MVC - validation attributes with error messages from database - asp.net-mvc

I need to keep my translations in database so users can add, delete, and change them. I hold all of my translations in a table with composite primary key (variableName, culture), where variableName is just a name of some text which can have multiple translations and they correspond to the culture which is a string, like "en-US". So for example I have a variable "submitLogin" which I display on login button and there are three languages in my database: English, German, and Polish. This means I keep three rows in my table for that particular text: ("submitLogin", "en-US", "English translation), ("submitLogin", "de-DE", "German translation") and ("submitLogin", "pl-PL", "Polish translation").
So far my application has been based on a class Resources.cs which contains all translation variables from database, e.g.:
public static string buttonContinueShopping {
get {
return (string) resourceProvider.GetResource("buttonContinueShopping", CultureInfo.CurrentUICulture.Name);
}
}
In views I use these static properties to get my translations like this:
#Resources.buttonContinueShopping
I can create a dynamic type which will behave exactly the same way in views (except not having static properties but I can create an object on every view, that's not the problem - although it doesn't seem nice):
public class Resource : DynamicObject
{
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
ResourceManager rsManager = new ResourceManager();
result = rsManager.GetString(binder.Name);
return true;
}
}
But I have a problem with my models' attributes. So far I've used them like this:
[Required(ErrorMessageResourceType = typeof(Resources.Resources), ErrorMessageResourceName = "errorRequired")]
[DataType(DataType.EmailAddress, ErrorMessageResourceType = typeof(Resources.Resources), ErrorMessageResourceName = "errorWrongDataType")]
[EmailAddress]
[Display(Name = "nameEmail", ResourceType = typeof(Resources.Resources))]
public string Email { get; set; }
Now I have to get rid of my Resources.cs because they are generated after running a console program which reads all unique values of translation variables from database and creates properties (like the one I showed above). I cannot have this file anymore because users can add new translation variables in runtime.
How do I change as little as possible and make these attributes read error messages, display names etc. from database?
I have three ideas but I don't know how to get them done:
Use custom attributes - I tried it for Required attribute but it just doesn't add any client-side validation nor any error messages in HTML.
Use custom DataAnnotationsModelMetadataProvider - I tried this but it doesn't work after reloading the page - on the first page load all errors exist (particularly this: 'Field Email is required.') but after reloading the page, required error message changes to 'Field is required'. This is what I do:
public class CustomDataAnnotationsProvider: DataAnnotationsModelMetadataProvider
{
private ResourceManager resourceManager = new ResourceManager();
protected override ModelMetadata CreateMetadata(IEnumerable<Attribute> attributes, Type containerType, Func<object> modelAccessor, Type modelType, string propertyName)
{
string key = string.Empty;
string localizedValue = string.Empty;
foreach (var attr in attributes)
{
if (attr != null)
{
if (attr is DisplayAttribute)
{
key = ((DisplayAttribute)attr).Name;
if (!string.IsNullOrEmpty(key) && !key.Contains(" "))
{
localizedValue = resourceManager.GetString(key);
((DisplayAttribute)attr).Name = localizedValue;
}
}
else if (attr is ValidationAttribute || attr is RequiredAttribute)
{
key = ((ValidationAttribute)attr).ErrorMessage;
if (!string.IsNullOrEmpty(key) && !key.Contains(" "))
{
localizedValue = resourceManager.GetString(key);
((ValidationAttribute)attr).ErrorMessage = localizedValue;
}
}
}
}
return base.CreateMetadata(attributes, containerType, modelAccessor, modelType, propertyName);
}
Global.asax:
ModelMetadataProviders.Current = new CustomDataAnnotationsProvider();
Model:
[Required(ErrorMessage = "errorRequired")]
[EmailAddress(ErrorMessage = "errorWrongDataType")]
[Display(Name = "nameEmail")]
public string Email { get; set; }
Use reflection (would be the best but I have no idea how to do it). Let's say I leave my attributes like that and remove all properties from my Resources.cs. Now what does RequiredAttribute do? It takes the type given and gets the property given, so e.g. It tries to do this:
Resources.Resources.nameEmail.get
The question is: is it possible to write some reflection code which would take care of 'requests' for non-existing properties (like nameEmail)?

I think the answer is to supply a default value in your Resources.cs file. Whilst users can supply translations dynamically, your application cannot use them unless they have the key, which you have used in the model.
