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  • Passing arguments between classes - use public properties or pass a properties class as argument?

    - by devoured elysium
    So let's assume I have a class named ABC that will have a list of Point objects. I need to make some drawing logic with them. Each one of those Point objects will have a Draw() method that will be called by the ABC class. The Draw() method code will need info from ABC class. I can only see two ways to make them have this info: Having Abc class make public some properties that would allow draw() to make its decisions. Having Abc class pass to draw() a class full of properties. The properties in both cases would be the same, my question is what is preferred in this case. Maybe the second approach is more flexible? Maybe not? I don't see here a clear winner, but that sure has more to do with my inexperience than any other thing. If there are other good approaches, feel free to share them. Here are both cases: class Abc1 { public property a; public property b; public property c; ... public property z; public void method1(); ... public void methodn(); } and here is approach 2: class Abc2 { //here we make take down all properties public void method1(); ... public void methodn(); } class Abc2MethodArgs { //and we put them here. this class will be passed as argument to //Point's draw() method! public property a; public property b; public property c; ... public property z; } Also, if there are any "formal" names for these two approaches, I'd like to know them so I can better choose the tags/thread name, so it's more useful for searching purposes. That or feel free to edit them.

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  • Developing web apps using ASP.NET MVC 3, Razor and EF Code First - Part 2

    - by shiju
    In my previous post Developing web apps using ASP.NET MVC 3, Razor and EF Code First - Part 1, we have discussed on how to work with ASP.NET MVC 3 and EF Code First for developing web apps. We have created generic repository and unit of work with EF Code First for our ASP.NET MVC 3 application and did basic CRUD operations against a simple domain entity. In this post, I will demonstrate on working with domain entity with deep object graph, Service Layer and View Models and will also complete the rest of the demo application. In the previous post, we have done CRUD operations against Category entity and this post will be focus on Expense entity those have an association with Category entity. You can download the source code from http://efmvc.codeplex.com . The following frameworks will be used for this step by step tutorial.    1. ASP.NET MVC 3 RTM    2. EF Code First CTP 5    3. Unity 2.0 Domain Model Category Entity public class Category   {       public int CategoryId { get; set; }       [Required(ErrorMessage = "Name Required")]       [StringLength(25, ErrorMessage = "Must be less than 25 characters")]       public string Name { get; set;}       public string Description { get; set; }       public virtual ICollection<Expense> Expenses { get; set; }   } Expense Entity public class Expense     {                public int ExpenseId { get; set; }                public string  Transaction { get; set; }         public DateTime Date { get; set; }         public double Amount { get; set; }         public int CategoryId { get; set; }         public virtual Category Category { get; set; }     } We have two domain entities - Category and Expense. A single category contains a list of expense transactions and every expense transaction should have a Category. Repository class for Expense Transaction Let’s create repository class for handling CRUD operations for Expense entity public class ExpenseRepository : RepositoryBase<Expense>, IExpenseRepository     {     public ExpenseRepository(IDatabaseFactory databaseFactory)         : base(databaseFactory)         {         }                } public interface IExpenseRepository : IRepository<Expense> { } Service Layer If you are new to Service Layer, checkout Martin Fowler's article Service Layer . According to Martin Fowler, Service Layer defines an application's boundary and its set of available operations from the perspective of interfacing client layers. It encapsulates the application's business logic, controlling transactions and coordinating responses in the implementation of its operations. Controller classes should be lightweight and do not put much of business logic onto it. We can use the service layer as the business logic layer and can encapsulate the rules of the application. Let’s create a Service class for coordinates the transaction for Expense public interface IExpenseService {     IEnumerable<Expense> GetExpenses(DateTime startDate, DateTime ednDate);     Expense GetExpense(int id);             void CreateExpense(Expense expense);     void DeleteExpense(int id);     void SaveExpense(); } public class ExpenseService : IExpenseService {     private readonly IExpenseRepository expenseRepository;            private readonly IUnitOfWork unitOfWork;     public ExpenseService(IExpenseRepository expenseRepository, IUnitOfWork unitOfWork)     {                  this.expenseRepository = expenseRepository;         this.unitOfWork = unitOfWork;     }     public IEnumerable<Expense> GetExpenses(DateTime startDate, DateTime endDate)     {         var expenses = expenseRepository.GetMany(exp => exp.Date >= startDate && exp.Date <= endDate);         return expenses;     }     public void CreateExpense(Expense expense)     {         expenseRepository.Add(expense);         unitOfWork.Commit();     }     public Expense GetExpense(int id)     {         var expense = expenseRepository.GetById(id);         return expense;     }     public void DeleteExpense(int id)     {         var expense = expenseRepository.GetById(id);         expenseRepository.Delete(expense);         unitOfWork.Commit();     }     public void SaveExpense()     {         unitOfWork.Commit();     } }   View Model for Expense Transactions In real world ASP.NET MVC applications, we need to design model objects especially for our views. Our domain objects are mainly designed for the needs for domain model and it is representing the domain of our applications. On the other hand, View Model objects are designed for our needs for views. We have an Expense domain entity that has an association with Category. While we are creating a new Expense, we have to specify that in which Category belongs with the new Expense transaction. The user interface for Expense transaction will have form fields for representing the Expense entity and a CategoryId for representing the Category. So let's create view model for representing the need for Expense transactions. public class ExpenseViewModel {     public int ExpenseId { get; set; }       [Required(ErrorMessage = "Category Required")]     public int CategoryId { get; set; }       [Required(ErrorMessage = "Transaction Required")]     public string Transaction { get; set; }       [Required(ErrorMessage = "Date Required")]     public DateTime Date { get; set; }       [Required(ErrorMessage = "Amount Required")]     public double Amount { get; set; }       public IEnumerable<SelectListItem> Category { get; set; } } The ExpenseViewModel is designed for the purpose of View template and contains the all validation rules. It has properties for mapping values to Expense entity and a property Category for binding values to a drop-down for list values of Category. Create Expense transaction Let’s create action methods in the ExpenseController for creating expense transactions public ActionResult Create() {     var expenseModel = new ExpenseViewModel();     var categories = categoryService.GetCategories();     expenseModel.Category = categories.ToSelectListItems(-1);     expenseModel.Date = DateTime.Today;     return View(expenseModel); } [HttpPost] public ActionResult Create(ExpenseViewModel expenseViewModel) {                      if (!ModelState.IsValid)         {             var categories = categoryService.GetCategories();             expenseViewModel.Category = categories.ToSelectListItems(expenseViewModel.CategoryId);             return View("Save", expenseViewModel);         }         Expense expense=new Expense();         ModelCopier.CopyModel(expenseViewModel,expense);         expenseService.CreateExpense(expense);         return RedirectToAction("Index");              } In the Create action method for HttpGet request, we have created an instance of our View Model ExpenseViewModel with Category information for the drop-down list and passing the Model object to View template. The extension method ToSelectListItems is shown below   public static IEnumerable<SelectListItem> ToSelectListItems(         this IEnumerable<Category> categories, int  selectedId) {     return           categories.OrderBy(category => category.Name)                 .Select(category =>                     new SelectListItem                     {                         Selected = (category.CategoryId == selectedId),                         Text = category.Name,                         Value = category.CategoryId.ToString()                     }); } In the Create action method for HttpPost, our view model object ExpenseViewModel will map with posted form input values. We need to create an instance of Expense for the persistence purpose. So we need to copy values from ExpenseViewModel object to Expense object. ASP.NET MVC futures assembly provides a static class ModelCopier that can use for copying values between Model objects. ModelCopier class has two static methods - CopyCollection and CopyModel.CopyCollection method will copy values between two collection objects and CopyModel will copy values between two model objects. We have used CopyModel method of ModelCopier class for copying values from expenseViewModel object to expense object. Finally we did a call to CreateExpense method of ExpenseService class for persisting new expense transaction. List Expense Transactions We want to list expense transactions based on a date range. So let’s create action method for filtering expense transactions with a specified date range. public ActionResult Index(DateTime? startDate, DateTime? endDate) {     //If date is not passed, take current month's first and last dte     DateTime dtNow;     dtNow = DateTime.Today;     if (!startDate.HasValue)     {         startDate = new DateTime(dtNow.Year, dtNow.Month, 1);         endDate = startDate.Value.AddMonths(1).AddDays(-1);     }     //take last date of start date's month, if end date is not passed     if (startDate.HasValue && !endDate.HasValue)     {         endDate = (new DateTime(startDate.Value.Year, startDate.Value.Month, 1)).AddMonths(1).AddDays(-1);     }     var expenses = expenseService.GetExpenses(startDate.Value ,endDate.Value);     //if request is Ajax will return partial view     if (Request.IsAjaxRequest())     {         return PartialView("ExpenseList", expenses);     }     //set start date and end date to ViewBag dictionary     ViewBag.StartDate = startDate.Value.ToShortDateString();     ViewBag.EndDate = endDate.Value.ToShortDateString();     //if request is not ajax     return View(expenses); } We are using the above Index Action method for both Ajax requests and normal requests. If there is a request for Ajax, we will call the PartialView ExpenseList. Razor Views for listing Expense information Let’s create view templates in Razor for showing list of Expense information ExpenseList.cshtml @model IEnumerable<MyFinance.Domain.Expense>   <table>         <tr>             <th>Actions</th>             <th>Category</th>             <th>                 Transaction             </th>             <th>                 Date             </th>             <th>                 Amount             </th>         </tr>       @foreach (var item in Model) {              <tr>             <td>                 @Html.ActionLink("Edit", "Edit",new { id = item.ExpenseId })                 @Ajax.ActionLink("Delete", "Delete", new { id = item.ExpenseId }, new AjaxOptions { Confirm = "Delete Expense?", HttpMethod = "Post", UpdateTargetId = "divExpenseList" })             </td>              <td>                 @item.Category.Name             </td>             <td>                 @item.Transaction             </td>             <td>                 @String.Format("{0:d}", item.Date)             </td>             <td>                 @String.Format("{0:F}", item.Amount)             </td>         </tr>          }       </table>     <p>         @Html.ActionLink("Create New Expense", "Create") |         @Html.ActionLink("Create New Category", "Create","Category")     </p> Index.cshtml @using MyFinance.Helpers; @model IEnumerable<MyFinance.Domain.Expense> @{     ViewBag.Title = "Index"; }    <h2>Expense List</h2>    <script src="@Url.Content("~/Scripts/jquery.unobtrusive-ajax.min.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery-ui.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.ui.datepicker.js")" type="text/javascript"></script> <link href="@Url.Content("~/Content/jquery-ui-1.8.6.custom.css")" rel="stylesheet" type="text/css" />      @using (Ajax.BeginForm(new AjaxOptions{ UpdateTargetId="divExpenseList", HttpMethod="Get"})) {     <table>         <tr>         <td>         <div>           Start Date: @Html.TextBox("StartDate", Html.Encode(String.Format("{0:mm/dd/yyyy}", ViewData["StartDate"].ToString())), new { @class = "ui-datepicker" })         </div>         </td>         <td><div>            End Date: @Html.TextBox("EndDate", Html.Encode(String.Format("{0:mm/dd/yyyy}", ViewData["EndDate"].ToString())), new { @class = "ui-datepicker" })          </div></td>          <td> <input type="submit" value="Search By TransactionDate" /></td>         </tr>     </table>         }   <div id="divExpenseList">             @Html.Partial("ExpenseList", Model)     </div> <script type="text/javascript">     $().ready(function () {         $('.ui-datepicker').datepicker({             dateFormat: 'mm/dd/yy',             buttonImage: '@Url.Content("~/Content/calendar.gif")',             buttonImageOnly: true,             showOn: "button"         });     }); </script> Ajax search functionality using Ajax.BeginForm The search functionality of Index view is providing Ajax functionality using Ajax.BeginForm. The Ajax.BeginForm() method writes an opening <form> tag to the response. You can use this method in a using block. In that case, the method renders the closing </form> tag at the end of the using block and the form is submitted asynchronously by using JavaScript. The search functionality will call the Index Action method and this will return partial view ExpenseList for updating the search result. We want to update the response UI for the Ajax request onto divExpenseList element. So we have specified the UpdateTargetId as "divExpenseList" in the Ajax.BeginForm method. Add jQuery DatePicker Our search functionality is using a date range so we are providing two date pickers using jQuery datepicker. You need to add reference to the following JavaScript files to working with jQuery datepicker. jquery-ui.js jquery.ui.datepicker.js For theme support for datepicker, we can use a customized CSS class. In our example we have used a CSS file “jquery-ui-1.8.6.custom.css”. For more details about the datepicker component, visit jquery UI website at http://jqueryui.com/demos/datepicker . In the jQuery ready event, we have used following JavaScript function to initialize the UI element to show date picker. <script type="text/javascript">     $().ready(function () {         $('.ui-datepicker').datepicker({             dateFormat: 'mm/dd/yy',             buttonImage: '@Url.Content("~/Content/calendar.gif")',             buttonImageOnly: true,             showOn: "button"         });     }); </script>   Source Code You can download the source code from http://efmvc.codeplex.com/ . Summary In this two-part series, we have created a simple web application using ASP.NET MVC 3 RTM, Razor and EF Code First CTP 5. I have demonstrated patterns and practices  such as Dependency Injection, Repository pattern, Unit of Work, ViewModel and Service Layer. My primary objective was to demonstrate different practices and options for developing web apps using ASP.NET MVC 3 and EF Code First. You can implement these approaches in your own way for building web apps using ASP.NET MVC 3. I will refactor this demo app on later time.

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  • ASP.NET MVC 3 Hosting :: How to Deploy Web Apps Using ASP.NET MVC 3, Razor and EF Code First - Part II

