Parsing HTML using HTTP Agility Pack
- by Pajci
Here is one table out of 5:
<h3>marec - maj 2009</h3>
<div class="graf_table">
<table summary="layout table">
<tr>
<th>DATUM</th>
<td class="datum">10.03.2009</td>
<td class="datum">24.03.2009</td>
<td class="datum">07.04.2009</td>
<td class="datum">21.04.2009</td>
<td class="datum">05.05.2009</td>
<td class="datum">06.05.2009</td>
</tr>
<tr>
<th>Maloprodajna cena [EUR/L]</th>
<td>0,96000</td>
<td>0,97000</td>
<td>0,99600</td>
<td>1,00800</td>
<td>1,00800</td>
<td>1,01000</td>
</tr>
<tr>
<th>Maloprodajna cena [SIT/L]</th>
<td>230,054</td>
<td>232,451</td>
<td>238,681</td>
<td>241,557</td>
<td>241,557</td>
<td>242,036</td>
</tr>
<tr>
<th>Prodajna cena brez dajatev</th>
<td>0,33795</td>
<td>0,34628</td>
<td>0,36795</td>
<td>0,37795</td>
<td>0,37795</td>
<td>0,37962</td>
</tr>
<tr>
<th>Trošarina</th>
<td>0,46205</td>
<td>0,46205</td>
<td>0,46205</td>
<td>0,46205</td>
<td>0,46205</td>
<td>0,46205</td>
</tr>
<tr>
<th>DDV</th>
<td>0,16000</td>
<td>0,16167</td>
<td>0,16600</td>
<td>0,16800</td>
<td>0,16800</td>
<td>0,16833</td>
</tr>
</table>
</div>
I have to extract out values, where table header is DATUM and Maloprodajna cena [EUR/L].
I am using Agility HTML pack.
this.htmlDoc = new HtmlAgilityPack.HtmlDocument();
this.htmlDoc.OptionCheckSyntax = true;
this.htmlDoc.OptionFixNestedTags = true;
this.htmlDoc.OptionAutoCloseOnEnd = true;
this.htmlDoc.OptionOutputAsXml = true; // is this necessary ??
this.htmlDoc.OptionDefaultStreamEncoding = System.Text.Encoding.Default;
I had a lot of trouble with getting those values out.
I started with:
var query = from html in doc.DocumentNode.SelectNodes("//div[@class='graf_table']").Cast<HtmlNode>()
from table in html.SelectNodes("//table").Cast<HtmlNode>()
from row in table.SelectNodes("tr").Cast<HtmlNode>()
from cell in row.SelectNodes("th|td").Cast<HtmlNode>()
select new { Table = table.Id, CellText = cell.InnerHtml };
but could not figure out a way to select only values where table header is DATUM and Maloprodajna cena[EUR/L]. Is it possible to do that with where clause?
Then I ended with those two queries:
var date = (from d in htmlDoc.DocumentNode.SelectNodes("//div[@class='graf_table']//table//tr[1]/td")
select DateTime.Parse(d.InnerText)).ToArray();
var price = (from p in htmlDoc.DocumentNode.SelectNodes("//div[@class='graf_table']//table//tr[2]/td")
select double.Parse(p.InnerText)).ToArray();
Is it possible to combine those two queries?
And how would I convert that to lambda expression?
I just started to learn those things and I would like to know how it is done so that in the future I would not have those question.
O, one more question ... does anybody know any graph control, cause I have to show those values in graph.
I started with Microsoft Chart Controls, but I am having trouble with setting it.
So if anyone has any experience with it I would like to know how to set it, so that x axle will show all values not every second ... example:
if I have: 10.03.2009, 24.03.2009, 07.04.2009, 21.04.2009, 05.05.2009, 06.05.2009
it show only: 10.03.2009, 07.04.2009, 05.05.2009, ect.
I bind data to graph like that:
chart1.Series["Series1"].Points.DataBindXY(date, price);
I lot of questions for my fist post ... hehe, hope that I was not indistinct or something.
Thank's for any reply!