If you modify your existing method to accept a default value then you can return this if there is not a database value present:
public static string buttonContinueShopping {
get {
return GetResource("buttonContinueShopping",
CultureInfo.CurrentUICulture.Name, "Continue Shopping");
}
}
public string GetResource(string key, string cultureName, string defaultText)
{
// Get db value
if (dbValue != null)
return dbValue;
return defaultText;
}
You control the keys by manually modifying them in Resources.cs which IMO is the best place for them, as they are maintained in the same project as they are being used. You can (and I have used this technique) then write a companion console app that can use reflection to generate the sql needed to update the database.
This example is taken directly from my project but you can get the idea
static void Main(string[] args)
{
var resources = typeof(Resources).GetProperties();
StreamWriter streamWriter = new StreamWriter(new FileStream(#"..\..\Resources.sql", FileMode.Create));
streamWriter.WriteLine(createTable);
for (int i = 0; i < resources.Count(); i++)
{
var line = GetValues(resources[i].Name, resources[i].GetValue(null, null) as string);
if (i == 0)
{
streamWriter.Write(insertValues + line);
}
else if (i == resources.Count() - 1)
{
streamWriter.Write(",\r\n" + line + "\r\nGO");
}
else if (i % 4 == 0)
{
streamWriter.Write("\r\nGO\r\n\r\n" + insertValues + line);
}
else
{
streamWriter.Write(",\r\n" + line);
}
}
streamWriter.Flush();
streamWriter.Close();
}
private static string createTable = "IF NOT EXISTS (SELECT * FROM sys.objects where Object_Id = OBJECT_ID(tempdb..#Resources))"
+ "\r\n\tCREATE TABLE Resources (StaticTextKey VARCHAR(100), DefaultText VARCHAR(MAX))\r\nGO\r\n";
private static string insertValues = "INSERT INTO #Resources (StaticTextKey, DefaultText) VALUES\r\n";
private static string GetValues(string staticTextKey, string defaultText)
{
return string.Format("('{0}', '{1}')", staticTextKey, defaultText.Replace("'", "''"));
}

Related

Want to save selected (i.e., more than 1) enums as string with NHibernate

I cannot for the life of me get this to work with my existing code, but I am trying to save my enum selections as strings in NHibernate. Basically, I have a UI check box and if the user selects multiple check boxes I want to store those selections. Now, I can get NHibernate to store ONE selection (e.g., from a drop down or radio button list, where the user is limited to one choice only).
This is the jist of what I have for an enum:
public enum IncomeType
{
[Display(Name = "Full-Time Employment")]
FullTime,
[Display(Name = "Part-Time Employment")]
PartTime,
[Display(Name = "Self-Employment")]
SelfEmployed,
[Display(Name = "Rental")]
Rental,
[Display(Name = "Social Security Payments")]
SocialSecurity,
[Display(Name = "Retirement / Pension Payments")]
Retirement,
[Display(Name = "Child Support Payments")]
ChildSupport,
[Display(Name = "Spousal Maintenance")]
Maintenance,
[Display(Name = "Other")]
Other
}
I use a method to "select" whether a checkbox list is shown (if my BulkItemThreshold equals the number of options, a checkbox list is displayed). Here is that method:
public static IEnumerable<SelectListItem> GetItemsFromEnumString<T>
(T selectedValue = default(T)) where T : struct
{
return from name in Enum.GetNames(typeof(T))
let enumValue = Convert.ToString((T)Enum.Parse(typeof(T), name, true))
select new SelectListItem
{
Text = GetEnumDescription(name, typeof(T)),
Value = enumValue,
Selected = enumValue.Equals(selectedValue)
};
}
(Note: some items in there are helpers, but I don't believe they are relevant; also, the selected input is displayed using a template .cshtml file - again, not sure if that's relevant)
Now, I call this thusly:
public class IncomeTypeSelectorAttribute : SelectorAttribute
{
public override IEnumerable<SelectListItem> GetItems()
{
return Selector.GetItemsFromEnumString<IncomeType>();
}
}
And finally, we get to the virtual property (using a proxy) but this is where NHibernate throws a wrench (Note: this was working fine for me before NHibernate, and now I am trying to get many lines of code working with it WITHOUT having to re-do everything; if I re-do everything I will probably triple the code I already have to get it to work):
Property (record):
[IncomeTypeSelector(BulkSelectionThreshold = 9)]
public virtual List<string> IndividualIncomeTypeCheckBox { get; set; }
proxy (part):
public List<string> IndividualIncomeTypeCheckBox
{
get { return Record.IndividualIncomeTypeCheckBox; }
set { Record.IndividualIncomeTypeCheckBox = value; }
}
Again, this is how I was doing things and it was working great before NHibernate. But now I have to use NHibernate. No getting around it.