    - by mbridge
    In previous post, I have discussed on how to work with ASP.NET MVC 3 and EF Code First for developing web apps. In this post, I will demonstrate on working with domain entity with deep object graph, Service Layer and View Models and will also complete the rest of the demo application. In the previous post, we have done CRUD operations against Category entity and this post will be focus on Expense entity those have an association with Category entity. Domain Model Category Entity public class Category   {       public int CategoryId { get; set; }       [Required(ErrorMessage = "Name Required")]       [StringLength(25, ErrorMessage = "Must be less than 25 characters")]       public string Name { get; set;}       public string Description { get; set; }       public virtual ICollection<Expense> Expenses { get; set; }   } Expense Entity public class Expense     {                public int ExpenseId { get; set; }                public string  Transaction { get; set; }         public DateTime Date { get; set; }         public double Amount { get; set; }         public int CategoryId { get; set; }         public virtual Category Category { get; set; }     } We have two domain entities - Category and Expense. A single category contains a list of expense transactions and every expense transaction should have a Category. Repository class for Expense Transaction Let’s create repository class for handling CRUD operations for Expense entity public class ExpenseRepository : RepositoryBase<Expense>, IExpenseRepository     {     public ExpenseRepository(IDatabaseFactory databaseFactory)         : base(databaseFactory)         {         }                } public interface IExpenseRepository : IRepository<Expense> { } Service Layer If you are new to Service Layer, checkout Martin Fowler's article Service Layer . According to Martin Fowler, Service Layer defines an application's boundary and its set of available operations from the perspective of interfacing client layers. It encapsulates the application's business logic, controlling transactions and coordinating responses in the implementation of its operations. Controller classes should be lightweight and do not put much of business logic onto it. We can use the service layer as the business logic layer and can encapsulate the rules of the application. Let’s create a Service class for coordinates the transaction for Expense public interface IExpenseService {     IEnumerable<Expense> GetExpenses(DateTime startDate, DateTime ednDate);     Expense GetExpense(int id);             void CreateExpense(Expense expense);     void DeleteExpense(int id);     void SaveExpense(); } public class ExpenseService : IExpenseService {     private readonly IExpenseRepository expenseRepository;            private readonly IUnitOfWork unitOfWork;     public ExpenseService(IExpenseRepository expenseRepository, IUnitOfWork unitOfWork)     {                  this.expenseRepository = expenseRepository;         this.unitOfWork = unitOfWork;     }     public IEnumerable<Expense> GetExpenses(DateTime startDate, DateTime endDate)     {         var expenses = expenseRepository.GetMany(exp => exp.Date >= startDate && exp.Date <= endDate);         return expenses;     }     public void CreateExpense(Expense expense)     {         expenseRepository.Add(expense);         unitOfWork.Commit();     }     public Expense GetExpense(int id)     {         var expense = expenseRepository.GetById(id);         return expense;     }     public void DeleteExpense(int id)     {         var expense = expenseRepository.GetById(id);         expenseRepository.Delete(expense);         unitOfWork.Commit();     }     public void SaveExpense()     {         unitOfWork.Commit();     } } View Model for Expense Transactions In real world ASP.NET MVC applications, we need to design model objects especially for our views. Our domain objects are mainly designed for the needs for domain model and it is representing the domain of our applications. On the other hand, View Model objects are designed for our needs for views. We have an Expense domain entity that has an association with Category. While we are creating a new Expense, we have to specify that in which Category belongs with the new Expense transaction. The user interface for Expense transaction will have form fields for representing the Expense entity and a CategoryId for representing the Category. So let's create view model for representing the need for Expense transactions. public class ExpenseViewModel {     public int ExpenseId { get; set; }       [Required(ErrorMessage = "Category Required")]     public int CategoryId { get; set; }       [Required(ErrorMessage = "Transaction Required")]     public string Transaction { get; set; }       [Required(ErrorMessage = "Date Required")]     public DateTime Date { get; set; }       [Required(ErrorMessage = "Amount Required")]     public double Amount { get; set; }       public IEnumerable<SelectListItem> Category { get; set; } } The ExpenseViewModel is designed for the purpose of View template and contains the all validation rules. It has properties for mapping values to Expense entity and a property Category for binding values to a drop-down for list values of Category. Create Expense transaction Let’s create action methods in the ExpenseController for creating expense transactions public ActionResult Create() {     var expenseModel = new ExpenseViewModel();     var categories = categoryService.GetCategories();     expenseModel.Category = categories.ToSelectListItems(-1);     expenseModel.Date = DateTime.Today;     return View(expenseModel); } [HttpPost] public ActionResult Create(ExpenseViewModel expenseViewModel) {                      if (!ModelState.IsValid)         {             var categories = categoryService.GetCategories();             expenseViewModel.Category = categories.ToSelectListItems(expenseViewModel.CategoryId);             return View("Save", expenseViewModel);         }         Expense expense=new Expense();         ModelCopier.CopyModel(expenseViewModel,expense);         expenseService.CreateExpense(expense);         return RedirectToAction("Index");              } In the Create action method for HttpGet request, we have created an instance of our View Model ExpenseViewModel with Category information for the drop-down list and passing the Model object to View template. The extension method ToSelectListItems is shown below public static IEnumerable<SelectListItem> ToSelectListItems(         this IEnumerable<Category> categories, int  selectedId) {     return           categories.OrderBy(category => category.Name)                 .Select(category =>                     new SelectListItem                     {                         Selected = (category.CategoryId == selectedId),                         Text = category.Name,                         Value = category.CategoryId.ToString()                     }); } In the Create action method for HttpPost, our view model object ExpenseViewModel will map with posted form input values. We need to create an instance of Expense for the persistence purpose. So we need to copy values from ExpenseViewModel object to Expense object. ASP.NET MVC futures assembly provides a static class ModelCopier that can use for copying values between Model objects. ModelCopier class has two static methods - CopyCollection and CopyModel.CopyCollection method will copy values between two collection objects and CopyModel will copy values between two model objects. We have used CopyModel method of ModelCopier class for copying values from expenseViewModel object to expense object. Finally we did a call to CreateExpense method of ExpenseService class for persisting new expense transaction. List Expense Transactions We want to list expense transactions based on a date range. So let’s create action method for filtering expense transactions with a specified date range. public ActionResult Index(DateTime? startDate, DateTime? endDate) {     //If date is not passed, take current month's first and last dte     DateTime dtNow;     dtNow = DateTime.Today;     if (!startDate.HasValue)     {         startDate = new DateTime(dtNow.Year, dtNow.Month, 1);         endDate = startDate.Value.AddMonths(1).AddDays(-1);     }     //take last date of start date's month, if end date is not passed     if (startDate.HasValue && !endDate.HasValue)     {         endDate = (new DateTime(startDate.Value.Year, startDate.Value.Month, 1)).AddMonths(1).AddDays(-1);     }     var expenses = expenseService.GetExpenses(startDate.Value ,endDate.Value);     //if request is Ajax will return partial view     if (Request.IsAjaxRequest())     {         return PartialView("ExpenseList", expenses);     }     //set start date and end date to ViewBag dictionary     ViewBag.StartDate = startDate.Value.ToShortDateString();     ViewBag.EndDate = endDate.Value.ToShortDateString();     //if request is not ajax     return View(expenses); } We are using the above Index Action method for both Ajax requests and normal requests. If there is a request for Ajax, we will call the PartialView ExpenseList. Razor Views for listing Expense information Let’s create view templates in Razor for showing list of Expense information ExpenseList.cshtml @model IEnumerable<MyFinance.Domain.Expense>   <table>         <tr>             <th>Actions</th>             <th>Category</th>             <th>                 Transaction             </th>             <th>                 Date             </th>             <th>                 Amount             </th>         </tr>       @foreach (var item in Model) {              <tr>             <td>                 @Html.ActionLink("Edit", "Edit",new { id = item.ExpenseId })                 @Ajax.ActionLink("Delete", "Delete", new { id = item.ExpenseId }, new AjaxOptions { Confirm = "Delete Expense?", HttpMethod = "Post", UpdateTargetId = "divExpenseList" })             </td>              <td>                 @item.Category.Name             </td>             <td>                 @item.Transaction             </td>             <td>                 @String.Format("{0:d}", item.Date)             </td>             <td>                 @String.Format("{0:F}", item.Amount)             </td>         </tr>          }       </table>     <p>         @Html.ActionLink("Create New Expense", "Create") |         @Html.ActionLink("Create New Category", "Create","Category")     </p> Index.cshtml @using MyFinance.Helpers; @model IEnumerable<MyFinance.Domain.Expense> @{     ViewBag.Title = "Index"; }    <h2>Expense List</h2>    <script src="@Url.Content("~/Scripts/jquery.unobtrusive-ajax.min.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery-ui.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.ui.datepicker.js")" type="text/javascript"></script> <link href="@Url.Content("~/Content/jquery-ui-1.8.6.custom.css")" rel="stylesheet" type="text/css" />      @using (Ajax.BeginForm(new AjaxOptions{ UpdateTargetId="divExpenseList", HttpMethod="Get"})) {     <table>         <tr>         <td>         <div>           Start Date: @Html.TextBox("StartDate", Html.Encode(String.Format("{0:mm/dd/yyyy}", ViewData["StartDate"].ToString())), new { @class = "ui-datepicker" })         </div>         </td>         <td><div>            End Date: @Html.TextBox("EndDate", Html.Encode(String.Format("{0:mm/dd/yyyy}", ViewData["EndDate"].ToString())), new { @class = "ui-datepicker" })          </div></td>          <td> <input type="submit" value="Search By TransactionDate" /></td>         </tr>     </table>         }   <div id="divExpenseList">             @Html.Partial("ExpenseList", Model)     </div> <script type="text/javascript">     $().ready(function () {         $('.ui-datepicker').datepicker({             dateFormat: 'mm/dd/yy',             buttonImage: '@Url.Content("~/Content/calendar.gif")',             buttonImageOnly: true,             showOn: "button"         });     }); </script> Ajax search functionality using Ajax.BeginForm The search functionality of Index view is providing Ajax functionality using Ajax.BeginForm. The Ajax.BeginForm() method writes an opening <form> tag to the response. You can use this method in a using block. In that case, the method renders the closing </form> tag at the end of the using block and the form is submitted asynchronously by using JavaScript. The search functionality will call the Index Action method and this will return partial view ExpenseList for updating the search result. We want to update the response UI for the Ajax request onto divExpenseList element. So we have specified the UpdateTargetId as "divExpenseList" in the Ajax.BeginForm method. Add jQuery DatePicker Our search functionality is using a date range so we are providing two date pickers using jQuery datepicker. You need to add reference to the following JavaScript files to working with jQuery datepicker. - jquery-ui.js - jquery.ui.datepicker.js For theme support for datepicker, we can use a customized CSS class. In our example we have used a CSS file “jquery-ui-1.8.6.custom.css”. For more details about the datepicker component, visit jquery UI website at http://jqueryui.com/demos/datepicker . In the jQuery ready event, we have used following JavaScript function to initialize the UI element to show date picker. <script type="text/javascript">     $().ready(function () {         $('.ui-datepicker').datepicker({             dateFormat: 'mm/dd/yy',             buttonImage: '@Url.Content("~/Content/calendar.gif")',             buttonImageOnly: true,             showOn: "button"         });     }); </script> Summary In this two-part series, we have created a simple web application using ASP.NET MVC 3 RTM, Razor and EF Code First CTP 5. I have demonstrated patterns and practices  such as Dependency Injection, Repository pattern, Unit of Work, ViewModel and Service Layer. My primary objective was to demonstrate different practices and options for developing web apps using ASP.NET MVC 3 and EF Code First. You can implement these approaches in your own way for building web apps using ASP.NET MVC 3. I will refactor this demo app on later time.

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  • Unable to use nMock GetProperty routine on a property of an inherited object...

    - by Chris
    I am getting this error when trying to set an expectation on an object I mocked that inherits from MembershipUser: ContactRepositoryTests.UpdateTest : FailedSystem.InvalidProgramException: JIT Compiler encountered an internal limitation. Server stack trace: at MockObjectType1.ToString() Exception rethrown at [0]: at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg) at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(ref MessageData msgData, Int32 type) at System.Object.ToString() at NMock2.Internal.ExpectationBuilder.On(Object receiver) Here are the tools I am using... VS2008 (SP1) Framework 3.5 nUnit 2.4.8 nMock 2.0.0.44 Resharper 4.1 I am at a loss as to why this would be happening. Any help would be appreciated. Test Class... [TestFixture] public class AddressRepositoryTests { private Mockery m_Mockery; private Data.IAddress m_MockDataAddress; private IUser m_MockUser; [SetUp] public void Setup() { m_Mockery = new Mockery(); m_MockDataAddress = m_Mockery.NewMock<Data.IAddress>(); m_MockUser = m_Mockery.NewMock<IUser>(); } [TearDown] public void TearDown() { m_Mockery.Dispose(); } [Test] public void CreateTest() { string line1 = "unitTestLine1"; string line2 = "unitTestLine2"; string city = "unitTestCity"; int stateId = 1893; string postalCode = "unitTestPostalCode"; int countryId = 223; bool active = false; int createdById = 1; Expect.Once .On(m_MockUser) .GetProperty("Identity") .Will(Return.Value(createdById)); Expect.Once .On(m_MockDataAddress) .Method("Insert") .With( line1, line2, city, stateId, postalCode, countryId, active, createdById, Is.Anything ) .Will(Return.Value(null)); IAddressRepository addressRepository = new AddressRepository(m_MockDataAddress); IAddress address = addressRepository.Create( line1, line2, city, stateId, postalCode, countryId, active, m_MockUser ); Assert.IsNull(address); } } User Class... public interface IUser { int? Identity { get; set; } int? CreatedBy { get; set; } DateTime CreatedOn { get; set; } int? ModifiedBy { get; set; } DateTime? ModifiedOn { get; set; } string UserName { get; } object ProviderUserKey { get; } string Email { get; set; } string PasswordQuestion { get; } string Comment { get; set; } bool IsApproved { get; set; } bool IsLockedOut { get; } DateTime LastLockoutDate { get; } DateTime CreationDate { get; } DateTime LastLoginDate { get; set; } DateTime LastActivityDate { get; set; } DateTime LastPasswordChangedDate { get; } bool IsOnline { get; } string ProviderName { get; } string ToString(); string GetPassword(); string GetPassword(string passwordAnswer); bool ChangePassword(string oldPassword, string newPassword); bool ChangePasswordQuestionAndAnswer(string password, string newPasswordQuestion, string newPasswordAnswer); string ResetPassword(string passwordAnswer); string ResetPassword(); bool UnlockUser(); } public class User : MembershipUser, IUser { #region Public Properties private int? m_Identity; public int? Identity { get { return m_Identity; } set { if (value <= 0) throw new Exception("Address.Identity must be greater than 0."); m_Identity = value; } } public int? CreatedBy { get; set; } private DateTime m_CreatedOn = DateTime.Now; public DateTime CreatedOn { get { return m_CreatedOn; } set { m_CreatedOn = value; } } public int? ModifiedBy { get; set; } public DateTime? ModifiedOn { get; set; } #endregion Public Properties #region Public Constructors public User() { } #endregion Public Constructors } Address Class... public interface IAddress { int? Identity { get; set; } string Line1 { get; set; } string Line2 { get; set; } string City { get; set; } string PostalCode { get; set; } bool Active { get; set; } int? CreatedBy { get; set; } DateTime CreatedOn { get; set; } int? ModifiedBy { get; set; } DateTime? ModifiedOn { get; set; } } public class Address : IAddress { #region Public Properties private int? m_Identity; public int? Identity { get { return m_Identity; } set { if (value <= 0) throw new Exception("Address.Identity must be greater than 0."); m_Identity = value; } } public string Line1 { get; set; } public string Line2 { get; set; } public string City { get; set; } public string PostalCode { get; set; } public bool Active { get; set; } public int? CreatedBy { get; set; } private DateTime m_CreatedOn = DateTime.Now; public DateTime CreatedOn { get { return m_CreatedOn; } set { m_CreatedOn = value; } } public int? ModifiedBy { get; set; } public DateTime? ModifiedOn { get; set; } #endregion Public Properties } AddressRepository Class... public interface IAddressRepository { IAddress Create(string line1, string line2, string city, int stateId, string postalCode, int countryId, bool active, IUser createdBy); } public class AddressRepository : IAddressRepository { #region Private Properties private Data.IAddress m_DataAddress; private Data.IAddress DataAddress { get { if (m_DataAddress == null) m_DataAddress = new Data.Address(); return m_DataAddress; } set { m_DataAddress = value; } } #endregion Private Properties #region Public Constructor public AddressRepository() { } public AddressRepository(Data.IAddress dataAddress) { DataAddress = dataAddress; } #endregion Public Constructor #region Public Methods public IAddress Create(string line1, string line2, string city, int stateId, string postalCode, int countryId, bool active, IUser createdBy) { if (String.IsNullOrEmpty(line1)) throw new Exception("You must enter a Address Line 1 to register."); if (String.IsNullOrEmpty(city)) throw new Exception("You must enter a City to register."); if (stateId <= 0) throw new Exception("You must select a State to register."); if (String.IsNullOrEmpty(postalCode)) throw new Exception("You must enter a Postal Code to register."); if (countryId <= 0) throw new Exception("You must select a Country to register."); DataSet dataSet = DataAddress.Insert( line1, line2, city, stateId, postalCode, countryId, active, createdBy.Identity, DateTime.Now ); return null; } #endregion Public Methods } DataAddress Class... public interface IAddress { DataSet GetByAddressId (int? AddressId); DataSet Update (int? AddressId, string Address1, string Address2, string City, int? StateId, string PostalCode, int? CountryId, bool? IsActive, Guid? ModifiedBy); DataSet Insert (string Address1, string Address2, string City, int? StateId, string PostalCode, int? CountryId, bool? IsActive, int? CreatedBy, DateTime? CreatedOn); } public class Address : IAddress { public DataSet GetByAddressId (int? AddressId) { Database database = DatabaseFactory.CreateDatabase(); DbCommand dbCommand = database.GetStoredProcCommand("prAddress_GetByAddressId"); DataSet dataSet; try { database.AddInParameter(dbCommand, "AddressId", DbType.Int32, AddressId); dataSet = database.ExecuteDataSet(dbCommand); } catch (SqlException sqlException) { string callMessage = "prAddress_GetByAddressId " + "@AddressId = " + AddressId; throw new Exception(callMessage, sqlException); } return dataSet; } public DataSet Update (int? AddressId, string Address1, string Address2, string City, int? StateId, string PostalCode, int? CountryId, bool? IsActive, Guid? ModifiedBy) { Database database = DatabaseFactory.CreateDatabase(); DbCommand dbCommand = database.GetStoredProcCommand("prAddress_Update"); DataSet dataSet; try { database.AddInParameter(dbCommand, "AddressId", DbType.Int32, AddressId); database.AddInParameter(dbCommand, "Address1", DbType.AnsiString, Address1); database.AddInParameter(dbCommand, "Address2", DbType.AnsiString, Address2); database.AddInParameter(dbCommand, "City", DbType.AnsiString, City); database.AddInParameter(dbCommand, "StateId", DbType.Int32, StateId); database.AddInParameter(dbCommand, "PostalCode", DbType.AnsiString, PostalCode); database.AddInParameter(dbCommand, "CountryId", DbType.Int32, CountryId); database.AddInParameter(dbCommand, "IsActive", DbType.Boolean, IsActive); database.AddInParameter(dbCommand, "ModifiedBy", DbType.Guid, ModifiedBy); dataSet = database.ExecuteDataSet(dbCommand); } catch (SqlException sqlException) { string callMessage = "prAddress_Update " + "@AddressId = " + AddressId + ", @Address1 = " + Address1 + ", @Address2 = " + Address2 + ", @City = " + City + ", @StateId = " + StateId + ", @PostalCode = " + PostalCode + ", @CountryId = " + CountryId + ", @IsActive = " + IsActive + ", @ModifiedBy = " + ModifiedBy; throw new Exception(callMessage, sqlException); } return dataSet; } public DataSet Insert (string Address1, string Address2, string City, int? StateId, string PostalCode, int? CountryId, bool? IsActive, int? CreatedBy, DateTime? CreatedOn) { Database database = DatabaseFactory.CreateDatabase(); DbCommand dbCommand = database.GetStoredProcCommand("prAddress_Insert"); DataSet dataSet; try { database.AddInParameter(dbCommand, "Address1", DbType.AnsiString, Address1); database.AddInParameter(dbCommand, "Address2", DbType.AnsiString, Address2); database.AddInParameter(dbCommand, "City", DbType.AnsiString, City); database.AddInParameter(dbCommand, "StateId", DbType.Int32, StateId); database.AddInParameter(dbCommand, "PostalCode", DbType.AnsiString, PostalCode); database.AddInParameter(dbCommand, "CountryId", DbType.Int32, CountryId); database.AddInParameter(dbCommand, "IsActive", DbType.Boolean, IsActive); database.AddInParameter(dbCommand, "CreatedBy", DbType.Int32, CreatedBy); database.AddInParameter(dbCommand, "CreatedOn", DbType.DateTime, CreatedOn); dataSet = database.ExecuteDataSet(dbCommand); } catch (SqlException sqlException) { string callMessage = "prAddress_Insert " + "@Address1 = " + Address1 + ", @Address2 = " + Address2 + ", @City = " + City + ", @StateId = " + StateId + ", @PostalCode = " + PostalCode + ", @CountryId = " + CountryId + ", @IsActive = " + IsActive + ", @CreatedBy = " + CreatedBy + ", @CreatedOn = " + CreatedOn; throw new Exception(callMessage, sqlException); } return dataSet; } }

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  • Help with Hibernate mapping

    - by GigaPr
    Hi i have the following classes public class RSS { private Integer id; private String title; private String description; private String link; private Date dateCreated; private Collection rssItems; private String url; private String language; private String rating; private Date pubDate; private Date lastBuildDate; private User user; private Date dateModified; public RSS() { } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public void setDescription(String description){ this.description = description; } public String getDescription(){ return this.description; } public void setLink(String link){ this.link = link; } public String getLink(){ return this.link; } public void setUrl(String url){ this.url = url; } public String getUrl(){ return this.url; } public void setLanguage(String language){ this.language = language; } public String getLanguage(){ return this.language; } public void setRating(String rating){ this.rating = rating; } public String getRating(){ return this.rating; } public Date getPubDate() { return pubDate; } public void setPubDate(Date pubDate) { this.pubDate = pubDate; } public Date getLastBuildDate() { return lastBuildDate; } public void setLastBuildDate(Date lastBuildDate) { this.lastBuildDate = lastBuildDate; } public Date getDateModified() { return dateModified; } public void setDateModified(Date dateModified) { this.dateModified = dateModified; } public Date getDateCreated() { return dateCreated; } public void setDateCreated(Date dateCreated) { this.dateCreated = dateCreated; } public Collection getRssItems() { return rssItems; } public void setRssItems(Collection rssItems) { this.rssItems = rssItems; } } public class RSSItem { private RSS rss; private Integer id; private String title; private String description; private String link; private Date dateCreated; private Date dateModified; private int rss_id; public RSSItem() {} public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public String getLink() { return link; } public void setLink(String link) { this.link = link; } public Date getDateCreated() { return dateCreated; } public void setDateCreated(Date dateCreated) { this.dateCreated = dateCreated; } public Date getDateModified() { return dateModified; } public void setDateModified(Date dateModified) { this.dateModified = dateModified; } public RSS getRss() { return rss; } public void setRss(RSS rss) { this.rss = rss; } } that i mapped as <hibernate-mapping> <class name="com.rssFeed.domain.RSS" schema="PUBLIC" table="RSS"> <id name="id" type="int"> <column name="ID"/> <generator class="native"/> </id> <property name="title" type="string"> <column name="TITLE" not-null="true"/> </property> <property name="lastBuildDate" type="java.util.Date"> <column name="LASTBUILDDATE"/> </property> <property name="pubDate" type="java.util.Date"> <column name="PUBDATE" /> </property> <property name="dateCreated" type="java.util.Date"> <column name="DATECREATED" not-null="true"/> </property> <property name="dateModified" type="java.util.Date"> <column name="DATEMODIFIED" not-null="true"/> </property> <property name="description" type="string"> <column name="DESCRIPTION" not-null="true"/> </property> <property name="link" type="string"> <column name="LINK" not-null="true"/> </property> <property name="url" type="string"> <column name="URL" not-null="true"/> </property> <property name="language" type="string"> <column name="LANGUAGE" not-null="true"/> </property> <property name="rating" type="string"> <column name="RATING"/> </property> <set inverse="true" lazy="false" name="rssItems"> <key> <column name="RSS_ID"/> </key> <one-to-many class="com.rssFeed.domain.RSSItem"/> </set> </class> </hibernate-mapping> <hibernate-mapping> <class name="com.rssFeed.domain.RSSItem" schema="PUBLIC" table="RSSItem"> <id name="id" type="int"> <column name="ID"/> <generator class="native"/> </id> <property name="title" type="string"> <column name="TITLE" not-null="true"/> </property> <property name="description" type="string"> <column name="DESCRIPTION" not-null="true"/> </property> <property name="link" type="string"> <column name="LINK" not-null="true"/> </property> <property name="dateCreated" type="java.util.Date"> <column name="DATECREATED"/> </property> <property name="dateModified" type="java.util.Date"> <column name="DATEMODIFIED"/> </property> <many-to-one class="com.rssFeed.domain.RSS" fetch="select" name="rss"> <column name="RSS_ID"/> </many-to-one> </class> </hibernate-mapping> But when i try to fetch an RSS I get the following error Exception occurred in target VM: failed to lazily initialize a collection of role: com.rssFeed.domain.RSS.rssItems, no session or session was closed org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.rssFeed.domain.RSS.rssItems, no session or session was closed at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:358) at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:350) at org.hibernate.collection.AbstractPersistentCollection.readSize(AbstractPersistentCollection.java:97) at org.hibernate.collection.PersistentSet.size(PersistentSet.java:139) at com.rssFeed.dao.hibernate.HibernateRssDao.get(HibernateRssDao.java:47) at com.rssFeed.ServiceImplementation.RssServiceImplementation.get(RssServiceImplementation.java:46) at com.rssFeed.mvc.ViewRssController.handleRequest(ViewRssController.java:20) at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:875) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:809) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:476) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:431) at javax.servlet.http.HttpServlet.service(HttpServlet.java:734) at javax.servlet.http.HttpServlet.service(HttpServlet.java:847) at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1523) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:279) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:188) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:641) at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:97) at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:85) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:185) at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:332) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:233) at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:165) at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:791) at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:693) at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:954) at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:170) at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:135) at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:102) at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:88) at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76) at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:53) at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:57) at com.sun.grizzly.ContextTask.run(ContextTask.java:69) at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:330) at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:309) at java.lang.Thread.run(Thread.java:619) < what does it mean? Thanks

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  • Should all public methods in an abstract class be marked virtual?

