Updating Grid with a WebService

[Tracy Cole]

I'm working with a Grid based on the online demo using the Stock Quote WebService.    I want to be able to use the name of the stock and/or index instead of the symbol.     I've changed the yahooFeedTemplate URL to return the name, but the code breaks whenever a name contains a comma.   Has anyone worked with the StockQuoteService and modified it to handle names with commas?   Also, would it be possible to return an additional field to my grid based on an evaluation of the change in price.   For example, if the change percentage is positive return GridImage.ImageUrl = "Images/Up.gif" or GridImage.Image.Url = "Images/Down.gif" if it is negative.    The code in the StockQuoteService is little more complex than I'm used to working with, so thanks in advance for any assistance.  Note, in the code below I'm still referring to StockTicker but the first item returned from the Yahoo feed is actually the name.

	Imports System
	Imports System.Collections.Generic
	Imports System.ComponentModel
	Imports System.Data
	Imports System.IO
	Imports System.Net
	Imports System.Text
	Imports System.Web
	Imports System.Web.Services
	Imports System.Xml
	Imports System.Globalization
	<WebService([Namespace]:="http://www.telerik.com/"), WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)> _
	Public Class StockQuoteService
	Inherits WebService
	Private random As Random
	Private yahooFeedTemplate As String = "http://finance.yahoo.com/d/quotes.csv?s={0}&f=nl1d1t1c1ohgv&e=.csv"
	Public Sub New()
	random = New Random(DateTime.Now.Millisecond)
	End Sub
	Property SessionQuotesData() As String
	Get
	Return HttpContext.Current.Session("TelerikAspAjaxGridApplication")
	End Get
	Set(ByVal value As String)
	HttpContext.Current.Session("TelerikAspAjaxGridApplication") = value
	End Set
	End Property
	<WebMethod(), Description("Gets stock quote for a specific symbol")> _
	Public Function GetStockQuotes(ByVal stockTickers As String) As DataSet
	Dim stockTickerList As String() = stockTickers.Split(","c)
	Dim index As Integer
	For index = 0 To stockTickerList.Length - 1
	stockTickerList(index) = stockTickerList(index).Trim()
	Next index
	Dim quotes As List(Of Quote) = New List(Of Quote)
	Dim url As String = String.Empty
	Dim webRequest As WebRequest = Nothing
	Dim webResponse As WebResponse = Nothing
	Dim stockTicker As String
	For Each stockTicker In stockTickerList
	url = String.Format(yahooFeedTemplate, HttpUtility.UrlEncode(stockTicker))
	webRequest = HttpWebRequest.Create(url)
	webResponse = webRequest.GetResponse()
	Dim quote As Quote = GetQuoteData(webResponse.GetResponseStream())
	quotes.Add(quote)
	Next stockTicker
	SerializeQuotesData(quotes)
	Dim dataset As New DataSet("QuotesDataSet")
	Dim data As XmlReader = XmlReader.Create(New System.IO.StringReader(SessionQuotesData))
	dataset.ReadXml(data)
	Return dataset
	End Function
	Private Overloads Function GetQuote(ByVal bufferList() As String) As Quote
	Dim stockTicker As String = bufferList(0)
	Dim stockQuote As [Decimal] = [Decimal].Parse(bufferList(1), CultureInfo.InvariantCulture)
	Dim lastUpdated As DateTime = DateTime.Parse((bufferList(2) + " " + bufferList(3)), CultureInfo.InvariantCulture)
	Dim change As [Decimal] = [Decimal].Parse(bufferList(4), CultureInfo.InvariantCulture)
	Dim dailyMaxRange As [Decimal] = 0D
	If (bufferList(6) <> "N/A") Then
	dailyMaxRange = [Decimal].Parse(bufferList(6), CultureInfo.InvariantCulture)
	End If
	Dim dailyMinRange As [Decimal] = 0D
	If (bufferList(7) <> "N/A") Then
	dailyMinRange = [Decimal].Parse(bufferList(7), CultureInfo.InvariantCulture)
	End If
	Return New Quote(stockTicker, stockQuote, lastUpdated, change, dailyMinRange, dailyMaxRange)
	End Function
	Private Overloads Function GetQuote(ByVal quoteNode As XmlNode) As Quote
	Dim stockTicker As String = quoteNode.Attributes("stockTicker").Value
	Dim stockQuote As [Decimal] = [Decimal].Parse(quoteNode.Attributes("lastTrade").Value, CultureInfo.InvariantCulture)
	Dim lastUpdated As DateTime = DateTime.Parse(quoteNode.Attributes("lastUpdated").Value, CultureInfo.InvariantCulture)
	Dim change As [Decimal] = [Decimal].Parse(quoteNode.Attributes("change").Value, CultureInfo.InvariantCulture)
	Dim dailyMaxRange As [Decimal] = IIf(quoteNode.Attributes("dailyMaxRange").Value = "N/A", 0D, [Decimal].Parse(quoteNode.Attributes("dailyMaxRange").Value, CultureInfo.InvariantCulture))
	Dim dailyMinRange As [Decimal] = IIf(quoteNode.Attributes("dailyMinRange").Value = "N/A", 0D, [Decimal].Parse(quoteNode.Attributes("dailyMinRange").Value, CultureInfo.InvariantCulture))
	Return New Quote(stockTicker, stockQuote, lastUpdated, change, dailyMinRange, dailyMaxRange)
	End Function
	Private Function GetQuoteData(ByVal dataStream As Stream) As Quote
	Dim buffer As String = Nothing
	Dim sr As New StreamReader(dataStream)
	Try
	buffer = sr.ReadToEnd()
	Finally
	sr.Dispose()
	End Try
	buffer = buffer.Replace("""", "")
	buffer = buffer.Replace(ControlChars.Cr + ControlChars.Lf, "")
	Dim bufferList As String() = buffer.Split(New Char() {","c})
	Dim quote As Quote = GetQuote(bufferList)
	Return quote
	End Function
	Private Function GetQuotesData(ByVal xmlData As String) As List(Of Quote)
	Dim xmlDocument As New XmlDocument()
	xmlDocument.LoadXml(xmlData)
	Dim quotes As List(Of Quote) = New List(Of Quote)
	Dim quote As Quote = Nothing
	Dim quoteNode As XmlNode
	For Each quoteNode In xmlDocument.DocumentElement.ChildNodes
	quote = GetQuote(quoteNode)
	quotes.Add(quote)
	Next quoteNode
	Return quotes
	End Function
	Private Sub SerializeQuotesData(ByVal quotes As List(Of Quote))
	Dim str As StringBuilder = New StringBuilder("<quotes>")
	Try
	Dim quote As Quote
	For Each quote In quotes
	str.Append("<quote ")
	str.Append("stockTicker=""" & quote.StockTicker & """ ")
	str.Append("lastTrade=""" & quote.StockQuote.ToString(CultureInfo.InvariantCulture) & """ ")
	str.Append("change=""" & quote.Change.ToString(CultureInfo.InvariantCulture) & """ ")
	str.Append("lastUpdated=""" & quote.LastUpdated.ToString("MM/dd/yyyy HH:mm:ss") & """ ")
	str.Append("dailyMaxRange=""" & quote.DailyMaxRange.ToString(CultureInfo.InvariantCulture) & """ ")
	str.Append("dailyMinRange=""" & quote.DailyMinRange.ToString(CultureInfo.InvariantCulture) & """ ")
	str.Append(" />")
	Next quote
	Catch e As Exception
	End Try
	str.Append("</quotes>")
	SessionQuotesData = str.ToString()
	End Sub
	End Class

