Architecture :: Getting All NewsCategories And Related NewsItems True The NewsCategorie Class?
Apr 19, 2010
I've been working my way true the OOP design patterns or Models in VB.NET with some simple databinding etc.
There is one thing that's not very clear to me, let me explain.
How would one merge objects or class objects to have a "one to many" or "many to many" relationship or other more complex databinding?
For example, lets say I have a class NEWS, in this class i have some properties like NewsID, NewTitle, NewMessage, ... and some functions like Function GetAllNews() As List(Of News). Now I have a Class NEWSCATEGORIES, with again some properties like NewsCatID, NewsCatTitle, .... and also a function GetNewsCategories() As List(Of NewsCategories).
How would I get All NewsCategories and related NewsItems true the NewsCategorie Class like for example GetNewsCategoriesJoinArticles() as List(Of ????). I know I can do this with a datareader and then in my webforms loop the datareader, but could this also be done in a typesafe manner?
The user can write articles and upload images related to that article. Let's say that there is a form that collect the article text and, under it, there is a FileUpload control for images. Here, I have a question. What if the user has uploaded some images and then he closed the browser, before submitting, cancelling the operation? the images have been uploaded to the server wasting space!
one solution I've figured out is to store "ImageInfo"s in a list, and store the list in the Session object. And when the user submit the article, the images in the list should be marked as "related" and then inserted. and in the Session_End event I should delete every image does not have the "related" mark.
how do you treat situations where there is the need of storing collections of object belonging to an object not persisted on db (not yet). For example , suppose we have a web application for submitting orders. The user click on 'Create new order" , then insert order's data , choose items from a catalog and add them to the order. Finally he "submit" the order. I can see two different way to persiste data :
a) create on db an empty order instance when user click on "create new order" , so that the orderitems collection could be directly associated (saved) with that instance in the db.
b) keep all data in memory and finally save order and orderitem.
The b option imply storing (in session?) the orderitems collection till submit. Are there, probably, other solutions. Which are best practices in these situation?
I am using ASP.NET (C# and sql server express 2005) for my web application project. I have three related tables. I want to do an insert using typed datasets,tableadapters and three tier architecture. I wish to know how to do simultaneous inserts in 3 tables. So i wish to insert a row in first table and get its primary key. Same with the second table. I will use the primary keys of those first two tables to do the insert in the third table. How can i accomplish this using formview control and what methods should i use??
I have a block of SQL statements that I like to use as a sort of function.
I was thinking that I could make a class and inherit all of the master function, then add the parts that I need for other sections of the program in a sub class.
The problem is, up to this point I've been programming ASP .Net through visual studio, and it's kind of just programming behind controls. I'm not sure where to put the class/function/method/interface, or whatever we call it.
Of course you probably know that visual studio creates a bunch of partial classes when you do an ASP. Net application... so.. to get access to a function like object, across classes.. use an Interface?
Task is to develop class libraries that can be re-use in projects but assambies should be copy righted. By this I mean developer will not give the code of class libraries to the clients yet they will provide the code of there sites/ applications, these libraries will be used just as internal development libraries. I want to make Business Logic Layer, DAL, Business Objects as class libraries
Q1. How I can control unathorised use of libraries ?
In a project im working on there are many sql tables containing different ID, Name pairs. Those are represented as Enums in classes that need them however that requires casting since tables contain ID only.Also when serialize the Enum contains the ID not value.
I know what Singleton Pattern means and Abstract class means.What I wanted to know was how would this apply to real world.Could anyone give me any good example or simple explanation.Say I have a simple website, why would I use any of the above if any.Why would it simplify my architechture.
I'm refactoring an old website that has product search code littered throught the codebehind. I'm trying to encapsulate the search logic into its own class so I've created a Product class with a Search() method. I would like some suggestions about OO best practices so that the class is reusable and maintainable. The questions I have are:
- Should I make the search() method an instance method or make it static? For now the class is just really there to encapsulate my search logic
- If I make it an instance method should it return a list of products or should it populate a member property that I can access like p.Search(); var x = p.ProductList;
- The search method requires upward of 7 parameters of different types, what's the best way to provide them? - pass them all i.e. p.Search (param1, param2, ..., param7) - create a SearchParams structure in the class, populate it and pass that i.e. p.Search(searchParams) - Instantiate a Product object and set properties on it that are used by the Search method i.e. p.ID = 123; etc.... p.Search();
I've used variations of the above before but would like to know what's the best way.
I have a single project. and I have two folder in it. In the 1st folder I have a class named Class1 and in the 2nd folder I have a class named Class2. Can anyone tell me how I can access members of Class1 in Class2. I have tried by adding namespace in Class1 and Using that namespace in Class2. But it is giving error. It is easy to access classes or their members from App_Code folder. I don't want to put my classes in app_code folder.
I want to undertand and change an existing website which was written long time back. It cntains a lot of code and I dont know where to start as there is no dicumentation.Is there any way by which i can create a class diagram and sequence diagram of the existing one as I want to incorporate all the existing functionalities in the new one and dont miss out anyone. Only way I know is to debug the current application and go through whole of the code individually. Is there any way out by which I can undertand the current application quickly?
what is considered a many-to-many relationship in a domain model class ? I mean how to implement a many-to-many relationship in a domain model class ? In SQL this is represented by a link table between two table but how this is represented in a domain model driven application ?
I need to make a webservice in .net (I know how this works) but then I need to get data out of a database. But my company wants to make it in a way that you can use the system with multiple databases.
So my option was make multiple abstract classes which contains the folowing code (depending on the database type, this would be a SQL database)
In page behind classes I am using a private and shared object (list<client> or just client) to temporary hold data coming from database or class library. This object is used temporarily to catch data and than to return, pass to some function or binding acontrol. 1st: Can this approach harm any way ? I couldnt analyse it but a thought was using such shared variables may replace data in it ?2nd: Please comment also on using such variables in BLL (to hold data coming from database) where new object of BLL class will be made everytime.
I am beginner in asp.net / vb.net and I developed a web application for inventory management. here I have my insertion procedure that I entered in my code behind all the different page of my application. My problem is the following:
* I would like to put my procedure in a class that I will call on my different page * how to create this class * how to call this class on my pages
here is my procedure:
Private Sub reqinsertion (ByVal sreq As String) Dim con As New System.Data.Odbc.OdbcConnection ("Dsn = dshealthboard") Sun ocommand As System.Data.Odbc.OdbcCommand con.Open () ocommand = New System.Data.Odbc.OdbcCommand (sreq, con) ocommand.ExecuteNonQuery () con.Close () End Sub
It took me a little while to figure this out, but the AllowPaging="true" on the FormView seems to be the culprit. I don't have much experience paging from a FormView, but for this requirement the customers wants this kind of UI.I have a FormView with DefaultMode="Edit", which is bound to an EntityDataSource. One of the entity's properties, "ExternalID", determines whether some of the other properties in the entity are read-only. For example, if IsExternal==null, the FirstName, LastName, and Email fields should be rendered as TextBoxes. If IsExternal!=null, the 3 properties should be rendered in Label controls.
I have an application that allows admins to add types such as document types and training types that are in seperate tables with a foreign key in a transaction table.
When structuring my class I decided to go with an abstract-like pattern (without the factory methods though). So I have a Type abstract class that defines my Save, Delete, and GetList methods. I have a training type class that inherits this class. The thing is all types have 3 main properties - defined in the abstract base - but have different source tables and thus different store procedures in my DbCommand object. So basically I repeat setting up the same parameters on all the derived classes. I would like to implement the common stuff in the base but I am getting thrown off by the difference in data sources.
