JSF Datepicker Example

Date: 2017-06-02

Creating a Date Picker in JSF with Bootstrap: A Step-by-Step Guide

This article explains how to implement a date picker component within a JavaServer Faces (JSF) application, leveraging the visual appeal and responsiveness of the Bootstrap CSS framework. A date picker enhances user experience by providing a calendar-based interface for selecting dates, eliminating manual date entry errors and improving the overall look of the application. This guide details the process, from setting up the development environment to deploying the application on a server.

Understanding the Date Picker Utility

At its core, a date picker simplifies date selection. Instead of typing a date, users interact with a visual calendar, selecting the desired day, month, and year. This visual approach minimizes input errors, as the calendar clearly displays the day of the week associated with each date. Furthermore, date pickers add a touch of interactivity, making the form more engaging and user-friendly. Libraries like jQuery UI provide pre-built date picker functionalities, offering features such as customizable date formats, the ability to restrict selectable date ranges, and the inclusion of buttons and navigational options for easy calendar manipulation. These libraries typically offer a function, often called datepicker(), to transform an HTML element (like an input field, div, or span) into a fully functional date picker. The function allows for considerable customization through options that control its behavior and appearance.

Setting up the Development Environment

Before building the JSF application, the necessary prerequisites must be installed. This includes a suitable Java Development Kit (JDK), an Integrated Development Environment (IDE) like Eclipse, a JSF implementation (like Mojarra), and the necessary libraries for Bootstrap and jQuery UI. The process involves creating a Dynamic Web Project within the chosen IDE, configuring the project to include JSF capabilities, and adding the required libraries for Bootstrap and jQuery UI. This often includes specifying these libraries in the project's build configuration or by manually adding the relevant JAR files to the project's classpath. The web.xml file, a crucial part of the web application deployment descriptor, needs to be configured to correctly handle JSF requests. This configuration typically involves specifying mappings for the JSF servlet and associated contexts. The exact steps for setting up the environment will vary slightly based on the IDE and specific versions of the software being used.

Building the Application: Creating the User Interface

The application consists of two main parts: an input page (typically an XHTML file) containing a registration form, and an output page displaying the submitted information. The input page uses JSF components to create the form. Crucially, it integrates the date picker functionality, which typically involves adding a script that initializes the date picker upon page load. This initialization often involves calling the datepicker() function from the jQuery UI library, targeting the relevant input field in the form. This script is often included using a <script> tag within the XHTML file itself or, for better organization and maintainability, by referencing an external JavaScript file using tags such as h:outputScript. The script ensures the date picker is properly attached to the date input field.

The input.xhtml file contains the form's visual elements, including input fields for first name, last name, and date of birth. The date of birth field is specifically designed to work with the date picker. A submit button triggers an action that processes the form data. The output.xhtml file displays the submitted data in a user-friendly format, often using JSF's expression language (#{}) to access and display the data stored in a managed bean. This managed bean handles the data submitted from the input form.

Creating the Managed Bean and Processing the Form

Behind the scenes, a managed bean manages the data entered in the form. This Java class serves as a model for the data, holding properties corresponding to the form fields (first name, last name, and date of birth). A method in the managed bean is responsible for handling the form submission, usually triggered by a button click. This method is invoked based on the JSF navigation logic (as defined in the input.xhtml file) upon form submission. The method receives the submitted values, performs any necessary validation, and might store the data.

Deployment and Testing

Once the application is developed, it must be deployed on a servlet container, such as Tomcat. This involves deploying the compiled application to the server, usually through the IDE or by manually copying the necessary files to the server's webapps directory. After successful deployment, the application can be accessed through a web browser by navigating to its URL. The URL will generally include the server address, port, and application context path. Testing the application involves submitting data through the form and verifying that the date picker functions correctly and the submitted data is displayed accurately on the output page.

Conclusion

This detailed explanation showcases how to integrate a date picker into a JSF application using Bootstrap, thereby enhancing the user interface and minimizing potential errors. The process involves careful setup of the development environment, structuring the user interface components, implementing the necessary Java code for data handling, and deploying the application to a server. This method provides a practical approach to building dynamic and user-friendly web applications using JSF. The key to success lies in understanding the interplay between the front-end interface (XHTML and JavaScript), the data handling logic (managed bean), and the server-side deployment and execution.

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