailHelperAsync.ProcessTemplate(emailBody, "Renewals.html", emailSubject), replyFromEmailAddress);
if (x.MailSent)
{
throw new Exception("after mail Test more service");
}
}
and the Task where it is being captured
var task= Task<PluginInstance>.Run<PluginInstance>(() => {
thisPlugin.LastRunStart = DateTime.Now.ToLocalTime();
try
{
thisPlugin.Plugin.Run();
thisPlugin.LastRunStatus = Enums.RunStatus.Success;
thisPlugin.LastRunMessage = "";
}
catch (Exception ex)
{
thisPlugin.LastRunStatus = Enums.RunStatus.Failed;
thisPlugin.LastRunMessage = ex.Message;
}
thisPlugin.LastRunEnd = DateTime.Now.ToLocalTime();
return thisPlugin;
});
ListOfTask.Add(task);
Now I am trying to capture the exception in the Task exception but is not. getting below exception
You must not use async void. This is a special case, reserved only for event handlers. Your async method must return a Task:
private async Task SendRenewalsEmail(…)
Then, your Plugin.Run method is broken. It should be async as well.
Once you start with async - await, you do it to the top.
I have a library that connects to a remote API:
class Client(access_token) {
void put(key, value, callback);
void get(key, callback);
}
I want to set up a Node.js REPL to make it easy to try things out:
var repl = require('repl');
var r = repl.start('> ');
r.context.client = new Client(...);
The problem is that an asynchronous API is not convenient for a REPL. I'd prefer a synchronous one that yields the result via the return value and signals an error with an exception. Something like:
class ReplClient(access_token) {
void put(key, value); // throws NetworkError
string get(key); // throws NetworkError
}
Is there a way to implement ReplClient using Client? I'd prefer to avoid any dependencies other than the standard Node.js packages.
You can synchronously wait for stuff with the magic of wait-for-stuff.
Based on your example specification:
const wait = require('wait-for-stuff')
class ReplClient {
constructor(access_token) {
this.client = new Client(access_token)
}
put(key, value) {
return checkErr(wait.for.promise(this.client.put(key, value)))
}
get(key) {
return checkErr(wait.for.promise(this.client.get(key)))
}
}
const checkErr = (maybeErr) => {
if (maybeErr instanceof Error) {
throw maybeErr
} else {
return maybeErr
}
}
I have a case where I need to call several different web endpoints and need to do the same setup and tear down for every call. I am trying to write a more generic method where I can pass in the method I want to execute along with the package to send to the endpoint and expect a string return.
From my code I can make this call:
var ret = WebServiceHandler.Execute(WebServiceHandler.LoadNewAsset(package));
The definition of Execute looks like:
internal static string Execute<T>(Func<T, string> executeThisAction)
{
Func<T, string> resp;
Setup();
resp = executeThisAction;
CleanUp();
return resp.ToString();
}
This is one of the methods I want to execute:
internal static Func<CarsWS_AssetLoad, string> LoadNewAsset(AssetLoad package)
{
string resp;
try
{
// Make the web service call...
var assetLoadReturn = _service.LoadNewAsset(new LoadNewAssetRequest {UserCredentialsHeader = _credentials, asset = package});
// Evaluate results...
if (assetLoadReturn.LoadNewAssetResult.responseType == "Success")
resp = (result != null && !String.IsNullOrEmpty(result.asset.assetID))
? "Got assetID: " + result.asset.assetID
: "No assetID returned.";
else
resp = result.responseDescription.Trim();
}
catch (Exception ex)
{
resp = "Error calling LoadNewAsset()." + Environment.NewLine + ex.GetFullMessage();
}
return resp; // <== THIS IS NOT A VALID RETURN <== //
}
My brain is shutting off at this point. How do I return the string back up the call stack correctly???
I assume that in your LoadNewAsset method the CarsWS_AssetLoad class is actually the same as AssetLoad and it was just a editing issue with your question.
That being the case, I think this is what you want:
internal static string Execute<T>(Func<T, string> executeThisAction, AssetLoad package)
{
string resp;
Setup();
resp = executeThisAction(package);
CleanUp();
return resp;
}
internal static Func<AssetLoad, string> LoadNewAsset()
{
return package =>
{
string resp;
var assetLoadReturn = _service.LoadNewAsset(new LoadNewAssetRequest {UserCredentialsHeader = _credentials, asset = package});
if (assetLoadReturn.LoadNewAssetResult.responseType == "Success")
resp = (result != null && !String.IsNullOrEmpty(result.asset.assetID))
? "Got assetID: " + result.asset.assetID
: "No assetID returned.";
else
resp = result.responseDescription.Trim();
return resp;
};
}
The use of the variable result in the LoadNewAsset is a little confusing too. Did you mean to use LoadNewAsset instead?
The above code should be able to workable for you, but it's really not the right way to go about coding this.
I assume that the Setup & CleanUp code is all about instantiating the _service that you're calling?
So the key is to code it this way:
internal static string Execute<T>(Func<IAssetService, T, string> serviceCall, AssetLoad package)
{
string resp;
var service = Setup();
resp = serviceCall(service, package);
CleanUp(service);
return resp;
}
internal static Func<IAssetService, AssetLoad, string> GetLoadNewAssetFunc()
{
return (service, package) =>
{
string resp;
var assetLoadReturn = service.LoadNewAsset(new LoadNewAssetRequest {UserCredentialsHeader = _credentials, asset = package});
if (assetLoadReturn.LoadNewAssetResult.responseType == "Success")
resp = (result != null && !String.IsNullOrEmpty(result.asset.assetID))
? "Got assetID: " + result.asset.assetID
: "No assetID returned.";
else
resp = result.responseDescription.Trim();
return resp;
};
}
Ideally if you would bring the Setup & CleanUp code into the Execute method so that the only way to call the set-up and clean-up code is thru the Execute method.
Even better, if the service class implements IDisposable then your execute code would look like this:
internal static string Execute<T>(Func<IAssetService, T, string> serviceCall, AssetLoad package)
{
using (var service = Setup())
{
return serviceCall(service, package);
}
}
Let me know if I've missed anything.
Replace:
internal static string Execute<T>(Func<T, string> executeThisAction)
with
internal static string Execute<T>(Func<T, string> executeThisAction, T argument)
then replace:
internal static Func<CarsWS_AssetLoad, string> LoadNewAsset(AssetLoad package)
with
internal static string LoadNewAsset(AssetLoad package)
then to call it:
var ret = WebServiceHandler.Execute(WebServiceHandler.LoadNewAsset, package);