Declarative Ajax Web Applications through SQL++ on a Unified Application State Yupeng Fu Kian Win Ong Yannis Papakonstantinou UCSD UCSD UCSD
[email protected] [email protected] [email protected] Abstract (c) the data tier in the database. Multiple mundane low-level tasks Implementing even a conceptually simple web application requires need to be performed in a coordinated fashion across all three tiers. an inordinate amount of time. FORWARD addresses three prob- The resulting problems (as follows) reduce developer productivity: Impedance mismatch lems that reduce developer productivity: (a) 1. Impedance mismatch arises because each tier uses different lan- across the multiple languages used at different tiers of the appli- guages (and data models) [5, 21]. The visual tier uses DOM Distributed data access cation architecture. (b) across the multi- (XHTML) / JavaScript (JSON); the application logic tier uses ple data sources of the application (user input of the browser page, an application programming language, such as Java, Python or Asyn- session data in the application server, SQL database etc). (c) PHP (objects); the data tier uses SQL (tables). To display a page, chronous, incremental modification of the pages , as performed by mundane and error-prone code is needed to translate SQL tables Ajax actions. into Java objects, and then into HTML / JavaScript objects. To FORWARD belongs to a novel family of web application frame- implement an action invocation, more code is needed to translate works that attack impedance mismatch by offering a single uni- in the opposite direction. fying language. FORWARD’s language is SQL++, which is SQL with necessary extensions for semi-structured data.