I have a custom activity where the user selects a variable from a drop down list in a rehosted designer environment. My problem is I want to get variable's name along with its value.
Let's say my custom activity has "InArgument MyVar{ get; set; }".
I'm currently getting the variable's name by parsing "((Microsoft.VisualBasic.Activities.VisualBasicValue)MyVar.Expression).ExpressionText". Is there any better way?
You can't surelly know the true value of an argument until the runtime.
But, you can take it's default value, using those extension methods:
public static T GetImediateValueOrDefault<T>(Activity<T> activity, ModelItem modelItem)
{
if (activity == null)
return default(T);
var exprAsLiteral = activity as Literal<T>;
if (exprAsLiteral != null)
return exprAsLiteral.Value;
var exprAsVbValue = activity as Microsoft.VisualBasic.Activities.VisualBasicValue<string>;
if (exprAsVbValue != null)
return modelItem.GetDefaultValueOfScopedVariable<T>(exprAsVbValue.ExpressionText);
return default(T);
}
public static T GetDefaultValueOfScopedVariable<T>(this ModelItem modelItem, string variableName)
{
IEnumerable<ModelItem> scopedVariables = modelItem.GetScopedVariables();
ModelItem variableModelItem = scopedVariables.FirstOrDefault(v => Equals(variableName, v.Properties["Name"].ComputedValue));
if (variableModelItem == null)
throw new KeyNotFoundException();
Variable<T> variable = variableModelItem.GetCurrentValue() as Variable<T>;
if (variable == null)
return default(T);
return GetImediateValueOrDefault(variable.Default, modelItem);
}
Not guaranteed, use with caution
Related
need small help about returning values based on arguments.
Setup of mocking contains expressions like
mockingObject
.Setup(_=>_.Select(It.IsAny<Expression<Func<Entity, bool>>>(),
It.IsAny<Func<IQueryable<Entity>, IOrderedQueryable<Entity>>>(),
It.IsAny<List<Expression<Func<Entity, object>>>>(), It.IsAny<int?>(), It.IsAny<int?>())))
.ReturnsAsync((Expression<Func<Entity,bool>>,Func<IQueryable<Entity>, IOrderedQueryable<Entity>>,List<Expression<Func<Entity,object>>>,int, int,EntityList());
But I'm getting error that Expression<Func<Entity,bool>> is a type which is not valid give context.
How should I manage Returns?
Need to mock:
public async Task<Result> UpdateNetworkStatus(string id, NetworkStatus status)
{
var network = _unitOfWork.NetworkRepository.SelectListAsync(x => x.Id == id).Result.FirstOrDefault();
if (network == null)
throw new Exception(nameof(network));
network.Status = status;
_unitOfWork.NetworkRepository.Update(network);
var saved = await _unitOfWork.Commit();
if (!saved)
return Result.Failure(new List<string>
{
"Failed to save"
});
return Result.Success();
}
Here I need to mock all possible scenarios.
Here is the example how I had manage to pass args to returns
unitOfWorkMock.Setup(_ => _.EntityRepository.SelectListAsync(It.IsAny<Expression<Func<Entity, bool>>>(),
It.IsAny<Func<IQueryable<Entity>, IOrderedQueryable<Entity>>>(),
It.IsAny<List<Expression<Func<Entity, object>>>>(), It.IsAny<int?>(), It.IsAny<int?>()))
.ReturnsAsync((Expression<Func<Entity, bool>> filter, Func<IQueryable<Entity>, IOrderedQueryable<Entity>> orderBy, List<Expression<Func<Entity, object>>> includes, int? page, int? pageSize) =>
{
if (filter == null)
return Entities();
return Entities().AsQueryable().Where(filter).ToList();
});
Lets say we have a 'Client' object:
(am just mentioning the attributes and the equals method alone of the 'Client' object below!!)
public class Client {
private Long clientId;
private String clientName;
private Integer status;
//getters and setters for above attributes
.....
...
//hashCode method
....
..
