Angular 5 - Complete guide to build SPA (Part 2)

Angular Architecture

One of the major design considerations in angular is to reduce the size of the final bundle, with this, some of the libraries that are required for angular app to work are provided through core libraries, and other optional libraries can be  imported as per needs.

Components are the basic building blocks of angular applications, this uses other dependencies like services, directives etc to perform its task.

Below architecture diagram can give a better idea on how each parts interact each other.

Modules

Angular Modules contains different parts of the application and are the way to group related component, services, directives and pipes to a single unit.

Component

Major development in angular is done using component. Each component is linked to view. It can be viewed as a reusable component as well.

Components are part of ngModules and each component can use other components as well. It can be viewed as a tree structure.

Template represents the html view and it communicates with the component through property and events.

Services are nothing but reusable functions that are separated from components but can be injected through dependency injection. This is very useful when you want to use same methods or properties in multiple places.

Routing

When it come to Single Page Application(SPA), we often hear angular associated with it. Angular is designed to mainly with the objective of SPA. Angular router framework evolved over the years and become a well matured framework to support all needs of SPA.

Routing works based on the URL structure. It allows us to define the routes and its corresponding components using a Route array.  When the URL matches the defined route, its component get loaded in to main template.

Angular 5 - Complete guide to build SPA (Part 1)

Angular 5 - Introduction

The purpose of this blog is to provide complete details about building an angular app using typescript and Angular CLI. 

Angular CLI is the new command line interface introduced with angular which helps the developer in the development process. It helps to create, build, run and test the required components through CLI commands.  

Why Angular 5?

Many developers who are familiar with previous version of angular like Angular JS, Angular 2/4 would certainly have doubts in their mind about this. Why angular 5?

To answer this, we need to compare each of these and what new changes have been introduced with  new version. There is a major difference in features with angular js and angular versions but angular 2,4 and 5 are almost same with some improvement iterations in the higher versions.

Angular JS vs Angular

Angular is a major update over angular js in terms of syntax as well as functionality.

1. JavaScript vs TypeScript   -  Angular is written using TypeScript which is the superset of  JavaScript. It takes the advantage that typescript is the only typed language that compiles into javascript. TypeScript makes code easier to read and understand.
2. Component based Architecture   - Angular application architecture helps to create components that don't depend on each other, which are loosely coupled as possible.
3. Mobile Oriented Architecture- Angular was designed keeping in mind about the present needs. It designed a framework that can support both mobile app development as wells as web apps. NativeScript helped in angular mobile development faster and effective.
4. View Engine -  The new view engine introduced helps in generating a smaller code using Ahead of Time (AOT) manner. 
5. Animation Package - Animation package was removed from the core package in angular. This was because most of the applications doesn't use animations, so this can be removed from core package which will help to reduce the size of the build. This was also done thinking about mobile application development.
6. Perfomance  - Angular applications are smaller and faster. It consumes less space and run faster which helps in increasing the overall performance of the application.

These differences listed above are with respect to angular js. There are not much difference in Angular 2 , 4 or 5. Its just the performance improvements or the minor functionality improvements. 

Why Angular 4 Not 3?

This would be a question in all developers mind why not 3 after angular 2.

Answer  is simple and it was nothing related to any functionalities introduced, but with the versioning of packages. 

Please refer below image:

When angular 2 was released, the version of angular/router package was already 3. This created some confusion in the developer mind regarding the versions. 

In order to make the versions of the packages same, version 3 was skipped and all the packages were versioned as 4 in the next major release. 

We will be discussing about angular architecture and development environment setup in next blog.

Performance Tuning Techniques for your web page

Some basic performance tuning techniques are shared below.

Minimize HTTP Requests:

Most of this time is tied up in downloading all the components in the page: images, style sheets, scripts, Flash, etc. Reducing the number of components in turn reduces the number of HTTP requests required to render the page. This is the key to faster pages.

To reduce the number HTTP requests, we can combine  the scripts into a single script page and refer that script in the page.

Loading the scripts in parallel:

          What we usually do is include script files as static links in head tag as shown below.

<head>

    <script type="text/javascript" src="Scripts/JQueryUI/jquery-1.9.1.js "></script>

    <script type="text/javascript" src="Scripts/JQueryUI/jquery-ui-1.10.1.js "></script>

</head>

What browsers usually do is download them serially one after the other. The browsers like IE or Firefox will wait for the first script to get downloaded before it starts downloading second one.

We can make them to download  in parallel by the below code.

<script type="text/javascript">

        document.writeln("<script src='Scripts/JQueryUI/jquery-1.9.1.js ?version=1.0

 ' type='text/javascript'><" +

                         "/script>");

        document.writeln("<script src='Scripts/JQueryUI/jquery-ui-1.10.1.js ?version=1.0

 ' type='text/javascript'><" +

                         "/script>");

</script>

Avoiding the Cache Problem:

          What most of the browsers do is that for the first time they download scripts to webpage but after that they take the script from the browser cache.so sometimes even if we make changes in the script and the style sheet ,that is not getting downloaded and changes are not reflecting.

                We can force the browser to download the latest version of script and style sheet by versioning them.

<script type="text/javascript">

        document.writeln("<script src='Scripts/JQueryUI/jquery-1.9.1.js ?version=1.0

 ' type='text/javascript'><" +

                         "/script>");

        document.writeln("<script src='Scripts/JQueryUI/jquery-ui-1.10.1.js ?version=1.0

 ' type='text/javascript'><" +

                         "/script>");

</script>

<link href="Styles/includes.css?version=1.0" rel="stylesheet" type="text/css" />

We have to increment the version number if we make changes to that script or style sheet.

