private IOrderedQueryable <CryptoCurrency> Query()
{
/* build query for databse */
var db = new CryptoCurrencyContext();
var query = from crypcur in db.CryptoCurrencies
where crypcur.Name == Name && (crypcur.TimeStamp <= TimeStamp)
orderby crypcur.TimeStamp
select crypcur;
/* if there is no data in the query result then print error */
if (query.Count() < 1)
{
Console.WriteLine("Query Error: Name=" + Name + "TimeStamp=" + TimeStamp);
}
return(query);
}
/* Database writing of scraped data */
private static void AddCryptoCurrency(CryptoCurrencyContext db, CryptoCurrency cryptoCurrency)
{
db.CryptoCurrencies.Add(cryptoCurrency);
db.SaveChanges();
}
public void Execute()
{
/* Set-up for using Chrome for to browse wesite */
IWebDriver driver = new ChromeDriver();
driver.Navigate().GoToUrl("https://coinmarketcap.com/");
/* Get reference to Currency table with unique identifier */
IWebElement table = driver.FindElement(By.Id("currencies"));
/* Get a collection tr tags in the table */
List <IWebElement> rows = table.FindElements(By.TagName("tr")).ToList();
//Console.WriteLine("rows: " + rows.Count);
/* Collection of CryptoCurrency */
var cryptocurrencies = new List <CryptoCurrency>();
CryptoCurrency cryptocurrency;
/* To capture and store date and time when scraping was done */
DateTime timestamp = DateTime.Now;
/* To setup delimiter to be used for splitting text into words */
char[] delimiterChars = { ' ' };
/* Go thru each table row(tr's) and then process the collection of td's for that row */
foreach (var row in rows)
{
/* Get collection of td's for each tr */
List <IWebElement> tds = row.FindElements(By.TagName("td")).ToList();
//Console.WriteLine("tds: " + rows.Count);
/* Setup counter to track data in a row */
int tdCounter = 1;
cryptocurrency = null;
bool finish = false;
/* Go thru each collection of td's */
foreach (var td in tds)
{ /* if first data element in a row create object for CryptoCurrency */
if (tdCounter == 1)
{
cryptocurrency = new CryptoCurrency();
}
//Console.WriteLine(td.Text);
/* Populate CryptoCurrency object with data from a row */
switch (tdCounter)
{
case 1:
{
int itemNo;
/* Convert String data to int without triggering an exception */
if (Int32.TryParse(td.Text, out itemNo))
{
cryptocurrency.Item = itemNo;
}
else
{
Console.WriteLine("ItemNo Conversion Failed");
}
break;
}
case 2:
{
cryptocurrency.Name = td.Text;
break;
}
case 3:
{
cryptocurrency.MarketCap = td.Text;
break;
}
case 4:
{
cryptocurrency.Price = td.Text;
break;
}
case 5:
{
cryptocurrency.Volume = td.Text;
break;
}
case 6:
{
/* Splitting data into separate words and using only word required */
string[] words = td.Text.Split(delimiterChars);
cryptocurrency.Supply = words[0];
break;
}
case 7:
{
cryptocurrency.Change = td.Text;;
break;
}
case 8:
{
/* Use common datetime for all Currenies during scraping session */
cryptocurrency.TimeStamp = timestamp;
/* Last item completed; mark object ready for collection */
finish = true;
break;
}
default:
{
/* catch all for data you are not interested in */
//System.Console.WriteLine("Other number");
break;
}
}
tdCounter++;
}
/* Move Currency object to collection */
if (finish)
{
cryptocurrencies.Add(cryptocurrency);
}
}
var db = new CryptoCurrencyContext();
/* Go thru Curreny Collection and echo to console and populate database */
foreach (var cc in cryptocurrencies)
{
//Console.WriteLine("Item:"+ cc.Item + " Name:" + cc.Name + " MarketCap:" + cc.MarketCap + " Price:" + cc.Price );
Console.WriteLine("Item:" + cc.Item + " Name:" + cc.Name + " MarketCap:" + cc.MarketCap + " Price:" + cc.Price + " Volume:" + cc.Volume + " Supply:" + cc.Supply + " Change:" + cc.Change + " TimeStamp:" + cc.TimeStamp);
/* Populate database */
AddCryptoCurrency(db, cc);
}
/* Generate a report from the database base on the name of the currency and a datetime value */
GetCryptoCurrency("Bitcoin", DateTime.Now);
}
