For this assignment you need to design and implement a social networking component that allows users to comment and denote when they have visited your web site. Such functionality is fundamental to ma

For this assignment you need to design and implement a social networking component that allows users to comment and denote when they have visited your web site. Such functionality is fundamental to many social networking sites such as Facebook. As a component of a social networking site, there is potential to incorporate this into many social sites while adding to it to create an extensive feature set. You will develop two versions of this component, one that uses a text file (for the first submission point), and one that uses a database table (for the final submission point). Both versions will be submitted as part of your final submission. Design Requirements Create an application that allows users to comment on a static posting that you provide. In one version, the user’s name, contact information (e-mail address), and comment will be saved to a single text file. In the other version, the same information will be saved to a database table. Include functionality that allows anyone to view who has visited the site and left comments. While the comments will automatically be displayed by date (as this is how they are saved to the text file and database table), allow the viewer to sort comments in ascending and descending order (by name) to more easily find a comment. Do not allow users to comment more than once to the posting. In doing so, prevent duplicates from being saved to the text file and/or database table. You will want to plan how to save data to the text file and database table for easy retrieval. To get started, create an XHTML document that will serve as a main page where you can enter your information and comments. This page should also provide the ability to get to the other existing comments on the posting. Upon providing a comment, you should acknowledge the addition of the entry by showing what values were added. You should also allow a different user to add an entry. 

If the user has already commented on the posting, you should let them know that you don’t allow more than one comment by the same user.

When the user views the comments on the posting, they should have the ability to sort the results in either ascending or descending order. For the text file version, this should be done using an indexed array that re-indexes depending on the sort order chosen. For the database version, you should use SQL to do the sorting. No matter where someone is in your web site, you should always provide a way to return to the main page where a new user could add a comment to the posting. In addition, you should allow a user to specify the index number of any user’s comment information they wish to delete. This functionality should be implemented in both text file and database versions. While this feature would traditionally require administrator authentication, you can keep it simple and allow any user to delete any existing entry. Upon deleting an entry, you should re-output the posting comment page showing the remaining entries renumbered. Notice that on all applicable pages while the email address does not show, the name is hypertext linked to their email address using a XHTML mailto: link. As shown in the comments page example, selecting the user name hyperlink should provide an email link to the email address of commenter. Constants should be used for values that do not change, and variables for values that change during the course of execution. You should include Last Modified Date information on your pages. This should be provided dynamically by using the built-in date()function within the getlastmod()function.