Develop Reference

Getting result from async call in a foreach loop

I am trying to get a list of offers that are fetched from an external service.
public void TriggerPurchase()
{
List<string> offers = listener.GetOffers();
Debug.Log("OFFERS " + offers[0]);
}
Here is the fetch function
public List<string> GetOffers()
{
var purchases = GetComponent<Purchases>();
purchases.GetOfferings((offerings, error) =>
{
if (offerings.Current != null && offerings.Current.AvailablePackages.Count != 0)
{
List<string> offers = new List<string>();
foreach (var package in offerings.Current.AvailablePackages)
{
//Debug.Log("Package " + package);
if (package == null) continue;
offers.Add(package.StoreProduct.PriceString);
}
return offers; // Anonymouse function converted to a void returning delegate cannot return a value
}
});
}
I get the Anonymouse function converted to a void returning
I would like to get a list with offers?
**UPDATE
Adding the implementation of GetOfferings
/// <summary>
/// Callback for <see cref="Purchases.GetOfferings"/>.
/// </summary>
/// <param name="offerings"> The <see cref="Offerings"/> object if the request was successful, null otherwise.</param>
/// <param name="error"> The error if the request was unsuccessful, null otherwise.</param>
public delegate void GetOfferingsFunc(Offerings offerings, Error error);
private GetOfferingsFunc GetOfferingsCallback { get; set; }
///
/// <param name="callback"> A completion block called when offerings are available.
/// Called immediately if offerings are cached. <see cref="Offerings"/> will be null if an error occurred.
/// </param>
///
/// <seealso href="https://docs.revenuecat.com/docs/displaying-products"/>
///
public void GetOfferings(GetOfferingsFunc callback)
{
GetOfferingsCallback = callback;
_wrapper.GetOfferings();
}

void methods don't return values. If you want your method to return a result you must change the type of the method and delegate:
public delegate Task<List<string>> GetOfferingsFuncAsync(Offerings offerings, Error error);
private GetOfferingsFunc GetOfferingsCallback { get; set; }
public async Task<List<string>> GetOfferingsAsync(GetOfferingsFunc callback)
{
GetOfferingsCallback = callback;
_wrapper.GetOfferings();
return await this.GetOfferingsCallback.Invoke(arg1, arg2);
}
Now you can handle the expected result properly:
public async Task<List<string>> GetOffers()
{
var purchases = GetComponent<Purchases>();
// Return the result.
return await purchases.GetOfferingsAsync(async (offerings, error) =>
{
if (offerings.Current != null && offerings.Current.AvailablePackages.Count != 0)
{
List<string> offers = new List<string>();
foreach (var package in offerings.Current.AvailablePackages)
{
//Debug.Log("Package " + package);
if (package == null) continue;
await SomeAsyncApiCall();
offers.Add(package.StoreProduct.PriceString);
}
// Because the delegate is no longer 'void'
// you can now return a result
return offers;
}
});
}

ASP.NET CORE 1.0, AppSettings from another assembly

I have an application splittet into two projects: a web application and a class library. The Startup is only in the web application:
var builder = new ConfigurationBuilder()
.AddJsonFile("appsettings.json")
I wanna have my appsettings.json in that class library and being loaded from there. Is that possible? How can I do that?

The best solution I have found requires creating a new IFileProvider and IFileInfo, and then embedding the JSON settings files in your assembly.
The solution reuses the existing AddJsonFile logic. This way you only need to tell the configuration system how and where to locate the JSON file, not how to parse it.
The solution is compatible with .NET Core 1.0.
Usage:
public class Startup
{
private readonly AppSettings _appSettings;
public Startup(IHostingEnvironment env)
{
Assembly assembly = GetType().GetTypeInfo().Assembly;
new ConfigurationBuilder()
.AddEmbeddedJsonFile(assembly, "appsettings.json")
.AddEmbeddedJsonFile(assembly, $"appsettings.{env.EnvironmentName.ToLower()}.json")
.Build();
}
...
}
Embed the files by updating the project.json for the class library:
...
"buildOptions": {
"embed": [
"appsettings.json",
"appsettings.development.json",
"appsettings.production.json"
]
}
...
IEmbeddedFileInfo implementation:
public class EmbeddedFileInfo : IFileInfo
{
private readonly Stream _fileStream;
public EmbeddedFileInfo(string name, Stream fileStream)
{
if (name == null) throw new ArgumentNullException(nameof(name));
if (fileStream == null) throw new ArgumentNullException(nameof(fileStream));
_fileStream = fileStream;
Exists = true;
IsDirectory = false;
Length = fileStream.Length;
Name = name;
PhysicalPath = name;
LastModified = DateTimeOffset.Now;
}
public Stream CreateReadStream()
{
return _fileStream;
}
public bool Exists { get; }
public bool IsDirectory { get; }
public long Length { get; }
public string Name { get; }
public string PhysicalPath { get; }
public DateTimeOffset LastModified { get; }
}
IFileInfo implementation:
public class EmbeddedFileProvider : IFileProvider
{
private readonly Assembly _assembly;
public EmbeddedFileProvider(Assembly assembly)
{
if (assembly == null) throw new ArgumentNullException(nameof(assembly));
_assembly = assembly;
}
public IFileInfo GetFileInfo(string subpath)
{
string fullFileName = $"{_assembly.GetName().Name}.{subpath}";
bool isFileEmbedded = _assembly.GetManifestResourceNames().Contains(fullFileName);
return isFileEmbedded
? new EmbeddedFileInfo(subpath, _assembly.GetManifestResourceStream(fullFileName))
: (IFileInfo) new NotFoundFileInfo(subpath);
}
public IDirectoryContents GetDirectoryContents(string subpath)
{
throw new NotImplementedException();
}
public IChangeToken Watch(string filter)
{
throw new NotImplementedException();
}
}
Create the easy to use AddEmbeddedJsonFile extension method.
public static class ConfigurationBuilderExtensions
{
public static IConfigurationBuilder AddEmbeddedJsonFile(this IConfigurationBuilder cb,
Assembly assembly, string name, bool optional = false)
{
// reload on change is not supported, always pass in false
return cb.AddJsonFile(new EmbeddedFileProvider(assembly), name, optional, false);
}
}

