Introduction
My name is Charles Henington and today I will be offering a short tutorial on a CodeProject search tool that I have created.
Background
While browsing many of the questions here in the Code Project Questions Boards, we notice that many questions which are asked could easily be found by searching Google or CodeProject. By the end of this tutorial, I hope you will understand a little more about structs, XmlDocuments, and switches.
First, we will take a look at the largest struct called SearchTerm. We have a string nested with this struct and nested within this string is an xmlDocument and a switch statement. Let's have a look at this now. Also keep in mind the XmlDocument and switch statement are actually larger than actually needed at the moment. The switch on each switch has an if, else if, else statement which returns 3 different scenarios, the reason for this being that I don't want to go in and rewrite the code every time a site changes their search criteria. So by adding a small change to the XML, I can simply rewrite the XML file to accommodate the changes. Ok...Ok... I know that's enough talk. Let's look at some code.
Using the Code
The only using statements that we will use through the entire project (besides designer generated) are:
using System;
using System.Xml;
using System.Windows.Forms;
using System;
using System.Xml;
namespace CodeProjectSearch
{
internal struct SearchTerm
{
internal const string xPathPart = "/CodeProject/";
internal const string SearchAttribute = "Url";
internal const string iParts = "Parts";
internal static string SearchString(string term, SearchMethod method)
{
XmlDocument SearchDoc = new XmlDocument();
SearchDoc.Load(CodeProject.SettingsDocument);
int AnswerParts = Int32.Parse(SearchDoc.SelectSingleNode
(xPathPart + SearchMethod.Answers.ToString()).Attributes[iParts].InnerText);
int ArticleParts = Int32.Parse(SearchDoc.SelectSingleNode
(xPathPart + SearchMethod.Articles.ToString()).Attributes[iParts].InnerText);
int CatalogItemsParts = Int32.Parse(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.CatalogItems.ToString()).Attributes[iParts].InnerText);
int EverythingParts = Int32.Parse(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.Everything.ToString()).Attributes[iParts].InnerText);
int JustYoursParts = Int32.Parse(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.JustYours.ToString()).Attributes[iParts].InnerText);
int MessagesParts = Int32.Parse(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.Messages.ToString()).Attributes[iParts].InnerText);
int NewsItemsParts = Int32.Parse(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.NewsItems.ToString()).Attributes[iParts].InnerText);
int QuestionsParts = Int32.Parse(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.Questions.ToString()).Attributes[iParts].InnerText);
int TechnicalBlogsParts = Int32.Parse(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.TechnicalBlogs.ToString()).Attributes[iParts].InnerText);
int TipsTricksParts = Int32.Parse(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.TipsTricks.ToString()).Attributes[iParts].InnerText);
int YourBookMarksParts = Int32.Parse(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.YourBookMarks.ToString()).Attributes[iParts].InnerText);
string search = null;
switch(method)
{
case SearchMethod.Answers:
if (AnswerParts == 1)
{
search = String.Format(SearchDoc.SelectSingleNode
(xPathPart + SearchMethod.Answers.ToString()).Attributes
[SearchAttribute].InnerText, term);
}
else if (AnswerParts == 2)
{
search = String.Format(SearchDoc.SelectSingleNode
(xPathPart + SearchMethod.Answers.ToString()).Attributes
[SearchAttribute].InnerText, term, term);
}
else
{
search = String.Format(SearchDoc.SelectSingleNode
(xPathPart + SearchMethod.Answers.ToString()).Attributes
[SearchAttribute].InnerText, term, term, term);
}
break;
case SearchMethod.Articles:
default:
if (ArticleParts == 1)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.Articles.ToString()).Attributes
[SearchAttribute].InnerText, term);
}
else if (ArticleParts == 2)
{
search = String.Format(SearchDoc.SelectSingleNode
(xPathPart + SearchMethod.Articles.ToString()).Attributes
[SearchAttribute].InnerText, term, term);
}
else
