WebPage.cs :  » Testing » NUnitAsp » NUnit » Extensions » Asp » C# / CSharp Open Source

#region Copyright (c) 2002, 2003, Brian Knowles, Jim Shore
/********************************************************************************************************************
'
' Copyright (c) 2002, 2003, Brian Knowles, Jim Shore
'
' Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated 
' documentation files (the "Software"), to deal in the Software without restriction, including without limitation 
' the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and
' to permit persons to whom the Software is furnished to do so, subject to the following conditions:
'
' The above copyright notice and this permission notice shall be included in all copies or substantial portions 
' of the Software.
'
' THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
' THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
' AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
' CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
' DEALINGS IN THE SOFTWARE.
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'*******************************************************************************************************************/
#endregion

using System;
using System.IO;
using System.Xml;
using System.Collections;
using System.Web;
using System.Text;
using System.Text.RegularExpressions;
using System.Net;

using Sgml;

namespace NUnit.Extensions.Asp{
  internal class WebPage
  {
    private static TimeSpan totalParseTime = TimeSpan.Zero;

    private string pageText;
    private XmlDocument document = null;
    public Hashtable formVariables = null;

    internal WebPage(string htmlPage)
    {
      pageText = htmlPage;
    }

    internal XmlDocument Document
    {
      get
      {
        if (document == null) ParsePageText();
        return document;
      }
    }

    internal FormVariables VariablesFor(string formHtmlId)
    {
      if (formVariables == null) ParsePageText();
      FormVariables result = (FormVariables)formVariables[formHtmlId];
      WebAssert.NotNull(result, "form ID '" + formHtmlId + "' not found on current page");
      return result;
    }

    private SgmlDtd ParseDtd(XmlNameTable nt)
    {
      string name = string.Format("{0}.{1}.Html.dtd",
        typeof(WebPage).Namespace, typeof(SgmlDtd).Namespace);

      Stream stream = typeof(SgmlDtd).Assembly.GetManifestResourceStream(name);
      StreamReader reader = new StreamReader(stream);
      return SgmlDtd.Parse(null, "HTML", null, reader, null, null, nt);
    }

    private void ParsePageText()
    {
//      DateTime startTime;
//      DateTime endTime;

      SgmlReader reader = new SgmlReader();
      try 
      {
        reader.InputStream = new StringReader(FixHtmlToAvoidParseErrors(pageText));
//        startTime = DateTime.Now;
        reader.Dtd = ParseDtd(reader.NameTable);  // note: this is last-found performance bottleneck; not yet fixed.  Retest before fixing.
//        endTime = DateTime.Now;
        reader.ErrorLog = Console.Error;
        reader.DocType = "HTML";

        document = new XhtmlDocument(reader.NameTable);
        try 
        {
          document.Load(reader);
        }
        catch (WebException e)
        {
          throw new DoctypeDtdException(e);
        }

        ParseForms();

//        totalParseTime += endTime - startTime;
//        Console.WriteLine("parser: " + totalParseTime);
      }
      catch (XmlException e)
      {
        Console.WriteLine("vvvvvv The following HTML could not be parsed by NUnitAsp vvvvvv");
        Console.WriteLine(pageText);
        Console.WriteLine("^^^^^^ The preceding HTML could not be parsed by NUnitAsp ^^^^^^");
        throw new ParseException("Could not parse HTML.  See standard out for the HTML and use a validator (such as the one at validator.w3.org) to troubleshoot.  Parser error was: " + e.Message);
      }
      finally
      {
        reader.Close();
      }
    }

    private string FixHtmlToAvoidParseErrors(string html)
    {
      return Regex.Replace(html, "<style>\\s+<!--", "<style><!--");
    }

    private void ParseForms()
    {
      formVariables = new Hashtable();
      foreach (XmlElement formElement in Document.SelectNodes("//form"))
      {
        ParseInitialFormValues(formElement);
      }
    }

    private void ParseInitialFormValues(XmlElement formElement) 
    {
      string id = formElement.GetAttribute("id");
      if (id == null) return;

      formVariables[id] = new FormVariables();
      ParseFormElementValues(id, "//input[@type='file']", "@name", "");
      ParseFormElementValues(id, "//input[@type='password']", "@name", "");
      ParseFormElementValues(id, "//input[@type='text']", "@name", "");
      ParseFormElementValues(id, "//input[@type='hidden']", "@name", "");
      ParseFormElementValues(id, "//input[@type='radio'][@checked]", "@name", "on");
      ParseFormElementValues(id, "//input[@type='checkbox'][@checked]", "@name", "on");
      ParseFormElementValues(id, "//textarea", "@name", null);
      ParseFormElementValues(id, "//select/option[@selected]", "../@name", null);
    }

    private void ParseFormElementValues(string formId, string elementExpr, string nameExpr, string defaultValue)
    {
      foreach (XmlElement element in Document.SelectNodes("//form[@id='" + formId + "']" + elementExpr)) 
      {
        XmlAttribute name = (XmlAttribute)element.SelectSingleNode(nameExpr);
        string value = element.GetAttribute("value");

        if (name == null) continue;
        if (value == null || value == "") 
        {
          if (defaultValue != null)
          {
            value = defaultValue;
          }
          else
          {
            // Last chance value for <option> and <textarea> element
            value = element.InnerText.Trim();
          }
        }
        VariablesFor(formId).Add(name.Value, value);
      }
    }

    public override string ToString()
    {
      return pageText;
    }

    private class XhtmlDocument : XmlDocument
    {
      private readonly Hashtable byHtmlId = new Hashtable();

      public XhtmlDocument(XmlNameTable nt) : base(nt)
      {
      }

      public override void Load(XmlReader reader)
      {
        XmlNodeChangedEventHandler insertHandler = 
          new XmlNodeChangedEventHandler(XhtmlDocument_NodeInserted);

        byHtmlId.Clear();
        NodeInserted += insertHandler;
        try
        {
          base.Load(reader);
        }
        finally
        {
          NodeInserted -= insertHandler;
        }
      }

      public override XmlElement GetElementById(string htmlId)
      {
        return (XmlElement)byHtmlId[htmlId];
      }

      private void XhtmlDocument_NodeInserted(object sender, XmlNodeChangedEventArgs e)
      {
        if (e.Node.NodeType != XmlNodeType.Element) return;

        XmlAttribute id = e.Node.Attributes["id"];
        if (id != null)
        {
          byHtmlId[id.Value] = e.Node;
        }
      }
    }
  }

  /// <summary>
  /// Problems with the DOCTYPE DTD; probably that it was incorrect.  Correct it.
  /// </summary>
  public class DoctypeDtdException : ApplicationException
  {
    internal DoctypeDtdException(WebException e) : base(GetMessage(e))
    {
    }

    private static string GetMessage(WebException e)
    {
      return "Problems with DOCTYPE DTD: <" + e.Message + ">.  Your DOCTYPE is probably " +
        "incorrect.  If you're not sure what the DOCTYPE should be, use <!DOCTYPE HTML " +
        "PUBLIC \"-//W3C//DTD HTML 4.0 Transitional//EN\" >, Visual Studio .NET's default.";
    }
  }
}