Yes you could implement IConfigurationProvider
There is a base class ConfigurationProvider that you can inherit from then override all the virtual methods.
You can also see how the JsonConfigurationProvider is implemented.
So I guess your implementation could use the Json provider code internally against embedded json files.
Then you would also want to implement ConfigurationBuilder extension to register your provider similar as the code for using json config.

Someone else can correct me, but I don't think what you are looking for exists.
App Configs and AppSettings files are read at runtime by the application that is running.
The Class Library cannot see any AppSettings specific to itself, because when it runs at run time, it is in the folder of the running application.
The only potential way I can see for you to get your class library contain the json file, is to have the json file as an embedded resource.
Eg: In the solution, select the json file, and set it to Embedded Resource instead of 'content'.
The problem becomes getting the embedded config file out of your assembly, and then loaded.
AddJsonFile accepts a path to the json file.
You could however extract the Json file to a temp directory, then load from there.
static byte[] StreamToBytes(Stream input)
{
int capacity = input.CanSeek ? (int)input.Length : 0;
using (MemoryStream output = new MemoryStream(capacity))
{
int readLength;
byte[] buffer = new byte[capacity/*4096*/]; //An array of bytes
do
{
readLength = input.Read(buffer, 0, buffer.Length); //Read the memory data, into the buffer
output.Write(buffer, 0, readLength);
}
while (readLength != 0); //Do all this while the readLength is not 0
return output.ToArray(); //When finished, return the finished MemoryStream object as an array.
}
}
Assembly yourAssembly = Assembly.GetAssembly(typeof(MyTypeWithinAssembly));
using (Stream input = yourAssembly.GetManifestResourceStream("NameSpace.Resources.Config.json")) // Acquire the dll from local memory/resources.
{
byte[] byteData = StreamToBytes(input);
System.IO.File.WriteAllBytes(Environment.GetFolderPath(System.Environment.SpecialFolder.LocalApplicationData)+"//Config.json",new byte[]{});
}
var builder = new ConfigurationBuilder()
.AddJsonFile(Environment.GetFolderPath(System.Environment.SpecialFolder.LocalApplicationData)+"//Config.json");
You should in theory be able to specify a type from the class library, in order to help the c# code target that class library specifically. Then you just need to provide the namespace and path to the embedded json file.