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.Articles.ToString()).Attributes
[SearchAttribute].InnerText, term, term, term);
}
break;
case SearchMethod.CatalogItems:
if (CatalogItemsParts == 1)
{
search = String.Format(SearchDoc.SelectSingleNode
(xPathPart + SearchMethod.CatalogItems.ToString()).Attributes
[SearchAttribute].InnerText, term);
}
else if (CatalogItemsParts == 2)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.CatalogItems.ToString()).Attributes
[SearchAttribute].InnerText, term, term);
}
else
{
search = String.Format(SearchDoc.SelectSingleNode
(xPathPart + SearchMethod.CatalogItems.ToString()).Attributes
[SearchAttribute].InnerText, term, term, term);
}
break;
case SearchMethod.Everything:
if (EverythingParts == 1)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.Everything.ToString()).Attributes
[SearchAttribute].InnerText, term);
}
else if (EverythingParts == 2)
{
search = String.Format(SearchDoc.SelectSingleNode
(xPathPart + SearchMethod.Everything.ToString()).Attributes
[SearchAttribute].InnerText, term, term);
}
else
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.Everything.ToString()).Attributes
[SearchAttribute].InnerText, term, term, term);
}
break;
case SearchMethod.JustYours:
if (JustYoursParts == 1)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.JustYours.ToString()).Attributes
[SearchAttribute].InnerText, term);
}
else if (JustYoursParts == 2)
{
search = String.Format(SearchDoc.SelectSingleNode
(xPathPart + SearchMethod.JustYours.ToString()).Attributes
[SearchAttribute].InnerText, term, term);
}
else
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.JustYours.ToString()).Attributes
[SearchAttribute].InnerText, term, term, term);
}
break;
case SearchMethod.Messages:
if (MessagesParts == 1)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.Messages.ToString()).Attributes
[SearchAttribute].InnerText, term);
}
else if (MessagesParts == 2)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.Messages.ToString()).Attributes
[SearchAttribute].InnerText, term, term);
}
else
{
search = String.Format(SearchDoc.SelectSingleNode
(xPathPart + SearchMethod.Messages.ToString()).Attributes
[SearchAttribute].InnerText, term, term, term);
}
break;
case SearchMethod.NewsItems:
if (NewsItemsParts == 1)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.NewsItems.ToString()).Attributes
[SearchAttribute].InnerText, term);
}
else if (NewsItemsParts == 2)
{
search = String.Format(SearchDoc.SelectSingleNode
(xPathPart + SearchMethod.NewsItems.ToString()).Attributes
[SearchAttribute].InnerText, term, term);
}
else
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.NewsItems.ToString()).Attributes
[SearchAttribute].InnerText, term, term, term);
}
break;
case SearchMethod.Questions:
if (QuestionsParts == 1)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.Questions.ToString()).Attributes
[SearchAttribute].InnerText, term);
}
else if (QuestionsParts == 2)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.Questions.ToString()).Attributes
[SearchAttribute].InnerText, term, term);
}
else
{
search = String.Format(SearchDoc.SelectSingleNode
(xPathPart + SearchMethod.Questions.ToString()).Attributes
[SearchAttribute].InnerText, term, term, term);
}
break;
case SearchMethod.TechnicalBlogs:
if (TechnicalBlogsParts == 1)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.TechnicalBlogs.ToString()).Attributes
[SearchAttribute].InnerText, term);
}
else if (TechnicalBlogsParts == 2)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.TechnicalBlogs.ToString()).Attributes
[SearchAttribute].InnerText, term, term);
}
else
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.TechnicalBlogs.ToString()).Attributes
[SearchAttribute].InnerText, term, term, term);
}
break;
case SearchMethod.TipsTricks:
if (TipsTricksParts == 1)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.TipsTricks.ToString()).Attributes
[SearchAttribute].InnerText, term);
}
else if (TipsTricksParts == 2)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.TipsTricks.ToString()).Attributes
[SearchAttribute].InnerText, term, term);
}
else
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.TipsTricks.ToString()).Attributes
[SearchAttribute].InnerText, term, term, term);
}
break;