<script type="text/javascript">

        document.writeln("<script src='Scripts/JQueryUI/jquery-1.9.1.js ?version=1.1

 ' type='text/javascript'><" +

                         "/script>");

        document.writeln("<script src='Scripts/JQueryUI/jquery-ui-1.10.1.js ?version=1.1

 ' type='text/javascript'><" +

                         "/script>");

</script>

<link href="Styles/includes.css?version=1.1" rel="stylesheet" type="text/css" />

Bundling and Minification:

                Bundling and Minification is the new feature included ASP.NET 4.5 to improve request load time.

To use Bundling and Minifcation, we have to add reference to System.Web.Optimization dll.

public class BundleConfig

    {

        // For more information on Bundling, visit http://go.microsoft.com/fwlink/?LinkId=254725

        public static void RegisterBundles(BundleCollection bundles)

        {

            bundles.Add(new ScriptBundle("~/bundles/jquery").Include(

                        "~/Scripts/jquery-{version}.js"));

           

            bundles.Add(new ScriptBundle("~/bundles/jquery").Include(

                        "~/Scripts/jquery-1.7.min.js"));

            bundles.Add(new ScriptBundle("~/bundles/jqueryui").Include(

                        "~/Scripts/jquery-ui-{version}.js"));

            bundles.Add(new ScriptBundle("~/bundles/jqueryval").Include(

                        "~/Scripts/jquery.unobtrusive*",

                        "~/Scripts/jquery.validate*"));

}

}

The bundled scripts can be rendered by the following code in html page.

  @System.Web.Optimization.Scripts.Render("~/bundles/modernizr")  

   

  @System.Web.Optimization.Scripts.Render("~/bundles/jquery")

SQL Server Parameter Sniffing:

                Parameter sniffing allows you to reduce the time taken to execute the stored procedure considerably.

This permits individual plans recompilation instead of compiling entire execution plan for single store procedure. You could find below some workaround when you are affecting by a performance issue.

       
                Using dummy variables that are not directly displayed on parameters also ensure execution plan stability without need to add recompile hint.

create procedure SearchProducts

    @Keyword varchar(100)

As

Declare @Keyworddummy as varchar(100)

Set @Keyworddummy = @Keyword

select ProductID,ProductName  from Products where Keyword like @Keyworddummy

end

                Here  the parameter @Keyword is assigned to @ Keyworddummy is which is used inside the stored procedure. Like this you can do for all the parameters that are used inside the stored procedure.

Always use the column name in the select list. Avoid using * in select.

This helps you to reduce the execution time considerably and get results faster.

Object Oriented JavaScript

   Some basic concepts in Object oriented JavaScript’s are discussed below

  <input type="button" id="btnCheck" onclick="GetData();" />

We have a button that calls a client side function GetData() on its click.

<script language="javascript" type="text/javascript">

    function GetData() {

        testBL.getTestData();

//calling function in testBLL.js

//with object testBL and function getTestData()

    }

    

   

    </script>

Now we will have to create testBLL.js

In this we can create the methods and expose those methods

Code in testBLL.js:

var testBL = new function () {

    ObjectOreientedScripttest = function () {

//you can write your function code here

    },

getTestDataByDate = function () {

   

//you can write your function code here

}

    return {

        testForObjectOreientedScript:ObjectOreientedScripttest ,

        getTestData: getTestDataByDate
    }

} ();

This return statement is mandatory to expose those methods.

For eg:

Inside the return statement we have the below statements

 getTestData: getTestDataByDate

 

getTestDataByDate  is the function we have created in the testBLL.js and second one getTestData is the name that we get when we are calling the method.

 I.e.    testBL.getTestData();

testBL is the variable name that we used for testBLL.js functions(refer first line testBLL.js)

Passing Table-valued Parameter to Stored procedure

Table-Valued Parameters:

                Table valued parameter provide the developer an easy way to work with Multiple rows and data. Table-Valued parameters were introduced in Sql Server 2008

Syntax:

create type TypeName AS TABLE(

column1 type,

column2 type...

)

Eg: create type EmployeeDetails AS TABLE(

RowID int,

EmployeeName varchar(25),

EmployeeTitle varchar(30),

EmployeeAge int

)

In the above eg,

We are creating a table valued type for EmployeeDetails,this table valued type replicate the same of a Sql Table.

Manipulation on Table Valued Type:

     Table valued parameters are same as Sql Table.

You can insert into table valued Type as same like how you insert value to a table.

Declare @EmployeeDt as EmployeeDetails

insert into @EmployeeDt values(1,'George','Manager',24)

insert into @EmployeeDt values(2,'Rahul','Tester',38)

You can select the entire data from that table-valued type by

a single select statement.

select * from @EmployeeDt

Passing Table-Valued type to StoredProcedure:

create procedure SaveEmployeeDetails

@EmployeeDt as EmployeeDetails Readonly

AS

Begin

--selecting from table valued parameter and inserting into table --in a single strech

insert into Tbl_Employee(ID,EmployeeName ,EmployeeTitle,EmployeeAge)

select  RowID,EmployeeName ,EmployeeTitle,EmployeeAge

from @EmployeeDt

End

C# Code:

SqlDatabase sqlConn;

DbCommand dbcmd;

SqlConn = new SqlDatabase ("your Connection string here");

dbcmd = sqlConn.GetStoredProcCommand(SaveEmployeeDetails);

dbcmd.CommandType = CommandType.StoredProcedure;

sqlConn.AddInParameter(dbcmd, "@EmployeeDt", SqlDbType.Structured, dt);

              

 sqlConn.ExecuteNonQuery (dbcmd);