/// <summary>
/// Deletes a tag and its associated posts.
/// </summary>
/// <param name="id"></param>
/// <returns></returns>
/// <remarks>
/// Tag and PostTag are related by FK with cascade delete.
/// </remarks>
public async Task DeleteAsync(int id)
{
var tag = await _entities.SingleAsync(t => t.Id == id);
_db.Remove(tag); // cascade delete will take care of PostTag assoc
await _db.SaveChangesAsync();
}
/// <summary>
/// Deletes a <see cref="Post"/> by Id, if the post is a root page,
/// it will also delete all child pages.
/// </summary>
public async Task DeleteAsync(int id)
{
// SingleAsync will throw if id is not found or not unique
var post = await _entities.SingleAsync(c => c.Id == id);
// root page
if (post.Type == EPostType.Page && post.RootId == 0)
{
var posts = _entities.Where(po => po.RootId == id);
_db.RemoveRange(posts);
}
else
{
_db.Remove(post);
}
await _db.SaveChangesAsync();
}
/// <summary>
/// Deletes a <see cref="Post"/> by Id, if the post is a parent page,
/// it will also delete all child pages.
/// </summary>
public new async Task DeleteAsync(int id)
{
// throws if id not found or not unique
var post = await _entities.SingleAsync(c => c.Id == id);
// if blog post or child page
if (post.Type == EPostType.BlogPost || (post.ParentId.HasValue && post.ParentId > 0))
{
_db.Remove(post);
}
else // parent page which may have children
{
var posts = _entities.Where(p => p.ParentId == id).ToArray();
Array.Resize(ref posts, posts.Length + 1); // put the parent itself in
posts[posts.Length - 1] = post;
_db.RemoveRange(posts);
}
await _db.SaveChangesAsync();
}
/// <summary>
/// Deletes a <see cref="Category"/> by id and re-categorize its posts to the given
/// default category id.
/// </summary>
/// <remarks>
/// Since <see cref="Post.CategoryId"/> is nullable, there is no Cascade Delete between
/// Post and Category, which happens to be what we want. User can choose to delete a
/// category and we should delete all posts associated with that category, instead we
/// apply the default category on these posts.
///
/// The defaultCategoryId is BlogSettings DefaultCategoryId, I choose to have it pass in
/// from BLL for convenience instead of querying Meta for it.
/// </remarks>
public async Task DeleteAsync(int id, int defaultCategoryId)
{
if (id == defaultCategoryId)
{
return;
}
// remove it
var category = await _entities.SingleAsync(c => c.Id == id);
_db.Remove(category);
// update its posts to default category
var posts = _db.Set <Post>().Where(p => p.CategoryId == id);
foreach (var post in posts)
{
post.CategoryId = defaultCategoryId;
}
await _db.SaveChangesAsync();
}
