/// <summary>
/// Called when either a new set of journeys or an extended set of journeys have been retrieved
/// </summary>
/// <param name="journeys"></param>
public void JourneysAvailable(TrainJourneys journeys)
{
// Display them
journeyAdapter.Items = journeys.Journeys.ToArray();
journeyAdapter.NotifyDataSetChanged();
// Update the manual update text
updateTimer.JustUpdated();
}
/// <summary>
/// Retrieve a set of journeys for the specified from and to stations.
/// </summary>
/// <param name="from"></param>
/// <param name="to"></param>
public async void GetJourneys(string from, string to, DateTime requestTime, CancellationToken cancelToken)
{
try
{
// Check if a previously obtained session id cookie is still valid
if ((DateTime.Now - sessionCookieTime).TotalMinutes > SeesionCookieValidTimeInMinutes)
{
// Must load the search page in order to set the session id cookie
await client.GetAsync("http://ojp.nationalrail.co.uk/service/planjourney/search", cancelToken);
// Save the time that this session id was obtained
sessionCookieTime = DateTime.Now;
}
// Set up the variable parameters
requestParameters["from.searchTerm"] = TrainTrip.ToWebFormat(from);
requestParameters["to.searchTerm"] = TrainTrip.ToWebFormat(to);
requestParameters["timeOfOutwardJourney.hour"] = requestTime.Hour.ToString();
requestParameters["timeOfOutwardJourney.minute"] = requestTime.Minute.ToString();
requestParameters["timeOfOutwardJourney.monthDay"] = requestTime.ToString("dd/MM/yy");
// Make the request
HttpResponseMessage response = await client.PostAsync("http://ojp.nationalrail.co.uk/service/planjourney/plan",
new FormUrlEncodedContent( requestParameters ), cancelToken);
// Load the result of the request into an HtmlDocument
HtmlDocument doc = new HtmlDocument();
doc.LoadHtml(await response.Content.ReadAsStringAsync());
// Extract the journey, changes and date change nodes
// The journeys are in table rows that contain cells of class 'dep'. Grab the containing row.
// The changes associated with a journey are not in the same row as the journey so look for a cell with class 'origin'.
// Changes are stored in the containing table. The extracted changes are stored with the last journey.
// Date changes between journeys are contained in table rows with class 'day-heading'.
// If date of the first journey are in an H3 element with class 'outward top ctf-h3'.
HtmlNodeCollection dormNodes = doc.DocumentNode.SelectNodes(
"//td[@class='dep']/..|//td[@class='origin']/..|//h3[@class='outward top ctf-h3']/.|//tr[@class='day-heading']/.");
if (dormNodes != null)
{
// Assume that the journeys found are initially for the same day as the request
DateTime responseDate = requestTime.Date;
TrainJourneys journeys = new TrainJourneys();
// Fill the journeys list with the results
foreach (HtmlNode journeyNode in dormNodes)
{
// Check if this is a train node
if (journeyNode.SelectSingleNode("./td[@class='dep']") != null)
{
TrainJourney newJourney = new TrainJourney {
ArrivalTime = journeyNode.SelectSingleNode("./td[@class='arr']").InnerText.Substring(0, 5),
DepartureTime = journeyNode.SelectSingleNode("./td[@class='dep']").InnerText.Substring(0, 5),
Duration = ReplaceWhitespace(journeyNode.SelectSingleNode("./td[@class='dur']").InnerText),
Status = ReplaceWhitespace(journeyNode.SelectSingleNode("./td[@class='status']").InnerText)
};
// Set the full departure timestamp from the responseDate and the departure time
newJourney.DepartureDateTime = responseDate + TimeSpan.ParseExact(newJourney.DepartureTime, "h\\:mm", CultureInfo.InvariantCulture);
journeys.Journeys.Add(newJourney);
}
else if (journeyNode.SelectSingleNode("./td[@class='origin']") != null)
{
// Only proceed with processing changes if a journey has been found
if (journeys.Journeys.Count > 0)
{
// Get the change data ignoring any empty cells and whitespace
HtmlNodeCollection cells = journeyNode.SelectNodes("./td");
if (cells != null)
{
// Somewhere to save the cell data
List <string> cellContents = new List <string>();
foreach (HtmlNode cell in cells)
{
string innerText = ReplaceWhitespace(cell.InnerText);
if (innerText.Length > 0)
{
cellContents.Add(innerText);
}
}
// There should be 4 entries for a journey leg
if (cellContents.Count == 4)
{
JourneyLeg leg = new JourneyLeg {
DepartureTime = cellContents[0], From = cellContents[1],
ArrivalTime = cellContents[2], To = cellContents[3]
};
journeys.Journeys[journeys.Journeys.Count - 1].Legs.Add(leg);
}
}
}
}
else
{
// If this is either the report header or a date change within the report.
// Extraxct the date
string headerDate = (journeyNode.Name == "h3") ?
ReplaceWhitespace(journeyNode.InnerText).Replace("+", " ").Substring(17, 10) :
ReplaceWhitespace(journeyNode.InnerText);
// Date is now of the format DDD nn MMM where nn could be one or two numeric digits
try
{
responseDate = DateTime.ParseExact(headerDate, new[] { "ddd dd MMM", "ddd d MMM" }, CultureInfo.InvariantCulture, DateTimeStyles.None);
}
catch (FormatException)
{
}
}
}
// Save the journeys so they can be accessed from outside the class
Journeys = journeys.Journeys;
JourneysAvailableEvent?.Invoke(this, new JourneysAvailableArgs {
JourneysAvailable = true
});
}
else
{
JourneysAvailableEvent?.Invoke(this, new JourneysAvailableArgs {
JourneysAvailable = false
});
}
}
catch (HttpRequestException)
{
JourneysAvailableEvent?.Invoke(this, new JourneysAvailableArgs {
JourneysAvailable = false, NetworkProblem = true
});
}
catch (TaskCanceledException)
{
// This can be caused either from a user request or a network problem
if (cancelToken.IsCancellationRequested == true)
{
JourneysAvailableEvent?.Invoke(this, new JourneysAvailableArgs {
JourneysAvailable = false, RequestCancelled = true
});
}
else
{
JourneysAvailableEvent?.Invoke(this, new JourneysAvailableArgs {
JourneysAvailable = false, NetworkProblem = true
});
}
}
catch (OperationCanceledException)
{
JourneysAvailableEvent?.Invoke(this, new JourneysAvailableArgs {
JourneysAvailable = false, NetworkProblem = true
});
}
}