Here is my solution, thanks Baaleos and Joe for your advices.
project.json
"resource": [
"appsettings.json"
]
startup.cs
var builder = new ConfigurationBuilder()
.Add(new SettingsConfigurationProvider("appsettings.json"))
.AddEnvironmentVariables();
this.Configuration = builder.Build();
namespace ClassLibrary
{
using Microsoft.Extensions.Configuration;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
/// <summary>
/// A JSON file based <see cref="ConfigurationProvider"/> for embedded resources.
/// </summary>
public class SettingsConfigurationProvider : ConfigurationProvider
{
/// <summary>
/// Initializes a new instance of <see cref="SettingsConfigurationProvider"/>.
/// </summary>
/// <param name="name">Name of the JSON configuration file.</param>
/// <param name="optional">Determines if the configuration is optional.</param>
public SettingsConfigurationProvider(string name)
: this(name, false)
{
}
/// <summary>
/// Initializes a new instance of <see cref="SettingsConfigurationProvider"/>.
/// </summary>
/// <param name="name">Name of the JSON configuration file.</param>
/// <param name="optional">Determines if the configuration is optional.</param>
public SettingsConfigurationProvider(string name, bool optional)
{
if (string.IsNullOrEmpty(name))
{
throw new ArgumentException("Name must be a non-empty string.", nameof(name));
}
this.Optional = optional;
this.Name = name;
}
/// <summary>
/// Gets a value that determines if this instance of <see cref="SettingsConfigurationProvider"/> is optional.
/// </summary>
public bool Optional { get; }
/// <summary>
/// The name of the file backing this instance of <see cref="SettingsConfigurationProvider"/>.
/// </summary>
public string Name { get; }
/// <summary>
/// Loads the contents of the embedded resource with name <see cref="Path"/>.
/// </summary>
/// <exception cref="FileNotFoundException">If <see cref="Optional"/> is <c>false</c> and a
/// resource does not exist with name <see cref="Path"/>.</exception>
public override void Load()
{
Assembly assembly = Assembly.GetAssembly(typeof(SettingsConfigurationProvider));
var resourceName = $"{assembly.GetName().Name}.{this.Name}";
var resources = assembly.GetManifestResourceNames();
if (!resources.Contains(resourceName))
{
if (Optional)
{
Data = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
}
else
{
throw new FileNotFoundException($"The configuration file with name '{this.Name}' was not found and is not optional.");
}
}
else
{
using (Stream settingsStream = assembly.GetManifestResourceStream(resourceName))
{
Load(settingsStream);
}
}
}
internal void Load(Stream stream)
{
JsonConfigurationFileParser parser = new JsonConfigurationFileParser();
try
{
Data = parser.Parse(stream);
}
catch (JsonReaderException e)
{
string errorLine = string.Empty;
if (stream.CanSeek)
{
stream.Seek(0, SeekOrigin.Begin);
IEnumerable<string> fileContent;
using (var streamReader = new StreamReader(stream))
{
fileContent = ReadLines(streamReader);
errorLine = RetrieveErrorContext(e, fileContent);
}
}
throw new FormatException($"Could not parse the JSON file. Error on line number '{e.LineNumber}': '{e}'.");
}
}
private static string RetrieveErrorContext(JsonReaderException e, IEnumerable<string> fileContent)
{
string errorLine;
if (e.LineNumber >= 2)
{
var errorContext = fileContent.Skip(e.LineNumber - 2).Take(2).ToList();
errorLine = errorContext[0].Trim() + Environment.NewLine + errorContext[1].Trim();
}
else
{
var possibleLineContent = fileContent.Skip(e.LineNumber - 1).FirstOrDefault();
errorLine = possibleLineContent ?? string.Empty;
}
return errorLine;
}
private static IEnumerable<string> ReadLines(StreamReader streamReader)
{
string line;
do
{
line = streamReader.ReadLine();
yield return line;
} while (line != null);
}
}
}
You need also the JsonConfigurationFileParser:
namespace ClassLibrary
{
using Microsoft.Extensions.Configuration;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
internal class JsonConfigurationFileParser
{
private readonly IDictionary<string, string> _data = new SortedDictionary<string, string>(StringComparer.OrdinalIgnoreCase);
private readonly Stack<string> _context = new Stack<string>();
private string _currentPath;
private JsonTextReader _reader;
public IDictionary<string, string> Parse(Stream input)
{
_data.Clear();
_reader = new JsonTextReader(new StreamReader(input));
_reader.DateParseHandling = DateParseHandling.None;
var jsonConfig = JObject.Load(_reader);
VisitJObject(jsonConfig);
return _data;
}
private void VisitJObject(JObject jObject)
{
foreach (var property in jObject.Properties())
{
EnterContext(property.Name);
VisitProperty(property);
ExitContext();
}
}
private void VisitProperty(JProperty property)
{
VisitToken(property.Value);
}
private void VisitToken(JToken token)
{
switch (token.Type)
{
case JTokenType.Object:
VisitJObject(token.Value<JObject>());
break;
case JTokenType.Array:
VisitArray(token.Value<JArray>());
break;
case JTokenType.Integer:
case JTokenType.Float:
case JTokenType.String:
case JTokenType.Boolean:
case JTokenType.Bytes:
case JTokenType.Raw:
case JTokenType.Null:
VisitPrimitive(token);
break;
default:
throw new FormatException($#"
Unsupported JSON token '{_reader.TokenType}' was found.
Path '{_reader.Path}',
line {_reader.LineNumber}
position {_reader.LinePosition}.");
}
}
private void VisitArray(JArray array)
{
for (int index = 0; index < array.Count; index++)
{
EnterContext(index.ToString());
VisitToken(array[index]);
ExitContext();
}
}
private void VisitPrimitive(JToken data)
{
var key = _currentPath;
if (_data.ContainsKey(key))
{
throw new FormatException($"A duplicate key '{key}' was found.");
}
_data[key] = data.ToString();
}
private void EnterContext(string context)
{
_context.Push(context);
_currentPath = string.Join(Constants.KeyDelimiter, _context.Reverse());
}
private void ExitContext()
{
_context.Pop();
_currentPath = string.Join(Constants.KeyDelimiter, _context.Reverse());
}
}
}

Your Thoughts: Entity Framework Data Context via a DataHelper class (centralized context and transactions) [closed]

