Conception and Development of a Dynamic Web Site: Dedicated to a University Library

The world wide web is a group of web pages related between them with hypertext links. That forms a huge and complex web mail. A single click allow us to surf from document to another. From each document we can refer to different types of information: text, sound, video. In most cases, first sites were static, their principal aim were suggesting products and services. In the opposite, the web pages feed actually more opportunities to make dynamic contacts with users, with allowing data exchanges : from and to both sides (server and client).To establish this practices, distinct environment and tools were developed such as: Script languages, Database servers, ...etc. A Part of this paper study a practical case, which is: Dynamic conception of university library site, with explaining different tools and environment incorporate


INTRODUCTION
The systems of classic information [1] limited themselves to local necessities of companies: effective access to data, competes of access, security and distribution on a network. At present new necessities appeared. Companies or any automated organization wish to exchange its information and its services with the external environment (an unity untied from the same company, another company, a customer,) what gave birth to the notion of systems of information opened [1]. The evolution of the data processing in material software and material and the appearance of new technologies such as Internet [2] answer pertinently these necessities. What stood out with more this last decade in the field of the systems of information, it is well this new tool of communication: Internet. This last one allows the users to send electronic messages worldwide complete, to exchange economic data, multimedia data (sounds, images,) and to surf on World Wide Web [2]. World Wide Web is a set of web sites connected among them by hypertext links forming an enormous cobweb. A simple click of mouse allows us to surf of a document Web in the other one, while calling texts, images, videos, sounds, etc. [3]. In their big majority, the first sites were static. Their main end was to propose information about products and services. Contrary to this practice, the current web sites offer more and more the possibility of entering interaction with the users by allowing to exchange in two senses data among the customer and the server : dynamic Web [4]. To assure this practice, various environments are developed such as the languages of script and server of database [5].
A part of this article consists in a study of actual case, on which we put into practice the various notions of Web, which is the conception of a dynamic Web site for the library of the university of Oran's Es-Sénia by defining various working environments. The Architecture of a Web Site: A Web site consists of one or several web sites being able to contain of the text, the images and the other interconnected elements. The front page of a site is called page of starting up or home page [3] (Fig. 1). Web sites are coded by the language Hypertext Markup language (HTML) [6,7]. It is about a language of pagination of documents and specifications of links which the navigator will analyze to show the contents of the document, including the text, the images and the other types of entities. This language offers also a means to realize interactive documents by using hypertext links, what allows to connect our document with the other documents, that they are on our system or somewhere on Web [5].
The Language of Universal Script for Web Definition: Hypertext Preprocessor (PHP) [8,9] is a language of quoted script server, he is used with Internet servers to create with a minimum of effort of the dynamic web sites intended for Internet applications multimedia or of e-business. The code of script is executed by the server in answer to a request Hypertext Transfer Protocol (HTTP) [8,10]. PHP's syntax is inspired widely by the language C, while presenting certain lines of relationship with languages Perl [11] and Java. [12] PHP is a language multiplate-forms: it was concerned numerous stations UNIX, such as Linux, and it so well on machines Windows [8]. PHP can be used or as a program portable CGI is as a module integrated into the server Web as Apache [13] (Fig. 2). What returns interesting language PHP is the faculty in interfacer in of numerous data base SQL [14] and the direct coverage of several server of management of database (DBMS) as :Adabase D, Dbase, Msql, Oracle… [8] PHP's Functioning: Code PHP can be an integral part of the HTML page or a pure script PHP. The user who calls such a page ignores everything on the code of this page, this code having been interpreted quoted server before being translated into code HTML. To do it, the server web throws the interpreter PHP, who translates the wanted document and executes code source of the page. Command appearing in the page are interpreted and result takes the shape of a HTML page published in the place of the code source in the same document. At the conclusion of this phase of translation, the modified page is sent to the customer to be shown there by the Navigator [8].

Treatment of Forms in PHP:
The point of departure of the programming of interactive web sites is constituted with forms HTML, these last ones constitute an interesting solution to transfer data of the customer towards the server http. One of the reasons of the success of the language PHP is that scripts allow to manipulate very easily the data of forms. It is dregs in the fact that every name indicated in a form to identify a zone of seizure HTML is automatically transformed into a variable by PHP. The general structure of a script of treatment of form owes ( Fig. 3a and b): * To prepare the very form; * To proceed to controls of seizure (PHP uses for it regular expressions); * To make actions as seizure is confirmed or not; MySQL's General View: MySQL [8,15] is a language of requests used for the interrogation of the data base relational [14], MySQL uses architecture multi-user, multiprocessing. The server of data base MySQL is situated on the server distant from the access provider with Internet (FAI). This one attributes an user account, a password and the straight correspondents which allows to administer the server of database. Access to the server of data base MySQL by using scripts PHP, allows to create the databases, tables, to insert data into tables and to interrogate bases by means of suited requests. For this to make PHP have a whole series of functions intended for the access to a server of data base and the manipulation of data [8]. MySQL's use with PHP is made in four stages: * Connection to the server of data * Selection of the base of data * Request * Exploitation of requests Tables required for the data base can be create directly to the guest of the customer mysql mysql. It turns out however more simple to write in a file ASCII SQL commands required in this end and to send this file to the server mysql by means of the utility of administration PhpMyAdmin [8].

Completion of Tables:
After the creation of the data base and the tables, their completion makes through the utility PhpMyAdmin.

Example: Completion of the table Book
INSERT INTO Book (Code, NameAut, Title, Edition, NbrPge, NbrExp, Disp) VALUES ("I774", "COCHET Claude", "Analyse Organique en Informatique de Gestion ", "Paris : Dunod Informatique", 156, 2, 2 ); // Insert into the table Book values for every attribute General Architecture of the Site: In the entrance of the site we shall have a page of reception which contains a static part (a set of web sites connected among them by hypertext links) and three dynamic columns: Registration, Loan, Search by keyword (Fig. 4). Fig. 4: General Architecture of the Site Navigation on the Site: A simple click on one of subjects (Data processing, Chemistry, Biology, Mathematical, physical) will lead us to another page which contains the in order alphabetical organized set of the works of titles. A click on a letter leads us or at the beginning of the works which begins with this letter in the same page (local link) or on the another page situated in the another file Html ( external link) (Fig. 5).

Fig. 5: Hypertext Link
Dynamic Part of the Site: The columns of this part allow to exchange data with the server Web Apache, this last one is in direct relation with the server of data base MySQL. Connection among the customer and the server is made through the language of script PHP which gets back the data of the user through a form, emits requests and get back results which will be posted on the navigator. Our application contains three important columns of this genre: search by keyword, registration and loan Online whom we are going to detail in what follows.
To interrogate a data base it is necessary at first to connect to the server MySQL, it makes by the following function: int mysql_connect (string hostname: port: connation, string username, string password)

CONCLUSION
Work made in this study joins within the framework of the conception and the realization of the systems of information, in particular Web applications. We gave general outline on Web, then we showed how creates web sites and how to make links among them, it by using the standard language of Web which is the HTML under the professional editor 'WebExpert' as well as the use of the language of script PHP and the language of requests MySQL to give a dynamic aspect to the site. We showed also the power of these two tools and we explained the functioning of dynamic Web: of the launch of the request http of highly-rated customer in the execution of scripts, the interrogation of data until the recovery of the page result. Finally we put into practice these various notions in a study of the case of a library of the university, by explaining the various stages of realization.