Utilities class for .Net including Dynamic property getters/setters, automatic IQueryable searching, LinqToSql shortcuts, FileStream shortcuts, String extensions and more

DynamicProperty

someObject.SetPropertyValue("Name", "new value")
// is the same as 
someObject.Name = "new value";
// no need to know which property to code in

IQueryableSearch

var results = cars.Search(new object[] {"chevy", 2007});
// will search cars for the string "chevy" 
// and the int 2007 across all fields

LinqToSql

Naspinski.Utilities.GetPrimaryKey<table>();
// will return the PropertyInfo of the Primary Key(s) of 'table'

someDataContext.Get<Car>(someKey); 
// is the same as writing:
someDataContext.Cars.FirstOrDefault(x => x.id == someKey);
// regardless of what Type someKey is or what the 
// PropertyInfo.Name of the Primary Key is; never write 
// a Get accessor again!

FileStreamSave

someFileStream.Save(@"C:\file.txt")
// will save the file to the given path
// 'file[1].txt' if the file is already there 
// the file name will be returned 

someFileStream.Save(@"C:\file.txt", false);
// will save the file to the given path,
// overwriting if the file already exists

StringConversions

string s = s.RemoveCharacters(new[] { 'a', 'b' })
// removes any instances of 'a' or 'b' from s

string s = Strings.Random(10)
// random string, all alphanumeric, length 10
string s = Strings.Random(10, 2)
// random string, min 2 special chars, length 10

double x = "8".To<double>; 
// converts string to any type 
// (double in this case)

EnumType et = "Something".ToEnum<EnumType>; 
// turns string into any enum 
// (EnumType.Something in this case)

int? x = "5".ToNullable<int>;
// turns a string into any Nullable Type you want 
// (int in this case)

cool way to shorten and make your code more readable with LINQ

public string DoStuff(string s) 
{ 
    //whole bunch of stuff
    return s; 
}

public IEnumerable DoThings(IEnumerable strs) 
{  
    var ret = new list();
    foreach(var s in strs)
        ret.Add(DoStuff(s));
    return ret;
}

public IEnumerable DoThings(IEnumerable strs) 
{  
    foreach(var s in strs)
        yield return DoStuff(s);
}

public IEnumerable DoThings(IEnumerable strs) 
{  
    strs.Select(x => DoStuff(x));
}

public IEnumerable DoThings(IEnumerable strs) 
{  
    strs.Select(DoStuff);
}

// Tnstead of:
var x = DoThings(strs);

// you can simply substitute: 
var y = strs.Select(DoStuff);

// giving you the same results without having to write 
// a method

You can use reflection to avoid manually entering a ton of fields

foreach(PropertyInfo prop in o.GetType().GetProperties()) 
{
    if(prop.PropertyType == typeof(int))
        prop.SetValue(o, newValue, null);
}

this error may be cause by a Foreign Key changed that gets missed by Linq-to-Entities

My old Linq-to-Entities project came back to haunt me. I had to make some changes to the DB to allow a couple things, and with that, I changed some INT NOT NULL REFERENCES change to INT REFERENCES - the obvious difference being that they now allowed null values. No big deal really, I went into my .edmx file and did 'Update Model from Database' and everything seemed to be working fine, until I tried a certain operation that kicked out this doozy:

A relationship is being added or deleted from an AssociationSet 'FK__Gizmo__CategoryI__0425A276'. With cardinality constraints, a corresponding 'Gizmo' must also be added or deleted.

Now those arent the actual values, but you get the idea. This is telling me that my Foreign Key relationship is being violated, which confused me. I had changed that FK to be nullable, so this should not be happenening. I then tried the same operation in SQL Server Management Studio, just to be sure it was legal on the SQL side, and it worked fine. So I figured, like so many times before, the problem lies with Linq-to-Entities. I opened my .edmx and saw something like this:
As you can see, it clearly shows a one-to-many relationship from Category->Gizmo. This was no longer the case, but L2E failed to pick up on it.

The bottom line is that 'Update Model from Database' did not catch the Foreign Key change

Once I figured this out, it is a simple to fix. Simply right-click on the relationship (in the box above) and click 'Properties'; that will bring up the Properties dialogue. Once this is open, change the End of the referenced table from '1 (One)' to '0...1 (Zero or One)' and save your .edmx.



This should not be necessary as you would assume 'Update Model from Database' would catch things like this, but like so many other things in L2E, it just doesn't work like you want it to. I can't wait for .Net 4.0, supposedly most of the problems with L2E are getting fixed; we'll just have to wait and see.

never write a Linq-to-SQL Get accessor again

var p = db.Products.FirstOrDefault(x => x.Id == someId);

Product p = db.Get<Product>(someId);

Guid gId = 
  new Guid("4fcc0b82-b137-4e4b-935e-872ed662ba53");
Gizmo g = db.Get<Gizmo>(gId);

Gizmo g = db.Get<Gizmo>(5);

public static T Get<T>(this DataContext dataContext,
  object primaryKey) 
    where T : class, INotifyPropertyChanged
{
  return dataContext.GetTable(typeof(T))
    .Cast<T>()
    .Where(GetPrimaryKey<T>()
    .Name + ".Equals(@0)", primaryKey)
    .FirstOrDefault();
}