On classification of XML document transformations Jana Dvoˇ ráková FMFI UK, Bratislava jana.dvorakova@dcs.fmph.uniba.sk DATESO 2005 DATESO 2005 – p. 1/14
Outline Introduction Formalization of XML concepts Classification hierarchy Type transformations Formal models Conclusion DATESO 2005 – p. 2/14
Introduction XML - popular standard for production of structured documents document standards, data exchange between applications Various transformations needed Many transformation systems exist, based on different techniques SynDoc, Scrimshaw, TREX, XSLT, Grif, Thot, VXT, CoST,... Aims 1. to define classification of XML document transformations 2. to examine relationships among defined groups of transformations DATESO 2005 – p. 3/14
Formalization of XML concepts (1) XML document tree, where internal nodes are elements and leaves contain textual content Document Type context-free grammar valid XML documents - derivation trees Restrictions XML documents without attributes element names from finite and known set DATESO 2005 – p. 4/14
Formalization of XML concepts (2) Transformation set of pairs of trees ( d 1 , d 2 ) d 1 - tree representing source XML document d 2 - tree representing target XML document Transformation model: Source grammar Transformation specification Target grammar Source Transformation Target tree process tree DATESO 2005 – p. 5/14
Classification hierarchy (1) Different possible criteria driving element, scope, purpose, level of user interaction, transformational power, source and target correctness... Basic groups: Source grammar transformations Target grammar transformations Two grammar (type) transformations In each group different transformation techniques used DATESO 2005 – p. 6/14
Classification hierarchy (2) XML transformations Driving element Source grammar Target grammar Two grammar (type) transformations transformations transformations Parsing Mapping TREX technique technique Event−driven Tree−based SDTS TTG DTT HAG transformations transformations CoST, SAX Scrimshaw, SynDoc, DGTS, SynDoc SIMON applications, XSLT SDTT, SIPEQ, OmniMark processors, ICA, HST Alchemist Metamorphosis ... DATESO 2005 – p. 7/14
Type transformations Transformation specification is created by grammar mapping Both source and target corectness Formal models used: Syntax directed translation schema (SDTS) Tree transformation grammar (TTG) Descending tree transducer (DTT) Higher order attribute grammar (HAG) 1. Common framework development 2. Mutual comparison DATESO 2005 – p. 8/14
Formal models - SDTS (1) Translates a sentence of a source grammar ( w s ) into a sentence of a target grammar ( w t ) according to translation groupings Simulates derivation of both sentences from the start symbol simultaneously Sentential form = current frontiers of the source tree and the target tree Translation grouping: A → u 1 . . . u n , v 1 . . . v m Translation: ( S, S ) ⇒ .. ⇒ ( xAy, x ′ Ay ′ ) ⇒ ( xu 1 . . . u n y, x ′ v 1 . . . v m y ′ ) ⇒ .. ⇒ ( w s , w t ) DATESO 2005 – p. 9/14
Formal models - SDTS (2) Standard defininition is not suitable in the case of XML Extension proposed: trees as sequential forms First sequential form - source derivation tree, last sequential form - target derivation tree DATESO 2005 – p. 10/14
Formal models - SDTS (3) Translation step: A u ...u n , v ... v 1 1 m β β z 1 z 1 Ω A u A u n v v 1 1 m ... ... s s m t t 1 1 n DATESO 2005 – p. 11/14
Formal models - comparison Results obtained by comparing syntax directed translation schema (SDTS), descending tree transducer (DTT) and their modifications: SDTS ESDTS d-DTT DTT � � � SDTS � ESDTS N N � d-DTT N ⊆ � DTT N ⊇ DATESO 2005 – p. 12/14
Conclusion Summary of results: formal definitions of XML concepts classification for XML document transformations introduced formal models for two grammar transformations defined in common framework several results of comparing these formal models Future work: add other comparisons of formal models include attribute transformations DATESO 2005 – p. 13/14
Thank you for your attention! DATESO 2005 – p. 14/14
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