I am using a service class that it tying the two together in a Create method to save in the DB with NHibernate, and for the above it would ordinarily look like this:
part.IndividualIncomeTypeCheckBox = record.IndividualIncomeTypeCheckBox;
This would work if it were just one selection.
Well, I've spent a good two (2) months trying to get this to work. It's tough because I have lots of code where the user can make only one selection (such as with a radiobutton list) and it works GREAT - even with NHibernate. Let me give you an example:
public virtual IncomeType? IndividualIncomeTypeCheckBox { get; set; }
If I do the above, it will display a drop down list, and NHibernate will store the ONE allowable option selected by the user in the DB no problem. But more than one option with List<string> does not work.
Now, I have tried everything I could find here or elsewhere and nothing works. Yes, I know it should be IList<IncomeType> or some other variant. But if I use this then NHibernate requires that IncomeType be another table in the DB. This is too much code to write for such a simple thing I believe. We are not talking a many-to-many relation in the sense that this is not a User with Multiple addresses (wherein addresses would have street, city, state, zip, etc.).
I have tried different types of proxy get and set code, but nothing works. I have tried [Flags] and other things working with string only, but to no avail. Those last solutions would "work" but ONLY to save the first item selected out of multiple (i.e., in my scenario, if the user selected "FullTime" and "Rental" as Income Types, then only "FullTime" (string) would be saved or "1" ([Flags]/int), not both items selected.
I have a situation where I re-display the choices using a ReadOnly attribute like this:
[IncomeTypeSelector]
[ReadOnly(true)]
public List<string> IndividualIncomeTypeCheckBoxPost
{
get { return IndividualIncomeTypeCheckBox; }
}
This would display on the UI, but I tried doing something like this with NHibernate and it wouldn't work.
Could anyone please show me, using the above, how I can go about getting NHibernate to store more than one enum in this checkbox list scenario?
UPDATE:
More poking around here and on the web, and I came up with the following (which still does not work).
Property (record):
[IncomeTypeSelector(BulkSelectionThreshold = 9)]
public virtual IList<IncomeTypeRecord> IndividualIncomeTypeCheckBox
{
get { return incomeType; }
set { incomeType= value; }
}
private IList<IncomeTypeRecord> incomeType =
new List<IncomeTypeRecord>();
Proxy (part):
public IList<IncomeTypeRecord> IndividualIncomeTypeCheckBox
{
get { return Record.IndividualIncomeTypeCheckBox; }
set { Record.IndividualIncomeTypeCheckBox= value; }
}
And a change to the enum:
public enum IncomeType : int // removing int & value still gives validate error
{
[Display(Name = "Full-Time Employment")]
FullTime = 1,
[Display(Name = "Part-Time Employment")]
PartTime,
....
}
And I added this class to support IncomeTypeRecord
public class IncomeTypeRecord
{
public virtual int Id { get; set; }
public virtual IncomeType Value { get; set; }
}
HOWEVER, when I get to the UI screen and pick one or more options I get a validation error (value not valid). For example, say I pick FullTime alone, or pick FullTime and Retirement, then the UI will display the following error:
The value 'FullTime' is invalid.
The value 'FullTime,Retirement' is invalid.
(respectively)
Even if I remove the int declaration for the enum and get rid of the value I started with "1", I still get this validation error. I tried messing around with and adding different model binders (which now has me stumped as to whether my original problem still exists and now I have a different problem - but you still get bounty points :) ).
Pulling my hair out. If I could offer more bounty I would. I need a definitive solution. I appreciate any help.
UPDATE
This is what I have so far:
Record:
public virtual string IndividualIncomeTypeCheckBox{ get; set; }
Part:
//If I do IEnumberable<string> my .Select throws a cast error
public IEnumerable<IncomeType> IndividualIncomeTypeCheckBox
{
get
{
return Record
.IndividualIncomeTypeCheckBox
.Split(',')
.Select(r => (IncomeType)Enum.Parse(typeof(IncomeType), r));
}
set { Record.IndividualIncomeTypeCheckBox= value
== null ? null : String.Join(",", value); }
}
Service Class:
public SimplePart CreateSimple(SimplePartRecord record)
{
SimplePart simple = Services.ContentManager.Create<SimplePart>("Simple");
...
//How I would save a FirstName property (example Part / PartRecord below)
//public virtual string FirstName { get; set; } - PartRecord
//public string FirstName - Part
//{
// get { return Record.FirstName ; }
// set { Record.FirstName= value; }
//}
simple.FirstName = record.FristName;
...