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Closed 10 years ago.
I want to get opinions on the code I have put together for a centralized DataContext via a DataHelper class that I have created to be re-used on projects.
NOTE - there is a ton of code here, sorry about that, but I really wanted to layout out the complete approach and uses for my ideas. I'm an not saying this is the right approach, but it works for me so far (still playing with the approach, nothing in production yet, but very similar to stuff I have built over the years) and I really want to get constructive feedback from the community on what I have built to see if it is insane, great, can be improved, etc...
A few thoughts I put into this:
Data Context needs to be stored in a common memory space, easily accessible
Transactions should take the same approach
It must be disposed of properly
Allows for better separation of business logic for Saving and Deleting in transactions.
Here is the code for each item:
1 - First the data context stored in either the current HttpContext.Current.Items collection (so it only lives for the life of the page and only is fired up once at the first requested) or if the HttpContext doesn't exist uses a ThreadSlot (in which case that code most clean it up itself, like a console app using it...):
public static class DataHelper {
/// <summary>
/// Current Data Context object in the HTTPContext or Current Thread
/// </summary>
public static TemplateProjectContext Context {
get {
TemplateProjectContext context = null;
if (HttpContext.Current == null) {
LocalDataStoreSlot threadSlot = Thread.GetNamedDataSlot("DataHelper.CurrentContext");
if (Thread.GetData(threadSlot) == null) {
context = new TemplateProjectContext();
Thread.SetData(threadSlot, context);
} else {
context = (TemplateProjectContext)Thread.GetData(threadSlot);
}
} else {
if (HttpContext.Current.Items["DataHelper.CurrentContext"] == null) {
context = new TemplateProjectContext();
HttpContext.Current.Items["DataHelper.CurrentContext"] = context;
} else {
context = (TemplateProjectContext)HttpContext.Current.Items["DataHelper.CurrentContext"];
}
}
return context;
}
set {
if (HttpContext.Current == null) {
if (value == null) {
Thread.FreeNamedDataSlot("DataHelper.CurrentContext");
} else {
LocalDataStoreSlot threadSlot = Thread.GetNamedDataSlot("DataHelper.CurrentContext");
Thread.SetData(threadSlot, value);
}
} else {
if (value == null)
HttpContext.Current.Items.Remove("DataHelper.CurrentContext");
else
HttpContext.Current.Items["DataHelper.CurrentContext"] = value;
}
}
}
...
2 - To support transactions, I use a similar approach, and also include helper methods to Begin, Commit and Rollback:
/// <summary>
/// Current Transaction object in the HTTPContext or Current Thread
/// </summary>
public static DbTransaction Transaction {
get {
if (HttpContext.Current == null) {
LocalDataStoreSlot threadSlot = Thread.GetNamedDataSlot("currentTransaction");
if (Thread.GetData(threadSlot) == null) {
return null;
} else {
return (DbTransaction)Thread.GetData(threadSlot);
}
} else {
if (HttpContext.Current.Items["currentTransaction"] == null) {
return null;
} else {
return (DbTransaction)HttpContext.Current.Items["currentTransaction"];
}
}
}
set {
if (HttpContext.Current == null) {
LocalDataStoreSlot threadSlot = Thread.GetNamedDataSlot("currentTransaction");
Thread.SetData(threadSlot, value);
} else {
HttpContext.Current.Items["currentTransaction"] = value;
}
}
}
/// <summary>
/// Begins a transaction based on the common connection and transaction
/// </summary>
public static void BeginTransaction() {
DataHelper.Transaction = DataHelper.CreateSqlTransaction();
}
/// <summary>
/// Creates a SqlTransaction object based on the current common connection
/// </summary>
/// <returns>A new SqlTransaction object for the current common connection</returns>
public static DbTransaction CreateSqlTransaction() {
return CreateSqlTransaction(DataHelper.Context.Connection);
}
/// <summary>
/// Creates a SqlTransaction object for the requested connection object
/// </summary>
/// <param name="connection">Reference to the connection object the transaction should be created for</param>
/// <returns>New transaction object for the requested connection</returns>
public static DbTransaction CreateSqlTransaction(DbConnection connection) {
if (connection.State != ConnectionState.Open) connection.Open();
return connection.BeginTransaction();
}
/// <summary>
/// Rolls back and cleans up the current common transaction
/// </summary>
public static void RollbackTransaction() {
if (DataHelper.Transaction != null) {
DataHelper.RollbackTransaction(DataHelper.Transaction);
if (HttpContext.Current == null) {
Thread.FreeNamedDataSlot("currentTransaction");
} else {
HttpContext.Current.Items.Remove("currentTransaction");
}
}
}
/// <summary>
/// Rolls back and disposes of the requested transaction
/// </summary>
/// <param name="transaction">The transaction to rollback</param>
public static void RollbackTransaction(DbTransaction transaction) {
transaction.Rollback();
transaction.Dispose();
}
/// <summary>
/// Commits and cleans up the current common transaction
/// </summary>
public static void CommitTransaction() {
if (DataHelper.Transaction != null) {
DataHelper.CommitTransaction(DataHelper.Transaction);
if (HttpContext.Current == null) {
Thread.FreeNamedDataSlot("currentTransaction");
} else {
HttpContext.Current.Items.Remove("currentTransaction");
