protected override IEnumerable <Post> PreSave(IEnumerable <Post> items, RedditEntities db)
{
documentRemover.RemoveDocuments(items.ToList <IDocument>());
// No need to filter posts.
return(items);
}
public virtual void Save(IEnumerable <T> items)
{
if (items.Any())
{
try
{
using (var db = new RedditEntities(Connection))
{
var filtered = PreSave(items, db);
GetDbSet(db).AddRange(filtered);
db.SaveChanges();
}
}
catch (DbEntityValidationException ex)
{
var list = string.Join(",", items);
Log.Error($"Error validating item of type {itemType}: {list}", ex);
var errors =
ex.EntityValidationErrors.Select(
e => string.Join(Environment.NewLine,
e.ValidationErrors.Select(v => $"{v.PropertyName} - {v.ErrorMessage}")) +
" Entity: " + e.Entry.Entity);
foreach (var error in errors)
{
Log.Error($"----Validation error: {error}");
}
}
}
protected override DbSet <PostCommentCount> GetDbSet(RedditEntities db)
{
return(db.PostCommentCounts);
}
protected override IEnumerable <PostCommentCount> PreSave(IEnumerable <PostCommentCount> items, RedditEntities db)
{
var ids = items.Select(x => x.PostId);
var existingItems = (from postCommentCount in db.PostCommentCounts
where ids.Contains(postCommentCount.PostId)
select postCommentCount).ToList();
db.PostCommentCounts.RemoveRange(existingItems);
db.SaveChanges();
return(items);
}
protected override DbSet <UserDefinedEntityDefinition> GetDbSet(RedditEntities db)
{
return(db.UserDefinedEntityDefinitions);
}
protected override DbSet <EmbeddedUrl> GetDbSet(RedditEntities db)
{
return(db.EmbeddedUrls);
}
/// <summary>
/// Pre-save hook. Allows user to filter items before the actual write.
/// </summary>
/// <param name="items"></param>
/// <param name="db"></param>
/// <returns>Items that will be written to the database</returns>
protected virtual IEnumerable <T> PreSave(IEnumerable <T> items, RedditEntities db)
{
return(items);
}
protected override IEnumerable <Comment> PreSave(IEnumerable <Comment> items, RedditEntities db)
{
// Delete all comments. Even the invalid comments.
// A comment may be made on Reddit, ingested by us, then deleted.
// On the next poll this comment will be seen as an InvalidComment. We want
// to remove it from the DB along with all the other comments.
this.documentRemover.RemoveDocuments(items.ToList <IDocument>());
// Do not write the invalid comments.
return(items.Where(x => !(x is InvalidComment)));
}
