Get Many Property Values From View To Presenter In WebFormsMvp?
Jun 11, 2010
What is the best way to get a number of property values of a business object from the View to the Presenter in a WebFormsMvp page?
Bearing in mind this issue with DataSources: [URL]
Here is what i propose:
The scenario is, I have a business object called Quote which i would like to load form the database, edit and then save. The Quote class has heaps of properties on it. The form is concerned with about 20 of these properties. I have existing methods to load/save a Quote object to/from the database. I now need to wire this all together.
So, in the View_Load handler on my presenter i intend to do something like this:
I have a ASP.NET Web Forms application and I'm using some dynamic controls in the view which depend on stuff that the presenter exposes. Is it okay for the view in this case to pull on the presenter for that data? Is there anything I should be extra careful about when considering testability and a loosely coupled design.
The page in this case has it's own page-life cycle and the presenter doesn't know about this. However, the page-life cycle dictates that somethings must occur at specific moments in the page-life cycle. This smells like trouble... Any known pit falls?
EDIT
When my concrete view hits the Init event it will pull on the presenter for a collection that will result in a bunch of ASP.NET server controls to be created. I'm wondering if this is a particular bad thing to do... The presenter doesn't know how to respond to the page-life cycle init event but it has to if the view is to be populated with dynamic controls.
I am using mvp pattern in small project. I have problems with view which contains html table with data(always 9 rows). How can i easily get data from html table and send it to the presenter? On the model side i want to keep data from html table as a generic List<some_type>
In Model-View-Presenter what is the correct pattern to do a page that: a) contains a grid for browsing a list of items
b) an alternate mode for editing single items .maybe you are toggling between two asp:panels.
Do you just make the presenter smart enough to do two types of presentations? Make 2 presenters?
I'm new to this pattern and want to do it correctly. I understand how I would do this functionality on two pages. Just not sure what is the accepted practice when the browse and detail exist on the same page.
I'm using Model-View-Presenter framework. When Loading a page, I'm having trouble setting the selected item that came from the Database.
In view, I know I need:
protected void ddlStatus_SelectedIndexChanged(object sender, EventArgs e) { presenter.DdlStatusSelectedIndexChanged(); // what should this pass? } Then in Presenter: public void DdlStatusSelectedIndexChanged() { view.DdlStatus = ??? // Should I pass the SelectedIndex? }
I also think that part of my problem is that DdlStatus I have as a List.
Interface:
List<StatusDTO> DdlStatus { set; get; }
The best I found is here (but needs formatted!) ---> [URL]
Currently we are using WebFormsMVP to allow better testability in our project. The framework does presenter binding in OnInitComplete and relies heavily on DataBind expressions e.g.
As i understand above article this would put Model.FirstName into ViewState. Because databinding happens late during page lifecycle when viewstate tracking is already enabled.
One option would be to disable ViewState altogether. Are there any other? Remeber, we can't use OnInit or OnInitComplete, because OnLoad is the first event presenters can handle.
I have a partial view that is rendered on a view. That partial view has textboxes in it. The user can enter values into them.
I need to put all the values from the textboxes in my partial view into an array, and then give the view (the parent page rendering that partial view) access to that array.
I recently read Phil Haack's post where he gives an example of implementing Model View Presenter for ASP.NET. One of the code snippets shows how the code for the view class.
public partial class _Default : System.Web.UI.Page, IPostEditView { PostEditController controller; public _Default() { this.controller = new PostEditController(this, new BlogDataService()); } }
However, here the view constructs the instance of the BlogDataService and passes it along to the presenter. Ideally the view should not know about BlogDataService or any of the presenter's lower layer dependencies. But i also prefer to keep the BlogDataService as a constructor injected dependency of the presenter as it makes the dependencies of the presenter explicit.
This same question has been asked on stackoverflow here.
One of the answers suggests using a service locator to get the instance of the BlogDataService and passing it along to the presenter's constructor.This solution however does not solve the problem of the view knowing about the BlogDataService and needing to explicitly get a reference to it.