//I obviously cannot do the following with the above IncomeType
//Getting cannot convert string to IEnumerable error
//How would I write this:
simple.IndividualIncomeTypeCheckBox = record.IndividualIncomeTypeCheckBox;
...
}
And this is how it's called in a controller (this persists to DB): (Updating Controller code)
public ActionResult Confirm(string backButton, string nextButton)
{
if (backButton != null)
return RedirectToAction("WrapUp");
else if ((nextButton != null) && ModelState.IsValid)
{
_myService.CreateSimple(myData.SimplePartRecord);
return RedirectToAction("Submitted");
}
else
return View(myData);
}
Updating with additional code (serialization and view model):
"myData" is defined in the controller (using Serialization) as:
private MyViewModel myData;
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
var serialized = Request.Form["myData"];
if (serialized != null)
{
myData = (MyViewModel)new MvcSerializer().Deserialize
(serialized, SerializationMode.Signed);
TryUpdateModel(myData);
}
else
myData = (MyViewModel)TempData["myData"] ?? new MyViewModel();
TempData.Keep();
}
protected override void OnResultExecuted(ResultExecutedContext filterContext)
{
if (filterContext.Result is RedirectToRouteResult)
TempData["myData"] = myData;
}
I use Serialization because I set up a multi-step wizard (as seen in the controller action "backButton" "nextButton) on the front-end. I am not using a driver (which can only display Admin or on the front-end but then only on .cshtml files directly under the ~/Views folder (not in a structured folder list like I am using)). No driver = no update view model type code = no mechanism to "create" the data in the DB. If I do not use some "create" type method, the form will submit but all the data will be "NULL".
When you say that the data should be persisted automatically, I am sorry but I do not see how. All the stuff I read or code I review has SOME method of updating the DB with whatever is entered in a form. If I am missing something, my apologies.
"MyViewModel" is pretty straightforward:
[Serializabel]
public class MyViewModel
{
public SimplePartRecord SimplePartRecord { get; set; }
}
And, just in case, here is the relevant portion of the migration (return 1 is a completely separate and unrelated table):
public int UpdateFrom1()
{
SchemaBuilder.CreateTable("SimplePartRecord",
table => table
.ContentPartRecord()
...
.Column("IndividualIncomeTypeCheckBox", DbType.String)
...
);
ContentDefinitionManager.AlterPartDefinition("SimplePart",
part => part
.Attachable(false));
return 2;
}
The error I am getting is
Cannot implicitly convert type 'string' to 'System.Collections.Generic.IEnumerable'"
when I do the following in the "Create" method of my service class:
simple.IndividualIncomeTypeCheckBox = record.IndividualIncomeTypeCheckBox;
One additional thought: I tried using the n-n Relation sample to handle this scenario. Aside from it being a lot of extra code for what I thought should be straightforward and simple, because of the way I am using Serialization I had a lot of object reference errors and could not figure out how to properly code my controller to handle it.
There's a lot of info to wade through here so hopefully I haven't missed the point. It appears to me that the goals are:
The business class has a collection property of IList<IncomeType> without requiring an additional table
The values in that collection should be persisted as a delimited string of the enum names
The best approach is to use a custom user type (an implementation of NHibernate.UserTypes.IUserType) to map the property. Below is a generic IUserType that will map an enum of type T from an IList<T> property to a comma delimited string in the database and back again. There's no easy way to restrict T to an enum but the code will only work with enums.
