What is the Grails Framework?

Grails Framework is one of the latest and more advanced frameworks used extensively in JAVA to build huge web-based enterprise applications. The framework is both lightweight and open source to easily approachable to users developing all kinds of applications. This framework can be thought of as a plugin to applications being coded in JAVA as the language in this framework is Apache Groovy. Currently, the internal system that is in place is Gant but there are significant plans to move to Gradle. When you download the Grails Framework, you will also find numerous pre-defined plugins that can also be extended onto the framework when developing apps.

Grails is very popular among novice and intermediate users as the language construct is extremely user-friendly and it allows for application development without any configuration. Therefore, users who do not have any experience in web development can also successfully build high-performance projects. One of the most liked features about this framework is its ability to support applications and services right from development until production.

Salient Features of Grails

• As the framework is extremely well structured and Groovy is comparatively easier to code in as compared to JAVA, developers can achieve the same result with fewer lines of code as opposed to using any other JAVA framework. Applications created using Grail, therefore, require minimal maintenance.
• Grails Scaffolding is a very important envelope that covers applications using this framework. Not only does it help in creating the ‘wow’ effect but also allows developers to build CRUD (Create, Read, Update, and Delete) features.
• The Grails framework is preferred more than other conventional frameworks because it is easily compatible with most upcoming technologies. A major part of this development is the 700 plugins that the framework provides. The more the plugins, the easier it becomes for developers to code.
• Grails has been successful as a company is building a good rapport with customers. At the end of the day, customer satisfaction matters the most in a user-dominated industry. The extremely supportive team of Grails helps users of all competencies every step of the way.

Grails Architecture (MVC – Driven)

The Spring Framework (which is also MVC driven) works as the underlying structure for Grails. It is from there that Grails derives its MVC design pattern. The Grails Architecture can be broken down into three significant blocks. They are the Controller, the Domain, and the Grails Servlet Page.

• Controller – When a request is made, it passed down from the Client Web browser onto the Controller. It passed three components in between namely the Spring Dispatcher Servlet, Grails Dispatcher Servlet, and the Simple Dispatcher Controller.
• Domain – Acts as the model that is responsible for storing data that will be used both by the Controller as well as the View.
• Groovy Server Pages – GSP acts as the View of the MVC design pattern where it prepares a final presentation that will act as a response against the query. It will be passed up to the Client Web browser where it will be displayed.

Advantages of Grails Framework

• The framework is extremely robust and very easy to understand because of detailed documentation.
• A lot of plugins make the life of developers easy. The number of CSS plugins is quite low so you do not have to stress about managing CSS.
• The setup process in Grails is quite easy and some smaller applications can be developed under an hour!

Example

As we are dealing with the basics of Grails here, this example is a very example of Grail in use. Through this application, you will be able to store or get names from the database.

//We will start by making the controller class
package test
class Controller {
def index(){}
def save() {
def user = new User (params)
user.save()
render (view: “user”, model:[user: user])
}
}
//Let us design the model class
package test
class ModelTest{
String firstName
String lastName
}
// We will finally create the view class that will bring out the final representation of the name requested.
<!DOCTYPE html>
<html>
<head>
<title> Sample Program </title>
</head>
<body>
<g:form name = “form” controller = “user” id = “form”>
<div class = “text-field”><label>First Name : </label><g:textField name = “firstName” value = “${firstName}”/></div>
<div class = “text-field”><label>Last Name : </label><g:textField name = “lastName” value = “${lastName}”/></div>
<div class = “submit”><g:actionSubmit value = “Submit” action = “save”/></div>
</g:form>
</body>
</html>