    - by Justin Pihony
    I recently had to update an abstract base class on some OSS that I was using so that it was more testable by making them virtual (I could not use an interface as it combined two). This got me thinking whether I should mark all of the methods that I needed virtual, or if I should mark every public method/property virtual. I generally agree with Roy Osherove that every method should be made virtual, but I came across this article that got me thinking about whether this was necessary or not. I am going to limit this down to abstract classes for simplicity, however (whether all concrete public methods should be virtual is especially debatable, I am sure). I could see where you might want to allow a sub-class to use a method, but not want it overriding the implementation. However, as long as you trust that Liskov's Substitution Principle will be followed, then why would you not allow it to be overriden? By marking it abstract, you are forcing a certain override anyway, so, it seems to me that all public methods inside of an abstract class should indeed be marked virtual. However, I wanted to ask in case there was something I might not be thinking. Should all public methods within an abstract class be made virtual?

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  • ASP.NET MVC2 custom rolemanager (webconfig problem)

    - by ile
    Structure of the web: SAMembershipProvider.cs namespace User.Membership { public class SAMembershipProvider : MembershipProvider { #region - Properties - private int NewPasswordLength { get; set; } private string ConnectionString { get; set; } //private MachineKeySection MachineKey { get; set; } //Used when determining encryption key values. public bool enablePasswordReset { get; set; } public bool enablePasswordRetrieval { get; set; } public bool requiresQuestionAndAnswer { get; set; } public bool requiresUniqueEmail { get; set; } public int maxInvalidPasswordAttempts { get; set; } public int passwordAttemptWindow { get; set; } public MembershipPasswordFormat passwordFormat { get; set; } public int minRequiredNonAlphanumericCharacters { get; set; } public int minRequiredPasswordLength { get; set; } public string passwordStrengthRegularExpression { get; set; } public override string ApplicationName { get; set; } // Indicates whether passwords can be retrieved using the provider's GetPassword method. // This property is read-only. public override bool EnablePasswordRetrieval { get { return enablePasswordRetrieval; } } // Indicates whether passwords can be reset using the provider's ResetPassword method. // This property is read-only. public override bool EnablePasswordReset { get { return enablePasswordReset; } } // Indicates whether a password answer must be supplied when calling the provider's GetPassword and ResetPassword methods. // This property is read-only. public override bool RequiresQuestionAndAnswer { get { return requiresQuestionAndAnswer; } } public override int MaxInvalidPasswordAttempts { get { return maxInvalidPasswordAttempts; } } // For a description, see MaxInvalidPasswordAttempts. // This property is read-only. public override int PasswordAttemptWindow { get { return passwordAttemptWindow; } } // Indicates whether each registered user must have a unique e-mail address. // This property is read-only. public override bool RequiresUniqueEmail { get { return requiresUniqueEmail; } } public override MembershipPasswordFormat PasswordFormat { get { return passwordFormat; } } // The minimum number of characters required in a password. // This property is read-only. public override int MinRequiredPasswordLength { get { return minRequiredPasswordLength; } } // The minimum number of non-alphanumeric characters required in a password. // This property is read-only. public override int MinRequiredNonAlphanumericCharacters { get { return minRequiredNonAlphanumericCharacters; } } // A regular expression specifying a pattern to which passwords must conform. // This property is read-only. public override string PasswordStrengthRegularExpression { get { return passwordStrengthRegularExpression; } } #endregion #region - Methods - public override void Initialize(string name, NameValueCollection config) { throw new NotImplementedException(); } public override bool ChangePassword(string username, string oldPassword, string newPassword) { throw new NotImplementedException(); } public override bool ChangePasswordQuestionAndAnswer(string username, string password, string newPasswordQuestion, string newPasswordAnswer) { throw new NotImplementedException(); } // Takes, as input, a user name, password, e-mail address, and other information and adds a new user // to the membership data source. CreateUser returns a MembershipUser object representing the newly // created user. It also accepts an out parameter (in Visual Basic, ByRef) that returns a // MembershipCreateStatus value indicating whether the user was successfully created or, if the user // was not created, the reason why. If the user was not created, CreateUser returns null. // Before creating a new user, CreateUser calls the provider's virtual OnValidatingPassword method to // validate the supplied password. It then creates the user or cancels the action based on the outcome of the call. public override MembershipUser CreateUser(string username, string password, string email, string passwordQuestion, string passwordAnswer, bool isApproved, object providerUserKey, out MembershipCreateStatus status) { throw new NotImplementedException(); } public override bool DeleteUser(string username, bool deleteAllRelatedData) { throw new NotImplementedException(); } public override MembershipUserCollection FindUsersByEmail(string emailToMatch, int pageIndex, int pageSize, out int totalRecords) { throw new NotImplementedException(); } // Returns a MembershipUserCollection containing MembershipUser objects representing users whose user names // match the usernameToMatch input parameter. Wildcard syntax is data source-dependent. MembershipUser objects // in the MembershipUserCollection are sorted by user name. If FindUsersByName finds no matching users, it // returns an empty MembershipUserCollection. // For an explanation of the pageIndex, pageSize, and totalRecords parameters, see the GetAllUsers method. public override MembershipUserCollection FindUsersByName(string usernameToMatch, int pageIndex, int pageSize, out int totalRecords) { throw new NotImplementedException(); } // Returns a MembershipUserCollection containing MembershipUser objects representing all registered users. If // there are no registered users, GetAllUsers returns an empty MembershipUserCollection // The results returned by GetAllUsers are constrained by the pageIndex and pageSize input parameters. pageSize // specifies the maximum number of MembershipUser objects to return. pageIndex identifies which page of results // to return. Page indexes are 0-based. // // GetAllUsers also takes an out parameter (in Visual Basic, ByRef) named totalRecords that, on return, holds // a count of all registered users. public override MembershipUserCollection GetAllUsers(int pageIndex, int pageSize, out int totalRecords) { throw new NotImplementedException(); } // Returns a count of users that are currently online-that is, whose LastActivityDate is greater than the current // date and time minus the value of the membership service's UserIsOnlineTimeWindow property, which can be read // from Membership.UserIsOnlineTimeWindow. UserIsOnlineTimeWindow specifies a time in minutes and is set using // the <membership> element's userIsOnlineTimeWindow attribute. public override int GetNumberOfUsersOnline() { throw new NotImplementedException(); } // Takes, as input, a user name and a password answer and returns that user's password. If the user name is not // valid, GetPassword throws a ProviderException. // Before retrieving a password, GetPassword verifies that EnablePasswordRetrieval is true. If // EnablePasswordRetrieval is false, GetPassword throws a NotSupportedException. If EnablePasswordRetrieval is // true but the password format is hashed, GetPassword throws a ProviderException since hashed passwords cannot, // by definition, be retrieved. A membership provider should also throw a ProviderException from Initialize if // EnablePasswordRetrieval is true but the password format is hashed. // // GetPassword also checks the value of the RequiresQuestionAndAnswer property before retrieving a password. If // RequiresQuestionAndAnswer is true, GetPassword compares the supplied password answer to the stored password // answer and throws a MembershipPasswordException if the two don't match. GetPassword also throws a // MembershipPasswordException if the user whose password is being retrieved is currently locked out. public override string GetPassword(string username, string answer) { throw new NotImplementedException(); } // Takes, as input, a user name or user ID (the method is overloaded) and a Boolean value indicating whether // to update the user's LastActivityDate to show that the user is currently online. GetUser returns a MembershipUser // object representing the specified user. If the user name or user ID is invalid (that is, if it doesn't represent // a registered user) GetUser returns null (Nothing in Visual Basic). public override MembershipUser GetUser(object providerUserKey, bool userIsOnline) { throw new NotImplementedException(); } // Takes, as input, a user name or user ID (the method is overloaded) and a Boolean value indicating whether to // update the user's LastActivityDate to show that the user is currently online. GetUser returns a MembershipUser // object representing the specified user. If the user name or user ID is invalid (that is, if it doesn't represent // a registered user) GetUser returns null (Nothing in Visual Basic). public override MembershipUser GetUser(string username, bool userIsOnline) { throw new NotImplementedException(); } // Takes, as input, an e-mail address and returns the first registered user name whose e-mail address matches the // one supplied. // If it doesn't find a user with a matching e-mail address, GetUserNameByEmail returns an empty string. public override string GetUserNameByEmail(string email) { throw new NotImplementedException(); } // Virtual method called when a password is created. The default implementation in MembershipProvider fires a // ValidatingPassword event, so be sure to call the base class's OnValidatingPassword method if you override // this method. The ValidatingPassword event allows applications to apply additional tests to passwords by // registering event handlers. // A custom provider's CreateUser, ChangePassword, and ResetPassword methods (in short, all methods that record // new passwords) should call this method. protected override void OnValidatingPassword(ValidatePasswordEventArgs e) { base.OnValidatingPassword(e); } // Takes, as input, a user name and a password answer and replaces the user's current password with a new, random // password. ResetPassword then returns the new password. A convenient mechanism for generating a random password // is the Membership.GeneratePassword method. // If the user name is not valid, ResetPassword throws a ProviderException. ResetPassword also checks the value of // the RequiresQuestionAndAnswer property before resetting a password. If RequiresQuestionAndAnswer is true, // ResetPassword compares the supplied password answer to the stored password answer and throws a // MembershipPasswordException if the two don't match. // // Before resetting a password, ResetPassword verifies that EnablePasswordReset is true. If EnablePasswordReset is // false, ResetPassword throws a NotSupportedException. If the user whose password is being changed is currently // locked out, ResetPassword throws a MembershipPasswordException. // // Before resetting a password, ResetPassword calls the provider's virtual OnValidatingPassword method to validate // the new password. It then resets the password or cancels the action based on the outcome of the call. If the new // password is invalid, ResetPassword throws a ProviderException. // // Following a successful password reset, ResetPassword updates the user's LastPasswordChangedDate. public override string ResetPassword(string username, string answer) { throw new NotImplementedException(); } // Unlocks (that is, restores login privileges for) the specified user. UnlockUser returns true if the user is // successfully unlocked. Otherwise, it returns false. If the user is already unlocked, UnlockUser simply returns true. public override bool UnlockUser(string userName) { throw new NotImplementedException(); } // Takes, as input, a MembershipUser object representing a registered user and updates the information stored for // that user in the membership data source. If any of the input submitted in the MembershipUser object is not valid, // UpdateUser throws a ProviderException. // Note that UpdateUser is not obligated to allow all the data that can be encapsulated in a MembershipUser object to // be updated in the data source. public override void UpdateUser(MembershipUser user) { throw new NotImplementedException(); } // Takes, as input, a user name and a password and verifies that they are valid-that is, that the membership data // source contains a matching user name and password. ValidateUser returns true if the user name and password are // valid, if the user is approved (that is, if MembershipUser.IsApproved is true), and if the user isn't currently // locked out. Otherwise, it returns false. // Following a successful validation, ValidateUser updates the user's LastLoginDate and fires an // AuditMembershipAuthenticationSuccess Web event. Following a failed validation, it fires an // // AuditMembershipAuthenticationFailure Web event. public override bool ValidateUser(string username, string password) { throw new NotImplementedException(); //if (string.IsNullOrEmpty(password.Trim())) return false; //string hash = EncryptPassword(password); //User user = _repository.GetByUserName(username); //if (user == null) return false; //if (user.Password == hash) //{ // User = user; // return true; //} //return false; } #endregion /// <summary> /// Procuses an MD5 hash string of the password /// </summary> /// <param name="password">password to hash</param> /// <returns>MD5 Hash string</returns> protected string EncryptPassword(string password) { //we use codepage 1252 because that is what sql server uses byte[] pwdBytes = Encoding.GetEncoding(1252).GetBytes(password); byte[] hashBytes = System.Security.Cryptography.MD5.Create().ComputeHash(pwdBytes); return Encoding.GetEncoding(1252).GetString(hashBytes); } } // End Class } SARoleProvider.cs namespace User.Membership { public class SARoleProvider : RoleProvider { #region - Properties - // The name of the application using the role provider. ApplicationName is used to scope // role data so that applications can choose whether to share role data with other applications. // This property can be read and written. public override string ApplicationName { get; set; } #endregion #region - Methods - public override void Initialize(string name, NameValueCollection config) { throw new NotImplementedException(); } // Takes, as input, a list of user names and a list of role names and adds the specified users to // the specified roles. // AddUsersToRoles throws a ProviderException if any of the user names or role names do not exist. // If any user name or role name is null (Nothing in Visual Basic), AddUsersToRoles throws an // ArgumentNullException. If any user name or role name is an empty string, AddUsersToRoles throws // an ArgumentException. public override void AddUsersToRoles(string[] usernames, string[] roleNames) { throw new NotImplementedException(); } // Takes, as input, a role name and creates the specified role. // CreateRole throws a ProviderException if the role already exists, the role name contains a comma, // or the role name exceeds the maximum length allowed by the data source. public override void CreateRole(string roleName) { throw new NotImplementedException(); } // Takes, as input, a role name and a Boolean value that indicates whether to throw an exception if there // are users currently associated with the role, and then deletes the specified role. // If the throwOnPopulatedRole input parameter is true and the specified role has one or more members, // DeleteRole throws a ProviderException and does not delete the role. If throwOnPopulatedRole is false, // DeleteRole deletes the role whether it is empty or not. // // When DeleteRole deletes a role and there are users assigned to that role, it also removes users from the role. public override bool DeleteRole(string roleName, bool throwOnPopulatedRole) { throw new NotImplementedException(); } // Takes, as input, a search pattern and a role name and returns a list of users belonging to the specified role // whose user names match the pattern. Wildcard syntax is data-source-dependent and may vary from provider to // provider. User names are returned in alphabetical order. // If the search finds no matches, FindUsersInRole returns an empty string array (a string array with no elements). // If the role does not exist, FindUsersInRole throws a ProviderException. public override string[] FindUsersInRole(string roleName, string usernameToMatch) { throw new NotImplementedException(); } // Returns the names of all existing roles. If no roles exist, GetAllRoles returns an empty string array (a string // array with no elements). public override string[] GetAllRoles() { throw new NotImplementedException(); } // Takes, as input, a user name and returns the names of the roles to which the user belongs. // If the user is not assigned to any roles, GetRolesForUser returns an empty string array // (a string array with no elements). If the user name does not exist, GetRolesForUser throws a // ProviderException. public override string[] GetRolesForUser(string username) { throw new NotImplementedException(); //User user = _repository.GetByUserName(username); //string[] roles = new string[user.Role.Rights.Count + 1]; //roles[0] = user.Role.Description; //int idx = 0; //foreach (Right right in user.Role.Rights) // roles[++idx] = right.Description; //return roles; } public override string[] GetUsersInRole(string roleName) { throw new NotImplementedException(); } // Takes, as input, a role name and returns the names of all users assigned to that role. // If no users are associated with the specified role, GetUserInRole returns an empty string array (a string array with // no elements). If the role does not exist, GetUsersInRole throws a ProviderException. public override bool IsUserInRole(string username, string roleName) { throw new NotImplementedException(); //User user = _repository.GetByUserName(username); //if (user != null) // return user.IsInRole(roleName); //else // return false; } // Takes, as input, a list of user names and a list of role names and removes the specified users from the specified roles. // RemoveUsersFromRoles throws a ProviderException if any of the users or roles do not exist, or if any user specified // in the call does not belong to the role from which he or she is being removed. public override void RemoveUsersFromRoles(string[] usernames, string[] roleNames) { throw new NotImplementedException(); } // Takes, as input, a role name and determines whether the role exists. public override bool RoleExists(string roleName) { throw new NotImplementedException(); } #endregion } // End Class } From Web.config: <membership defaultProvider="SAMembershipProvider" userIsOnlineTimeWindow="15"> <providers> <clear/> <add name="SAMembershipProvider" type="User.Membership.SAMembershipProvider, User" /> </providers> </membership> <roleManager defaultProvider="SARoleProvider" enabled="true" cacheRolesInCookie="true"> <providers> <clear/> <add name="SARoleProvider" type="User.Membership.SARoleProvider" /> </providers> </roleManager> When running project, I get following error: Server Error in '/' Application. Configuration Error Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately. Parser Error Message: The method or operation is not implemented. Source Error: Line 71: <providers> Line 72: <clear/> Line 73: <add name="SARoleProvider" type="User.Membership.SARoleProvider" /> Line 74: </providers> Line 75: </roleManager> I tried: <add name="SARoleProvider" type="User.Membership.SARoleProvider, User" /> and <add name="SARoleProvider" type="User.Membership.SARoleProvider, SARoleProvider" /> and <add name="SARoleProvider" type="User.Membership.SARoleProvider, User.Membership" /> but none works Any idea what's wrong here? Thanks, Ile