Mapping a property using the custom type is simple with Fluent NHibernate:
public class Person
{
public Person()
{
IncomeTypes = new List<IncomeType>();
}
public virtual int PersonId { get; protected set; }
public virtual string FirstName { get; set; }
public virtual string LastName { get; set; }
public virtual IList<IncomeType> IncomeTypes { get; protected set; }
}
public class PersonMap : ClassMap<Person>
{
public PersonMap()
{
Table("Person");
Id(x => x.PersonId).GeneratedBy.Identity();
Map(x => x.FirstName);
Map(x => x.LastName);
Map(x => x.IncomeTypes).CustomType<EnumAsDelimitedStringType<IncomeType>>();
}
}
And here's the code for the user type:
public class EnumAsDelimitedStringType<T> : IUserType
{
public new bool Equals(object x, object y)
{
if (ReferenceEquals(x, y))
{
return true;
}
var xList = x as IList<T>;
var yList = y as IList<T>;
if (xList == null || yList == null)
{
return false;
}
// compare set contents
return xList.OrderBy(xValue => xValue).SequenceEqual(yList.OrderBy(yValue => yValue));
}
public int GetHashCode(object x)
{
return x.GetHashCode();
}
public object NullSafeGet(IDataReader rs, string[] names, object owner)
{
var outValue = NHibernateUtil.AnsiString.NullSafeGet(rs, names[0]) as string;
if (string.IsNullOrEmpty(outValue))
{
return new List<T>();
}
var getValueArray = outValue.Split(new[] {','}, StringSplitOptions.RemoveEmptyEntries);
return Array.ConvertAll(getValueArray, s => (T)Enum.Parse(typeof(T), s)).ToList();
}
public void NullSafeSet(IDbCommand cmd, object value, int index)
{
var inValue = value as IList<T>;
// set to string.Empty if you prefer to store that instead of null when the collection is null or empty
object setValue = null;
if (inValue != null && inValue.Any())
{
var setValueArray = Array.ConvertAll(inValue.ToArray(), v => Enum.GetName(typeof(T), v));
setValue = string.Join(",", setValueArray);
}
NHibernateUtil.AnsiString.NullSafeSet(cmd, setValue, index);
}
public object DeepCopy(object value)
{
return value;
}
public object Replace(object original, object target, object owner)
{
return original;
}
public object Assemble(object cached, object owner)
{
return cached;
}
public object Disassemble(object value)
{
return value;
}
public SqlType[] SqlTypes
{
get { return new[] {new SqlType(DbType.AnsiString)}; }
}
public Type ReturnedType
{
get { return typeof(IList<T>); }
}
public bool IsMutable
{
get { return false; }
}
}
I think you're on the right track pursuing a [Flags] enum. You may have done this, but just in case -- making an enum flags-worthy is more than adding the attribute. You also have to specify the value for the items in a binary-friendly manner. I've found the easiest way to do this is as follows:
[Flags]
public enum IncomeType : long // you'll need the room with several options
{
FullTime = 1,
PartTime = 1 << 1,
SelfEmployed = 1 << 2
// And so on
}
If you don't do this, then you'll get sequential integer values, which breaks the bitwise comparison that allows you to do multiple values in a single integer.
Your code to create the SelectList looks fine. Your options should construct form values that get posted back with the same name. If you want to use the default modelbinder, that means the associated property on your view model would need to be List<int>. If you're not using a view model (you probably should) you can pull it out of the forms collection.
Once you have this set up, then translating from your view model to your NHibernate entity is simple if a little annoying. You basically have to cycle through the values in the list and |= them onto your NHibernate entity's single enum property.
So let's assume you have a view model like this:
public class MyEditViewModel
{
public string Name { get; set; }
public List<int> IncomeSelections { get; set; }
// You'll probably have this to populate the initial view rendering
public SelectList AllIncomeOptions { get; set; }
}
You'll build your view using your helpers and all that, then build the checkboxes using the SelectList but making sure the input name is IncomeSelections, then when it's posted back you will push the view model data into your NHibernate entity something like this:
var myNHEntity = new NHEntity();
// If you're editing an existing entity, then be sure to reset the enum
// value to 0 before going into the following foreach loop...
foreach (var incomeSelection in viewModel.IncomeSelections)
{
myNHEntity.IncomeSelection |= incomeSelection;
}
There's probably a more clever way to do this, and you might have to cast the int to your enum type, but you'll figure that out (I'd do it for you, but it is Friday and I already have a beer open).
NHibernate should persist it without you having to do anything funky on the NH side.
In summary...
It seems like this is more a problem of how you handle the posted data than the NHibernate side. If you implement something like this, then be sure to use Fiddler or FireBug to inspect the posted values to make sure 1) they're integers and 2) the names are the same so they'll be added to the list.
Good luck!
The problem is simply that it won't be able to map a List without building a full relationship with an intermediate association table. It is way simpler to have the record store the values as a comma-separated string (so your record property is a string, not a list of string) and your part can map back and forth between string and List.
You can find an example of something very close here:
https://bitbucket.org/bleroy/nwazet.commerce/src/d722cbebea525203b22c445905c9f28d2af7db46/Models/ProductAttributesPartRecord.cs?at=default
https://bitbucket.org/bleroy/nwazet.commerce/src/d722cbebea525203b22c445905c9f28d2af7db46/Models/ProductAttributesPart.cs?at=default
It's not using enum values, instead it's a list of ids, but that should give you a good idea about how to make this work fairly simply: parsing enums you already know how to do.
Let me know if you need more details, but I think that's what you needed to get unblocked.

