public async Task AddScrapeEvent(int templateId, ScrapeEvent scrapeEvent)
{
// Get the target template.
var dbTemplate = DbContext.Templates
.First(t => t.TemplateId == templateId);
// Map the object to the corresponding DAL model.
var dbScrapeEvent = Mapper.Map <DAL.ScrapeEvent>(scrapeEvent);
// Add the mapped event to the database and save the changes.
dbTemplate.ScrapeEvents.Add(dbScrapeEvent);
await DbContext.SaveChangesAsync();
}
public static async Task ScrapeAllSources()
{
//var dataSources = await SourceClient.GetSourcesAsync();
var areasOfConcern = await AreaClient.GetAreasAsync();
var allTemplates = await TemplateClient.GetTemplatesAsync();
var topLevelBrowser = new ScrapingBrowser();
// Dunno what these do but the tutorial had them.
//topLevelBrowser.AllowAutoRedirect = true;
//topLevelBrowser.AllowMetaRedirect = true;
foreach (var area in areasOfConcern)
{
foreach (var entryPoint in area.EntryPoints)
{
// Get a scraping Template for the Source associated with the current Entry Point.
var topLevelTemplate = allTemplates
.First(t => t.SourceId == entryPoint.SourceId && t.IsTopLevel);
// Create new scraping event and assign the area ID.
var scrapingEvent = new ScrapeEvent();
scrapingEvent.AreaId = area.AreaId;
// Create the record collection.
scrapingEvent.Records = new System.Collections.ObjectModel.ObservableCollection <ScrapeRecord>();
// Begin scraping from the top-level Template.
ScrapeFromTemplate(topLevelBrowser, scrapingEvent, entryPoint.EntryPointUri, topLevelTemplate, allTemplates);
// Send scraping event to the WebServices to be added to the database.
await TemplateClient.AddScrapeEventAsync(topLevelTemplate.TemplateId, scrapingEvent);
}
}
}
private static void ScrapeFromTemplate(ScrapingBrowser scrapingBrowser, ScrapeEvent scrapingEvent, string templateUri, TemplateInstructions sourceTemplate, System.Collections.ObjectModel.ObservableCollection <TemplateInstructions> allTemplates)
{
// If the lock is not set to true, then scraping has begun for a new record (new property).
//if (!scrapingEvent.LockOnCurrentRecord)
//{
// scrapingEvent.Records.Add(new ScrapeRecord());
//}
var entryUri = new Uri(templateUri);
var pageResult = scrapingBrowser.NavigateToPage(entryUri);
var scraperPointer = pageResult.Html;
// Perform setup actions for current Template.
scraperPointer = PerformTemplateSetup(scraperPointer, sourceTemplate.OrderedSetup);
// If the source template is a top-level template then looping over several items is necessary.
if (sourceTemplate.IsTopLevel)
{
Console.WriteLine($"Traveling to top-level template @ {templateUri}");
// Loop through each scrapable item and following all Scraping Steps for each Template Field to gather together the complete record.
while (scraperPointer != null)
{
// If this record violates any disqualifiers then skip it.
if (sourceTemplate.Disqualifiers.Count() != 0)
{
var disqualifyRecord = false;
foreach (var disqualifier in sourceTemplate.Disqualifiers)
{
switch (disqualifier.DisqualificationType)
{
case DisqualificationType.RecordNodeHasClass:
var classAttr = scraperPointer.Attributes["class"];
if (classAttr != null && classAttr.Value.Contains(disqualifier.Parameters))
{
disqualifyRecord = true;
}
break;
default:
throw new Exception("Invalid or unknown disqualifier.");
}
if (disqualifyRecord)
{
break;
}
}
if (disqualifyRecord)
{
// Move pointer to next property and continue.
scraperPointer = scraperPointer.NextSibling;
continue;
}
}
// Create a record for the new property.
var newRecord = new ScrapeRecord();
// Create needed dictionaries.
newRecord.TargetFieldIdToValueDictionary = new Dictionary <string, string>();
newRecord.TemporaryFieldIdToValueDictionary = new Dictionary <string, string>();
// Add the new record to the current event.
scrapingEvent.Records.Add(newRecord);
SinglePassScrapeTemplate(scrapingBrowser, scrapingEvent, scraperPointer, sourceTemplate, allTemplates);
// Move pointer to next property.
scraperPointer = scraperPointer.NextSibling;
}
}
else
{
Console.WriteLine($"\nTraveling to child template @ {templateUri}");
SinglePassScrapeTemplate(scrapingBrowser, scrapingEvent, scraperPointer, sourceTemplate, allTemplates);
// Child templates are the last things that are handled in the scraping order. Once a child template is broken out of set the record lock to false since a new record is about to begin (nested child template depth should be irrelevant).
