My Woot! Google gadget

My Woot! Google gadget

Though I have known about woot for a while now I have recently started tracking it on a daily basis and decided I needed a woot gadget for my google home. A look at the API reveals that google gadgets are quite easy to create, as you can see in the "Hello World" example below.

<?xml version="1.0" encoding="UTF-8" ?>

<Module>

<ModulePrefs title="hello world example" />

<Content type="html">

<![CDATA[

Hello, world!

]]>

</Content>

</Module>

Inside The CDATA section you can put whatever html you want. I want to put html containing the url of the woot main image, the title and the price. These are all easily scraped from the woot website. I used the HTML Agility pack found on codeplex

http://www.codeplex.com/htmlagilitypack

Using the HTML Agility pack allows you parse HTML documents using XPATH. This is an amazing intuitive mechanism for scraping and allowed me to get what I wanted in just a few minutes.

Code to retrieve the title, image path, and price listed below

HtmlWeb hw = new HtmlWeb();

string url = @"http://www.woot.com";

HtmlDocument doc = hw.Load(url);

HtmlNode ImageNode = doc.DocumentNode.SelectSingleNode("//img[@class='salePic']");

HtmlNode PriceNode = doc.DocumentNode.SelectSingleNode("//span[@id='PriceSpan']");

HtmlNode TitleNode = doc.DocumentNode.SelectSingleNode("//h3[@id='TitleHeader']");

string imgSrc = ImageNode.Attributes["src"].Value;

string priceSpan = PriceNode.InnerText;

string titleText = TitleNode.InnerText;

As you can see, using the HTML Agility pack takes all the pain out of screen scraping a website. Just write the out put to the CDATA section and you are done. I just did this in an aspx page by removing all the standard mark up and replacing it with the xml surrounding CDATA.

%@ Page Language="C#" AutoEventWireup="true" CodeBehind="wootGadget.aspx.cs" Inherits="MyGames.Gadgets.wootGadget" %>

<?xml version="1.0" encoding="UTF-8"?>

<Module>

<ModulePrefs title="woot!" />

<Content type="html"><![CDATA[

<% GetWoot(); %>

]]></Content>

</Module>

The code behind.

sing System;

using System.Collections;

using System.Configuration;

using System.Data;

using System.Linq;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.HtmlControls;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Xml.Linq;

using HtmlAgilityPack;

namespace MyGames.Gadgets

{

public partial class wootGadget : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

}

public void GetWoot()

{

HtmlWeb hw = new HtmlWeb();

string url = @"http://www.woot.com";

HtmlDocument doc = hw.Load(url);

//HtmlNode node = doc.DocumentNode.SelectSingleNode("/html/body/div[position()=1]/div[position()=1]");

HtmlNode ImageNode = doc.DocumentNode.SelectSingleNode("//img[@class='salePic']");

HtmlNode PriceNode = doc.DocumentNode.SelectSingleNode("//span[@id='PriceSpan']");

HtmlNode TitleNode = doc.DocumentNode.SelectSingleNode("//h3[@id='TitleHeader']");

string imgSrc = ImageNode.Attributes["src"].Value;

string priceSpan = PriceNode.InnerText;

string titleText = TitleNode.InnerText;

Response.Write("<span><strong>woot!</strong></span><br />");

Response.Write("<a href='http://www.woot.com/' target='_blank' ><img src='" + imgSrc + "' height='150' style='border:none;float:left;' /></a>");

Response.Write("<span style='font-size:.8em;'>" + titleText + "</span><br />");

Response.Write("<span><strong>" + priceSpan + "</strong></span>");

}

}

}

Log4net .NET Logging

Log4net makes logging in .NET easy. For myself I can say that using logging makes me a far more effective developer. Plus you can turn up interesting stuff :P

3 steps to get log4net

1.) Add the log4net.dll assembly to your project
2.) Modify a *.config file to include an appender
3.) Add code to load the config

1.) Is self explanatory



2.)

<?xml version="1.0"?><configuration>
<configSections> <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,Log4net"/>
</configSections>
<appSettings> <add key="log4net.Internal.Debug" value="true" /> </appSettings>
<log4net>
<root>
<level value="DEBUG" />
<appender-ref ref="LogFileAppender" /> <appender-ref ref="ConsoleAppender" />
</root>
<appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender" >
<param name="File" value="logs/log2.txt" />
<param name="AppendToFile" value="true" />
<rollingStyle value="Size" />
<maxSizeRollBackups value="10" />
<maximumFileSize value="10MB" />
<staticLogFileName value="true" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
</layout>
</appender>
</log4net>
</configuration>

3.) In assembly.info add
[assembly: log4net.Config.XmlConfigurator(Watch = true)]
or
Log4net.Config.XmlConfigurator.Configure()

SQL Cursor Example

I am rarely required to do anything very difficult in SQL, and really SQL doesn’t get THAT difficult so this is maybe the second time I have used a cursor. What follows is a very basic SQL cursor example that I used earlier today. If it mattered more and I had more time I probably would have taken a look at doing this without using a cursor as cursors are non-performant. None-the-less it was a fun exercise. Another fine example,including the non-cursor implementation, can be seen here http://www.sql-server-performance.com/articles/per/operations_no_cursors_p1.aspx

DECLARE @customerId int,

@firstName nvarchar(255)

DECLARE Customer CURSOR FOR

SELECT customerId,

firstName,

FROM CustomerTable

OPEN Customer

FETCH Customer INTO @customerId,

@firstName

WHILE @@Fetch_Status = 0

BEGIN

-- row by row operations

Print

FETCH Customer INTO @customerId,

@firstName,

@vchCustomerName

END

CLOSE Customer

DEALLOCATE Customer

Go