Custom dynamic dataannotation for field visibility c#

I am trying to create a dataannotations attribute that controls field visiblity based on settings in a database. The attribute will be used within a system that will be used by multiple clients. Further, the visibility of the field needs to be able to change on the fly. I know I could do an if statement around each field in the view, but I am trying to avoid that and keep the visibility control within the view model as follows:
[Visible(FirstName)]
public string FirstName { get; set; }
I have tried creating this custom attribute that gets the value from a method from a resource class called ResourceType (which is generated using T4 and contains the necessary code to hit the database):
public class VisibleAttribute : Attribute, IMetadataAware
{
/// <summary>
/// Whether this field is visible
/// </summary>
public bool Hidden { get; set; }
public VisibleAttribute(string theFieldName)
{
ResourceType resources = new ResourceType();
Type _resourceType = typeof(ResourceType);
MethodInfo getHidden = _resourceType.GetMethod("IsHidden");
object[] requiredParams = new object[] { theFieldName };
Hidden = (bool)getHidden.Invoke(resources, requiredParams);
}
public void OnMetadataCreated(ModelMetadata metadata)
{
metadata.ShowForEdit = !Hidden;
metadata.HideSurroundingHtml = Hidden;
}
}
Here is an excerpt of the ResourceType class:
public class ResourceType
{
public const string Creditors_SecondaryCreditorsPayOffYesNo_Require = "Prop_Creditors_SecondaryCreditorsPayOffYesNo_Require";
public static string Prop_FieldName_Require
{
get { return GetHiddenOption(FieldName) ? "true" : "false"; }
}
internal static bool GetHiddenOption(string fieldName)
{
< < Logic here to get the option from the database > >
}
I have also tried the same attribute but with the following constructor:
public VisibleAttribute(string theFieldName)
{
ResourceType resources = new ResourceType();
Type _resourceType = typeof(ResourceType);
PropertyInfo getHidden = _resourceType.GetProperty(theFieldName);
Hidden = (bool)getHidden.GetValue
}
The problem I have with these two attempts is that, since the code is in the constructor, it only runs the first time I load the page after an IIS reset. So, any further changes I make to the visibility settings are not reflected without amother IIS reset.
I also tried creating a custom DataAnnotationsModelMetadataProvider that attempts to only load the setting once per page request:
public class EGTDataAnnotationsModelMetadataProvider : DataAnnotationsModelMetadataProvider
{
protected override ModelMetadata CreateMetadata(IEnumerable<Attribute> attributes, Type containerType,
Func<object> modelAccessor, Type modelType, string propertyName)
{
var data = base.CreateMetadata(attributes, containerType, modelAccessor, modelType, propertyName);
var visibleAttributeMetadata = attributes.SingleOrDefault(a => typeof(VisibleAttribute) == a.GetType());
if (visibleAttributeMetadata != null)
{
VisibleAttribute visibleAttribte = (VisibleAttribute)visibleAttributeMetadata;
if (!visibleAttribte.VisibleIsSet)
{
PropertyInfo getHidden = visibleAttribte.ResourceType.GetProperty("Prop_" + WebUtils.RemoveSectionNameSpace(visibleAttribte.SectionName) + "_" + visibleAttribte.FieldName + "_Hide");
visibleAttribte.IsHidden = bool.Parse(getHidden.GetValue(null, null).ToString());
data.HideSurroundingHtml = visibleAttribte.IsHidden;
data.ShowForEdit = !visibleAttribte.IsHidden;
visibleAttribte.VisibleIsSet = true;
}
else
{
data.HideSurroundingHtml = visibleAttribte.IsHidden;
data.ShowForEdit = !visibleAttribte.IsHidden;
}
}
return data;
}
}
One issue I have with the ModelMetadataProvider is that the CreateMetadata method runs many times for a single field during a single request. It is very inefficient code, and a huge decrease in performace, to call the database 5-10+ times per request to get a setting that has not changed since the beginning of the request. If I try to set a flag indicating I've already loaded the setting, I'm back to the same scenario as above where I don't see the setting change until after an IIS reset.
I'm hoping someone can give me some pointers as to what methods I can employ to see the database changes real time. Or am I trying to do the impossible? Thanks in advance.
You could combine the metadata provider approach with caching the value just that single request.
For this you could use the Items dictionary in the current HttpContext. Be careful with this as a redirect will cause the items to be cleared:
string cacheKey = String.Format("IsVisible-{0}", propertyName)
if(!HttpContext.Current.Items.Contains(cacheKey))
HttpContext.Current.Items[cacheKey] = //get setting from db
bool isVisible = (bool)HttpContext.Current.Items[cacheKey];
You can also consider using the ASP .Net Cache in case that you prefer caching the value not just for the current request (Although you mentioned that within your metadata provider you were trying to load the setting once per request)

MongoDB custom serializer implementation

I am new to MongoDB, and am trying to get the C# driver to work serializing F# classes. I have it working with the class automapper using mutable F# fields & a parameterless constructor, but really I need to retain immutability, so I started looking at implementing an IBsonSerializer to perform custom serialization. I haven't found any documentation for writing one of these so have just tried to infer from the driver source code.