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Client other = (Client) obj;
if (clientId == null) {
if (other.clientId != null)
return false;
} else if (!clientId.equals(other.clientId))
return false;
if (clientName == null) {
if (other.clientName != null)
return false;
} else if (!clientName.equals(other.clientName))
return false;
if (status == null) {
if (other.status != null)
return false;
} else if (!status.equals(other.status))
return false;
return true;
}
}
From the above equals method itz clear that 'two' client objects are said to be equal if all the attributes of the two objects are identical.
Now assume a scenario where I need to compare two collections(named say incomingClients and existingClients) of Client objects.
The first collection(Collection incomingClients) was generated after reading the 'client' data from a csv/xls file.
The second collection(Collection existingClients) contains, all the existing clients currently in the system.
I can do the following code (using apache CollectionUtils)to get the 'common' clients.
Collection<Client> commonClients = (Collection<Client>)CollectionUtils.intersection(incomingClients,existingClients);
Now with the below code I can remove these commonClients from both the collections.
incomingClients.removeAll(commonClients);
existingClients.removeAll(commonClients);
The intention of removing the 'common clients objects' was that, we dont need to do 'any processing' for these records,
as we are really not at all interested in those records.
Now how can I figure out which are the entirely 'new clients' in the 'Collection incomingClients' collection?
(When I say 'new' it means a client having a new 'clientId' which doesnt exist in the 'Collection existingClients')
Also, how can I figure out which are the clients which needs 'modification'
(When I say 'modification' it means that the 'Collection incomingClients' and Collection existingClients'
have the same clientId, but, say, different 'clientName')
I know that we can do the normal 'for' loop('check below') to figure out the 'new'/'modification needed' clients.
But I thought of writing 'something new', whether we can achieve this using some classes/function in the 'Apache CollectionUtils' package.
Collection<Client> newClients = new ArrayList<Client>();
Collection<Client> toBeModifiedClients = new ArrayList<Client>();
boolean foundClient = false;
Client client = null;
for(Client incomingClient :incomingClients){
foundClient = false;
for(Client existingClient : existingClients){
if(existingClient.getClientId().equals(incomingClient.getClientId())){
client = existingClient;
foundClient = true;
break;
}
}
if(foundClient){
toBeModifiedClients.add(client);
}else{
//not found in existing. so this is completely new
newClients.add(incomingClient);
}
}
Am I 'complicating' a simple stuff??
Any thoughts??
First, yes, you are complicating "simple stuff". Your entire question could be summarized as follows:
Given collections A and B, how can I get the following using CollectionUtils:
A-B, using a particular function that determines equality
A∩B, using a particular function that determines equality
So, yes. CollectionUtils has what you need. Look at CollectionUtils.select().
I am new to ASP.NET MVC and I am stuck on a point. I am working on a classified site. My situation is, I have a lot of categories in which a user can post their ads and each ad category have different View. I have created a Controller Action like
public ActionResult PostAd(string CategoryName, string SubCategoryName)
{
if(categoryName == "Vehicle" && SubCategoryName == "Cars")
{
var model = new CarAdViewModel();
// set CarAdViewModel properties...
return View("CarAdCreateView", model);
}
else if(categoryName == "Vehicle" && SubCategoryName == "Bikes")
{
var model = new BikeAdViewModel();
// set BikeAdViewModel properties...
return View("BikeAdViewModel", model);
}
else if(categoryName == "Property" && SubCategoryName == "RentHouse")
{
var model = new RentHouseAdViewModel();
// set RentHouseAdViewModel properties...
return View("RentHouseAdViewModel", model);
}
else................... so on and so on
}
My problem is I have huge number of Categories and Sub Categories almost 60+. And if I keep on coding like above for 60+ categories and subcategories, my PostAd method is going to blast and become unmanageable.
Please tell me some best practice or pattern which can bring me out of this problem.
Unfortunately, some of what you are doing cannot be avoided. There needs to be some form of model and view selection based on category.
Use a factory pattern. Create a base class:
public abstract class BaseCategory
{
public abstract string GetViewName();
public abstract Object CreateModelFromFormData();
}
For each category, create a sub-class derived from BaseCategory and implement the abstract functions.
