Custom Web Scrapping

Custom software Development of the Screen-scrapping applications

In the today’s connected world, the World Wide Web (WWW) is a mimic of the old mainframe scenario. Scenario is that the powerful machines are web-servers and application servers serving the dumb and thin browser based clients.

This has rejuvenated the old legacy system’s screen scrapping solution a new dimension of the web-pages screen scrapping. But for currently working systems that are currently performing the critical business tasks, it is difficult and expensive to re-engineer or rewrite the code. The new open architecture software that are now being developed using web-services with SOA will be having the information exchange infrastructure ready, but prevailing current circumstances, screen scrapping becomes the most viable option for business to develop the reliable workable solution.

Screen scraping is an enticing prospect for the businesses that wish to gather or processes some data of their application but wish to bypass the difficulty of replicating exiting other system’s reliability and scalability.

e-Zest has extensively worked on web-screen scrapping projects, where other application’s published information, change of information, after-login navigation with session management, and secure connection with SSL certificates are managed.

e-Zest has developed the reusable framework and a suit of utility tools that helps any future screen scrapping application development a viable option meeting following challenges:

Performance
The complete and correct data representation of each target screen must flow to the screen-scraping application before it is to be processed. This involves a wait-time for each call client to the host and back again, As these performance issues became more and more apparent, screen scraping becomes sluggish, the application needs to be developed with such constraints. The application developed at e-Zest makes it easier to address such session-time out, no response, delay in response of target application related performance specific issues.

Synchronization
Synchronization is maintaining the correct sequence of navigation and links for the target application. When the screen scrapping application sends a CGI command of login, it must wait for the session, this session might be maintained at server in a specific type, After login and confirming it to be successful, then only the next set of action or navigation should proceed. At any point the screen scrapping application must know how to re-request correctly on the response provided by the target web-server . The target web-server behaves independently and is unaware of the client application. It may get disconnected, receive an unexpected error message, or follow a path that the screen scrapper application might not expect. Any of these conditions can cause the screen scrapping application and target server applications to get out of sync and produce an error condition. Error exception handling is to be addressed only on the screen scrapper application side and is usually the most time intensive part of a screen-scraping development project. Proper synchronization handling makes the screen scrapping application the reliable application.

Change control
One more critical factor of the screen scraping application depends on the way it handles the target application’s changes. Because the code controlling the interaction between the screen scrapper application and target web application is embedded in the screen scrapper application, and as such do not have the any control on the target web-application, changes at the target server will cause the screen scrapper application to fail. Generally that means our client application might be required to rewrite and redeploy, but with e-Zest’s framework and its pattern-matching and ready made, pre-built regular-expression libraries developed, it is faster and efficient to re-align the screen scrapper application to work properly overcoming the changes made in the remote server.