I have run into a problem whereby when the Deserialize method is called on the serializer, the CurrentBsonType is set to EndOfDocument rather than the start as I am expecting. I wrote the equivalent in C# just to make sure it wasn't some F# weirdness, but the problem persists. The serialization part seems to work fine and is queryable from the shell. Here is the sample code:
class Calendar {
public string Id { get; private set; }
public DateTime[] Holidays { get; private set; }
public Calendar(string id, DateTime[] holidays) {
Id = id;
Holidays = holidays;
}
}
class CalendarSerializer : BsonBaseSerializer {
public override void Serialize(BsonWriter bsonWriter, Type nominalType, object value, IBsonSerializationOptions options) {
var calendar = (Calendar) value;
bsonWriter.WriteStartDocument();
bsonWriter.WriteString("_id", calendar.Id);
bsonWriter.WriteName("holidays");
var ser = new ArraySerializer<DateTime>();
ser.Serialize(bsonWriter, typeof(DateTime[]), calendar.Holidays, null);
bsonWriter.WriteEndDocument();
}
public override object Deserialize(BsonReader bsonReader, Type nominalType, Type actualType, IBsonSerializationOptions options) {
if (nominalType != typeof(Calendar) || actualType != typeof(Calendar))
throw new BsonSerializationException();
if (bsonReader.CurrentBsonType != BsonType.Document)
throw new FileFormatException();
bsonReader.ReadStartDocument();
var id = bsonReader.ReadString("_id");
var ser = new ArraySerializer<DateTime>();
var holidays = (DateTime[])ser.Deserialize(bsonReader, typeof(DateTime[]), null);
bsonReader.ReadEndDocument();
return new Calendar(id, holidays);
}
public override bool GetDocumentId(object document, out object id, out Type idNominalType, out IIdGenerator idGenerator) {
var calendar = (Calendar) document;
id = calendar.Id;
idNominalType = typeof (string);
idGenerator = new StringObjectIdGenerator();
return true;
}
public override void SetDocumentId(object document, object id) {
throw new NotImplementedException("SetDocumentId is not implemented");
}
}
This blows up with FileFormatException in Deserialize when the CurrentBsonType is not Document. I am using the latest version 1.4 of the driver source.
I figured this out in the end. I should have used bsonReader.GetCurrentBsonType() instead of bsonReader.CurrentBsonType. This reads the BsonType in from the buffer rather than just looking at the last thing there. I also fixed a subsequent bug derserializing. The updated method looks like this:
public override object Deserialize(BsonReader bsonReader, Type nominalType, Type actualType, IBsonSerializationOptions options) {
if (nominalType != typeof(Calendar) || actualType != typeof(Calendar))
throw new BsonSerializationException();
if (bsonReader.GetCurrentBsonType() != BsonType.Document)
throw new FileFormatException();
bsonReader.ReadStartDocument();
var id = bsonReader.ReadString("_id");
bsonReader.ReadName();
var ser = new ArraySerializer<DateTime>();
var holidays = (DateTime[])ser.Deserialize(bsonReader, typeof(DateTime[]), null);
bsonReader.ReadEndDocument();
return new Calendar(id, holidays);
}

MVC 3 Reusable Remote Validation with DB Lookup

I have an MVC 3 appliation which I have many integer fields on a form. They all require range validation but the ranges exists in a table in my database. So I would like to create a reusable remote validation tool which will look up the min and max value and return the validation to the view.