//scrapingEvent.LockOnCurrentRecord = false;
}
}
private static void PerformScrapingForTemplateField(HtmlNode pointer, TargetTemplateField templateField, ScrapeEvent scrapeEvent, string rootUri)
{
string targetValue = null;
var jsonSerializer = new JavaScriptSerializer();
foreach (var setupStep in templateField.OrderedScrapingSteps)
{
switch (setupStep.ActionType)
{
case ScrapingActionType.CssSelect:
pointer = pointer
.CssSelect(setupStep.Parameters)
.First();
break;
case ScrapingActionType.FirstDescendantNodeOfType:
pointer = pointer
.Descendants()
.First(c => c.Name == setupStep.Parameters);
break;
case ScrapingActionType.FirstDescendantNodeOfTypeAttrsVals:
var firstDescendantNodeOfTypeAttrsValsParams = new FirstDescendantNodeOfTypeAttrsValsParams();
firstDescendantNodeOfTypeAttrsValsParams = jsonSerializer
.Deserialize <FirstDescendantNodeOfTypeAttrsValsParams>(setupStep.Parameters);
var possibleChoices = pointer
.Descendants()
.Where(n => n.Name == firstDescendantNodeOfTypeAttrsValsParams.Node);
// All attribute-value pairs must be present.
for (var i = 0; i < firstDescendantNodeOfTypeAttrsValsParams.Attributes.Count(); i++)
{
var attribute = firstDescendantNodeOfTypeAttrsValsParams.Attributes[i];
var correspondingValue = firstDescendantNodeOfTypeAttrsValsParams.Values[i];
possibleChoices = possibleChoices
.Where(n =>
n.Attributes.Contains(attribute) &&
n.Attributes[attribute].Value == correspondingValue);
}
// If a depth value is given, grab the Nth descendant. Otherwise, grab the first.
if (firstDescendantNodeOfTypeAttrsValsParams.Depth.HasValue)
{
pointer = possibleChoices.ElementAt(firstDescendantNodeOfTypeAttrsValsParams.Depth.Value - 1);
}
else
{
pointer = possibleChoices.First();
}
break;
case ScrapingActionType.NthDescendantNodeOfType:
break;
case ScrapingActionType.SelectInnerText:
targetValue = pointer.InnerText;
break;
case ScrapingActionType.SelectAttributeValue:
targetValue = pointer.Attributes[setupStep.Parameters].Value;
break;
//case ScrapingActionType.SelectInnerTextTemporaryValue:
// temporaryValueKey = setupStep.Parameters;
// targetValue = pointer.InnerText;
// break;
// Perform no action - navigation can't ocur in a static method.
case ScrapingActionType.TravelToChildTemplate:
break;
case ScrapingActionType.TemporaryTravelToDerivedLocation:
var temporaryBrowser = new ScrapingBrowser();
var entryUri = new Uri(rootUri + targetValue);
var pageResult = temporaryBrowser.NavigateToPage(entryUri);
pointer = pageResult.Html;
break;
case ScrapingActionType.SplitData:
var splitDataParams = new SplitDataParams();
splitDataParams = jsonSerializer
.Deserialize <SplitDataParams>(setupStep.Parameters);
var location = pointer.InnerText.IndexOf(splitDataParams.Split);
for (var i = 0; i < splitDataParams.Index; i++)
{
location = pointer.InnerText.IndexOf(splitDataParams.Split, location);
}
//var splitSubstring = pointer.InnerText.Substring()
break;
case ScrapingActionType.ReplaceInstancesOf:
var replaceInstancesOfParams = new ReplaceInstancesOfParams();
replaceInstancesOfParams = jsonSerializer
.Deserialize <ReplaceInstancesOfParams>(setupStep.Parameters);
targetValue = targetValue.Replace(replaceInstancesOfParams.Replace, replaceInstancesOfParams.With);
break;
case ScrapingActionType.RemoveOutsideOfBordersExclusive:
var removeOutsideOfBordersParams = new RemoveOutsideOfBordersParams();
removeOutsideOfBordersParams = jsonSerializer
.Deserialize <RemoveOutsideOfBordersParams>(setupStep.Parameters);
var left = removeOutsideOfBordersParams.Left;
