Dynamic Data in Asp.net

8/3/2019 Dynamic Data in Asp.net

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Dynamic Data

in .NET 4.0

I n f i n i t e C o m p u t i n g S y s t e m s

C e d a r R a p i d s , M u m b a i , B a n g k o k

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Kunal Uppal

Document explains the features of Dynamic Data and their

use in a web application. This includes the scenarios in

which an architect or an application designer should choose

to use Dynamic Data features.


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INTRODUCTION

Almost all web application that we create has always needed some kind of an interface to

manage the data in the underlying table. Even to manage the basic CRUD (Create, Read ,

Update and Delete) operations on a table, it still takes some amount of doing for developers

to create data access classes, validations, data bound controls such as Gridview with sorting

and paging, form or list views. Entire development of a single screen for a table takes hours

of development causing estimates to bloat up which in turns gets passed to your clients,

who is already reeling under the high cost of maintenance.

In our recent project, we had some 7 screens to create for the application administrators to

perform add/edit/delete operation on the master data. Something which looked very obvious

was actually not less than 120 hour of development and testing.

Now with Dynamic Data in .NET 4.0, managing this is very easy. Precisely, ASP.NET

dynamic data provides a framework which enables quick building of functional data driven

application that are based on Microsoft ORM i.e. LINQ TOSQL or Entity framework data

model. It has added smart validation and ability to change the display with templates to

DetailsView, FormView, GridView, and ListView controls. As per Microsoft, the dynamic

data framework enables major usability and RAD development changes to work with data

model. The LINQTOSQL or EF can be registered with dynamic data to result into a fully

functional web site. Even though the entire code is generated for you but its purely

customizable and even third party controls like Telerik and Devexpress are giving support

to dynamic data in their data bound controls.

It supports all CRUD operations. We will explore dynamic data website with .NET

framework 4.0.


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Scenarios

Use of Dynamic Data in web application is specific and is not meant for all the scenarios of

application design. In cases, when you dont have direct access to the database or dontwant yourself to open your database directly to have unrestricted access of your schema,

you would find Dynamic data of less use.

Dynamic data has lot of use in a small scale application or a part in big application where

you need to build admin specific functionality to add, edit or delete records from a table.

This is still some saving in a small to medium size application where the entire admin

section can easily take 10-15% of your overall development cost.

Below are the scenarios in which you can leverage the power of Dynamic Data.

Looking for CRUD operations on a table

If you are looking for a standard implementation of providing Create/Update/Delete

operations on your tables, you will find Dynamic data as a great time savior that too with a

very stable implementation. With Standard UI screens, validation messages and consistent

layout of controls, it becomes easy to develop and test the basic scenarios. In our recent

sample version, we were able to create 7-8 screens in less than 5 minutes.

Rapid Application Development in a data driven web application

Time is a big factor and cost depends on it. If all you need is to give a feature in your

application that will enable the users to perform CRUD operations and abstracting the

relational constraints on the underlying table

If you need to create something much customized for your clients then you will find lot of

pain in customizing the dynamic data implementation although the entire source code is

generated is open for use. It still involves some amount of learning curve when you need big

changes in the dynamic data source code.

Use Microsoft built in framework to build User Interface and data

validation

Dynamic data works on templates, Microsoft has provided default templates which can be

changed as well. If you want a feature rich UI including form views, grid views or list to


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perform CRUD operations, Dynamic data gives you a ready-made implementation and

makes it very easy for developers to implement them in quicktime. Through Data

Annotations on your entity you can easily build validations over your entities. It will pick

up things like required fields, data types and maximum lengths. You can also manually

assign validation rules to your classes using metadata and validation attributes.

Separation of concerns along with Rapid Development Methodology

Dynamic data provide a separation of concerns between business logic and web forms.

Database-tier objects are used to describe the attributes of a column, such as validation

rules and column name. The web form no longer needs to determine the right data entry

control or validators. Instead, smart web controls gather and format those controls for you.


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Features

Dynamic data Framework inludes the following features.

1. DataModelling2. Scaffolding

3. Templating

4. Customization

Data Modelling:

It is a method used to define and analyze data requirements needed to support the business

porcess of an organization. The data requirements are recorded as a conceptual data model

with associated data definitions.

Dynamic Data supports the LINQ-to-SQL data model and the ADO.NET Entity Framework

data model. You can include multiple instances of data models in a Web application, but the

models that are used in Dynamic Data must be of the same type.

Scaffolding:

Scaffolding is a mechanism that enhances the existing ASP.NET page framework by

dynamically displaying pages based on the data model. Scaffolding provides the following

capabilities:

1.) Minimal or no code to create a data-driven Web application.2.) Quick development time.

3.) Built-in data validation based on the database schema.

4.) Automatic data selection created for each foreign key or Boolean field .

Templating:

Dynamic data uses templates to provide the Default view of the dataContext with the

Scaffolding.

1. Page templates are ASP.NET Web pages that are configured to display data from anytable that is available to Dynamic Data.

2. Dynamic Data uses field templates to render the UI for displaying and editing individual

data fields. It determines the appropriate field template from the data field types.

The DetailsView and GridView controls have been extended to display fields by using

templates instead of by using hard-coded rules that are programmed in the controls.


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Customization:

We can customize the templates to change their appearance or to specify which controls

they use for rendering. This makes it very easy to make a change in one place in your site

that specifies how to present dates for editing, as one example. FormView and ListView

controls can implement similar behavior by using a DynamicControl object in their

templates and by specifying which field in the row to display. Dynamic Data will then

automatically build the UI for these controls based on the templates that you specify.

Validation is significantly improved in the controls as well. For example, if a column in the

database is limited to 50 characters, and if a column is marked as not nullable, a

RequiredFieldValidator control is automatically enabled for the column.


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Sample Application using Dynamic DataEnvironment : .NET 4.0, Visual Studio 2010

Database : Sample Adventure Works DB

Step 1Create a web application using a template ASP.Net Dynamic Data Entities Web Application. You can

also choose LINQToSQL but if you are looking for POCO templating and other specific features of Entity

Framework such as lazy loading then it is always better to consider it over LINQ to SQL.


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Step 2Add an ADO.NET Entity Data Model into the project.

Step 3

If you are taking a top down approach of building entities then choose Empty model but as we are going

to use AdventureWorks database, choose option Generate from Database for generating the data

model from database.


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Step 4:

Choose the database and database connection.


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Step 5

Select the database objects like Tables, views to be included in the model.

Step 6:

Register your model in Global.asax. This is where you set the scaffolding as well. Usually set it to false

and mention it only for the tables you want to make it enabled. To enable scaffolding individually, you

have to mention that at class level.


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Step 7:

Make sure that model namespace is referred in the connection string of web.config file.

Run the application and you will find name of all tables for which scaffolding was set to true.


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Screen 1

This is the default page loaded into the browser when one runs the application. This lists all the tables in

the data model.

Screen 2:

This is the List page loadedinto the browser when one clicks the table in the default page and show

the records in the selected table with options for performing CRUD operations.


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Conclusion

ASP.NET Dynamic Data can be used for lookup and Master table maintenance, but that is not the only

use of it. We can use dynamic data for prototyping the applications, rapid development of web sites.

Although dynamic data is fully customizable but it is to be carefully evaluated during design whether it

will be worth customizing it or not.

The great advantage of this framework is that it makes it super easy for us to build those really simple

UIs that we always need for managing administrative data, etc. Framework has a lot of promise for mid-

level apps too. It provides a really nice layer of abstraction for pushing data in and out of a UI. With a

little work, the templates could be customized as well.

Documents

Dynamic Data in Asp.net