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  • Hosting the Razor Engine for Templating in Non-Web Applications

    - by Rick Strahl
    Microsoft’s new Razor HTML Rendering Engine that is currently shipping with ASP.NET MVC previews can be used outside of ASP.NET. Razor is an alternative view engine that can be used instead of the ASP.NET Page engine that currently works with ASP.NET WebForms and MVC. It provides a simpler and more readable markup syntax and is much more light weight in terms of functionality than the full blown WebForms Page engine, focusing only on features that are more along the lines of a pure view engine (or classic ASP!) with focus on expression and code rendering rather than a complex control/object model. Like the Page engine though, the parser understands .NET code syntax which can be embedded into templates, and behind the scenes the engine compiles markup and script code into an executing piece of .NET code in an assembly. Although it ships as part of the ASP.NET MVC and WebMatrix the Razor Engine itself is not directly dependent on ASP.NET or IIS or HTTP in any way. And although there are some markup and rendering features that are optimized for HTML based output generation, Razor is essentially a free standing template engine. And what’s really nice is that unlike the ASP.NET Runtime, Razor is fairly easy to host inside of your own non-Web applications to provide templating functionality. Templating in non-Web Applications? Yes please! So why might you host a template engine in your non-Web application? Template rendering is useful in many places and I have a number of applications that make heavy use of it. One of my applications – West Wind Html Help Builder - exclusively uses template based rendering to merge user supplied help text content into customizable and executable HTML markup templates that provide HTML output for CHM style HTML Help. This is an older product and it’s not actually using .NET at the moment – and this is one reason I’m looking at Razor for script hosting at the moment. For a few .NET applications though I’ve actually used the ASP.NET Runtime hosting to provide templating and mail merge style functionality and while that works reasonably well it’s a very heavy handed approach. It’s very resource intensive and has potential issues with versioning in various different versions of .NET. The generic implementation I created in the article above requires a lot of fix up to mimic an HTTP request in a non-HTTP environment and there are a lot of little things that have to happen to ensure that the ASP.NET runtime works properly most of it having nothing to do with the templating aspect but just satisfying ASP.NET’s requirements. The Razor Engine on the other hand is fairly light weight and completely decoupled from the ASP.NET runtime and the HTTP processing. Rather it’s a pure template engine whose sole purpose is to render text templates. Hosting this engine in your own applications can be accomplished with a reasonable amount of code (actually just a few lines with the tools I’m about to describe) and without having to fake HTTP requests. It’s also much lighter on resource usage and you can easily attach custom properties to your base template implementation to easily pass context from the parent application into templates all of which was rather complicated with ASP.NET runtime hosting. Installing the Razor Template Engine You can get Razor as part of the MVC 3 (RC and later) or Web Matrix. Both are available as downloadable components from the Web Platform Installer Version 3.0 (!important – V2 doesn’t show these components). If you already have that version of the WPI installed just fire it up. You can get the latest version of the Web Platform Installer from here: http://www.microsoft.com/web/gallery/install.aspx Once the platform Installer 3.0 is installed install either MVC 3 or ASP.NET Web Pages. Once installed you’ll find a System.Web.Razor assembly in C:\Program Files\Microsoft ASP.NET\ASP.NET Web Pages\v1.0\Assemblies\System.Web.Razor.dll which you can add as a reference to your project. Creating a Wrapper The basic Razor Hosting API is pretty simple and you can host Razor with a (large-ish) handful of lines of code. I’ll show the basics of it later in this article. However, if you want to customize the rendering and handle assembly and namespace includes for the markup as well as deal with text and file inputs as well as forcing Razor to run in a separate AppDomain so you can unload the code-generated assemblies and deal with assembly caching for re-used templates little more work is required to create something that is more easily reusable. For this reason I created a Razor Hosting wrapper project that combines a bunch of this functionality into an easy to use hosting class, a hosting factory that can load the engine in a separate AppDomain and a couple of hosting containers that provided folder based and string based caching for templates for an easily embeddable and reusable engine with easy to use syntax. If you just want the code and play with the samples and source go grab the latest code from the Subversion Repository at: http://www.west-wind.com:8080/svn/articles/trunk/RazorHosting/ or a snapshot from: http://www.west-wind.com/files/tools/RazorHosting.zip Getting Started Before I get into how hosting with Razor works, let’s take a look at how you can get up and running quickly with the wrapper classes provided. It only takes a few lines of code. The easiest way to use these Razor Hosting Wrappers is to use one of the two HostContainers provided. One is for hosting Razor scripts in a directory and rendering them as relative paths from these script files on disk. The other HostContainer serves razor scripts from string templates… Let’s start with a very simple template that displays some simple expressions, some code blocks and demonstrates rendering some data from contextual data that you pass to the template in the form of a ‘context’. Here’s a simple Razor template: @using System.Reflection Hello @Context.FirstName! Your entry was entered on: @Context.Entered @{ // Code block: Update the host Windows Form passed in through the context Context.WinForm.Text = "Hello World from Razor at " + DateTime.Now.ToString(); } AppDomain Id: @AppDomain.CurrentDomain.FriendlyName Assembly: @Assembly.GetExecutingAssembly().FullName Code based output: @{ // Write output with Response object from code string output = string.Empty; for (int i = 0; i < 10; i++) { output += i.ToString() + " "; } Response.Write(output); } Pretty easy to see what’s going on here. The only unusual thing in this code is the Context object which is an arbitrary object I’m passing from the host to the template by way of the template base class. I’m also displaying the current AppDomain and the executing Assembly name so you can see how compiling and running a template actually loads up new assemblies. Also note that as part of my context I’m passing a reference to the current Windows Form down to the template and changing the title from within the script. It’s a silly example, but it demonstrates two-way communication between host and template and back which can be very powerful. The easiest way to quickly render this template is to use the RazorEngine<TTemplateBase> class. The generic parameter specifies a template base class type that is used by Razor internally to generate the class it generates from a template. The default implementation provided in my RazorHosting wrapper is RazorTemplateBase. Here’s a simple one that renders from a string and outputs a string: var engine = new RazorEngine<RazorTemplateBase>(); // we can pass any object as context - here create a custom context var context = new CustomContext() { WinForm = this, FirstName = "Rick", Entered = DateTime.Now.AddDays(-10) }; string output = engine.RenderTemplate(this.txtSource.Text new string[] { "System.Windows.Forms.dll" }, context); if (output == null) this.txtResult.Text = "*** ERROR:\r\n" + engine.ErrorMessage; else this.txtResult.Text = output; Simple enough. This code renders a template from a string input and returns a result back as a string. It  creates a custom context and passes that to the template which can then access the Context’s properties. Note that anything passed as ‘context’ must be serializable (or MarshalByRefObject) – otherwise you get an exception when passing the reference over AppDomain boundaries (discussed later). Passing a context is optional, but is a key feature in being able to share data between the host application and the template. Note that we use the Context object to access FirstName, Entered and even the host Windows Form object which is used in the template to change the Window caption from within the script! In the code above all the work happens in the RenderTemplate method which provide a variety of overloads to read and write to and from strings, files and TextReaders/Writers. Here’s another example that renders from a file input using a TextReader: using (reader = new StreamReader("templates\\simple.csHtml", true)) { result = host.RenderTemplate(reader, new string[] { "System.Windows.Forms.dll" }, this.CustomContext); } RenderTemplate() is fairly high level and it handles loading of the runtime, compiling into an assembly and rendering of the template. If you want more control you can use the lower level methods to control each step of the way which is important for the HostContainers I’ll discuss later. Basically for those scenarios you want to separate out loading of the engine, compiling into an assembly and then rendering the template from the assembly. Why? So we can keep assemblies cached. In the code above a new assembly is created for each template rendered which is inefficient and uses up resources. Depending on the size of your templates and how often you fire them you can chew through memory very quickly. This slighter lower level approach is only a couple of extra steps: // we can pass any object as context - here create a custom context var context = new CustomContext() { WinForm = this, FirstName = "Rick", Entered = DateTime.Now.AddDays(-10) }; var engine = new RazorEngine<RazorTemplateBase>(); string assId = null; using (StringReader reader = new StringReader(this.txtSource.Text)) { assId = engine.ParseAndCompileTemplate(new string[] { "System.Windows.Forms.dll" }, reader); } string output = engine.RenderTemplateFromAssembly(assId, context); if (output == null) this.txtResult.Text = "*** ERROR:\r\n" + engine.ErrorMessage; else this.txtResult.Text = output; The difference here is that you can capture the assembly – or rather an Id to it – and potentially hold on to it to render again later assuming the template hasn’t changed. The HostContainers take advantage of this feature to cache the assemblies based on certain criteria like a filename and file time step or a string hash that if not change indicate that an assembly can be reused. Note that ParseAndCompileTemplate returns an assembly Id rather than the assembly itself. This is done so that that the assembly always stays in the host’s AppDomain and is not passed across AppDomain boundaries which would cause load failures. We’ll talk more about this in a minute but for now just realize that assemblies references are stored in a list and are accessible by this ID to allow locating and re-executing of the assembly based on that id. Reuse of the assembly avoids recompilation overhead and creation of yet another assembly that loads into the current AppDomain. You can play around with several different versions of the above code in the main sample form:   Using Hosting Containers for more Control and Caching The above examples simply render templates into assemblies each and every time they are executed. While this works and is even reasonably fast, it’s not terribly efficient. If you render templates more than once it would be nice if you could cache the generated assemblies for example to avoid re-compiling and creating of a new assembly each time. Additionally it would be nice to load template assemblies into a separate AppDomain optionally to be able to be able to unload assembli es and also to protect your host application from scripting attacks with malicious template code. Hosting containers provide also provide a wrapper around the RazorEngine<T> instance, a factory (which allows creation in separate AppDomains) and an easy way to start and stop the container ‘runtime’. The Razor Hosting samples provide two hosting containers: RazorFolderHostContainer and StringHostContainer. The folder host provides a simple runtime environment for a folder structure similar in the way that the ASP.NET runtime handles a virtual directory as it’s ‘application' root. Templates are loaded from disk in relative paths and the resulting assemblies are cached unless the template on disk is changed. The string host also caches templates based on string hashes – if the same string is passed a second time a cached version of the assembly is used. Here’s how HostContainers work. I’ll use the FolderHostContainer because it’s likely the most common way you’d use templates – from disk based templates that can be easily edited and maintained on disk. The first step is to create an instance of it and keep it around somewhere (in the example it’s attached as a property to the Form): RazorFolderHostContainer Host = new RazorFolderHostContainer(); public RazorFolderHostForm() { InitializeComponent(); // The base path for templates - templates are rendered with relative paths // based on this path. Host.TemplatePath = Path.Combine(Environment.CurrentDirectory, TemplateBaseFolder); // Add any assemblies you want reference in your templates Host.ReferencedAssemblies.Add("System.Windows.Forms.dll"); // Start up the host container Host.Start(); } Next anytime you want to render a template you can use simple code like this: private void RenderTemplate(string fileName) { // Pass the template path via the Context var relativePath = Utilities.GetRelativePath(fileName, Host.TemplatePath); if (!Host.RenderTemplate(relativePath, this.Context, Host.RenderingOutputFile)) { MessageBox.Show("Error: " + Host.ErrorMessage); return; } this.webBrowser1.Navigate("file://" + Host.RenderingOutputFile); } You can also render the output to a string instead of to a file: string result = Host.RenderTemplateToString(relativePath,context); Finally if you want to release the engine and shut down the hosting AppDomain you can simply do: Host.Stop(); Stopping the AppDomain and restarting it (ie. calling Stop(); followed by Start()) is also a nice way to release all resources in the AppDomain. The FolderBased domain also supports partial Rendering based on root path based relative paths with the same caching characteristics as the main templates. From within a template you can call out to a partial like this: @RenderPartial(@"partials\PartialRendering.cshtml", Context) where partials\PartialRendering.cshtml is a relative to the template root folder. The folder host example lets you load up templates from disk and display the result in a Web Browser control which demonstrates using Razor HTML output from templates that contain HTML syntax which happens to me my target scenario for Html Help Builder.   The Razor Engine Wrapper Project The project I created to wrap Razor hosting has a fair bit of code and a number of classes associated with it. Most of the components are internally used and as you can see using the final RazorEngine<T> and HostContainer classes is pretty easy. The classes are extensible and I suspect developers will want to build more customized host containers for their applications. Host containers are the key to wrapping up all functionality – Engine, BaseTemplate, AppDomain Hosting, Caching etc in a logical piece that is ready to be plugged into an application. When looking at the code there are a couple of core features provided: Core Razor Engine Hosting This is the core Razor hosting which provides the basics of loading a template, compiling it into an assembly and executing it. This is fairly straightforward, but without a host container that can cache assemblies based on some criteria templates are recompiled and re-created each time which is inefficient (although pretty fast). The base engine wrapper implementation also supports hosting the Razor runtime in a separate AppDomain for security and the ability to unload it on demand. Host Containers The engine hosting itself doesn’t provide any sort of ‘runtime’ service like picking up files from disk, caching assemblies and so forth. So my implementation provides two HostContainers: RazorFolderHostContainer and RazorStringHostContainer. The FolderHost works off a base directory and loads templates based on relative paths (sort of like the ASP.NET runtime does off a virtual). The HostContainers also deal with caching of template assemblies – for the folder host the file date is tracked and checked for updates and unless the template is changed a cached assembly is reused. The StringHostContainer similiarily checks string hashes to figure out whether a particular string template was previously compiled and executed. The HostContainers also act as a simple startup environment and a single reference to easily store and reuse in an application. TemplateBase Classes The template base classes are the base classes that from which the Razor engine generates .NET code. A template is parsed into a class with an Execute() method and the class is based on this template type you can specify. RazorEngine<TBaseTemplate> can receive this type and the HostContainers default to specific templates in their base implementations. Template classes are customizable to allow you to create templates that provide application specific features and interaction from the template to your host application. How does the RazorEngine wrapper work? You can browse the source code in the links above or in the repository or download the source, but I’ll highlight some key features here. Here’s part of the RazorEngine implementation that can be used to host the runtime and that demonstrates the key code required to host the Razor runtime. The RazorEngine class is implemented as a generic class to reflect the Template base class type: public class RazorEngine<TBaseTemplateType> : MarshalByRefObject where TBaseTemplateType : RazorTemplateBase The generic type is used to internally provide easier access to the template type and assignments on it as part of the template processing. The class also inherits MarshalByRefObject to allow execution over AppDomain boundaries – something that all the classes discussed here need to do since there is much interaction between the host and the template. The first two key methods deal with creating a template assembly: /// <summary> /// Creates an instance of the RazorHost with various options applied. /// Applies basic namespace imports and the name of the class to generate /// </summary> /// <param name="generatedNamespace"></param> /// <param name="generatedClass"></param> /// <returns></returns> protected RazorTemplateEngine CreateHost(string generatedNamespace, string generatedClass) { Type baseClassType = typeof(TBaseTemplateType); RazorEngineHost host = new RazorEngineHost(new CSharpRazorCodeLanguage()); host.DefaultBaseClass = baseClassType.FullName; host.DefaultClassName = generatedClass; host.DefaultNamespace = generatedNamespace; host.NamespaceImports.Add("System"); host.NamespaceImports.Add("System.Text"); host.NamespaceImports.Add("System.Collections.Generic"); host.NamespaceImports.Add("System.Linq"); host.NamespaceImports.Add("System.IO"); return new RazorTemplateEngine(host); } /// <summary> /// Parses and compiles a markup template into an assembly and returns /// an assembly name. The name is an ID that can be passed to /// ExecuteTemplateByAssembly which picks up a cached instance of the /// loaded assembly. /// /// </summary> /// <param name="namespaceOfGeneratedClass">The namespace of the class to generate from the template</param> /// <param name="generatedClassName">The name of the class to generate from the template</param> /// <param name="ReferencedAssemblies">Any referenced assemblies by dll name only. Assemblies must be in execution path of host or in GAC.</param> /// <param name="templateSourceReader">Textreader that loads the template</param> /// <remarks> /// The actual assembly isn't returned here to allow for cross-AppDomain /// operation. If the assembly was returned it would fail for cross-AppDomain /// calls. /// </remarks> /// <returns>An assembly Id. The Assembly is cached in memory and can be used with RenderFromAssembly.</returns> public string ParseAndCompileTemplate( string namespaceOfGeneratedClass, string generatedClassName, string[] ReferencedAssemblies, TextReader templateSourceReader) { RazorTemplateEngine engine = CreateHost(namespaceOfGeneratedClass, generatedClassName); // Generate the template class as CodeDom GeneratorResults razorResults = engine.GenerateCode(templateSourceReader); // Create code from the codeDom and compile CSharpCodeProvider codeProvider = new CSharpCodeProvider(); CodeGeneratorOptions options = new CodeGeneratorOptions(); // Capture Code Generated as a string for error info // and debugging LastGeneratedCode = null; using (StringWriter writer = new StringWriter()) { codeProvider.GenerateCodeFromCompileUnit(razorResults.GeneratedCode, writer, options); LastGeneratedCode = writer.ToString(); } CompilerParameters compilerParameters = new CompilerParameters(ReferencedAssemblies); // Standard Assembly References compilerParameters.ReferencedAssemblies.Add("System.dll"); compilerParameters.ReferencedAssemblies.Add("System.Core.dll"); compilerParameters.ReferencedAssemblies.Add("Microsoft.CSharp.dll"); // dynamic support! // Also add the current assembly so RazorTemplateBase is available compilerParameters.ReferencedAssemblies.Add(Assembly.GetExecutingAssembly().CodeBase.Substring(8)); compilerParameters.GenerateInMemory = Configuration.CompileToMemory; if (!Configuration.CompileToMemory) compilerParameters.OutputAssembly = Path.Combine(Configuration.TempAssemblyPath, "_" + Guid.NewGuid().ToString("n") + ".dll"); CompilerResults compilerResults = codeProvider.CompileAssemblyFromDom(compilerParameters, razorResults.GeneratedCode); if (compilerResults.Errors.Count > 0) { var compileErrors = new StringBuilder(); foreach (System.CodeDom.Compiler.CompilerError compileError in compilerResults.Errors) compileErrors.Append(String.Format(Resources.LineX0TColX1TErrorX2RN, compileError.Line, compileError.Column, compileError.ErrorText)); this.SetError(compileErrors.ToString() + "\r\n" + LastGeneratedCode); return null; } AssemblyCache.Add(compilerResults.CompiledAssembly.FullName, compilerResults.CompiledAssembly); return compilerResults.CompiledAssembly.FullName; } Think of the internal CreateHost() method as setting up the assembly generated from each template. Each template compiles into a separate assembly. It sets up namespaces, and assembly references, the base class used and the name and namespace for the generated class. ParseAndCompileTemplate() then calls the CreateHost() method to receive the template engine generator which effectively generates a CodeDom from the template – the template is turned into .NET code. The code generated from our earlier example looks something like this: //------------------------------------------------------------------------------ // <auto-generated> // This code was generated by a tool. // Runtime Version:4.0.30319.1 // // Changes to this file may cause incorrect behavior and will be lost if // the code is regenerated. // </auto-generated> //------------------------------------------------------------------------------ namespace RazorTest { using System; using System.Text; using System.Collections.Generic; using System.Linq; using System.IO; using System.Reflection; public class RazorTemplate : RazorHosting.RazorTemplateBase { #line hidden public RazorTemplate() { } public override void Execute() { WriteLiteral("Hello "); Write(Context.FirstName); WriteLiteral("! Your entry was entered on: "); Write(Context.Entered); WriteLiteral("\r\n\r\n"); // Code block: Update the host Windows Form passed in through the context Context.WinForm.Text = "Hello World from Razor at " + DateTime.Now.ToString(); WriteLiteral("\r\nAppDomain Id:\r\n "); Write(AppDomain.CurrentDomain.FriendlyName); WriteLiteral("\r\n \r\nAssembly:\r\n "); Write(Assembly.GetExecutingAssembly().FullName); WriteLiteral("\r\n\r\nCode based output: \r\n"); // Write output with Response object from code string output = string.Empty; for (int i = 0; i < 10; i++) { output += i.ToString() + " "; } } } } Basically the template’s body is turned into code in an Execute method that is called. Internally the template’s Write method is fired to actually generate the output. Note that the class inherits from RazorTemplateBase which is the generic parameter I used to specify the base class when creating an instance in my RazorEngine host: var engine = new RazorEngine<RazorTemplateBase>(); This template class must be provided and it must implement an Execute() and Write() method. Beyond that you can create any class you chose and attach your own properties. My RazorTemplateBase class implementation is very simple: public class RazorTemplateBase : MarshalByRefObject, IDisposable { /// <summary> /// You can pass in a generic context object /// to use in your template code /// </summary> public dynamic Context { get; set; } /// <summary> /// Class that generates output. Currently ultra simple /// with only Response.Write() implementation. /// </summary> public RazorResponse Response { get; set; } public object