In your action, do the following:
public ActionResult PostAd(string categoryName, string subCategoryName)
{
BaseFactory factory;
if (categoryName == "Vehicle")
{
if (subCategoryName == "Cars")
{
factory = new CarsFactory();
}
else ...
}
else ...
return View(factory.GetViewName(), factory.CreateModelFromFormData());
}
I have a couple reasons for this schema:
I am purposefully using if/else for the factory selection. Your controller is going to be created and re-created for every action call. So pre-populating a list will constantly and needlessly create objects for categories that will not be selected. A simple if/else will be more efficient. If you want to prevent the if/else, you can put your factories in a Dictionary and select based on the categories, but that would be a lot of needless constructor actions.
I made the CreateModelFromFormData a function because I assume you'll need to copy data from the posted form data. This may require passing in data, but I left the function parameterless.
I used base/derived classes because the copying of the form data will probably need to be custom from the model being created and the form data being posted. Also, saving to persistent storage (file or database) may be category-specific as well.
It would be one of some possible solutions
public class PostAdData
{
public string CategoryName;
public string SubCategoryName;
public string ViewName;
public Type Model;
}
public class PostController : Controller
{
private readonly List<PostAdData> _theData;
public HomeController()
{
_theData = InitializeData();
}
public ActionResult PostAd(string categoryName, string subCategoryName)
{
var data = _theData.FirstOrDefault(c => c.CategoryName == categoryName && c.SubCategoryName == subCategoryName);
if (data != null)
{
var model = Activator.CreateInstance(data.Model);
return View(data.ViewName, model);
}
return View("Error");
}
[NonAction]
public List<PostAdData> InitializeData()
{
var result = new List<PostAdData>
{
new PostAdData
{
CategoryName = "Vehicle",
SubCategoryName = "Cars",
ViewName = "CarAdCreateView",
Model = typeof (CarAdViewModel)
}
};
return result;
}
}
You should make this data driven. You create a lookup table that has a compound primary key of category and subcategory. Then it has a table with View in it. Then you simply ad rows for each category/subcategory/view combination.
If you absolutely don't want a database, then you can use a simple hashset or dictionary.
var views = new Dictionary<Tuple<string,string>,string>();
views.Add(new Tuple<string,string>("Vehicle", "Cars"), "CarAdCreateView");
Then in your PostAd you just lookup the correct view.
What a beautiful solution on www.asp.net to my question, here is the link : http://forums.asp.net/t/1923868.aspx/1?ASP+NET+MVC+Conditional+ViewModel+Abstraction
Edit:
My code is :
public class AdsController : Controller
{
private readonly IAdService _adService;
public AdsController(IAdService adService)
{
_adService = adService;
}
public ActionResult PostAd(string Category, string SubCategory)
{
//Here I will call
var strategy = GetStrategy(CategoryName, SubCategoryName);
strategy.FillModel(_adService );
return View(strategy.ViewName, strategy.Model);
}
}
Given is a Workflow Foundation 4 runtime that is working against a website ;)
We need to get the arguments of workflows to show the user an editor to enter the arguments. For that we need all arguments with names, types and - default values, as well as an indication whether an argument is required.
Workflows are stored as XAML files.
How to do that? The data seems to be in the Activity Metadata which seems to be not avaialble outside the Workflow. In addition, the Workflow Engine ModelService is for the Designer and has a lot of overhead.
Any easy way to retrieve this information?
I've already done something similar. Reflection might be your best (and only) option if you want a generic approach.