case SearchMethod.YourBookMarks:
if (YourBookMarksParts == 1)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.YourBookMarks.ToString()).Attributes
[SearchAttribute].InnerText, term);
}
else if (YourBookMarksParts == 2)
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.YourBookMarks.ToString()).Attributes
[SearchAttribute].InnerText, term, term);
}
else
{
search = String.Format(SearchDoc.SelectSingleNode(xPathPart +
SearchMethod.YourBookMarks.ToString()).Attributes
[SearchAttribute].InnerText, term, term, term);
}
break;
}
return search;
}
}
}
Now that we have this class, you will notice that our switch statement switches between our SearchMethod enum. The code for this looks like this:
using System;
namespace CodeProjectSearch
{
public enum SearchMethod
{
Answers,
Articles,
Everything,
CatalogItems,
JustYours,
Messages,
NewsItems,
Questions,
TechnicalBlogs,
TipsTricks,
YourBookMarks
}
}
Nice small little .cs file doesn't take up much room. :) Now to get the two classes to work together to retrieve our search link to load in our browser, we have a few other small little .cs files. I could have made this class call it directly but I wanted to call as an object in a way to show you a nice way to call and enum via Enum.Parse. Here is the object struct.
using System;
namespace CodeProjectSearch
{
internal struct SearchMethodObject
{
internal static SearchMethod NewSearchMethod(Object obj)
{
return (SearchMethod)obj;
}
}
}
Now that we have our enum correctly converted to an object, it's time to put our large .cs switch struct slash string and our SearchMethod object together to create our URL. Here is the code to do just that:
using System;
namespace CodeProjectSearch
{
public struct CodeProjectUrl
{
public static string Get(string term, Object obj)
{
return SearchTerm.SearchString(term, SearchMethodObject.NewSearchMethod(obj));
}
}
}
Now that our URL is constructed, all we have to do is call webrowser1.Navigate("url to navigate to"); but I have never been a fan of calling webbrowser1.Navigate so I have a small little trick I would like to share. First click on your WebBrowser control and look in the properties for a setting called modifiers and change it to internal. This property allows you to set the visibility of a control [Note by default Controls visibility are set to private]. YOU NEVER WANT TO SET A CONTROL'S VISIBILITY TO PUBLIC!! This opens the Control up to using outside of your application which makes your application weak to security and virus threats, when internal the control is accessible from within the application over other forms but not outside of your application. Now comes the tricky part. Look for the code in Form1 by default but my main form is MainForm. Look for code in MainForm.Designer.cs that reads internal WebBrowser webBrowser1 and change to internal static Webbrowser webBrowser1. Now that this is done, you will notice that the designer is showing errors, this is because this and base cannot be called within a static or abstract class or on a static control, so all we have to do is remove this. From this.webBrowser1 anywhere it appears in our code. Now that this is done, add a class - the name that I have chosen is CodeProject once the .cs file shows change public class CodeProject {} to public abstract class CodeProject : MainForm { } then we will create a void a static void in this class for our webBrowser1.Navigate command, and this is what it will look like:
using System;
using System.Windows.Forms;
namespace CodeProjectSearch
{
public abstract class CodeProject : MainForm
{
internal static readonly string SettingsDocument =
Application.StartupPath + @"\CodeSearch.xml";
public static void GoSearch(string term, Object obj)
{
SearchNavigator.Navigate(CodeProjectUrl.Get(term, obj));
}
}
}
Now from our MainForm, we would call the method as such:
CodeProject.GoSearch(SearchBox.Text, Enum.Parse((typeof(SearchMethod)), "Articles"));
Quick Point: You can use Enum.Parse on any enum :) like this:
public Keys KeyBoard_Key()
{
return (Keys)Enum.Parse((typeof(Keys)),"A");
}
Points of Interest
Please feel free to leave a comment or questions below and I will get back to you.
History
- 2011, Tuesday May 3: Initial post
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