HostContainer {get; set; } public object Engine { get; set; } public RazorTemplateBase() { Response = new RazorResponse(); } public virtual void Write(object value) { Response.Write(value); } public virtual void WriteLiteral(object value) { Response.Write(value); } /// <summary> /// Razor Parser implements this method /// </summary> public virtual void Execute() {} public virtual void Dispose() { if (Response != null) { Response.Dispose(); Response = null; } } } Razor fills in the Execute method when it generates its subclass and uses the Write() method to output content. As you can see I use a RazorResponse() class here to generate output. This isn’t necessary really, as you could use a StringBuilder or StringWriter() directly, but I prefer using Response object so I can extend the Response behavior as needed. The RazorResponse class is also very simple and merely acts as a wrapper around a TextWriter: public class RazorResponse : IDisposable { /// <summary> /// Internal text writer - default to StringWriter() /// </summary> public TextWriter Writer = new StringWriter(); public virtual void Write(object value) { Writer.Write(value); } public virtual void WriteLine(object value) { Write(value); Write("\r\n"); } public virtual void WriteFormat(string format, params object[] args) { Write(string.Format(format, args)); } public override string ToString() { return Writer.ToString(); } public virtual void Dispose() { Writer.Close(); } public virtual void SetTextWriter(TextWriter writer) { // Close original writer if (Writer != null) Writer.Close(); Writer = writer; } } The Rendering Methods of RazorEngine At this point I’ve talked about the assembly generation logic and the template implementation itself. What’s left is that once you’ve generated the assembly is to execute it. The code to do this is handled in the various RenderXXX methods of the RazorEngine class. Let’s look at the lowest level one of these which is RenderTemplateFromAssembly() and a couple of internal support methods that handle instantiating and invoking of the generated template method: public string RenderTemplateFromAssembly( string assemblyId, string generatedNamespace, string generatedClass, object context, TextWriter outputWriter) { this.SetError(); Assembly generatedAssembly = AssemblyCache[assemblyId]; if (generatedAssembly == null) { this.SetError(Resources.PreviouslyCompiledAssemblyNotFound); return null; } string className = generatedNamespace + "." + generatedClass; Type type; try { type = generatedAssembly.GetType(className); } catch (Exception ex) { this.SetError(Resources.UnableToCreateType + className + ": " + ex.Message); return null; } // Start with empty non-error response (if we use a writer) string result = string.Empty; using(TBaseTemplateType instance = InstantiateTemplateClass(type)) { if (instance == null) return null; if (outputWriter != null) instance.Response.SetTextWriter(outputWriter); if (!InvokeTemplateInstance(instance, context)) return null; // Capture string output if implemented and return // otherwise null is returned if (outputWriter == null) result = instance.Response.ToString(); } return result; } protected virtual TBaseTemplateType InstantiateTemplateClass(Type type) { TBaseTemplateType instance = Activator.CreateInstance(type) as TBaseTemplateType; if (instance == null) { SetError(Resources.CouldnTActivateTypeInstance + type.FullName); return null; } instance.Engine = this; // If a HostContainer was set pass that to the template too instance.HostContainer = this.HostContainer; return instance; } /// <summary> /// Internally executes an instance of the template, /// captures errors on execution and returns true or false /// </summary> /// <param name="instance">An instance of the generated template</param> /// <returns>true or false - check ErrorMessage for errors</returns> protected virtual bool InvokeTemplateInstance(TBaseTemplateType instance, object context) { try { instance.Context = context; instance.Execute(); } catch (Exception ex) { this.SetError(Resources.TemplateExecutionError + ex.Message); return false; } finally { // Must make sure Response is closed instance.Response.Dispose(); } return true; } The RenderTemplateFromAssembly method basically requires the namespace and class to instantate and creates an instance of the class using InstantiateTemplateClass(). It then invokes the method with InvokeTemplateInstance(). These two methods are broken out because they are re-used by various other rendering methods and also to allow subclassing and providing additional configuration tasks to set properties and pass values to templates at execution time. In the default mode instantiation sets the Engine and HostContainer (discussed later) so the template can call back into the template engine, and the context is set when the template method is invoked. The various RenderXXX methods use similar code although they create the assemblies first. If you’re after potentially cashing assemblies the method is the one to call and that’s exactly what the two HostContainer classes do. More on that in a minute, but before we get into HostContainers let’s talk about AppDomain hosting and the like. Running Templates in their own AppDomain With the RazorEngine class above, when a template is parsed into an assembly and executed the assembly is created (in memory or on disk – you can configure that) and cached in the current AppDomain. In .NET once an assembly has been loaded it can never be unloaded so if you’re loading lots of templates and at some time you want to release them there’s no way to do so. If however you load the assemblies in a separate AppDomain that new AppDomain can be unloaded and the assemblies loaded in it with it. In order to host the templates in a separate AppDomain the easiest thing to do is to run the entire RazorEngine in a separate AppDomain. Then all interaction occurs in the other AppDomain and no further changes have to be made. To facilitate this there is a RazorEngineFactory which has methods that can instantiate the RazorHost in a separate AppDomain as well as in the local AppDomain. The host creates the remote instance and then hangs on to it to keep it alive as well as providing methods to shut down the AppDomain and reload the engine. Sounds complicated but cross-AppDomain invocation is actually fairly easy to implement. Here’s some of the relevant code from the RazorEngineFactory class. Like the RazorEngine this class is generic and requires a template base type in the generic class name: public class RazorEngineFactory<TBaseTemplateType> where TBaseTemplateType : RazorTemplateBase Here are the key methods of interest: /// <summary> /// Creates an instance of the RazorHost in a new AppDomain. This /// version creates a static singleton that that is cached and you /// can call UnloadRazorHostInAppDomain to unload it. /// </summary> /// <returns></returns> public static RazorEngine<TBaseTemplateType> CreateRazorHostInAppDomain() { if (Current == null) Current = new RazorEngineFactory<TBaseTemplateType>(); return Current.GetRazorHostInAppDomain(); } public static void UnloadRazorHostInAppDomain() { if (Current != null) Current.UnloadHost(); Current = null; } /// <summary> /// Instance method that creates a RazorHost in a new AppDomain. /// This method requires that you keep the Factory around in /// order to keep the AppDomain alive and be able to unload it. /// </summary> /// <returns></returns> public RazorEngine<TBaseTemplateType> GetRazorHostInAppDomain() { LocalAppDomain = CreateAppDomain(null); if (LocalAppDomain == null) return null; /// Create the instance inside of the new AppDomain /// Note: remote domain uses local EXE's AppBasePath!!! RazorEngine<TBaseTemplateType> host = null; try { Assembly ass = Assembly.GetExecutingAssembly(); string AssemblyPath = ass.Location; host = (RazorEngine<TBaseTemplateType>) LocalAppDomain.CreateInstanceFrom(AssemblyPath, typeof(RazorEngine<TBaseTemplateType>).FullName).Unwrap(); } catch (Exception ex) { ErrorMessage = ex.Message; return null; } return host; } /// <summary> /// Internally creates a new AppDomain in which Razor templates can /// be run. /// </summary> /// <param name="appDomainName"></param> /// <returns></returns> private AppDomain CreateAppDomain(string appDomainName) { if (appDomainName == null) appDomainName = "RazorHost_" + Guid.NewGuid().ToString("n"); AppDomainSetup setup = new AppDomainSetup(); // *** Point at current directory setup.ApplicationBase = AppDomain.CurrentDomain.BaseDirectory; AppDomain localDomain = AppDomain.CreateDomain(appDomainName, null, setup); return localDomain; } /// <summary> /// Allow unloading of the created AppDomain to release resources /// All internal resources in the AppDomain are released including /// in memory compiled Razor assemblies. /// </summary> public void UnloadHost() { if (this.LocalAppDomain != null) { AppDomain.Unload(this.LocalAppDomain); this.LocalAppDomain = null; } } The static CreateRazorHostInAppDomain() is the key method that startup code usually calls. It uses a Current singleton instance to an instance of itself that is created cross AppDomain and is kept alive because it’s static. GetRazorHostInAppDomain actually creates a cross-AppDomain instance which first creates a new AppDomain and then loads the RazorEngine into it. The remote Proxy instance is returned as a result to the method and can be used the same as a local instance. The code to run with a remote AppDomain is simple: private RazorEngine<RazorTemplateBase> CreateHost() { if (this.Host != null) return this.Host; // Use Static Methods - no error message if host doesn't load this.Host = RazorEngineFactory<RazorTemplateBase>.CreateRazorHostInAppDomain(); if (this.Host == null) { MessageBox.Show("Unable to load Razor Template Host", "Razor Hosting", MessageBoxButtons.OK, MessageBoxIcon.Exclamation); } return this.Host; } This code relies on a local reference of the Host which is kept around for the duration of the app (in this case a form reference). To use this you’d simply do: this.Host = CreateHost(); if (host == null) return; string result = host.RenderTemplate( this.txtSource.Text, new string[] { "System.Windows.Forms.dll", "Westwind.Utilities.dll" }, this.CustomContext); if (result == null) { MessageBox.Show(host.ErrorMessage, "Template Execution Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation); return; } this.txtResult.Text = result; Now all templates run in a remote AppDomain and can be unloaded with simple code like this: RazorEngineFactory<RazorTemplateBase>.UnloadRazorHostInAppDomain(); this.Host = null; One Step further – Providing a caching ‘Runtime’ Once we can load templates in a remote AppDomain we can add some additional functionality like assembly caching based on application specific features. One of my typical scenarios is to render templates out of a scripts folder. So all templates live in a folder and they change infrequently. So a Folder based host that can compile these templates once and then only recompile them if something changes would be ideal. Enter host containers which are basically wrappers around the RazorEngine<t> and RazorEngineFactory<t>. They provide additional logic for things like file caching based on changes on disk or string hashes for string based template inputs. The folder host also provides for partial rendering logic through a custom template base implementation. There’s a base implementation in RazorBaseHostContainer, which provides the basics for hosting a RazorEngine, which includes the ability to start and stop the engine, cache assemblies and add references: public abstract class RazorBaseHostContainer<TBaseTemplateType> : MarshalByRefObject where TBaseTemplateType : RazorTemplateBase, new() { public RazorBaseHostContainer() { UseAppDomain = true; GeneratedNamespace = "__RazorHost"; } /// <summary> /// Determines whether the Container hosts Razor /// in a separate AppDomain. Seperate AppDomain /// hosting allows unloading and releasing of /// resources. /// </summary> public bool UseAppDomain { get; set; } /// <summary> /// Base folder location where the AppDomain /// is hosted. By default uses the same folder /// as the host application. /// /// Determines where binary dependencies are /// found for assembly references. /// </summary> public string BaseBinaryFolder { get; set; } /// <summary> /// List of referenced assemblies as string values. /// Must be in GAC or in the current folder of the host app/ /// base BinaryFolder /// </summary> public List<string> ReferencedAssemblies = new List<string>(); /// <summary> /// Name of the generated namespace for template classes /// </summary> public string GeneratedNamespace {get; set; } /// <summary> /// Any error messages /// </summary> public string ErrorMessage { get; set; } /// <summary> /// Cached instance of the Host. Required to keep the /// reference to the host alive for multiple uses. /// </summary> public RazorEngine<TBaseTemplateType> Engine; /// <summary> /// Cached instance of the Host Factory - so we can unload /// the host and its associated AppDomain. /// </summary> protected RazorEngineFactory<TBaseTemplateType> EngineFactory; /// <summary> /// Keep track of each compiled assembly /// and when it was compiled. /// /// Use a hash of the string to identify string /// changes. /// </summary> protected Dictionary<int, CompiledAssemblyItem> LoadedAssemblies = new Dictionary<int, CompiledAssemblyItem>(); /// <summary> /// Call to start the Host running. Follow by a calls to RenderTemplate to /// render individual templates. Call Stop when done. /// </summary> /// <returns>true or false - check ErrorMessage on false </returns> public virtual bool Start() { if (Engine == null) { if (UseAppDomain) Engine = RazorEngineFactory<TBaseTemplateType>.CreateRazorHostInAppDomain(); else Engine = RazorEngineFactory<TBaseTemplateType>.CreateRazorHost(); Engine.Configuration.CompileToMemory = true; Engine.HostContainer = this; if (Engine == null) { this.ErrorMessage = EngineFactory.ErrorMessage; return false; } } return true; } /// <summary> /// Stops the Host and releases the host AppDomain and cached /// assemblies. /// </summary> /// <returns>true or false</returns> public bool Stop() { this.LoadedAssemblies.Clear(); RazorEngineFactory<RazorTemplateBase>.UnloadRazorHostInAppDomain(); this.Engine = null; return true; } … } This base class provides most of the mechanics to host the runtime, but no application specific implementation for rendering. There are rendering functions but they just call the engine directly and provide no caching – there’s no context to decide how to cache and reuse templates. The key methods are Start and Stop and their main purpose is to start a new AppDomain (optionally) and shut it down when requested. The RazorFolderHostContainer – Folder Based Runtime Hosting Let’s look at the more application specific RazorFolderHostContainer implementation which is defined like this: public class RazorFolderHostContainer : RazorBaseHostContainer<RazorTemplateFolderHost> Note that a customized RazorTemplateFolderHost class template is used for this implementation that supports partial rendering in form of a RenderPartial() method that’s available to templates. The folder host’s features are: Render templates based on a Template Base Path (a ‘virtual’ if you will) Cache compiled assemblies based on the relative path and file time stamp File changes on templates cause templates to be recompiled into new assemblies Support for partial rendering using base folder relative pathing As shown in the startup examples earlier host containers require some startup code with a HostContainer tied to a persistent property (like a Form property): // The base path for templates - templates are rendered with relative paths // based on this path. HostContainer.TemplatePath = Path.Combine(Environment.CurrentDirectory, TemplateBaseFolder); // Default output rendering disk location HostContainer.RenderingOutputFile = Path.Combine(HostContainer.TemplatePath, "__Preview.htm"); // Add any assemblies you want reference in your templates HostContainer.ReferencedAssemblies.Add("System.Windows.Forms.dll"); // Start up the host container HostContainer.Start(); Once that’s done, you can render templates with the host container: // Pass the template path for full filename seleted with OpenFile Dialog // relativepath is: subdir\file.cshtml or file.cshtml or ..\file.cshtml var relativePath = Utilities.GetRelativePath(fileName, HostContainer.TemplatePath); if (!HostContainer.RenderTemplate(relativePath, Context, HostContainer.RenderingOutputFile)) { MessageBox.Show("Error: " + HostContainer.ErrorMessage); return; } webBrowser1.Navigate("file://" + HostContainer.RenderingOutputFile); The most critical task of the RazorFolderHostContainer implementation is to retrieve a template from disk, compile and cache it and then deal with deciding whether subsequent requests need to re-compile the template or simply use a cached version. Internally the GetAssemblyFromFileAndCache() handles this task: /// <summary> /// Internally checks if a cached assembly exists and if it does uses it /// else creates and compiles one. Returns an assembly Id to be /// used with the LoadedAssembly list. /// </summary> /// <param name="relativePath"></param> /// <param name="context"></param> /// <returns></returns> protected virtual CompiledAssemblyItem GetAssemblyFromFileAndCache(string relativePath) { string fileName = Path.Combine(TemplatePath, relativePath).ToLower(); int fileNameHash = fileName.GetHashCode(); if (!File.Exists(fileName)) { this.SetError(Resources.TemplateFileDoesnTExist + fileName); return null; } CompiledAssemblyItem item = null; this.LoadedAssemblies.TryGetValue(fileNameHash, out item); string assemblyId = null; // Check for cached instance if (item != null) { var fileTime = File.GetLastWriteTimeUtc(fileName); if (fileTime <= item.CompileTimeUtc) assemblyId = item.AssemblyId; } else item = new CompiledAssemblyItem(); // No cached instance - create assembly and cache if (assemblyId == null) { string safeClassName = GetSafeClassName(fileName); StreamReader reader = null; try { reader = new StreamReader(fileName, true); } catch (Exception ex) { this.SetError(Resources.ErrorReadingTemplateFile + fileName); return null; } assemblyId = Engine.ParseAndCompileTemplate(this.ReferencedAssemblies.ToArray(), reader); // need to ensure reader is closed if (reader != null) reader.Close(); if (assemblyId == null) { this.SetError(Engine.ErrorMessage); return null; } item.AssemblyId = assemblyId; item.CompileTimeUtc = DateTime.UtcNow; item.FileName = fileName; item.SafeClassName = safeClassName; this.LoadedAssemblies[fileNameHash] = item; } return item; } This code uses a LoadedAssembly dictionary which is comprised of a structure that holds a reference to a compiled assembly, a full filename and file timestamp and an assembly id. LoadedAssemblies (defined on the base class shown earlier) is essentially a cache for compiled assemblies and they are identified by a hash id. In the case of files the hash is a GetHashCode() from the full filename of the template. The template is checked for in the cache and if not found the file stamp is checked. If that’s newer than the cache’s compilation date the template is recompiled otherwise the version in the cache is used. All the core work defers to a RazorEngine<T> instance to ParseAndCompileTemplate(). The three rendering specific methods then are rather simple implementations with just a few lines of code dealing with parameter and return value parsing: /// <summary> /// Renders a template to a TextWriter. Useful to write output into a stream or /// the Response object. Used for partial rendering. /// </summary> /// <param name="relativePath">Relative path to the file in the folder structure</param> /// <param name="context">Optional context object or null</param> /// <param name="writer">The textwriter to write output into</param> /// <returns></returns> public bool RenderTemplate(string relativePath, object context, TextWriter writer) { // Set configuration data that is to be passed to the template (any object) Engine.TemplatePerRequestConfigurationData = new RazorFolderHostTemplateConfiguration() { TemplatePath = Path.Combine(this.TemplatePath, relativePath), TemplateRelativePath = relativePath, }; CompiledAssemblyItem item = GetAssemblyFromFileAndCache(relativePath); if (item == null) { writer.Close(); return false; } try { // String result will be empty as output will be rendered into the // Response object's stream output. However a null result denotes // an error string result = Engine.RenderTemplateFromAssembly(item.AssemblyId, context, writer); if (result == null) { this.SetError(Engine.ErrorMessage); return false; } } catch (Exception ex) { this.SetError(ex.Message); return false; } finally { writer.Close(); } return true; } /// <summary> /// Render a template from a source file on disk to a specified outputfile. /// </summary> /// <param name="relativePath">Relative path off the template root folder. Format: path/filename.cshtml</param> /// <param name="context">Any object that will be available in the template as a dynamic of this.Context</param> /// <param name="outputFile">Optional - output file where output is written to. If not specified the /// RenderingOutputFile property is used instead /// </param> /// <returns>true if rendering succeeds, false on failure - check ErrorMessage</returns> public bool RenderTemplate(string relativePath, object context, string outputFile) { if (outputFile == null) outputFile = RenderingOutputFile; try { using (StreamWriter writer = new StreamWriter(outputFile, false, Engine.Configuration.OutputEncoding, Engine.Configuration.StreamBufferSize)) { return RenderTemplate(relativePath, context, writer); } } catch (Exception ex) { this.SetError(ex.Message); return false; } return true; } /// <summary> /// Renders a template to string. Useful for RenderTemplate /// </summary> /// <param name="relativePath"></param> /// <param name="context"></param> /// <returns></returns> public string RenderTemplateToString(string relativePath, object context) { string result = string.Empty; try { using (StringWriter writer = new StringWriter()) { // String result will be empty as output will be rendered into the // Response object's stream output. However a null result denotes // an error if (!RenderTemplate(relativePath, context, writer)) { this.SetError(Engine.ErrorMessage); return null; } result = writer.ToString(); } } catch (Exception ex) { this.SetError(ex.Message); return null; } return result; } The idea is that you can create custom host container implementations that do exactly what you want fairly easily. Take a look at both the RazorFolderHostContainer and RazorStringHostContainer classes for the basic concepts you can use to create custom implementations. Notice also that you can set the engine’s PerRequestConfigurationData() from the host container: // Set configuration data that is to be passed to the template (any object) Engine.TemplatePerRequestConfigurationData = new RazorFolderHostTemplateConfiguration() { TemplatePath = Path.Combine(this.TemplatePath, relativePath), TemplateRelativePath = relativePath, }; which when set to a non-null value is passed to the Template’s InitializeTemplate() method. This method receives an object parameter which you can cast as needed: public override void InitializeTemplate(object configurationData) { // Pick up configuration data and stuff into Request object RazorFolderHostTemplateConfiguration config = configurationData as RazorFolderHostTemplateConfiguration; this.Request.TemplatePath = config.TemplatePath; this.Request.TemplateRelativePath = config.TemplateRelativePath; } With this data you can then configure any custom properties or objects on your main template class. It’s an easy way to pass data from the HostContainer all the way down into the template. The type you use is of type object so you have to cast it yourself, and it must be serializable since it will likely run in a separate AppDomain. This might seem like an ugly way to pass data around – normally I’d use an event delegate to call back from the engine to the host, but since this is running over AppDomain boundaries events get really tricky and passing a template instance back up into the host over AppDomain boundaries doesn’t work due to serialization issues. So it’s easier to pass the data from the host down into the template using this rather clumsy approach of set and forward. It’s ugly, but it’s something that can be hidden in the host container implementation as I’ve done here. It’s also not something you have to do in every implementation so this is kind of an edge case, but I know I’ll need to pass a bunch of data in some of my applications and this will be the easiest way to do so. Summing Up Hosting the Razor runtime is something I got jazzed up about quite a bit because I have an immediate need for this type of templating/merging/scripting capability in an application I’m working on. I’ve also been using templating in many apps and it’s always been a pain to deal with. The Razor engine makes this whole experience a lot cleaner and more light weight and with these wrappers I can now plug .NET based templating into my code literally with a few lines of code. That’s something to cheer about… I hope some of you will find this useful as well… Resources The examples and code require that you download the Razor runtimes. Projects are for Visual Studio 2010 running on .NET 4.0 Platform Installer 3.0 (install WebMatrix or MVC 3 for Razor Runtimes) Latest Code in Subversion Repository Download Snapshot of the Code Documentation (CHM Help File) © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  .NET  

