app-sample

Build

Prerequisites:

• JDK 7 must be installed

• ant must be installed

    cd app-sample
    ant clean
    ant assemble
  

This builds the following WARs located jre-1.7/app-sample/deployment-unit/:

• opentdc-app-sample.war: sample app which demonstrates basic principals of how opentdc apps are built.

Deploy

Copy the opentdc-app-sample.war manually to the webapps directory of Tomcat and launch the app with the URL http://localhost:8080/opentdc-app-sample/.

Architecture

The following figure gives an overview of the architecture of the sample app:

Service

• The service implements the API of the app as REST/JSON service. It offers all methods required by the Javascript GUI (in this case ./index.html).
• The service is implemented as a Java servlet, namely as JSP (./Api.jsp). The JSP approach allows on-the-fly compiling and allows ultra-fast and flexible development roundtrips.

The service implementation Api.jsp has the following layout:

Api.jsp:

   <%@page contentType="text/html;charset=UTF-8" language="java" pageEncoding="UTF-8" %>
   <%!

      // ContactModel bean
      public static class ContactModel {
         ...
      }
		
      public static ContactModel getContact(request, path) {
         // delegate to backend
      }
		
      public static ContactModel createContact(request, path) {
         // delegate to backend
      }
		
      public static ContactModel updateContact(request, path) {
         // delegate to backend
      }
		
      public static List<ContactModel> findContacts(request, path, query) {
         // delegate to backend
      }

   %>
   <%
   	* dispatch request and invoke methods
   	* return result as JSON response 
   %>

GUI

The GUI is a standard webapp. It communicates with the service over REST/JSON.

Below is the screenshot of the sample app which allows to get, update and create contacts using the APIs provider/{pid}/segment/{sid}/contact/{cid} and provider/{pid}/segment/{sid}/contact.

Backend

• The backend can be any database or application service (ERP, CRM, CM, DM, etc.). The service-tier delegates to the backend in order to store and retrieve data and execute business-logic.
• The project app-generic offers a very simple file-based StoreManager which allows to store objects as JSON-formatted files. This allows to quickly build prototypes and proof-of-concepts.

WebApp Layout

The file layout of the webapp looks as follows:

	opentdc-app-sample
	   + WEB-INF
	     + web.xml
	   + index.html
	   + Api.jsp
	   + js
	   	+ bootstrap
	   	+ jquery

Of course, instead of bootstrap any other webapp framework can be used (Polymer, AngularJ, ...).