public bool Accept(XQueryNavigator nav)
{
return targets == null || targets.Contains(nav.DmNode);
}
/// <summary>
/// Runs the solutions to all problems
/// </summary>
public static void Main()
{
XmlDocument doc = new XmlDocument();
doc.Load(PathToXmlFile);
XmlNode root = doc.DocumentElement ?? doc.CreateElement("root");
// Problem 2: Write program that extracts all different artists which are found in the catalog.xml.
// For each author you should print the number of albums in the catalogue.
// Use the DOM parser and a hash - table.
PrintNumbersOfAlbumsForEachArtist(root);
// Problem 3: Implement the previous using XPath.
PrintArtistsNumberOfAlbumsUsingXPath(root);
// Problem 4: Using the DOM parser write a program to delete from catalog.xml all albums having price > 20.
DeleteAlbumsByPrice(root, 20.0);
// Check that albums are deleted:
PrintNumbersOfAlbumsForEachArtist(root);
// Problem 5: Write a program, which using XmlReader extracts all song titles from catalog.xml.
var songTitles = ExtractSongTitlesFromCatalogue(PathToXmlFile);
Console.WriteLine("Song titles: " + string.Join(", ", (songTitles as List <string>).ToArray()));
// Problem 6: Rewrite the same using XDocument and LINQ query.
XDocument xDoc = XDocument.Load(PathToXmlFile);
var songTitlesUsingLinq = from songs in xDoc.Descendants("title") select songs.Value.Trim();
Console.WriteLine("Song titles (using LINQ): " + string.Join(", ", songTitlesUsingLinq));
// Problem 7: In a text file we are given the name, address and phone number of given person (each at a single line).
// Write a program, which creates new XML document, which contains these data in structured XML format.
CreateXmlPhonebook("../../phonebook.txt");
// Problem 8: Write a program, which (using XmlReader and XmlWriter) reads the file catalog.xml and creates the file album.xml,
// in which stores in appropriate way the names of all albums and their authors.
CreateAlbumsXml(PathToXmlFile);
// Problem 9: Write a program to traverse given directory and write to a XML file its contents together with all subdirectories and files.
// Use tags < file > and < dir > with appropriate attributes.
// For the generation of the XML document use the class XmlWriter.
using (var writer = new XmlTextWriter("../../traverseWithXmlWriter.xml", Encoding.UTF8))
{
writer.WriteStartDocument();
writer.WriteStartElement("DirectoriesRoot");
CreateFileSystemXmlTreeUsingXmlWriter("../../..", writer);
writer.WriteEndElement();
writer.WriteEndDocument();
writer.Close();
}
// Problem 10: Rewrite the last exercises using XDocument, XElement and XAttribute.
var xDocument = new XDocument();
xDocument.Add(CreateFileSystemXmlTree("../../../"));
xDocument.Save("../../traverseWithXElement.xml");
// Problem 11: Write a program, which extract from the file catalog.xml the prices for all albums, published 5 years ago or earlier.
// Use XPath query.
doc.Load(PathToXmlFile);
root = doc.DocumentElement;
// returns all (no albums in the catalogue are newer...)
var oldAlbumsPrices = root.SelectNodes("album/price[../year/text() < 2010]");
//// var oldAlbumsPrices = root.SelectNodes("album/price[../year/text() < 1980]"); // returns 2 albums' prices
Console.WriteLine(new string('-', 50));
Console.WriteLine("Prices of the albums, published before 2010: ");
foreach (var price in oldAlbumsPrices)
{
Console.WriteLine((price as XmlElement).InnerXml.Trim());
}
// Problem 12: Rewrite the previous using LINQ query.
Console.WriteLine(new string('-', 50));
Console.WriteLine("Prices of the albums, published before 2010 (using LINQ): ");
var oldAlbumsPricesUsingLinq = from album in xDoc.Descendants("album")
where int.Parse(album.Element("year").Value) < 2010
select album.Descendants("price").FirstOrDefault();
foreach (var price in oldAlbumsPricesUsingLinq)
{
Console.WriteLine(price.Value.Trim());
}
// Problem 13: Create an XSL stylesheet, which transforms the file catalog.xml into HTML document,
// formatted for viewing in a standard Web-browser.
// Problem 14: Write a C# program to apply the XSLT stylesheet transformation on the file catalog.xml
// using the class XslTransform.
XslCompiledTransform catalogueXslt = new XslCompiledTransform();
catalogueXslt.Load("../../catalogue.xslt");
catalogueXslt.Transform(PathToXmlFile, "../../catalogue.html");
// Problem 15:
// *Read some tutorial about the XQuery language.