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  • Design by Contract with Microsoft .Net Code Contract

    - by Fredrik N
    I have done some talks on different events and summits about Defensive Programming and Design by Contract, last time was at Cornerstone’s Developer Summit 2010. Next time will be at SweNug (Sweden .Net User Group). I decided to write a blog post about of some stuffs I was talking about. Users are a terrible thing! Protect your self from them ”Human users have a gift for doing the worst possible thing at the worst possible time.” – Michael T. Nygard, Release It! The kind of users Michael T. Nygard are talking about is the users of a system. We also have users that uses our code, the users I’m going to focus on is the users of our code. Me and you and another developers. “Any fool can write code that a computer can understand. Good programmers write code that humans can understand.” – Martin Fowler Good programmers also writes code that humans know how to use, good programmers also make sure software behave in a predictable manner despise inputs or user actions. Design by Contract   Design by Contract (DbC) is a way for us to make a contract between us (the code writer) and the users of our code. It’s about “If you give me this, I promise to give you this”. It’s not about business validations, that is something completely different that should be part of the domain model. DbC is to make sure the users of our code uses it in a correct way, and that we can rely on the contract and write code in a way where we know that the users will follow the contract. It will make it much easier for us to write code with a contract specified. Something like the following code is something we may see often: public void DoSomething(Object value) { value.DoIKnowThatICanDoThis(); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Where “value” can be uses directly or passed to other methods and later be used. What some of us can easily forget here is that the “value” can be “null”. We will probably not passing a null value, but someone else that uses our code maybe will do it. I think most of you (including me) have passed “null” into a method because you don’t know if the argument need to be specified to a valid value etc. I bet most of you also have got the “Null reference exception”. Sometimes this “Null reference exception” can be hard and take time to fix, because we need to search among our code to see where the “null” value was passed in etc. Wouldn’t it be much better if we can as early as possible specify that the value can’t not be null, so the users of our code also know it when the users starts to use our code, and before run time execution of the code? This is where DbC comes into the picture. We can use DbC to specify what we need, and by doing so we can rely on the contract when we write our code. So the code above can actually use the DoIKnowThatICanDoThis() method on the value object without being worried that the “value” can be null. The contract between the users of the code and us writing the code, says that the “value” can’t be null.   Pre- and Postconditions   When working with DbC we are specifying pre- and postconditions.  Precondition is a condition that should be met before a query or command is executed. An example of a precondition is: “The Value argument of the method can’t be null”, and we make sure the “value” isn’t null before the method is called. Postcondition is a condition that should be met when a command or query is completed, a postcondition will make sure the result is correct. An example of a postconditon is “The method will return a list with at least 1 item”. Commands an Quires When using DbC, we need to know what a Command and a Query is, because some principles that can be good to follow are based on commands and queries. A Command is something that will not return anything, like the SQL’s CREATE, UPDATE and DELETE. There are two kinds of Commands when using DbC, the Creation commands (for example a Constructor), and Others. Others can for example be a Command to add a value to a list, remove or update a value etc. //Creation commands public Stack(int size) //Other commands public void Push(object value); public void Remove(); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   A Query, is something that will return something, for example an Attribute, Property or a Function, like the SQL’s SELECT.   There are two kinds of Queries, the Basic Queries  (Quires that aren’t based on another queries), and the Derived Queries, queries that is based on another queries. Here is an example of queries of a Stack: //Basic Queries public int Count; public object this[int index] { get; } //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } To understand about some principles that are good to follow when using DbC, we need to know about the Commands and different Queries. The 6 Principles When working with DbC, it’s advisable to follow some principles to make it easier to define and use contracts. The following DbC principles are: Separate commands and queries. Separate basic queries from derived queries. For each derived query, write a postcondition that specifies what result will be returned, in terms of one or more basic queries. For each command, write a postcondition that specifies the value of every basic query. For every query and command, decide on a suitable precondition. Write invariants to define unchanging properties of objects. Before I will write about each of them I want you to now that I’m going to use .Net 4.0 Code Contract. I will in the rest of the post uses a simple Stack (Yes I know, .Net already have a Stack class) to give you the basic understanding about using DbC. A Stack is a data structure where the first item in, will be the first item out. Here is a basic implementation of a Stack where not contract is specified yet: public class Stack { private object[] _array; //Basic Queries public uint Count; public object this[uint index] { get { return _array[index]; } set { _array[index] = value; } } //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } //Is related to Count and this[] Query public object Top() { return this[Count]; } //Creation commands public Stack(uint size) { Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { this[++Count] = value; } public void Remove() { this[Count] = null; Count--; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Note: The Stack is implemented in a way to demonstrate the use of Code Contract in a simple way, the implementation may not look like how you would implement it, so don’t think this is the perfect Stack implementation, only used for demonstration.   Before I will go deeper into the principles I will simply mention how we can use the .Net Code Contract. I mention before about pre- and postcondition, is about “Require” something and to “Ensure” something. When using Code Contract, we will use a static class called “Contract” and is located in he “System.Diagnostics.Contracts” namespace. The contract must be specified at the top or our member statement block. To specify a precondition with Code Contract we uses the Contract.Requires method, and to specify a postcondition, we uses the Contract.Ensure method. Here is an example where both a pre- and postcondition are used: public object Top() { Contract.Requires(Count > 0, "Stack is empty"); Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   The contract above requires that the Count is greater than 0, if not we can’t get the item at the Top of a Stack. We also Ensures that the results (By using the Contract.Result method, we can specify a postcondition that will check if the value returned from a method is correct) of the Top query is equal to this[Count].   1. Separate Commands and Queries   When working with DbC, it’s important to separate Command and Quires. A method should either be a command that performs an Action, or returning information to the caller, not both. By asking a question the answer shouldn’t be changed. The following is an example of a Command and a Query of a Stack: public void Push(object value) public object Top() .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   The Push is a command and will not return anything, just add a value to the Stack, the Top is a query to get the item at the top of the stack.   2. Separate basic queries from derived queries There are two different kinds of queries,  the basic queries that doesn’t rely on another queries, and derived queries that uses a basic query. The “Separate basic queries from derived queries” principle is about about that derived queries can be specified in terms of basic queries. So this principles is more about recognizing that a query is a derived query or a basic query. It will then make is much easier to follow the other principles. The following code shows a basic query and a derived query: //Basic Queries public uint Count; //Derived Queries //Is related to Count Query public bool IsEmpty() { return Count == 0; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   We can see that IsEmpty will use the Count query, and that makes the IsEmpty a Derived query.   3. For each derived query, write a postcondition that specifies what result will be returned, in terms of one or more basic queries.   When the derived query is recognize we can follow the 3ed principle. For each derived query, we can create a postcondition that specifies what result our derived query will return in terms of one or more basic queries. Remember that DbC is about contracts between the users of the code and us writing the code. So we can’t use demand that the users will pass in a valid value, we must also ensure that we will give the users what the users wants, when the user is following our contract. The IsEmpty query of the Stack will use a Count query and that will make the IsEmpty a Derived query, so we should now write a postcondition that specified what results will be returned, in terms of using a basic query and in this case the Count query, //Basic Queries public uint Count; //Derived Queries public bool IsEmpty() { Contract.Ensures(Contract.Result<bool>() == (Count == 0)); return Count == 0; } The Contract.Ensures is used to create a postcondition. The above code will make sure that the results of the IsEmpty (by using the Contract.Result to get the result of the IsEmpty method) is correct, that will say that the IsEmpty will be either true or false based on Count is equal to 0 or not. The postcondition are using a basic query, so the IsEmpty is now following the 3ed principle. We also have another Derived Query, the Top query, it will also need a postcondition and it uses all basic queries. The Result of the Top method must be the same value as the this[] query returns. //Basic Queries public uint Count; public object this[uint index] { get { return _array[index]; } set { _array[index] = value; } } //Derived Queries //Is related to Count and this[] Query public object Top() { Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   4. For each command, write a postcondition that specifies the value of every basic query.   For each command we will create a postconditon that specifies the value of basic queries. If we look at the Stack implementation we will have three Commands, one Creation command, the Constructor, and two others commands, Push and Remove. Those commands need a postcondition and they should include basic query to follow the 4th principle. //Creation commands public Stack(uint size) { Contract.Ensures(Count == 0); Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { Contract.Ensures(Count == Contract.OldValue<uint>(Count) + 1); Contract.Ensures(this[Count] == value); this[++Count] = value; } public void Remove() { Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   As you can see the Create command will Ensures that Count will be 0 when the Stack is created, when a Stack is created there shouldn’t be any items in the stack. The Push command will take a value and put it into the Stack, when an item is pushed into the Stack, the Count need to be increased to know the number of items added to the Stack, and we must also make sure the item is really added to the Stack. The postconditon of the Push method will make sure the that old value of the Count (by using the Contract.OldValue we can get the value a Query has before the method is called)  plus 1 will be equal to the Count query, this is the way we can ensure that the Push will increase the Count with one. We also make sure the this[] query will now contain the item we pushed into the Stack. The Remove method must make sure the Count is decreased by one when the top item is removed from the Stack. The Commands is now following the 4th principle, where each command now have a postcondition that used the value of basic queries. Note: The principle says every basic Query, the Remove only used one Query the Count, it’s because this command can’t use the this[] query because an item is removed, so the only way to make sure an item is removed is to just use the Count query, so the Remove will still follow the principle.   5. For every query and command, decide on a suitable precondition.   We have now focused only on postcondition, now time for some preconditons. The 5th principle is about deciding a suitable preconditon for every query and command. If we starts to look at one of our basic queries (will not go through all Queries and commands here, just some of them) the this[] query, we can’t pass an index that is lower then 1 (.Net arrays and list are zero based, but not the stack in this blog post ;)) and the index can’t be lesser than the number of items in the stack. So here we will need a preconditon. public object this[uint index] { get { Contract.Requires(index >= 1); Contract.Requires(index <= Count); return _array[index]; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Think about the Contract as an documentation about how to use the code in a correct way, so if the contract could be specified elsewhere (not part of the method body), we could simply write “return _array[index]” and there is no need to check if index is greater or lesser than Count, because that is specified in a “contract”. The implementation of Code Contract, requires that the contract is specified in the code. As a developer I would rather have this contract elsewhere (Like Spec#) or implemented in a way Eiffel uses it as part of the language. Now when we have looked at one Query, we can also look at one command, the Remove command (You can see the whole implementation of the Stack at the end of this blog post, where precondition is added to more queries and commands then what I’m going to show in this section). We can only Remove an item if the Count is greater than 0. So we can write a precondition that will require that Count must be greater than 0. public void Remove() { Contract.Requires(Count > 0); Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   6. Write invariants to define unchanging properties of objects.   The last principle is about making sure the object are feeling great! This is done by using invariants. When using Code Contract we can specify invariants by adding a method with the attribute ContractInvariantMethod, the method must be private or public and can only contains calls to Contract.Invariant. To make sure the Stack feels great, the Stack must have 0 or more items, the Count can’t never be a negative value to make sure each command and queries can be used of the Stack. Here is our invariant for the Stack object: [ContractInvariantMethod] private void ObjectInvariant() { Contract.Invariant(Count >= 0); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Note: The ObjectInvariant method will be called every time after a Query or Commands is called. Here is the full example using Code Contract:   public class Stack { private object[] _array; //Basic Queries public uint Count; public object this[uint index] { get { Contract.Requires(index >= 1); Contract.Requires(index <= Count); return _array[index]; } set { Contract.Requires(index >= 1); Contract.Requires(index <= Count); _array[index] = value; } } //Derived Queries //Is related to Count Query public bool IsEmpty() { Contract.Ensures(Contract.Result<bool>() == (Count == 0)); return Count == 0; } //Is related to Count and this[] Query public object Top() { Contract.Requires(Count > 0, "Stack is empty"); Contract.Ensures(Contract.Result<object>() == this[Count]); return this[Count]; } //Creation commands public Stack(uint size) { Contract.Requires(size > 0); Contract.Ensures(Count == 0); Count = 0; _array = new object[size]; } //Other commands public void Push(object value) { Contract.Requires(value != null); Contract.Ensures(Count == Contract.OldValue<uint>(Count) + 1); Contract.Ensures(this[Count] == value); this[++Count] = value; } public void Remove() { Contract.Requires(Count > 0); Contract.Ensures(Count == Contract.OldValue<uint>(Count) - 1); this[Count] = null; Count--; } [ContractInvariantMethod] private void ObjectInvariant() { Contract.Invariant(Count >= 0); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Summary By using Design By Contract we can make sure the users are using our code in a correct way, and we must also make sure the users will get the expected results when they uses our code. This can be done by specifying contracts. To make it easy to use Design By Contract, some principles may be good to follow like the separation of commands an queries. With .Net 4.0 we can use the Code Contract feature to specify contracts.