}
}
}
/// <summary>
/// Commits and disposes of the requested transaction
/// </summary>
/// <param name="transaction">The transaction to commit</param>
public static void CommitTransaction(DbTransaction transaction) {
transaction.Commit();
transaction.Dispose();
}
3 - Clean and easy Disposal
/// <summary>
/// Cleans up the currently active connection
/// </summary>
public static void Dispose() {
if (HttpContext.Current == null) {
LocalDataStoreSlot threadSlot = Thread.GetNamedDataSlot("DataHelper.CurrentContext");
if (Thread.GetData(threadSlot) != null) {
DbTransaction transaction = DataHelper.Transaction;
if (transaction != null) {
DataHelper.CommitTransaction(transaction);
Thread.FreeNamedDataSlot("currentTransaction");
}
((TemplateProjectContext)Thread.GetData(threadSlot)).Dispose();
Thread.FreeNamedDataSlot("DataHelper.CurrentContext");
}
} else {
if (HttpContext.Current.Items["DataHelper.CurrentContext"] != null) {
DbTransaction transaction = DataHelper.Transaction;
if (transaction != null) {
DataHelper.CommitTransaction(transaction);
HttpContext.Current.Items.Remove("currentTransaction");
}
((TemplateProjectContext)HttpContext.Current.Items["DataHelper.CurrentContext"]).Dispose();
HttpContext.Current.Items.Remove("DataHelper.CurrentContext");
}
}
}
3b - I'm building this in MVC, so I have a "base" Controller class that all my controllers inherit from - this way the Context only lives from when first accessed on a request, and until the page is disposed, that way its not too "long running"
using System.Web.Mvc;
using Core.ClassLibrary;
using TemplateProject.Business;
using TemplateProject.ClassLibrary;
namespace TemplateProject.Web.Mvc {
public class SiteController : Controller {
protected override void Dispose(bool disposing) {
DataHelper.Dispose();
base.Dispose(disposing);
}
}
}
4 - So I am big on business classes, separation of concerns, reusable code, all that wonderful stuff. I have an approach that I call "Entity Generic" that can be applied to any entity in my system - for example, Addresses and Phones
A Customer can have 1 or more of each, along with a Store, Person, or anything really - so why add street, city, state, etc to every thing that needs it when you can just build an Address entity, that takes a Foreign Type and Key (what I call EntityType and EntityId) - then you have a re-usable business object, supporting UI control, etc - so you build it once and re-use it everywhere.
This is where the centralized approach I am pushing for here really comes in handy and I think makes the code much cleaner than having to pass the current data context/transaction into every method.
Take for example that you have a Page for a customer, the Model includes the Customer data, Contact, Address and a few Phone Numbers (main, fax, or cell, whatever)
When getting a Customer Edit Model for the page, here is a bit of the code I have put together (see how I use the DataHelper.Context in the LINQ):
public static CustomerEditModel FetchEditModel(int customerId) {
if (customerId == 0) {
CustomerEditModel model = new CustomerEditModel();
model.MainContact = new CustomerContactEditModel();
model.MainAddress = new AddressEditModel();
model.ShippingAddress = new AddressEditModel();
model.Phone = new PhoneEditModel();
model.Cell = new PhoneEditModel();
model.Fax = new PhoneEditModel();
return model;
} else {
var output = (from c in DataHelper.Context.Customers
where c.CustomerId == customerId
select new CustomerEditModel {
CustomerId = c.CustomerId,
CompanyName = c.CompanyName
}).SingleOrDefault();
if (output != null) {
output.MainContact = CustomerContact.FetchEditModelByPrimary(customerId) ?? new CustomerContactEditModel();
output.MainAddress = Address.FetchEditModelByType(BusinessEntityTypes.Customer, customerId, AddressTypes.Main) ?? new AddressEditModel();
output.ShippingAddress = Address.FetchEditModelByType(BusinessEntityTypes.Customer, customerId, AddressTypes.Shipping) ?? new AddressEditModel();
output.Phone = Phone.FetchEditModelByType(BusinessEntityTypes.Customer, customerId, PhoneTypes.Main) ?? new PhoneEditModel();
output.Cell = Phone.FetchEditModelByType(BusinessEntityTypes.Customer, customerId, PhoneTypes.Cell) ?? new PhoneEditModel();
output.Fax = Phone.FetchEditModelByType(BusinessEntityTypes.Customer, customerId, PhoneTypes.Fax) ?? new PhoneEditModel();
}
return output;
}
}
And here is a sample of the the phone returning the Edit model to be used:
public static PhoneEditModel FetchEditModelByType(byte entityType, int entityId, byte phoneType) {
return (from p in DataHelper.Context.Phones
where p.EntityType == entityType
&& p.EntityId == entityId
&& p.PhoneType == phoneType
select new PhoneEditModel {
PhoneId = p.PhoneId,
PhoneNumber = p.PhoneNumber,
Extension = p.Extension
}).FirstOrDefault();
}
Now the page has posted back and this all needs to be save, so the Save method in my control just lets the business object handle this all:
[Authorize(Roles = SiteRoles.SiteAdministrator + ", " + SiteRoles.Customers_Edit)]
[HttpPost]
public ActionResult Create(CustomerEditModel customer) {
return CreateOrEdit(customer);
}
[Authorize(Roles = SiteRoles.SiteAdministrator + ", " + SiteRoles.Customers_Edit)]
[HttpPost]
public ActionResult Edit(CustomerEditModel customer) {
return CreateOrEdit(customer);
}
private ActionResult CreateOrEdit(CustomerEditModel customer) {
if (ModelState.IsValid) {
SaveResult result = Customer.SaveEditModel(customer);