Is there a way to automatically construct the presenter object using an IoC or DI container tool such that the view does not have to deal with explicitly creating the BlogDataService object and also injecting the view and service instances into the presenter's constructor. I prefer to use the constructor injection pattern as far as possible.
Or is there a better design available to solve the problem?. Can there be a better way to implement this If i am building a WinForms application instead of a ASP.NET WebForms application?
I have a custom control that inherits from .NET's CompositeControl class. This control overrides the CreateChildControls in order to build its child controls dynamically. I need the page to post back after a couple different javascript events occur on the client side.
In order to accomplish this, I create two hidden controls on the page so I can set their values with javascript, submit the page, and read the values out on server side. Here's is the code I use to create these two hiddens:
As what other member said in this community, the data assign a public variable may be shared among users, therefore, how am be able to declare a property that will accept an array of values using List<string>? The variable will be use in about fifteen pages...if I am going to declare this on each of the page, this will result to difficulty in maintaining the code of my program.
I have a very simple user control with 5 radio buttons on it, and 3 properties (ID, RatingSetID, and Rating). On the initial load of the page they are on, the code acquires data and places the data into the 3 properties. However, when the submit button is clicked the page reloads and the 3 properties get reset to 0, they are in the !IsPostBack as well.
this is about ASP.NET, ViewState, UserControls and loosing the values of my properties. It is an classic question by know, I know, and even though I have searched here and on Google for a resolution to this problem, I havent succeeded. On the contrary, the more I test different things, the less I understand it seems.
On top of this I am using ext.net and their so called DirectMethod's but I dont think that has much to do with this problem. There are numerous questions I have and I hope that this text will be fairly readable and understandable =)
The UserControl
I have a UserControl, Customers.ascx, that contains some Properties. The "most" important is *_CustomerId*. The _CustomerId is set in code-behind, in ext.net's "DirectMethod" like this (code below from the Page Customers.aspx):
I have a ASPxGridView. In it(for the uninformed) is only a DataSource property for telling it what data to load. My problem is that I'm simply trying to mock up an example and don't need to tie it to an actual database. How would I do this? I basically just want a few rows and some columns but since it only takes a datasource I'm not sure how to do it. Would ObjectDataSource be what I'm looking for?
I am working on a page whereby all the controls within the page get translated to another language.
This is handled within the master page prerender event and generally works fine.
However my page consists of a multiview control that is made up of 2 views. By default the INSERT formview is displayed so the user can enter form detials. This translates fine.
On clicking the save button the multiview active index is set to 1 and the EDIT formview displayed so as the user can update any of their details. This view does not get translated.
It would seem this is due to the controls not being available at this point in the page cycle or when this button event fires.
So i opted to do the translate process within the prerender event of the EDIT formview, and the method does have access to all the controls within this formview and runs after the master page prerender event. So all should be good.
However it seems that all th epage properties at this point in time are cleared. So the translation doesnt work. At the point of master page prerender i have verified they are populated with the values, but as soon as i hit the formview prerender all the page properties get cleared to nothing...
The following action in my controller does not update the Model property which is bound by a radio buttons group (all are named "ListType") when the form is submitted. On the Edit.ASPX form, I used JQuery to reset the radio buttons group. When setting other type of input elements on the form to blank or checked=false, those Model properties are set accordingly upon submission. Does anyone know how to set radio buttons to unched state?
Also I am trying to get the SqlException to show up in my form where I have Html.ValidationSummary helper. My ModelState helper captures the know business rules violations, but I am unable to pass any SqlException and its Message property to this helper class due to unexected exception.
1: I have a .html file that has some markup with some placeholder tags.
[code]...
4: PersonInfo.aspx is literally empty since I am injecting html from code-behind.
When the PersonInfo.aspx is called the html-template markup with appropriate values in the placeholder will be displayed. Also there are chances I would like to send the final markup in an html email (though that is not part of the question as I know how to email).
Is this the best way to fill values in my html-template or is the any other better alternative?
Note: This is a very simple sample example. My class is very complex involving objects as properties and also my html template have 40-50 placeholders.
So code in my step 3 will need 40-50 Replace statements.