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  • How to create a simple adf dashboard application with EJB 3.0

    - by Rodrigues, Raphael
    In this month's Oracle Magazine, Frank Nimphius wrote a very good article about an Oracle ADF Faces dashboard application to support persistent user personalization. You can read this entire article clicking here. The idea in this article is to extend the dashboard application. My idea here is to create a similar dashboard application, but instead ADF BC model layer, I'm intending to use EJB3.0. There are just a one small trick here and I'll show you. I'm using the HR usual oracle schema. The steps are: 1. Create a ADF Fusion Application with EJB as a layer model 2. Generate the entities from table (I'm using Department and Employees only) 3. Create a new Session Bean. I called it: HRSessionEJB 4. Create a new method like that: public List getAllDepartmentsHavingEmployees(){ JpaEntityManager jpaEntityManager = (JpaEntityManager)em.getDelegate(); Query query = jpaEntityManager.createNamedQuery("Departments.allDepartmentsHavingEmployees"); JavaBeanResult.setQueryResultClass(query, AggregatedDepartment.class); return query.getResultList(); } 5. In the Departments entity, create a new native query annotation: @Entity @NamedQueries( { @NamedQuery(name = "Departments.findAll", query = "select o from Departments o") }) @NamedNativeQueries({ @NamedNativeQuery(name="Departments.allDepartmentsHavingEmployees", query = "select e.department_id, d.department_name , sum(e.salary), avg(e.salary) , max(e.salary), min(e.salary) from departments d , employees e where d.department_id = e.department_id group by e.department_id, d.department_name")}) public class Departments implements Serializable {...} 6. Create a new POJO called AggregatedDepartment: package oramag.sample.dashboard.model; import java.io.Serializable; import java.math.BigDecimal; public class AggregatedDepartment implements Serializable{ @SuppressWarnings("compatibility:5167698678781240729") private static final long serialVersionUID = 1L; private BigDecimal departmentId; private String departmentName; private BigDecimal sum; private BigDecimal avg; private BigDecimal max; private BigDecimal min; public AggregatedDepartment() { super(); } public AggregatedDepartment(BigDecimal departmentId, String departmentName, BigDecimal sum, BigDecimal avg, BigDecimal max, BigDecimal min) { super(); this.departmentId = departmentId; this.departmentName = departmentName; this.sum = sum; this.avg = avg; this.max = max; this.min = min; } public void setDepartmentId(BigDecimal departmentId) { this.departmentId = departmentId; } public BigDecimal getDepartmentId() { return departmentId; } public void setDepartmentName(String departmentName) { this.departmentName = departmentName; } public String getDepartmentName() { return departmentName; } public void setSum(BigDecimal sum) { this.sum = sum; } public BigDecimal getSum() { return sum; } public void setAvg(BigDecimal avg) { this.avg = avg; } public BigDecimal getAvg() { return avg; } public void setMax(BigDecimal max) { this.max = max; } public BigDecimal getMax() { return max; } public void setMin(BigDecimal min) { this.min = min; } public BigDecimal getMin() { return min; } } 7. Create the util java class called JavaBeanResult. The function of this class is to configure a native SQL query to return POJOs in a single line of code using the utility class. Credits: http://onpersistence.blogspot.com.br/2010/07/eclipselink-jpa-native-constructor.html package oramag.sample.dashboard.model.util; /******************************************************************************* * Copyright (c) 2010 Oracle. All rights reserved. * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 * which accompanies this distribution. * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html * and the Eclipse Distribution License is available at * http://www.eclipse.org/org/documents/edl-v10.php. * * @author shsmith ******************************************************************************/ import java.lang.reflect.Constructor; import java.lang.reflect.InvocationTargetException; import java.util.ArrayList; import java.util.List; import javax.persistence.Query; import org.eclipse.persistence.exceptions.ConversionException; import org.eclipse.persistence.internal.helper.ConversionManager; import org.eclipse.persistence.internal.sessions.AbstractRecord; import org.eclipse.persistence.internal.sessions.AbstractSession; import org.eclipse.persistence.jpa.JpaHelper; import org.eclipse.persistence.queries.DatabaseQuery; import org.eclipse.persistence.queries.QueryRedirector; import org.eclipse.persistence.sessions.Record; import org.eclipse.persistence.sessions.Session; /*** * This class is a simple query redirector that intercepts the result of a * native query and builds an instance of the specified JavaBean class from each * result row. The order of the selected columns musts match the JavaBean class * constructor arguments order. * * To configure a JavaBeanResult on a native SQL query use: * JavaBeanResult.setQueryResultClass(query, SomeBeanClass.class); * where query is either a JPA SQL Query or native EclipseLink DatabaseQuery. * * @author shsmith * */ public final class JavaBeanResult implements QueryRedirector { private static final long serialVersionUID = 3025874987115503731L; protected Class resultClass; public static void setQueryResultClass(Query query, Class resultClass) { JavaBeanResult javaBeanResult = new JavaBeanResult(resultClass); DatabaseQuery databaseQuery = JpaHelper.getDatabaseQuery(query); databaseQuery.setRedirector(javaBeanResult); } public static void setQueryResultClass(DatabaseQuery query, Class resultClass) { JavaBeanResult javaBeanResult = new JavaBeanResult(resultClass); query.setRedirector(javaBeanResult); } protected JavaBeanResult(Class resultClass) { this.resultClass = resultClass; } @SuppressWarnings("unchecked") public Object invokeQuery(DatabaseQuery query, Record arguments, Session session) { List results = new ArrayList(); try { Constructor[] constructors = resultClass.getDeclaredConstructors(); Constructor javaBeanClassConstructor = null; // (Constructor) resultClass.getDeclaredConstructors()[0]; Class[] constructorParameterTypes = null; // javaBeanClassConstructor.getParameterTypes(); List rows = (List) query.execute( (AbstractSession) session, (AbstractRecord) arguments); for (Object[] columns : rows) { boolean found = false; for (Constructor constructor : constructors) { javaBeanClassConstructor = constructor; constructorParameterTypes = javaBeanClassConstructor.getParameterTypes(); if (columns.length == constructorParameterTypes.length) { found = true; break; } // if (columns.length != constructorParameterTypes.length) { // throw new ColumnParameterNumberMismatchException( // resultClass); // } } if (!found) throw new ColumnParameterNumberMismatchException( resultClass); Object[] constructorArgs = new Object[constructorParameterTypes.length]; for (int j = 0; j < columns.length; j++) { Object columnValue = columns[j]; Class parameterType = constructorParameterTypes[j]; // convert the column value to the correct type--if possible constructorArgs[j] = ConversionManager.getDefaultManager() .convertObject(columnValue, parameterType); } results.add(javaBeanClassConstructor.newInstance(constructorArgs)); } } catch (ConversionException e) { throw new ColumnParameterMismatchException(e); } catch (IllegalArgumentException e) { throw new ColumnParameterMismatchException(e); } catch (InstantiationException e) { throw new ColumnParameterMismatchException(e); } catch (IllegalAccessException e) { throw new ColumnParameterMismatchException(e); } catch (InvocationTargetException e) { throw new ColumnParameterMismatchException(e); } return results; } public final class ColumnParameterMismatchException extends RuntimeException { private static final long serialVersionUID = 4752000720859502868L; public ColumnParameterMismatchException(Throwable t) { super( "Exception while processing query results-ensure column order matches constructor parameter order", t); } } public final class ColumnParameterNumberMismatchException extends RuntimeException { private static final long serialVersionUID = 1776794744797667755L; public ColumnParameterNumberMismatchException(Class clazz) { super( "Number of selected columns does not match number of constructor arguments for: " + clazz.getName()); } } } 8. Create the DataControl and a jsf or jspx page 9. Drag allDepartmentsHavingEmployees from DataControl and drop in your page 10. Choose Graph > Type: Bar (Normal) > any layout 11. In the wizard screen, Bars label, adds: sum, avg, max, min. In the X Axis label, adds: departmentName, and click in OK button 12. Run the page, the result is showed below: You can download the workspace here . It was using the latest jdeveloper version 11.1.2.2.

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  • How to revoke gnupg public key without private key?

    - by danijelc
    Long story short I have an key generated with seahorse and mistakenly deleted it from my system. I do remember passphrase but I don't have this key anywhere on my system. Scanned trough Ask Ubuntu but couldn't find any aplicabile solution on similar issue. However public key is still updated on keyring servers and I would like to revoke it. Since I have no revocation certificate and I can't get hold of private key (only public key is available from keyservers which I imported to seahorse) I have no idea how to accomplish it. Spent some time searching for solution acros net, various manuals and so on, but so far no luck. gpg --list-secret-keys - returns no output at all. gpg --list-keys - returns public key info gpg --gen-revoke *user-id* - returns - gpg: secret key *user-id* not found: eof gpg (GnuPG) version 1.4.11. Anyone able to suggest a solution?

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  • Where to store front-end data for "object calculator"

    - by Justin Grahn
    I recently have completed a language library that acts as a giant filter for food items, and flows a bit like this :Products -> Recipes -> MenuItems -> Meals and finally, upon submission, creates an Order. I have also completed a database structure that stores all the pertinent information to each class, and seems to fit my needs. The issue I'm having is linking the two. I imagined all of the information being local to each instance of the product, where there exists one backend user who edits and manipulates data, and multiple front end users who select their Meal(s) to create an Order. Ideally, all of the front end users would have all of this information stored locally within the library, and would update the library on startup from a database. How should I go about storing the data so that I can load it into the library every time the user opens the application? Do I package a database onboard and just load and populate every time? The only method I can currently conceive of doing this, even if I only have 500 possible Product objects, would require me to foreach the list for every Product that I need to match to a Recipe and so on and so forth every time I relaunch the program, which seems like a lot of wasteful loading. Here is a general flow of my architecture: Products: public class Product : IPortionable { public Product(string n, uint pNumber = 0) { name = n; productNumber = pNumber; } public string name { get; set; } public uint productNumber { get; set; } } Recipes: public Recipe(string n, decimal yieldAmt, Volume.Unit unit) { name = n; yield = new Volume(yieldAmt, unit); yield.ConvertUnit(); } /// <summary> /// Creates a new ingredient object /// </summary> /// <param name="n">Name</param> /// <param name="yieldAmt">Recipe Yield</param> /// <param name="unit">Unit of Yield</param> public Recipe(string n, decimal yieldAmt, Weight.Unit unit) { name = n; yield = new Weight(yieldAmt, unit); } public Recipe(Recipe r) { name = r.name; yield = r.yield; ingredients = r.ingredients; } public string name { get; set; } public IMeasure yield; public Dictionary<IPortionable, IMeasure> ingredients = new Dictionary<IPortionable,IMeasure>(); MenuItems: public abstract class MenuItem : IScalable { public static string title = null; public string name { get; set; } public decimal maxPortionSize { get; set; } public decimal minPortionSize { get; set; } public Dictionary<IPortionable, IMeasure> ingredients = new Dictionary<IPortionable, IMeasure>(); and Meal: public class Meal { public Meal(int guests) { guestCount = guests; } public int guestCount { get; private set; } //TODO: Make a new MainCourse class that holds pasta and Entree public Dictionary<string, int> counts = new Dictionary<string, int>(){ {MainCourse.title, 0}, {Side.title , 0}, {Appetizer.title, 0} }; public List<MenuItem> items = new List<MenuItem>(); The Database just stores and links each of these basic names and amounts together usings ID's (RecipeID, ProductID and MenuItemID)

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  • Problem with boundary collision

    - by James Century
    The problem: When the player hits the left boundary he stops (this is exactly what I want), when he hits the right boundary. He continues until his rectangle's left boundary meets with the right boundary. Outcome: https://www.youtube.com/watch?v=yuJfIWZ_LL0&feature=youtu.be My Code public class Player extends GameObject{ BufferedImageLoader loader; Texture tex = Game.getInstance(); BufferedImage image; Animation playerWalkLeft; private HealthBarManager healthBar; private String username; private int width; private ManaBarManager manaBar; public Player(float x, float y, ObjectID ID) { super(x, y, ID, null); loader = new BufferedImageLoader(); playerWalkLeft = new Animation(5,tex.player[10],tex.player[11],tex.player[12],tex.player[13],tex.player[14],tex.player[15],tex.player[17],tex.player[18]); } public void tick(LinkedList<GameObject> object) { setX(getX()+velX); setY(getY()+velY); playerWalkLeft.runAnimation(); } public void render(Graphics g) { g.setColor(Color.BLACK); FontMetrics fm = g.getFontMetrics(g.getFont()); if(username != null) width = fm.stringWidth(username); if(username != null){ g.drawString(username,(int) x-width/2+15,(int) y); } if(velX != 0){ playerWalkLeft.drawAnimation(g, (int)x, (int)y); }else{ g.drawImage(tex.player[16], (int)x, (int)y, null); } g.setColor(Color.PINK); g.drawRect((int)x,(int)y,33,48); g.drawRect(0,0,(int)Game.getWalkableBounds().getWidth(), (int)Game.getWalkableBounds().getHeight()); } @SuppressWarnings("unused") private Image getCurrentImage() { return image; } public float getX() { return x; } public float getY() { return y; } public void setX(float x) { Rectangle gameBoundry = Game.getWalkableBounds(); if(x >= gameBoundry.getMinX() && x <= gameBoundry.getMaxX()){ this.x = x; } } public void setY(float y) { //IGNORE THE SetY please. this.y = y; } public float getVelX() { return velX; } public void setHealthBar(HealthBarManager healthBar){ this.healthBar = healthBar; } public HealthBarManager getHealthBar(){ return healthBar; } public float getVelY() { return velY; } public void setVelX(float velX) { this.velX = velX; } public void setVelY(float velY) { this.velY = velY; } public ObjectID getID() { return ID; } public void setUsername(String playerName) { this.username = playerName; } public String getUsername(){ return this.username; } public void setManaBar(ManaBarManager manaBar) { this.manaBar = manaBar; } public ManaBarManager getManaBar(){ return manaBar; } public int getLevel(){ return 1; } public boolean isPlayerInsideBoundry(float x, float y){ Rectangle boundry = Game.getWalkableBounds(); if(boundry.contains(x,y)){ return true; } return false; } } What I've tried: - Using a method that checks if the game boundary contains player boundary rectangle. This gave me the same result as what the check statement in my setX did.

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  • Why do some open source projects do not allow to report issues in a public issue tracker?

    - by linquize
    Why do some open source projects do not allow to report issues in a public issue tracker? Those projects requires the issues to be reported via email, and the issues may be forwarded to people in mailing list. Users may repeatedly report the same issue if there is no public issue tracker, as they have no easy way to know what have been reported before. The project team members need to spend extra time answering those repeated issues. Some projects do have a public issue tracker, but the issues are still reported through email and they are posted only by the project team only after filtering. It does not allow anyone to report directly in issue tracker. (example: SVN) Such arrangement is not transparent nor open, which I think it violates the philosophy of open source. And it is outdated.

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  • How can I design my classes to include calendar events stored in a database?

    - by Gianluca78
    I'm developing a web calendar in php (using Symfony2) inspired by iCal for a project of mine. At this moment, I have two classes: a class "Calendar" and a class "CalendarCell". Here you are the two classes properties and method declarations. class Calendar { private $month; private $monthName; private $year; private $calendarCellList = array(); private $translator; public function __construct($month, $year, $translator) {} public function getCalendarCellList() {} public function getMonth() {} public function getMonthName() {} public function getNextMonth() {} public function getNextYear() {} public function getPreviousMonth() {} public function getPreviousYear() {} public function getYear() {} private function calculateDaysPreviousMonth() {} private function calculateNumericDayOfTheFirstDayOfTheWeek() {} private function isCurrentDay(\DateTime $dateTime) {} private function isDifferentMonth(\DateTime $dateTime) {} } class CalendarCell { private $day; private $month; private $dayNameAbbreviation; private $numericDayOfTheWeek; private $isCurrentDay; private $isDifferentMonth; private $translator; public function __construct(array $parameters) {} public function getDay() {} public function getMonth() {} public function getDayNameAbbreviation() {} public function isCurrentDay() {} public function isDifferentMonth() {} } Each calendar day can includes many calendar events (such as appointments or schedules) stored in a database. My question is: which is the best way to manage these calendar events in my classes? I think to add a eventList property in CalendarCell and populate it with an array of CalendarEvent objects fetched by the database. This kind of solution doesn't allow other coders to reuse the classes without db (because I should inject at least a repository services also) just to create and visualize a calendar... so maybe it could be better to extend CalendarCell (for instance in CalendarCellEvent) and add the database features? I feel like I'm missing some crucial design pattern! Any suggestion will be very appreciated!

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  • Why do some open-source projects NOT have a public issue tracker?

    - by linquize
    Why do some open source projects not allow to report issues in a public issue tracker? Those projects require the issues to be reported via email, and the issues may be forwarded to people in a mailing list. Users may repeatedly report the same issue if there is no public issue tracker, as they have no easy way to know what has been reported before. The project team members need to spend extra time answering those repeated issues. Some projects do have a public issue tracker but the issues are still reported through email and they are posted by the project team only after filtering. It does not allow anyone to report directly in issue tracker (example: SVN). Such arrangement is not transparent nor open, which I think violates the philosophy of open source. And it is outdated.

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  • How can I design my classes for a calendar based on database events?

    - by Gianluca78
    I'm developing a web calendar in php (using Symfony2) inspired by iCal for a project of mine. At this moment, I have two classes: a class "Calendar" and a class "CalendarCell". Here you are the two classes properties and method declarations. class Calendar { private $month; private $monthName; private $year; private $calendarCellList = array(); private $translator; public function __construct($month, $year, $translator) {} public function getCalendarCells() {} public function getMonth() {} public function getMonthName() {} public function getNextMonth() {} public function getNextYear() {} public function getPreviousMonth() {} public function getPreviousYear() {} public function getYear() {} private function calculateDaysPreviousMonth() {} private function calculateNumericDayOfTheFirstDayOfTheWeek() {} private function isCurrentDay(\DateTime $dateTime) {} private function isDifferentMonth(\DateTime $dateTime) {} } class CalendarCell { private $day; private $month; private $dayNameAbbreviation; private $numericDayOfTheWeek; private $isCurrentDay; private $isDifferentMonth; private $translator; public function __construct(array $parameters) {} public function getDay() {} public function getMonth() {} public function getDayNameAbbreviation() {} public function isCurrentDay() {} public function isDifferentMonth() {} } Each calendar day can includes many events stored in a database. My question is: which is the best way to manage these events in my classes? I think to add a eventList property in CalendarCell and populate it with an array of CalendarEvent objects fetched by the database. This kind of solution doesn't allow other coders to reuse the classes without db (because I should inject at least a repository services also) just to create and visualize a calendar... so maybe it could be better to extend CalendarCell (for instance in CalendarCellEvent) and add the database features? I feel like I'm missing some crucial design pattern! Any suggestion will be very appreciated!

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  • What are the pros and cons of public sector vs private sector software development? [closed]

    - by j.i.h.
    I'm currently considering a job working for my state of residence. However, besides the obvious drawback of far less compensation than I could get in the private sector, are there any other drawbacks? Are there any upsides to public work, besides helping society at large and benefits? My main concern is that if I work in the public sector, I might be stained with the perception that I "got along" in an uncompetitive environment. I have no idea if this would be the actual environment, but it seems to be the preconception about government work--unionized workers who are simply there because the union keeps them from being fired. So, does anyone have experience working for the government? Do you have experiences working with people transitioning from public to private sector?