var right = removeOutsideOfBordersParams.Right;
var leftLen = left.Length;
var indexOfRight = targetValue.IndexOf(right);
var indexOfLeft = targetValue.LastIndexOf(left, indexOfRight);
targetValue = targetValue.Substring(indexOfLeft + left.Length, indexOfRight - indexOfLeft - leftLen);
break;
case ScrapingActionType.Trim:
targetValue = targetValue.Trim();
break;
case ScrapingActionType.NodeWithInnerTextSubstring:
var nodeWithInnerTextSubstringParams = new NodeWithInnerTextSubstringParams();
nodeWithInnerTextSubstringParams = jsonSerializer
.Deserialize <NodeWithInnerTextSubstringParams>(setupStep.Parameters);
pointer = pointer
.Descendants()
.First(n => n.Name == nodeWithInnerTextSubstringParams.Node &&
n.InnerText.Contains(nodeWithInnerTextSubstringParams.Substring));
break;
default:
throw new Exception("Invalid or unknown setup step.");
}
}
var scrapeRecord = scrapeEvent.Records.Last();
// Add recovered value to the scrape event field value dictionary.
var stringTempFieldId = templateField.TargetFieldId.ToString(); // .TemplateFieldId.Value
if (targetValue != null)
{
if (templateField.IsTemporaryField)
{
scrapeRecord.TemporaryFieldIdToValueDictionary.Add(stringTempFieldId, targetValue);
}
else
{
scrapeRecord.TargetFieldIdToValueDictionary.Add(stringTempFieldId, targetValue);
}
}
}
private static void SinglePassScrapeTemplate(ScrapingBrowser scrapingBrowser, ScrapeEvent scrapingEvent, HtmlNode scraperPointer, TemplateInstructions sourceTemplate, System.Collections.ObjectModel.ObservableCollection <TemplateInstructions> allTemplates)
{
var absoluteUri = scrapingBrowser.Referer.AbsoluteUri;
var rootUri = absoluteUri.Substring(0, absoluteUri.IndexOf('/', 8));
foreach (var templateField in sourceTemplate.TemplateFields)
{
if (templateField.OrderedScrapingSteps.Count() == 0)
{
continue;
}
try
{
PerformScrapingForTemplateField(scraperPointer, templateField, scrapingEvent, rootUri);
}
catch (Exception ex)
{
Console.WriteLine($"\t\"{templateField.Name}\" field missing from entry.");
}
// Perform navigation action if the last step of a template's scraping instructions dictates it.
var lastStep = templateField.OrderedScrapingSteps.Last();
if (lastStep.ActionType == ScrapingActionType.TravelToChildTemplate)
{
var jsonSerializer = new JavaScriptSerializer();
var travelToChildTemplateParams = new TravelToChildTemplateParams();
travelToChildTemplateParams = jsonSerializer
.Deserialize <TravelToChildTemplateParams>(lastStep.Parameters);
// Need child template instructions.
var childTemplateId = travelToChildTemplateParams.Child;
var childTemplate = allTemplates
.First(t => t.TemplateId == childTemplateId && !t.IsTopLevel);
int targetFieldId;
var sourceIsNumericId = int.TryParse(travelToChildTemplateParams.Source, out targetFieldId);
string targetUri;
// The target URI was saved as a temporary field.
if (travelToChildTemplateParams.IsFromTemporaryField)
{
targetUri = scrapingEvent.Records.Last().TemporaryFieldIdToValueDictionary[targetFieldId.ToString()];
}
// The target URI is a standard, non-temporary field.
else
{
targetUri = scrapingEvent.Records.Last().TargetFieldIdToValueDictionary[targetFieldId.ToString()];
}
// Set record lock so that the same record is used.
scrapingEvent.LockOnCurrentRecord = true;
ScrapeFromTemplate(scrapingBrowser, scrapingEvent, rootUri + targetUri, childTemplate, allTemplates);
}
}
}
public async Task AddScrapeEvent(int templateId, [FromBody] ScrapeEvent scrapeEvent)
{
await TempSvc.AddScrapeEvent(templateId, scrapeEvent);
}
