public static void EnsureTag(Tag[] allTags, ITaggable taggable, Tag tag)
{
// we change taggable (e.g. Link) but do not call dbContext.Update as this is done
// by caller. this way we can prevent Modified-property on taggable being updated,
// just because TagString changed (e.g. when tag hierarchy has changed). if we add
// a tag to a taggable, dbContext.Update should be called by caller, as he is actually
// changing the taggable.
string currentTagString = taggable.TagString ?? string.Empty;
bool hasTags = !string.IsNullOrEmpty(currentTagString);
string tagPath = GetTagPath(allTags, tag);
if (hasTags && currentTagString.Contains(tagPath))
{
return;
}
taggable.TagString = hasTags
? string.Concat(currentTagString, Separator, tagPath)
: tagPath;
}
private static string GetTagPath(Tag[] allTags, Tag tag)
{
Tag current = tag;
var tagIds = new List<int>();
while (current != null)
{
tagIds.Add(current.Id);
current = allTags.SingleOrDefault(t => t.Id == current.ParentId);
}
tagIds.Reverse();
return string.Concat(PathStarter, JoinTagPathElements(tagIds.ToArray()), PathEnder);
}
public static void EnsureTag(IDbContext dbContext, ITaggable taggable, Tag tag)
{
EnsureTag(dbContext.Tags.ToArray(), taggable, tag);
}
public static void SyncTagStringWithTagIds(IDbContext dbContext, Tag[] allTags, Link link)
{
link.ClearTagString();
foreach (Tag tag in link.TagIds
.Select(tagId => allTags.FirstOrDefault(t => t.Id == tagId))
.Where(t => t != null))
{
EnsureTag(allTags, link, tag);
}
}