// Implement the XML to HTML transformation with XQuery (instead of XSLT).
// Download some open source XQuery library for .NET and execute the XQuery to transform the catalog.xml to HTML.
XQueryNavigatorCollection col = new XQueryNavigatorCollection();
// Add the XML document catalogue.xml to the collection using cat as the name to reference.
col.AddNavigator("../../catalogue.xml", "cat");
var expr = new XQueryExpression(
"<html><body><head><title>Catalogue</title></head>" +
"<h1>Catalogue generated using XQuery</h1>" +
"{For $a IN document(\"cat\")/catalogue/album " +
"RETURN <div><strong>Title:</strong> {$a/name/text()}<br />" +
"<strong>Artist:</strong> {$a/artist/text()}<br />" +
"<strong>Year:</strong> {$a/year/text()}<br />" +
"<strong>Producer:</strong> {$a/producer/text()}<br />" +
"<strong>Price:</strong> {$a/price/text()}<br />" +
"<strong>Songs:</strong><ol>{For $s IN $a/songs/song RETURN <li>{$s/title/text()}</li>}</ol>" +
"</div><hr />}</body></html>");
StreamWriter str = new StreamWriter("../../catalogueUsingXQuery.html");
XQueryNavigator nav = expr.Execute(col);
nav.ToXml(str);
str.Close();
// Problem 16:
// Using Visual Studio generate an XSD schema for the file catalog.xml.
// Write a C# program that takes an XML file and an XSD file (schema) and validates the XML file against the schema.
// Test it with valid XML catalogs and invalid XML catalogs.
string xsdMarkup = File.ReadAllText("../../catalogue.xsd");
XmlSchemaSet schemas = new XmlSchemaSet();
schemas.Add(string.Empty, XmlReader.Create(new StringReader(xsdMarkup)));
XDocument valid = XDocument.Load(PathToXmlFile);
XDocument invalid = new XDocument(
new XElement(
"Root",
new XElement("Child1", "content1"),
new XElement("Child2", "content2")));
Console.WriteLine(new string('-', 50));
Console.WriteLine("Validating valid document:");
bool errors = false;
valid.Validate(schemas, (o, e) =>
{
Console.WriteLine("{0}", e.Message);
errors = true;
});
Console.WriteLine("Valid {0}", errors ? "did not validate" : "validated");
Console.WriteLine();
Console.WriteLine("Validating invalid document:");
errors = false;
invalid.Validate(schemas, (o, e) =>
{
Console.WriteLine("{0}", e.Message);
errors = true;
});
Console.WriteLine("doc2 {0}", errors ? "did not validate" : "validated");
}
private IEnumerable<XPathItem> Iterator(XQueryNavigator src)
{
int inf;
int sup;
int length = src.GetLength();
DmNode node = src.DmNode;
NodeSet nset;
lock (node)
{
nset = node.GetNodeSet(this);
if (nset == null)
nset = node.CreateNodeSet(this, _path);
nset.GetBounds(out inf, out sup);
}
int index;
if (src.Position < inf)
{
index = inf;
length -= inf - src.Position;
}
else
index = src.Position;
length = Math.Min(length, sup - inf + 1);
XQueryNavigator res = (XQueryNavigator)src.Clone();
PageFile pf = src.Document.pagefile;
int[] buffer = new int[XQueryLimits.DirectAcessBufferSize];
while (length > 0)
{
int size = pf.Select(nset.hindex, ref index, ref length, buffer);
for (int k = 0; k < size; k++)
{
res.Position = buffer[k];
if (nset.Accept(res))
yield return res;
if (nset.mixed && res.IsLeafTextElement)
{
res.MoveToFirstChild();
if (nset.Accept(res))
yield return res;
}
}
}
}
public XPathItem this[int i]
{
get
{
if (i < pos)
{
current = null;
pos = 0;
}
if (current == null)
{
index = 0;
offset = 0;
if (owner.segments.Count == 0)
return null;
current = owner.segments[0];
nav = null;
}
while (pos < i)
{
if (offset == current.Count - 1)
{
index++;
if (index == owner.segments.Count)
return null;
current = owner.segments[index];
offset = 0;
nav = null;
}
else
offset++;
pos++;
}
object packedItem = current[offset];
XPathItem item = packedItem as XPathItem;
if (item != null)
return item;
if (nav == null)
nav = current.document.CreateNavigator();
nav.Position = (int)packedItem;
return nav;
}
}