if (result.Success) {
return RedirectToAction("Index");
} else {
foreach (KeyValuePair<string, string> error in result.ErrorMessages) ModelState.AddModelError(error.Key, error.Value);
}
}
return View(customer);
}
And inside the Customer business object - it handles the transaction centrally and lets the Contact, Address and Phone business classes do their thing and really not worry about the transaction:
public static SaveResult SaveEditModel(CustomerEditModel model) {
SaveResult output = new SaveResult();
DataHelper.BeginTransaction();
try {
Customer customer = null;
if (model.CustomerId == 0) customer = new Customer();
else customer = DataHelper.Context.Customers.Single(c => c.CustomerId == model.CustomerId);
if (customer == null) {
output.Success = false;
output.ErrorMessages.Add("CustomerNotFound", "Unable to find the requested Customer record to update");
} else {
customer.CompanyName = model.CompanyName;
if (model.CustomerId == 0) {
customer.SiteGroup = CoreSession.CoreSettings.CurrentSiteGroup;
customer.CreatedDate = DateTime.Now;
customer.CreatedBy = SiteLogin.Session.ActiveUser;
DataHelper.Context.Customers.AddObject(customer);
} else {
customer.ModifiedDate = DateTime.Now;
customer.ModifiedBy = SiteLogin.Session.ActiveUser;
}
DataHelper.Context.SaveChanges();
SaveResult result = Address.SaveEditModel(model.MainAddress, BusinessEntityTypes.Customer, customer.CustomerId, AddressTypes.Main, false);
if (!result.Success) {
output.Success = false;
output.ErrorMessages.Concat(result.ErrorMessages);
}
result = Address.SaveEditModel(model.ShippingAddress, BusinessEntityTypes.Customer, customer.CustomerId, AddressTypes.Shipping, false);
if (!result.Success) {
output.Success = false;
output.ErrorMessages.Concat(result.ErrorMessages);
}
result = Phone.SaveEditModel(model.Phone, BusinessEntityTypes.Customer, customer.CustomerId, PhoneTypes.Main, false);
if (!result.Success) {
output.Success = false;
output.ErrorMessages.Concat(result.ErrorMessages);
}
result = Phone.SaveEditModel(model.Fax, BusinessEntityTypes.Customer, customer.CustomerId, PhoneTypes.Fax, false);
if (!result.Success) {
output.Success = false;
output.ErrorMessages.Concat(result.ErrorMessages);
}
result = Phone.SaveEditModel(model.Cell, BusinessEntityTypes.Customer, customer.CustomerId, PhoneTypes.Cell, false);
if (!result.Success) {
output.Success = false;
output.ErrorMessages.Concat(result.ErrorMessages);
}
result = CustomerContact.SaveEditModel(model.MainContact, customer.CustomerId, false);
if (!result.Success) {
output.Success = false;
output.ErrorMessages.Concat(result.ErrorMessages);
}
if (output.Success) {
DataHelper.Context.SaveChanges();
DataHelper.CommitTransaction();
} else {
DataHelper.RollbackTransaction();
}
}
} catch (Exception exp) {
DataHelper.RollbackTransaction();
ErrorHandler.Handle(exp, true);
output.Success = false;
output.ErrorMessages.Add(exp.GetType().ToString(), exp.Message);
output.Exceptions.Add(exp);
}
return output;
}
Notice how each Address, Phone, Etc is handled by its own business class, here is the Phone's save method - notice how it doesn't actually do the save here unless you tell it to (save is handled in the Customer's method so save is called just once for the context)
public static SaveResult SaveEditModel(PhoneEditModel model, byte entityType, int entityId, byte phoneType, bool saveChanges) {
SaveResult output = new SaveResult();
try {
if (model != null) {
Phone phone = null;
if (model.PhoneId != 0) {
phone = DataHelper.Context.Phones.Single(x => x.PhoneId == model.PhoneId);
if (phone == null) {
output.Success = false;
output.ErrorMessages.Add("PhoneNotFound", "Unable to find the requested Phone record to update");
}
}
if (string.IsNullOrEmpty(model.PhoneNumber)) {
if (model.PhoneId != 0 && phone != null) {
DataHelper.Context.Phones.DeleteObject(phone);
if (saveChanges) DataHelper.Context.SaveChanges();
}
} else {
if (model.PhoneId == 0) phone = new Phone();
if (phone != null) {
phone.EntityType = entityType;
phone.EntityId = entityId;
phone.PhoneType = phoneType;
phone.PhoneNumber = model.PhoneNumber;
phone.Extension = model.Extension;
if (model.PhoneId == 0) {
phone.CreatedDate = DateTime.Now;
phone.CreatedBy = SiteLogin.Session.ActiveUser;
DataHelper.Context.Phones.AddObject(phone);
} else {
phone.ModifiedDate = DateTime.Now;
phone.ModifiedBy = SiteLogin.Session.ActiveUser;
}
if (saveChanges) DataHelper.Context.SaveChanges();
}
}
}
} catch (Exception exp) {
ErrorHandler.Handle(exp, true);
output.Success = false;
output.ErrorMessages.Add(exp.GetType().ToString(), exp.Message);
output.Exceptions.Add(exp);
}
return output;
}
FYI - SaveResult is just a little container class that I used to get detailed information back if a save fails:
public class SaveResult {
private bool _success = true;
public bool Success {
get { return _success; }
set { _success = value; }
}
private Dictionary<string, string> _errorMessages = new Dictionary<string, string>();
public Dictionary<string, string> ErrorMessages {
get { return _errorMessages; }
set { _errorMessages = value; }
}
private List<Exception> _exceptions = new List<Exception>();
public List<Exception> Exceptions {
get { return _exceptions; }
set { _exceptions = value; }
}
}
The other piece to this is the re-usable UI code for the Phone, Address, etc - which handles all the validation, etc in just one location too.
So, let your thoughts flow and thanks for taking the time to read/review this huge post!