// Just an holder for InArgument informations
class InArgumentInfo
{
public string InArgumentName { get; set; }
public string InArgumentDescription { get; set; }
public bool InArgumentIsRequired { get; set; }
}
static ICollection<InArgumentInfo> GetInArgumentsInfos(Activity activity)
{
var properties = activity.GetType()
.GetProperties()
.Where(p => typeof(InArgument).IsAssignableFrom(p.PropertyType))
.ToList();
var argumentsCollection = new Collection<InArgumentInfo>();
foreach (var property in properties)
{
var descAttribute = property
.GetCustomAttributes(false)
.OfType<DescriptionAttribute>()
.FirstOrDefault();
string description = descAttribute != null && !string.IsNullOrEmpty(descAttribute.Description) ?
descAttribute.Description :
string.Empty;
bool isRequired = property
.GetCustomAttributes(false)
.OfType<RequiredArgumentAttribute>()
.Any();
argumentsCollection.Add(new InArgumentInfo
{
InArgumentName = property.Name,
InArgumentDescription = description,
InArgumentIsRequired = isRequired
});
}
return argumentsCollection;
}
This way you can not only retrieve the argument's name but also other information hold by the argument's attributes. For example I choose to give argument an user-friendly name through [Description] attribute (eg. instead of MyPropertyName user sees "My Property Name").
Note: if you can ensure that you activity is an ActivityBuilder or DynamicActivity they both have Properties property that you can use, but the principle is the same.
Load it as DynamicActivity and iterate over Properties property
var dynamicActivity = ActivityXamlServices.Load(foo) as DynamicActivity
foreach(DynamicActivityProperty prop in dynamicActivity.Properties)
{
// ...
}
UPDATE: Missed default value part
foreach (var prop in dynamicActivity .Properties)
{
object defaultValue;
if (prop.Value == null)
{
defaultValue = null;
}
else
{
Type genericTypeDefinition = prop.Type.GetGenericTypeDefinition();
if (genericTypeDefinition == typeof(InArgument<>) || genericTypeDefinition == typeof(InOutArgument<>))
{
var valueProp = prop.Value.GetType().GetProperty("Expression", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.DeclaredOnly);
var expression = valueProp.GetValue(prop.Value, null);
var expressionValueProp = expression.GetType().GetProperty("Value");
defaultValue = expressionValueProp.GetValue(expression, null);
}
}
}
Not totally guaranteed, there are some checks you have to do.
I have declared my c# application constant this way:
public class Constant
public struct profession
{
public const string STUDENT = "Student";
public const string WORKING_PROFESSIONAL = "Working Professional";
public const string OTHERS = "Others";
}
public struct gender
{
public const string MALE = "M";
public const string FEMALE = "F";
}
}
My validation function:
public static bool isWithinAllowedSelection(string strValueToCheck, object constantClass)
{
//convert object to struct
//loop thru all const in struct
//if strValueToCheck matches any of the value in struct, return true
//end of loop
//return false
}
During runtime, I will like pass in the user inputted value and the struct to check if the value exist in the struct. The struct can be profession and gender. How can I achieve it?
Example:
if(!isWithinAllowedSelection(strInput,Constant.profession)){
response.write("invalid profession");
}
if(!isWithinAllowedSelection(strInput,Constant.gender)){
response.write("invalid gender");
}
You probably want to use enums, not structs with constants.
Enums gives you a lot of possibilities, it is not so hard to use its string values to save it to the database etc.
public enum Profession
{
Student,
WorkingProfessional,
Others
}
And now:
To check existence of value in Profession by value's name:
var result = Enum.IsDefined(typeof(Profession), "Retired"));
// result == false
To get value of an enum as a string:
var result = Enum.GetName(typeof(Profession), Profession.Student));
// result == "Student"
If you really can't avoid using value names with whitespaces or other special characters, you can use DescriptionAttribute:
public enum Profession
{
Student,
[Description("Working Professional")] WorkingProfessional,
[Description("All others...")] Others
}
And now, to get description from Profession value you can use this code (implemented here as an extension method):
public static string Description(this Enum e)
{
var members = e.GetType().GetMember(e.ToString());
if (members != null && members.Length != 0)
{
var attrs = members.First()
.GetCustomAttributes(typeof(DescriptionAttribute), false);
if (attrs != null && attrs.Length != 0)
return ((DescriptionAttribute) attrs.First()).Description;
}
return e.ToString();
}
This method fetches description defined in attribute and if there's none, returns value name. Usage:
var e = Profession.WorkingProfessional;
var result = e.Description();
// result == "Working Professional";