XML is spreading out as a standard for semistructured documents on the Web, so the possibility of querying XML documents which are linked by XML links is becoming a goal to achieve. In this paper we present an extended version of the graphical query language for XML documents XML-GL. XML-GL allows to extract and restructure information from XML specified WWW documents. We extend XML-GL in the following directions: (i) our proposal allows to represent XML simple links, so that it is possible to query whole XML specified WWW sites in a simple and intuitive way; (ii) our proposal improves the expressive power of XML-GL, where only transitive closure can be expressed, by allowing generic recursion; (iii) finally, we permit the user to specify queries in an easier fashion, by allowing sequences of nested query, in the same way as in SQL.
A visual language should be easy to use: a step forward for XML-GL
OLIBONI, Barbara;
2002-01-01
Abstract
XML is spreading out as a standard for semistructured documents on the Web, so the possibility of querying XML documents which are linked by XML links is becoming a goal to achieve. In this paper we present an extended version of the graphical query language for XML documents XML-GL. XML-GL allows to extract and restructure information from XML specified WWW documents. We extend XML-GL in the following directions: (i) our proposal allows to represent XML simple links, so that it is possible to query whole XML specified WWW sites in a simple and intuitive way; (ii) our proposal improves the expressive power of XML-GL, where only transitive closure can be expressed, by allowing generic recursion; (iii) finally, we permit the user to specify queries in an easier fashion, by allowing sequences of nested query, in the same way as in SQL.
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