C# Wolfram aplha API working example

I have been trying to get the Wolframalpha API for C# working to no avail. I have been trying to use these two resources:
Stack Question
Wolfram API demos
The answer in the post was semi helpful but I can't get anything to compile. I'm new to C# so its a bit overwhelming. I am really having trouble trying to just get it to accept input and then output the result.
If anyone could either help me get this code working so I can work with a valid example or knows of an example project that I can model from it would be appreciated.
This is the code I cut and pasted into a C# (Visual Studio) console project:
namespace WolframAlpha {
using System;
using System.Collections.Generic;
using System.Data.Services.Client;
using System.Net;
using System.IO;
public partial class DefaultPodEntity {
private String _PlainText;
private String _Img;
private String _Title;
private String _ParentTitle;
private Int16 _ParentPosition;
private String _ParentId;
public String PlainText {
get {
return this._PlainText;
}
set {
this._PlainText = value;
}
}
public String Img {
get {
return this._Img;
}
set {
this._Img = value;
}
}
public String Title {
get {
return this._Title;
}
set {
this._Title = value;
}
}
public String ParentTitle {
get {
return this._ParentTitle;
}
set {
this._ParentTitle = value;
}
}
public Int16 ParentPosition {
get {
return this._ParentPosition;
}
set {
this._ParentPosition = value;
}
}
public String ParentId {
get {
return this._ParentId;
}
set {
this._ParentId = value;
}
}
}
public partial class HtmlPodEntity {
private String _Markup;
private String _Title;
private Int16 _Position;
private String _Id;
private String _Css;
private String _Scripts;
public String Markup {
get {
return this._Markup;
}
set {
this._Markup = value;
}
}
public String Title {
get {
return this._Title;
}
set {
this._Title = value;
}
}
public Int16 Position {
get {
return this._Position;
}
set {
this._Position = value;
}
}
public String Id {
get {
return this._Id;
}
set {
this._Id = value;
}
}
public String Css {
get {
return this._Css;
}
set {
this._Css = value;
}
}
public String Scripts {
get {
return this._Scripts;
}
set {
this._Scripts = value;
}
}
}
public partial class PlainTextPodEntity {
private String _PlainText;
private String _Title;
private String _ParentTitle;
private Int16 _ParentPosition;
private String _ParentId;
public String PlainText {
get {
return this._PlainText;
}
set {
this._PlainText = value;
}
}
public String Title {
get {
return this._Title;
}
set {
this._Title = value;
}
}
public String ParentTitle {
get {
return this._ParentTitle;
}
set {
this._ParentTitle = value;
}
}
public Int16 ParentPosition {
get {
return this._ParentPosition;
}
set {
this._ParentPosition = value;
}
}
public String ParentId {
get {
return this._ParentId;
}
set {
this._ParentId = value;
}
}
}
public partial class WolframAlphaFactsContainer : System.Data.Services.Client.DataServiceContext {
public WolframAlphaFactsContainer(Uri serviceRoot) :
base(serviceRoot) {
}
/// <summary>
/// </summary>
/// <param name="Input">Query string Sample Values : weather|msft|derivative of x^4 sin x|SAT scores</param>
/// <param name="Location">Location used for computation Sample Values : Madrid|Springfield, IL</param>
/// <param name="LatitudeLongitude">Latitude/Longitude used for computation Sample Values : 40.42,-3.71|-22.54,-43.12</param>
/// <param name="Width">Width in pixels for images returned Sample Values : 300|500</param>
public DataServiceQuery<DefaultPodEntity> GetImageResults(String Input, String Location, String LatitudeLongitude, Int16? Width) {
if ((Input == null)) {
throw new System.ArgumentNullException("Input", "Input value cannot be null");
}
DataServiceQuery<DefaultPodEntity> query;
query = base.CreateQuery<DefaultPodEntity>("GetImageResults");
if ((Input != null)) {
query = query.AddQueryOption("Input", string.Concat("\'", Input, "\'"));
}
if ((Location != null)) {
query = query.AddQueryOption("Location", string.Concat("\'", Location, "\'"));
}
if ((LatitudeLongitude != null)) {
query = query.AddQueryOption("LatitudeLongitude", string.Concat("\'", LatitudeLongitude, "\'"));
}
if (((Width != null)
&& (Width.HasValue == true))) {
query = query.AddQueryOption("Width", Width.Value);
}
return query;
}
/// <summary>
/// </summary>
/// <param name="Input">Query string Sample Values : weather|msft|derivative of x^4 sin x|SAT scores</param>
/// <param name="Location">Location used for computation Sample Values : Madrid|Springfield, IL</param>
/// <param name="LatitudeLongitude">Latitude/Longitude used for computation Sample Values : 40.42,-3.71|-22.54,-43.12</param>
/// <param name="Width">Width in pixels for images returned Sample Values : 300|500</param>
public DataServiceQuery<HtmlPodEntity> GetHtmlResults(String Input, String Location, String LatitudeLongitude, Int16? Width) {
if ((Input == null)) {
throw new System.ArgumentNullException("Input", "Input value cannot be null");
}
DataServiceQuery<HtmlPodEntity> query;
query = base.CreateQuery<HtmlPodEntity>("GetHtmlResults");
if ((Input != null)) {
query = query.AddQueryOption("Input", string.Concat("\'", Input, "\'"));
}
if ((Location != null)) {
query = query.AddQueryOption("Location", string.Concat("\'", Location, "\'"));
}
if ((LatitudeLongitude != null)) {
query = query.AddQueryOption("LatitudeLongitude", string.Concat("\'", LatitudeLongitude, "\'"));
}
if (((Width != null)
&& (Width.HasValue == true))) {
query = query.AddQueryOption("Width", Width.Value);
}
return query;
}
/// <summary>
/// </summary>
/// <param name="Input">Query string Sample Values : weather|msft|derivative of x^4 sin x|SAT scores</param>
/// <param name="Location">Location used for computation Sample Values : Madrid|Springfield, IL</param>
/// <param name="LatitudeLongitude">Latitude/Longitude used for computation Sample Values : 40.42,-3.71|-22.54,-43.12</param>
/// <param name="Width">Width in pixels for images returned Sample Values : 300|500</param>
public DataServiceQuery<PlainTextPodEntity> GetPlainTextResults(String Input, String Location, String LatitudeLongitude, Int16? Width) {
if ((Input == null)) {
throw new System.ArgumentNullException("Input", "Input value cannot be null");
}
DataServiceQuery<PlainTextPodEntity> query;
query = base.CreateQuery<PlainTextPodEntity>("GetPlainTextResults");
if ((Input != null)) {
query = query.AddQueryOption("Input", string.Concat("\'", Input, "\'"));
}
if ((Location != null)) {
query = query.AddQueryOption("Location", string.Concat("\'", Location, "\'"));
}
if ((LatitudeLongitude != null)) {
query = query.AddQueryOption("LatitudeLongitude", string.Concat("\'", LatitudeLongitude, "\'"));
}
if (((Width != null)
&& (Width.HasValue == true))) {
query = query.AddQueryOption("Width", Width.Value);
}
return query;
}
}
}

This codeplex project claims to cover the latest Wolfram Alpha API and includes a sample:
http://wolframalphaapi20.codeplex.com/
Console applications use a static Main method as their entry point. This routine can normally be found in a file program.cs that is created automatically when a new project for a console application is created.
If the compiler says it can't find Main then it probably was deleted or was never created. Difficult to say without any code to look at. More errors may show when the issue with the Main method was resolved.