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  • Sqlite returns error

    - by ruruma
    I'm trying to implement loading data from database and put it into different views. But log cat returns error, that it cannot find "_id" column. Can somebody help me with this? SqlHelper Code public class FiboSqlHelper extends SQLiteOpenHelper { public static final String TABLE_FILMDB = "FiboFilmTop250"; public static final String COLUMN_ID = "_id"; private static final String DATABASE_NAME = "FiboFilmDb250.sqlite"; private static final int DATABASE_VERSION = 1; public static final String COLUMN_TITLE = "Title"; public static final String COLUMN_RATING = "Rating"; public static final String COLUMN_GENRE = "Genre"; public static final String COLUMN_TIME = "Time"; public static final String COLUMN_PREMDATE = "PremDate"; public static final String COLUMN_PLOT = "Plot"; private static final String DATABASE_CREATE = "create table "+TABLE_FILMDB+"("+COLUMN_ID +" integer primary key autoincrement, " +COLUMN_TITLE+" text not null "+COLUMN_RATING+" text not null "+COLUMN_GENRE+" text not null "+COLUMN_TIME+" text not null "+COLUMN_PREMDATE+" text not null "+COLUMN_PLOT+" "+"text not null)"; public FiboSqlHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); // TODO Auto-generated constructor stub } @Override public void onCreate(SQLiteDatabase db) { // TODO Auto-generated method stub db.execSQL(DATABASE_CREATE); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // TODO Auto-generated method stub Log.w(FiboSqlHelper.class.getName(), "Upgrading database from version " + oldVersion + " to " + newVersion + ", which will destroy all old data"); db.execSQL("DROP TABLE IF EXISTS " + TABLE_FILMDB); onCreate(db); } }` SqlAdapterCode: public class FiboSqlAdapter { private SQLiteDatabase database; private FiboSqlHelper dbHelper; private String[] allColumns = {FiboSqlHelper.COLUMN_ID, FiboSqlHelper.COLUMN_TITLE, FiboSqlHelper.COLUMN_GENRE, FiboSqlHelper.COLUMN_PREMDATE, FiboSqlHelper.COLUMN_TIME, FiboSqlHelper.COLUMN_PLOT}; public FiboSqlAdapter (Context context){ dbHelper = new FiboSqlHelper(context); } public void open() throws SQLException { database = dbHelper.getWritableDatabase(); } public void close(){ dbHelper.close(); } public List<FilmDataEntity> getAllFilmData(){ List<FilmDataEntity> fDatas = new ArrayList<FilmDataEntity>(); Cursor cursor = database.query(FiboSqlHelper.TABLE_FILMDB, allColumns, null,null,null,null,null); cursor.moveToFirst(); while(!cursor.isAfterLast()){ FilmDataEntity fData = cursorToData(cursor); fDatas.add(fData); cursor.moveToNext(); } cursor.close(); return fDatas; } private FilmDataEntity cursorToData(Cursor cursor){ FilmDataEntity fData = new FilmDataEntity(); fData.setId(cursor.getLong(1)); fData.setTitle(cursor.getString(2)); fData.setRating(cursor.getString(6)); fData.setGenre(cursor.getString(4)); fData.setPremDate(cursor.getString(5)); fData.setShortcut(cursor.getString(8)); return fData; }} DataEntity: ` public class FilmDataEntity { private long id; private String title; private String rating; private String genre; private String premDate; private String shortcut; public String getShortcut() { return shortcut; } public void setShortcut(String shortcut) { this.shortcut = shortcut; } public String getGenre() { return genre; } public void setGenre(String genre) { this.genre = genre; } public String getPremDate() { return premDate; } public void setPremDate(String premDate) { this.premDate = premDate; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getRating() { return rating; } public void setRating(String rating) { this.rating = rating; } public long getId() { return id; } public void setId(long id) { this.id = id; } } Part from main activity: `List<FilmDataEntity> fE1; sqA = new FiboSqlAdapter(this); sqA.open(); fE1 = sqA.getAllFilmData(); `

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  • java: List wrapper where get()/set() is allowed but add/remove is not

    - by Jason S
    I need to wrap a List<T> with some class that allows calls to set/get but does not allow add/remove calls, so that the list remains "stuck" at a fixed length. I think I have a thin wrapper class (below) that will work, but I'm not 100% positive. Did I miss anything obvious? import java.util.Collection; import java.util.Iterator; import java.util.List; import java.util.ListIterator; class RestrictedListWrapper<T> implements List<T> { static <T> T fail() throws UnsupportedOperationException { throw new UnsupportedOperationException(); } static private class IteratorWrapper<T> implements ListIterator<T> { final private ListIterator<T> iter; private IteratorWrapper(ListIterator<T> iter) { this.iter = iter; } static public <T> RestrictedListWrapper.IteratorWrapper<T> wrap(ListIterator<T> target) { return new RestrictedListWrapper.IteratorWrapper<T>(target); } @Override public void add(T e) { fail(); } @Override public boolean hasNext() { return this.iter.hasNext(); } @Override public boolean hasPrevious() { return this.iter.hasPrevious(); } @Override public T next() { return this.iter.next(); } @Override public int nextIndex() { return this.iter.nextIndex(); } @Override public T previous() { return this.iter.previous(); } @Override public int previousIndex() { return this.iter.previousIndex(); } @Override public void remove() { fail(); } @Override public void set(T e) { this.iter.set(e); } } final private List<T> list; private RestrictedListWrapper(List<T> list) { this.list = list; } static public <T> RestrictedListWrapper<T> wrap(List<T> target) { return new RestrictedListWrapper<T>(target); } @Override public boolean add(T arg0) { return fail(); } @Override public void add(int index, T element) { fail(); } @Override public boolean addAll(Collection<? extends T> arg0) { return fail(); } @Override public boolean addAll(int arg0, Collection<? extends T> arg1) { return fail(); } /** * clear() allows setting all members of the list to null */ @Override public void clear() { ListIterator<T> it = this.list.listIterator(); while (it.hasNext()) { it.set(null); it.next(); } } @Override public boolean contains(Object o) { return this.list.contains(o); } @Override public boolean containsAll(Collection<?> c) { return this.list.containsAll(c); } @Override public T get(int index) { return this.list.get(index); } @Override public int indexOf(Object o) { return this.list.indexOf(o); } @Override public boolean isEmpty() { return false; } @Override public Iterator<T> iterator() { return listIterator(); } @Override public int lastIndexOf(Object o) { return this.list.lastIndexOf(o); } @Override public ListIterator<T> listIterator() { return IteratorWrapper.wrap(this.list.listIterator()); } @Override public ListIterator<T> listIterator(int index) { return IteratorWrapper.wrap(this.list.listIterator(index)); } @Override public boolean remove(Object o) { return fail(); } @Override public T remove(int index) { fail(); return fail(); } @Override public boolean removeAll(Collection<?> c) { return fail(); } @Override public boolean retainAll(Collection<?> c) { return fail(); } @Override public T set(int index, T element) { return this.list.set(index, element); } @Override public int size() { return this.list.size(); } @Override public List<T> subList(int fromIndex, int toIndex) { return new RestrictedListWrapper<T>(this.list.subList(fromIndex, toIndex)); } @Override public Object[] toArray() { return this.list.toArray(); } @Override public <T> T[] toArray(T[] a) { return this.list.toArray(a); } }

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  • mappedBy reference an unknown target entity property - hibernate error

    - by tommy
    first, my classes: User package com.patpuc.model; import java.util.List; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.Id; import javax.persistence.OneToMany; import javax.persistence.Table; import com.patpuc.model.RolesMap; @Entity @Table(name = "users") public class User { @Id @Column(name = "USER_ID", unique = true, nullable = false) private int user_id; @Column(name = "NAME", nullable = false) private String name; @Column(name = "SURNAME", unique = true, nullable = false) private String surname; @Column(name = "USERNAME_U", unique = true, nullable = false) private String username_u; // zamiast username @Column(name = "PASSWORD", unique = true, nullable = false) private String password; @Column(name = "USER_DESCRIPTION", nullable = false) private String userDescription; @Column(name = "AUTHORITY", nullable = false) private String authority = "ROLE_USER"; @Column(name = "ENABLED", nullable = false) private int enabled; @OneToMany(mappedBy = "rUser") private List<RolesMap> rolesMap; public List<RolesMap> getRolesMap() { return rolesMap; } public void setRolesMap(List<RolesMap> rolesMap) { this.rolesMap = rolesMap; } /** * @return the user_id */ public int getUser_id() { return user_id; } /** * @param user_id * the user_id to set */ public void setUser_id(int user_id) { this.user_id = user_id; } /** * @return the name */ public String getName() { return name; } /** * @param name * the name to set */ public void setName(String name) { this.name = name; } /** * @return the surname */ public String getSurname() { return surname; } /** * @param surname * the surname to set */ public void setSurname(String surname) { this.surname = surname; } /** * @return the username_u */ public String getUsername_u() { return username_u; } /** * @param username_u * the username_u to set */ public void setUsername_u(String username_u) { this.username_u = username_u; } /** * @return the password */ public String getPassword() { return password; } /** * @param password * the password to set */ public void setPassword(String password) { this.password = password; } /** * @return the userDescription */ public String getUserDescription() { return userDescription; } /** * @param userDescription * the userDescription to set */ public void setUserDescription(String userDescription) { this.userDescription = userDescription; } /** * @return the authority */ public String getAuthority() { return authority; } /** * @param authority * the authority to set */ public void setAuthority(String authority) { this.authority = authority; } /** * @return the enabled */ public int getEnabled() { return enabled; } /** * @param enabled * the enabled to set */ public void setEnabled(int enabled) { this.enabled = enabled; } @Override public String toString() { StringBuffer strBuff = new StringBuffer(); strBuff.append("id : ").append(getUser_id()); strBuff.append(", name : ").append(getName()); strBuff.append(", surname : ").append(getSurname()); return strBuff.toString(); } } RolesMap.java package com.patpuc.model; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.ManyToOne; import javax.persistence.Table; import com.patpuc.model.User; @Entity @Table(name = "roles_map") public class RolesMap { private int rm_id; private String username_a; private String username_l; //private String username_u; private String password; private int role_id; @ManyToOne @JoinColumn(name="username_u", nullable=false) private User rUser; public RolesMap(){ } /** * @return the user */ public User getUser() { return rUser; } /** * @param user the user to set */ public void setUser(User rUser) { this.rUser = rUser; } @Id @Column(name = "RM_ID", unique = true, nullable = false) public int getRmId() { return rm_id; } public void setRmId(int rm_id) { this.rm_id = rm_id; } @Column(name = "USERNAME_A", unique = true) public String getUsernameA() { return username_a; } public void setUsernameA(String username_a) { this.username_a = username_a; } @Column(name = "USERNAME_L", unique = true) public String getUsernameL() { return username_l; } public void setUsernameL(String username_l) { this.username_l = username_l; } @Column(name = "PASSWORD", unique = true, nullable = false) public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } @Column(name = "ROLE_ID", unique = true, nullable = false) public int getRoleId() { return role_id; } public void setRoleId(int role_id) { this.role_id = role_id; } } when i try run this on server i have exception like this: Error creating bean with name 'SessionFactory' defined in ServletContext resource [/WEB-INF/classes/baseBeans.xml]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: mappedBy reference an unknown target entity property: com.patpuc.model.RolesMap.users in com.patpuc.model.User.rolesMap But i don't exaclu know what i'm doing wrong. Can somebody help me fix this problem?

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  • Trying to draw 2 objects on screen and store the selected item names in an array

    - by thefonso
    Ok...this is a homework question, here is what i'm asked to do.... "Allow the user to draw two Shapes, which when instantiated, get put into the array myShapes...(store the shapes in the createShape() method." I want to know if I'm going in the right direction. Do I need to modify only Model.java or GUIDemo.java as well? Am I sufficient in thinking of only storing the values for the array via a loop inside my createShape() method? How do I go a bout checking to see if things work so far. There are many steps for this homework project after this one but i'm stuck here. Please point me in the right direction. The array myShapes lives inside my model class inside Model.java: package model; import java.awt.Color; import java.awt.Container; import shapes.Line; import shapes.Oval; import shapes.Rectangle; import shapes.Shape; import shapes.Triangle; import interfaces.Resettable; public class Model implements Resettable { private Container container; private String message; public final static String DRAW = "Draw"; public final static String MOVE = "Move"; public final static String REMOVE = "Remove"; public final static String RESIZE = "Resize"; public final static String FILL = "Fill"; public final static String CHANGE = "Change"; public final static String RECTANGLE = "Rectangle"; public final static String OVAL = "Oval"; public final static String LINE = "Line"; public final static String TRIANGLE = "Triangle"; private String action = DRAW; private boolean fill = false; public static String[] selections = {"Rectangle", "Oval", "Line", "Triangle"}; //project 9 begin public Shape[] myShapes = new Shape[2]; //project 9 stop private String currentShapeType; private Shape currentShape; public Color lineColor; private Color fillColor = Color.gray; public Shape createShape() { if(currentShapeType == RECTANGLE){ currentShape = new Rectangle(0, 0, 0, 0, lineColor, fillColor, fill); } if(currentShapeType == OVAL) { currentShape = new Oval(0,0,0,0, lineColor, fillColor, fill); } if(currentShapeType == LINE) { currentShape = new Line(0,0,0,0, lineColor, fillColor, fill); } if(currentShapeType == TRIANGLE) { currentShape = new Triangle(0,0,0,0, lineColor, fillColor, fill); } //project 9 start if(myShapes[0] == null) { myShapes[0]=currentShape; } else { myShapes[1]=currentShape; } //project 9 stop return currentShape; } public Shape getCurrentShape() { return currentShape; } public String getCurrentShapeType(){ return currentShapeType; } public void setCurrentShapeType(String shapeType){ currentShapeType = shapeType; } public Model(Container container) { this.container = container; } public void repaint() { container.repaint(); } public void resetComponents() { action = DRAW; currentShape = null; if (container instanceof Resettable) { ((Resettable) container).resetComponents(); } } public String getAction() { return action; } public void setAction(String action) { this.action = action; } public boolean isFill() { return fill; } public void setFill(boolean fill) { this.fill = fill; } public void setMessage(String msg) { this.message = msg; } public String getMessage() { return this.message; } public Color getLineColor() { return this.lineColor; } public void setLineColor(Color c) { this.lineColor = c; } public String toString() { return "Model:\n\tAction: " + action + "\n\tFill: " + fill; } } The application is run from GUIDemo.java: package ui.applet; import interfaces.Resettable; import java.applet.Applet; import java.awt.Graphics; import event.ShapeMouseHandler; import shapes.Shape; //import ui.panels.ButtonPanel; import ui.panels.ChoicePanel; import ui.panels.MainPanel; import model.Model; @SuppressWarnings("serial") public class GUIDemo extends Applet implements Resettable { MainPanel mainPanel; Model model; ChoicePanel choicePanel; public void init() { resize(600,400); model = new Model(this); choicePanel = new ChoicePanel(model); mainPanel = new MainPanel(model); this.add(choicePanel);//this is the drop down list this.add(mainPanel);//these are the radio buttons and reset button ShapeMouseHandler mouseHandler = new ShapeMouseHandler(model); addMouseListener(mouseHandler); addMouseMotionListener(mouseHandler); } public void paint(Graphics g) { Shape shape; shape = model.getCurrentShape(); if(shape != null) { shape.draw(g); } System.out.println(model); System.out.println(shape); } public void resetComponents() { mainPanel.resetComponents(); choicePanel.resetComponents(); } }

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  • How to define a collection in a POCO in Entity Framework 4?

    - by Stef
    Lets say I've a Team class which contains 0 or more Players. The Player class is easy: public class Player { public long Id { get; set; } public string Name { get; set; } public Team Team { get; set; } } But whats the best to define the Team class? Option 1 public class Team { public long Id { get; set; } public string Name { get; set; } public ICollection<Player> Players { get; set; } } Option 2: public class Team { public Team() { Players = new Collection<Player>(); } public long Id { get; set; } public string Name { get; set; } public ICollection<Player> Players { get; set; } } Option 3: public class Team { public long Id { get; set; } public string Name { get; set; } public IQueryable<Player> Players { get; set; } } Option 4: public class Team { public long Id { get; set; } public string Name { get; set; } public ObjectSet<Player> Players { get; set; } }

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  • Replacement for public folder workflow, I'm confused as to how sharepoint does it.

    - by RodH257
    For years Microsoft has been slowly phasing out public folders, perhaps exchange 2010 really is the LAST TIME they'll be shipped... I've heard sharepoint is the replacement, but I don't understand full, can someone give me an idea of how to replace this workflow? In our office, we have projects, they have a project number, ie 10353. Each job folder has a public folder, organized in a hierachy like Projects Year Folder Subfolders The main subfolder we use is for genera correspondence. When an email is received that relates to a project, it is dragged and dropped (or right click move to) a public folder. Adding public folder favourites for each user helps this. When an email is sent, we have a custom email form, which is the default email form, but with a project number field next to the subject line. When you enter the job number in there, it carbon copies our filing system in, which reads the job number and puts the email in the public folder for you. if you need to refer to emails, you go to public folder and find them there. This isn't the best with large jobs, but it works ok. Now, I have limited experience with sharepoint (well, WSS), we've used it to do some neat discussion boards/polls etc as an intranet site, but I haven't seen much of its integration with outlook. The great thing about our solution is how tightly it integrates with outlook which is exactly where the emails are. If you want to forward an old email, you go to public folder and forward it, simple. Any solution that replaces it should be at least as easy as this. Improvements we would like would be to have better searching of emails, better support in exchange (ie future version) and also, custom forms in outlook are being phased out (the VBA kind), so avoiding these would be good. Does sharepoint do this? or what solutions do this kind of thing?

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  • Returning different data types C#

    - by user1810659
    i have create a class library (DLL) with many different methods. and the return different types of data(string string[] double double[]). Therefore i have created one class i called CustomDataType for all the methods containing different data types so each method in the Library can return object of the custom class and this way be able to return multiple data types I have done it like this: public class CustomDataType { public double Value; public string Timestamp; public string Description; public string Unit; // special for GetparamterInfo public string OpcItemUrl; public string Source; public double Gain; public double Offset; public string ParameterName; public int ParameterID; public double[] arrayOfValue; public string[] arrayOfTimestamp; // public string[] arrayOfParameterName; public string[] arrayOfUnit; public string[] arrayOfDescription; public int[] arrayOfParameterID; public string[] arrayOfItemUrl; public string[] arrayOfSource; public string[] arrayOfModBusRegister; public string[] arrayOfGain; public string[] arrayOfOffset; } The Library contains methods like these: public CustomDataType GetDeviceParameters(string deviceName) { ...................... code getDeviceParametersObj.arrayOfParameterName; return getDeviceParametersObj; } public CustomDataType GetMaxMin(string parameterName, string period, string maxMin) { .....................................code getMaxMingObj.Value = (double)reader["MaxMinValue"]; getMaxMingObj.Timestamp = reader["MeasurementDateTime"].ToString(); getMaxMingObj.Unit = reader["Unit"].ToString(); getMaxMingObj.Description = reader["Description"].ToString(); return getMaxMingObj; } public CustomDataType GetSelectedMaxMinData(string[] parameterName, string period, string mode) {................................code selectedMaxMinObj.arrayOfValue = MaxMinvalueList.ToArray(); selectedMaxMinObj.arrayOfTimestamp = MaxMintimeStampList.ToArray(); selectedMaxMinObj.arrayOfDescription = MaxMindescriptionList.ToArray(); selectedMaxMinObj.arrayOfUnit = MaxMinunitList.ToArray(); return selectedMaxMinObj; } As illustrated thi different methods returns different data types,and it works fine for me but when i import the DLL and want to use the methods Visual studio shwos all the data types in the CustomDataType class as suggestion for all the methods even though the return different data.This is illusrtated in the picture below. As we can see from the picture with the suggestion of all the different return data the user can get confused and choose wrong return data for some of the methods. So my question is how can i improve this. so Visual studio suggest just the belonging return data type for each method.

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