[Tracy Cole]

I'm still trying to figure this out on my own and I'm focusing in on the GetQuoteData function, which is parsing the stream based on the comma.   What I think I need is a function that will work with a CSV that contains quotes in addition to the comma delimiters.    For example, the Yahoo CSV for the S&P 500 looks like this:

"S&P 500 INDEX,RTH",979.62,"7/28/2009","4:42pm",-2.56,981.48,982.35,969.35,4272553984





The StockQuoteService as written bombs on the name since it has a comma in it.

[Nikolay Rusev]

Hello Tracy,

The demo simply illustrates possible way of binding RadGrid it is really out of it's scope to demonstrate how to parse any data returned from service.

However for your scenario you can use the following code to parse CSV format:

protected void Page_Load(object sender, EventArgs e)
    {
           string s = @"""S&P 500 INDEX,RTH"",979.62,""7/28/2009"",""4:42pm"",-2.56,981.48,982.35,969.35,4272553984";
           List<string> parsedData = ParseData(s);
    }

    public List<string> ParseData(string data)
    {
        Regex reg = new Regex(@"\s*(""[^""]*""|.*?)\s*,", RegexOptions.Compiled);
        return reg.Split(data).Where(str=>str != string.Empty).Select(str=>str).ToList();
    }

I hope this helps.

Regards,
Nikolay
the Telerik team

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