Which of the following Tags names are valid, which are not? Explain your answers. <lecture> <student and teacher> <student&teacher>

Size: px

Start display at page:

Download "Which of the following Tags names are valid, which are not? Explain your answers. <lecture> <student and teacher> <student&teacher>"

Rachel Parks
5 years ago
Views:

1 Exercise 1 (XML Tags) Which of the following Tags names are valid, which are not? Explain your answers. <lecture <student and teacher <student&teacher <smørebrød <DilbertComicStrip <XMLisFun <4u <student.and.teacher < Exercise 2 (Well-formed XML documents) The following XML document describes some entries of a library. <library <book id=2003-blanken <titleintelligent XML Search</title <editorhenk A. Blanken et al.</editor <publisherspringer Verlag</PUBLISHER </book <journal id="tods_1_2003 publ_year="2003" <titleacm Transactions on Databases</title <volume24<number1</number</volume </journal <misc id="dipl " id="tr " <authoru. Known</author <titlethe Diploma Thesis that didn t appear <year2002</year <pages0</pages </misc </library Check if the XML document is well-formed. If it is not, change it so that it becomes wellformed, making as little changes as possible. Write a DTD for this XML document such that the corrected version of the example is a valid XML document and the following requirements hold: 1 book, journal and misc can occur in any sequence within the library tag 2 title is mandatory 3 there can be only one title, editor, publisher, volume, and year for a library entry 4 there may be more than one author for an entry Exercise 3 (XML Design) The SmartPhone Company wants to develop a mobile application for java enabled mobile devices (like PDAs or mobile phones) for weather forecasts. In mobile application data usually is transferred in XML via HTTP over the internet to a server. Design two XML formats given as example files. One format for the weather forecast request. It should contain the region and date for which the weather forecast is requested. Feel free to add other content if necessary. Another format for the servers reply to this request. It should contain a short description and a long description of the forecasted weather. Add other content that

2 enables the mobile application to add additional weather information, like day and night temperature. Search the WWW for Web-based examples of weather forecasts to get a feeling for this additional content. Design the formats for multi-languages. Exercise 4 (XML and formal languages) a) Give an example of an XML dialect (a DTD and a document example) that is contextfree but not regular. Explain your answer. b) Give an example of a regular language that is regular but not an XML dialect. Explain our answer. Give an example of a context-free language that is not an XML dialect. Explain your answer.

3 Solutions Exercise 1 <lecture Valid: name consists only of letters <smørebrød Valid (Unicode characters allowed) <4u Invalid: name must not start with a digit <student and teacher Invalid: names must not contain spaces <DilbertComicStrip Valid: name consists only of letters <student.and.teacher Valid: name consists of letters and dot; name starts with letter <student&teacher Invalid: names must not contain symbols other than letters, digits, dots, colons, hyphens, or underscore <XMLisFun Valid: name consists only of letters and starts not with xml (lower case) < Invalid: there is no name Exercise 2 <library <!-- quotes missing for value -- <book id="2003-blanken" <titleintelligent XML Search</title <editorhenk A. Blanken et al.</editor <!-- tags are case sensitive -- <publisherspringer Verlag</publisher </book <!-- quote after TODS_1_2003 missing -- <journal id="tods_1_2003" publ_year="2003" <titleacm Transactions on Databases</title <volume24<number1</number</volume </journal <!-- double attribute name, change second id to bib_id -- <misc id="dipl " bib_id="tr " <authoru. Known</author <titlethe Diploma Thesis that didn't appear</title <year2002</year <pages0</pages </misc </library

4 <?xml version="1.0" encoding="utf-8"? <!ELEMENT library (book*, journal*, misc*) <!ELEMENT book (author*, title, editor?, publisher?, volume?, year?, pages?) <!ATTLIST book id CDATA #REQUIRED <!ELEMENT journal (author*, title, editor?, publisher?, volume?, year?, pages?) <!ATTLIST journal id CDATA #REQUIRED <!ELEMENT misc <!ATTLIST misc (author*, title, editor?, publisher?, volume?, year?, pages?) id CDATA #REQUIRED bib_id CDATA #IMPLIED <!ELEMENT title (#PCDATA) <!ELEMENT editor (#PCDATA) <!ELEMENT publisher (#PCDATA) <!ELEMENT volume (#PCDATA number)* <!ELEMENT number (#PCDATA) <!ELEMENT year (#PCDATA)

5 Exercise 3 <?xml version="1.0"? <weather-forecast-request <regionkarlsruhe</region <!-- Format DD.MM.YYYY -- <date </date <!-- Two letter language ISO code -- <languagede</language </weather-forecast-request <?xml version="1.0"? <weather-forecast-reply language="de" <regionkarlsruhe</region <date </date <short-description Sonnig und trocken. </short-description <long-description Wieder einmal sehr sonniges und warmes Wetter... </long-description <temperatures unit="celsius" <temperature when="day" 20.0 </temperature <temperature when="night" 5.0 </temperature </temperatures <!-- additional data -- <wind <directionsw</direction <speed1</speed </wind <sunshine-duration 10.0 <!-- in hours -- </sunshine-duration </weather-forecast-reply Exercise 4 a) The DTD <!ELEMENT a EMPTY defines a linear (but not regular language) It consists of all words <a n </a n with n a natural number. b) The language a* (regular-expression) is not an XML dialect, because there is no tag at all (root tag is mandatory) c) The programming language Java is context-free, but not expressible via XML. Same reason as b).

DTDs and XML Attributes

DTDs and XML Attributes Lecture 33 Robb T. Koether Hampden-Sydney College Mon, Apr 8, 2013 Robb T. Koether (Hampden-Sydney College) DTDs and XML Attributes Mon, Apr 8, 2013 1 / 21 1 Attribute Definitions