Today I struggle with the same problem all day. I am still starting ASP MVC coming from the Flex world. But now I am working on some ASP MVC project.
I think this is a rather complicated problem, so I describe the problem in great detail. So thanks in advance for saying the time to go through this!
System Description:
I am trying to create a "ProjectManagementSystem". You can have several projects where each project has a name and description. The project also has a list of additional information. A normal form would allow me to enter a name and description for a new project, right?
Now the requirement is to add additional form elements. For example, I want to add a new input that will allow me to enter an affordable budget for all existing and new projects.
Budget - additional detail of the project. IE when element a is added from the budget, a new project detail is added for all projects.
Classes:
I got the Project class, which has a ProjectDetails list, and also provides some interface for getting, adding and removing ProjectDetail from Project:
public class Project : ProjectItem { public virtual IList<ProjectDetail> Details { get; set; } public Project(string name, string description) : base(name, description) { Details = new List<ProjectDetail>(); } public Project() : this("new project", "this is a new project") { } public virtual void AddDetail(string name) { var detail = GetDetail(name); if (detail == null) { detail = new ProjectDetail(name, "empty"); detail.Project = this; Details.Add(detail); } } public virtual void RemoveDetail(string name) { var detail = GetDetail(name); if (detail != null) { detail.Project = null; Details.Remove(detail); } } public virtual ProjectDetail GetDetail(string name) { ProjectDetail result = null; foreach (ProjectDetail detail in Details) { if (detail.Name.Equals(name)) { result = detail; } } return result; } }
The "ProjectDetail" class is as follows:
public class ProjectDetail : ProjectItemDetail { [NotNull] public virtual Project Project { get; set; } public ProjectDetail(string name, string value) : base(name, value) { } public ProjectDetail() : this("new project detail", "empty") { } }
Note that "ProjectDetail" inherits the name and value from the ProjectItem base class.
I am trying to create a view that allows me to edit one Value for all ProjectDetails in the details list of a specific Project. Now each "ProjectDetail" is associated with a "FormElement", and they correspond to the Name property.
public class FormElement { public static string TYPE_UNKNOWN = "typeUnknown"; public static string TYPE_NUMERIC = "typeNumeric"; public static string TYPE_CHAR = "typeChar"; public static string TYPE_DATE = "typeDate"; [NotNull] public virtual string Name { get; set; } [NotNull] public virtual int Position { get; set; } [NotNull] public virtual string Type { get; set; } [NotNull] public virtual Form Form { get; set; } public FormElement(string name, int position, string type) { Name = name; Position = position; Type = type; } public FormElement() : this("unknownFormElement", -1, TYPE_UNKNOWN) { } }
And the class "Form":
public class Form : Entity { [NotNull] public virtual string Name { get; set; } public virtual IList<FormElement> FormElements { get; set; } public Form(string name) { Name = name; FormElements = new List<FormElement>(); } public Form() : this("unknownWebform") { }
Thus, the view will have to display the “Form” and populate the elements with the value of the associated “ProjectDetail”.
So, the view is passed to "ProjectEditModel":
public class ProjectEditModel { public Form Form; public Project Project; public ProjectViewModel() {} }
In the "ProjectEditModel" the following view is strictly indicated:
<% using (Html.BeginForm("Edit", "Project", FormMethod.Post)) {%> <div> <fieldset> <legend>Edit Project</legend> <div class="editor-label"> <%: Html.LabelFor(m => m.Project.Name) %> </div> <div class="editor-field"> <%: Html.TextBoxFor(m => m.Project.Name)%> </div> <div class="editor-label"> <%: Html.LabelFor(m => m.Project.Description)%> </div> <div class="editor-field"> <%: Html.TextBoxFor(m => m.Project.Description)%> </div> <% foreach (var formElement in Model.Form.FormElements) { if (formElement.Type.Equals(Domain.Model.FormElement.TYPE_CHAR)) { %> <div class="editor-label"> <%: Html.Label(Model.Project.GetDetail(formElement.Name).Name)%> </div> <div class="editor-field"> <%: Html.TextBoxFor(m => m.Project.GetDetail(formElement.Name).Value)%> </div> <% } if (formElement.Type.Equals(Domain.Model.FormElement.TYPE_NUMERIC)) { } } %> <p> <input type="hidden" name="Id" value="<%: Model.Project.Id %>" /> <input type="submit" value="Save" /> </p> </fieldset> </div> <% } %>
This will display correctly and show the form element for each additional part. But when I return the POST model, the constructor will be called, and thus I will lose all my links. PENG!
I read that MVC "just works" like this, and I am ready to accept it, but how can I solve my problem? Do you need more information?
Thank you, I would love the help!