Objektno orijentirani pristup izradi sučelja s bazom podataka

Baze podataka osnova su većine modernih informacijskih sustava. Sučelje između korisnika i informacijskog sustava ključni je dio programske podrške koja se za jedan informacijski sustav razvija. Osnovni elementi sučelja prema bazi podataka najčešće su ekranske forme. Objektno-orijentirano oblikovanje programske podrške uz upotrebu metoda koje povećavaju ponovno iskorištenje kôda i dizajna dobar su pristup za istraživanje načina poboljšavanja procesa izgradnje programskih sustava. Programski kostur koji sadrži funkcionalnost i apstraktne razrede kombiniran s konkretnim razredima koji modeliraju konkretnu aplikaciju, pristup je koji ima niz prednosti. Većina funkcionalnosti zatvorena je u programski kostur, a konkretne razrede moguće je automatski generirati iz rječnika podataka. Učinci su smanjenje vremena razvoja programske podrške jer se programiranje svodi na opisivanje meta-podataka i generiranje kôda te manji broj pogrešaka kao posljedica jednoličnosti i manje količine kôda.Databases are the basis of the most modern information systems. Applications of various architectures and purposes can be built upon the same database. One of the most common application architectures is two-tier architecture, also known as fat client. Two-tier architecture is characterized by rich user interface based on screen forms. The task of software development assumes development of a certain number of screen forms. The number of screen forms to be developed is proportional to the number of relations in the database. There is a great similarity among the program code of the screen forms because of the identical operations with data performed on the forms. Object-oriented approach is dominant methodology in software development today because of its good abstraction of real world and inherent support for code reuse. By splitting application in two parts, one with shared functionality of all forms and one with description of data structure of the concrete form, it is possible to improve the software development process. The common part is put into the application framework that contains abstract classes with description of data structure and shared functionality. The fully functional application is obtained by adding of concrete classes with data structure description. Because concrete classes reflect structure of data from the database, they can be generated from data dictionary automatically, and that programming becomes describing of meta-data and code generating. That approach reduces amount of code because the majority of code implementing functionality remained inside framework, and application code is reduced to code describing data structure and specific behavior. Finally, there is less code that is less complex. In the introduction, motivation for development of programming system has been given. Such a system is object-oriented and based on application frameworks. In the second chapter, the brief overview of concepts from the area of information system development has been given. These concepts are databases, object-oriented modeling, layered application architecture and user interfaces. In the third chapter, the analysis of existing solutions for the similar classes of problems has been described. Also, guidelines for solution development have been presented. Architecture of application framework and layers it consists of has been defined. In the fourth chapter, the database access layer has been described. This layer presents an object extension of relational model and helps the programmer working with database. In the fifth chapter, the GUI development layer has been described. This layer allows simple and fast generation of the quality and ergonomic GUI for applications accessing databases. In the sixth chapter, the development process of the complete application has been described using a simple example. In the conclusion, the résumé has been given and all the aspects of the work done have been analyzed