Delphi XML traversing -
i new delphi.
i wanted find authors under each subject.
here xml
<?xml version="1.0"?> <catalog> <subject id="computer"> <book id="bk101"> <author>gambardella, matthew</author> <title>xml developer's guide</title> <genre>computer</genre> <price>44.95</price> <publish_date>2000-10-01</publish_date> <description>an in-depth @ creating applications xml.</description> </book> <book id="bk112"> <author>galos, mike</author> <title>visual studio 7: comprehensive guide</title> <genre>computer</genre> <price>49.95</price> <publish_date>2001-04-16</publish_date> <description>microsoft visual studio 7 explored in depth, looking @ how visual basic, visual c++, c#, , asp+ integrated comprehensive development environment.</description> </book> </subject> <subject id="literature"> <book id="bk102"> <author>ralls, kim</author> <title>midnight rain</title> <genre>fantasy</genre> <price>5.95</price> <publish_date>2000-12-16</publish_date> <description>a former architect battles corporate zombies, evil sorceress, , own childhood become queen of world.</description> </book> <book id="bk103"> <author>corets, eva</author> <title>maeve ascendant</title> <genre>fantasy</genre> <price>5.95</price> <publish_date>2000-11-17</publish_date> <description>after collapse of nanotechnology society in england, young survivors lay foundation new society.</description> </book> <book id="bk104"> <author>corets, eva</author> <title>oberon's legacy</title> <genre>fantasy</genre> <price>5.95</price> <publish_date>2001-03-10</publish_date> <description>in post-apocalypse england, mysterious agent known oberon helps create new life inhabitants of london. sequel maeve ascendant.</description> </book> <book id="bk105"> <author>corets, eva</author> <title>the sundered grail</title> <genre>fantasy</genre> <price>5.95</price> <publish_date>2001-09-10</publish_date> <description>the 2 daughters of maeve, half-sisters, battle 1 control of england. sequel oberon's legacy.</description> </book> <book id="bk106"> <author>randall, cynthia</author> <title>lover birds</title> <genre>romance</genre> <price>4.95</price> <publish_date>2000-09-02</publish_date> <description>when carla meets paul @ ornithology conference, tempers fly feathers ruffled.</description> </book> <book id="bk107"> <author>thurman, paula</author> <title>splish splash</title> <genre>romance</genre> <price>4.95</price> <publish_date>2000-11-02</publish_date> <description>a deep sea diver finds true love twenty thousand leagues beneath sea.</description> </book> <book id="bk108"> <author>knorr, stefan</author> <title>creepy crawlies</title> <genre>horror</genre> <price>4.95</price> <publish_date>2000-12-06</publish_date> <description>an anthology of horror stories roaches, centipedes, scorpions , other insects.</description> </book> <book id="bk109"> <author>kress, peter</author> <title>paradox lost</title> <genre>science fiction</genre> <price>6.95</price> <publish_date>2000-11-02</publish_date> <description>after inadvertant trip through heisenberg uncertainty device, james salway discovers problems of being quantum.</description> </book> <book id="bk110"> <author>o'brien, tim</author> <title>microsoft .net: programming bible</title> <genre>computer</genre> <price>36.95</price> <publish_date>2000-12-09</publish_date> <description>microsoft's .net initiative explored in detail in deep programmer's reference.</description> </book> <book id="bk111"> <author>o'brien, tim</author> <title>msxml3: comprehensive guide</title> <genre>computer</genre> <price>36.95</price> <publish_date>2000-12-01</publish_date> <description>the microsoft msxml3 parser covered in detail, attention xml dom interfaces, xslt processing, sax , more.</description> </book> </subject> </catalog>
you can use xpath select authors, using expression //catalog/subject/book/author, delphi have lot of options manage xml file, in case easy use microsoft xml dom implementation
check sample application
{$apptype console} uses activex, variants, comobj, sysutils; procedure readxmlfile(const filename:tfilename); const msxml2_domdocument='msxml2.domdocument.6.0'; var xmldoc : olevariant; nodes : olevariant; lnodes : integer; : integer; begin //create instance xml dom xmldoc := createoleobject(msxml2_domdocument); try xmldoc.async := false; //load file xmldoc.load(filename); //set xpath mode xmldoc.setproperty('selectionlanguage','xpath'); //check errors in xml file if (xmldoc.parseerror.errorcode <> 0) raise exception.createfmt('error in xml data %s',[xmldoc.parseerror]); //select nodes match expression nodes := xmldoc.selectnodes('//catalog/subject/book/author'); //get number of nodes selected lnodes:= nodes.length; writeln(format('%d authors found',[lnodes])); //traverse nodes i:=0 nodes.length - 1 writeln(format('author name %s',[nodes.item(i).text])); xmldoc :=unassigned; end; end; begin try coinitialize(nil); try readxmlfile(extractfilepath(paramstr(0))+'test.xml'); couninitialize; end; except on e:exception writeln(e.classname, ':', e.message); end; writeln('press enter exit'); readln; end. finally application return this
12 authors found author name gambardella, matthew author name galos, mike author name ralls, kim author name corets, eva author name corets, eva author name corets, eva author name randall, cynthia author name thurman, paula author name knorr, stefan author name kress, peter author name o'brien, tim author name o'brien, tim
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