I am updating this with some example code of what I would like to do to see my request might clarify what I am looking for:
In my validation class:
[Remote("CheckIntegerRange", "Validation", ErrorMessage = "Value outside of range")]
public object UW1_Web_Tension_SP { get; set; }
[Remote("CheckIntegerRange", "Validation", ErrorMessage = "Value outside of range")]
public object UW2_Web_Tension_SP { get; set; }
[Remote("CheckIntegerRange", "Validation", ErrorMessage = "Value outside of range")]
public object UW3_Web_Tension_SP { get; set; }
In my ValidationController I tried to create a function with multiple parameters but I dont think I can - however I think it shows what I am trying to do more clearly:
public class ValidationController : Controller
{
public JsonResult CheckIntegerRange(int integer, string EntityName, string AttributeName)
{
var result = false;
int MinInteger = 0;
int MaxInteger = 100;
//declare recipe entities
var context = new MadicoRecipeEntities();
//set sql statements and get description, etc from attributes view
var esqlIntegerAttributeDetails = "SELECT VALUE c FROM MadicoRecipeEntities.v_AttributeIntegerRangeDetails AS c " +
"WHERE c.EntityName = '" + EntityName + "' AND c.Attribute = '" + AttributeName + "'";
var queryAttributeDetails = context.CreateQuery<v_AttributeIntegerRangeDetails>(esqlIntegerAttributeDetails);
var RecipeAttributes = queryAttributeDetails.ToList();
foreach (var AttributeDetails in RecipeAttributes)
{
MinInteger = AttributeDetails.Min;
MaxInteger = AttributeDetails.Max;
}
return Json(result, JsonRequestBehavior.AllowGet);
}
}
I have found the following post on the asp.net forums which handled my first obstacle - passing different named attributes to the same validator. However, in this example the name is passed in generically - I need to have the name in order to query the table to get the applicable min and max ranges.
http://forums.asp.net/t/1625928.aspx/3/10
Can anyone point me in the right direction?
Thanks!
It is called remote validation! Here is an example:
remote validation

How do I convert a datatable into a POCO object in Asp.Net MVC?

How do I convert a datatable into a POCO object in Asp.Net MVC?
Pass each DataRow into the class constructor (or use getters/setters) and translate each column into the corresponding property. Be careful with nullable columns to extract them properly.
public class POCO
{
public int ID { get; set; }
public string Name { get; set; }
public DateTime? Modified { get; set; }
...
public POCO() { }
public POCO( DataRow row )
{
this.ID = (int)row["id"];
this.Name = (string)row["name"];
if (!(row["modified"] is DBNull))
{
this.Modified = (DateTime)row["modified"];
}
...
}
}
A data table typically holds many rows - do you want to convert each row into an object instance?
In that case, you could e.g. add a constructor to your POCO object that will accept a DataRow as parameter, and then extracts the bits and pieces from that DataRow:
public YourPOCO(DataRow row)
{
this.Field1 = row["Field1"].ToString();
...
this.FieldN = Convert.ToInt32(row["FieldN"]);
}
and so on, and then call that constructor on each of the rows in the DataTable.Rows collection:
List<YourPOCO> list = new List<YourPOCO>();
foreach(DataRow row in YourDataTable.Rows)
{
list.Add(new YourPOCO(row));
}
And you could then create a ASP.NET MVC view or partial view based on this "YourPOCO" type and use the "List" template to create a list of "YourPOCO" instances in a list-like display.
Marc
Old question, anyway this can be usefull for somebody:
private static T CreatePocoObject<T>(DataRow dr) where T : class, new()
{
try
{
T oClass = new T();
Type tClass = typeof (T);
MemberInfo[] methods = tClass.GetMethods();
ArrayList aMethods = new ArrayList();
object[] aoParam = new object[1];
//Get simple SET methods
foreach (MethodInfo method in methods)
{
if (method.DeclaringType == tClass && method.Name.StartsWith("set_"))
aMethods.Add(method);
}
//Invoke each set method with mapped value
for (int i = 0; i < aMethods.Count; i++)
{
try
{
MethodInfo mInvoke = (MethodInfo)aMethods[i];
//Remove "set_" from method name
string sColumn = mInvoke.Name.Remove(0, 4);
//If row contains value for method...
if (dr.Table.Columns.Contains(sColumn))
{
//Get the parameter (always one for a set property)
ParameterInfo[] api = mInvoke.GetParameters();
ParameterInfo pi = api[0];
//Convert value to parameter type
aoParam[0] = Convert.ChangeType(dr[sColumn], pi.ParameterType);
//Invoke the method
mInvoke.Invoke(oClass, aoParam);
}
}
catch
{
System.Diagnostics.Debug.Assert(false, "SetValuesToObject failed to set a value to an object");
}
}
return oClass;
}
catch
{
System.Diagnostics.Debug.Assert(false, "SetValuesToObject failed to create an object");
}
return null;
}
Source is http://blog.developers.ie/cgreen/archive/2007/09/14/using-reflection-to-copy-a-datarow-to-a-class.aspx
I saw your other question about using a datatable in the data access layer. If you return POCO at some point its a good idea to let your DAL return POCO already.
You would use an SqlDataReader to fill the POCO. This is more light weight. Sometimes its easier to use DataSet and DataTable for Lists of entries, but if you tranform the rows into stronly typed POCOS anyway I am pretty shure that this is the way to go.

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