I am currently playing with a lib call WolframAlpha.NET. Code source is on github. There is a nuget package (Last published 2019-06-24).
Examples (from readme)
Here is the simplest form of getting data from Wolfram|Alpha:
static void Main(string[] args)
{
//First create the main class:
WolframAlpha wolfram = new WolframAlpha("APPID HERE");
//Then you simply query Wolfram|Alpha like this
//Note that the spelling error will be correct by Wolfram|Alpha
QueryResult results = wolfram.Query("Who is Danald Duck?");
//The QueryResult object contains the parsed XML from Wolfram|Alpha. Lets look at it.
//The results from wolfram is split into "pods". We just print them.
if (results != null)
{
foreach (Pod pod in results.Pods)
{
Console.WriteLine(pod.Title);
if (pod.SubPods != null)
{
foreach (SubPod subPod in pod.SubPods)
{
Console.WriteLine(subPod.Title);
Console.WriteLine(subPod.Plaintext);
}
}
}
}
}
For more examples, take a look at the WolframAlphaNet.Examples and WolframAlphaNet.Tests projects.

You have copy-pasted class definitions (like DefaultPodEntity and WolframAlphaFactsContainer) that allow you to interact with the Wolfram API, but you do not have a definition for the Main() function that defines what your program should be doing with those classes. You will need to add the method definition
static void Main(string[] args)
{
// TODO: call methods of WolframAlphaFactsContainer
}
to one of the classes (e.g. WolframAlphaFactsContainer or a new one, like Program, that is not listed in your question. Once this compiles, you need to replace the TODO comment with C# statements that specify how you are interacting with the WolframAlphaFactsContainer class (e.g. create an instance of that class and call its GetImageResults() method with the proper parameters).
Note: you will need to learn basic C# programming idioms before you can successfully tackle the problem of writing a working, correct program in C# that does what you want to do (as opposed to relying on other people's code).
Note: Read the documentation on Main() and how to pass command line parameters to your program (should you want to do that).
Note: the class WolframAlphaFactsContainer is marked partial, which means there might be other parts of this class (see documentation). If there are, you will need to include those in your code as well.

I know this post is old, but seeing as how it comes up in google near the top:
https://wapiex.codeplex.com/
This is the wrapper I just finished. It includes much more than the other codeplex project. Feel free to use it

Edit Object with xml without creating new Instance

I have a class which needs to be a Singleton.
It must also be able to load and save its field data in an xml file.
The following method will return a new instance, which breaks my Singleton pattern, leaving potential bugs in my code.
public Settings Load()
{
using (Stream stream = File.OpenRead(FileName))
{
XmlSerializer serializer = new XmlSerializer(typeof(Settings));
return (Settings)serializer.Deserialize(stream);
}
}
What method can I use in order to update the data in my existing instance, instead of returning a entirely new instance?
I've studied a bit of Linq to Xml, but haven't found any good example of this.
Is it necessary for me to keep all my field data in a Dictionary?

I used to run into all sorts of bugs making an Xml Singleton class and ended up scrapping it as I had handles all over the place. I replaced it with using two ways. One a read-only version that was for reading data, and a second Using method/statement for writing changes.
This in general is the pattern I use:
public class Settings : IDisposable
{
string file = "my settings file";
XElement root;
private Settings()
{
root = XElement.Load(file);
}
private void Dispose()
{
root.Save(file);
}
public static Settings Read { get { return new Settings(); } } // return read-only version
public static void Write(Action<Settings> handler)
{
using(Setting settings = new Settings())
handler(settings);
}
// below here is implentation specific
public XElement Root { get { return root; } }
public string SettingA
{
get { return (string)(Root.Attribute("SettingA") ?? (object)string.Empty); }
set { Set(Root, "SettingsA", value, true); }
}
// I wrote this for another StackOverflow thread
/// <summary>
/// Set any value via its .ToString() method.
/// <para>Returns XElement of source or the new XElement if is an ELEMENT</para>
/// </summary>
/// <param name="isAttribute">true for ATTRIBUTE or false for ELEMENT</param>
/// <returns>source or XElement value</returns>
private XElement Set(XElement source, string name, object value, bool isAttribute)
{
string sValue = value.ToString();
XElement eValue = source.Element(name), result = source;
XAttribute aValue = source.Attribute(name);
if (null != eValue)
eValue.ReplaceWith(result = new XElement(name, sValue));
else if (null != aValue)
aValue.ReplaceWith(new XAttribute(name, sValue));
else if (isAttribute)
source.Add(new XAttribute(name, sValue));
else
source.Add(result = new XElement(name, sValue));
return result;
}
/// <summary>
/// Replace with for XAttribute
/// </summary>
/// <param name="source"></param>
/// <param name="value"></param>
/// <returns></returns>
public static XAttribute ReplaceWith(this XAttribute source, XAttribute value)
{
XElement parent = source.Parent;
if (null == parent)
throw new Exception("Source has no parent");
source.Remove();
parent.Add(value);
return value;
}
}
I've not used the serializer, so don't know if my pattern will fit for you. I prefer XElement.
So to use this you'd probably write a singleton class that makes use of your non-singleton XmlSerialize class. You'd only access it through the singleton.
But this is how I'd end up using it as is:
string settingA = Settings.Read.SettingA;
To save a value it would be:
Settings.Write(s => s.SettingA = "new value");

why dont you have something like
public Class TheClassHoldingYourObject
{
private static XmlSerializer _instance;
public static Settings Load()
{
if(_instance != null) return _instance
using (Stream stream = File.OpenRead(FileName))
{
XmlSerializer serializer = new XmlSerializer(typeof(Settings));
return (Settings)serializer.Deserialize(stream);
}
}
}
Now you will always get the same instance