How to set Umbraco Child Node to List<T>

I have a blog export package which exports blog content in Umbraco to XML.

Now I want to export comment data, the comments section is set as a childNode on the NewsItem node, how can I use this format to grab the data from the childNode into the list?

Here is my code:

public List<BlogPosts> getPostList()
{
    var contentType = ApplicationContext.Current.Services.ContentTypeService
        .GetContentType("umbNewsItem");
    var nodes = ApplicationContext.Current.Services.ContentService
        .GetContentOfContentType(contentType.Id).Select(content => new Node(content.Id));

    return nodes.Select(node => new BlogPosts()
    {
        Title = node.GetProperty("title").ToNullSafeString(),
        BodyText = node.GetProperty("bodyText").ToNullSafeString(),
        PublishDate = node.GetProperty("publishDate").ToNullSafeString(),
        Author = node.GetProperty("author").ToNullSafeString(),
        Image = node.GetProperty("image").ToNullSafeString(),
        //This is where I want to grab the blog comments content
        Comments = node.ChildrenAsList.Add("comments") 
    }).ToList();
}

My first attempt with this, I get an error on the .Add("comments") line which reads:

The best overloaded method match for 'System.Collections.Generic.List<umbraco.interfaces.INode>.Add(umbraco.interfaces.INode)' has some invalid arguments

the next thing I tried was this:

Comments = node.ChildrenAsList<BlogComment>.Add("comments").ToList()

which returns the following error:

The property 'umbraco.NodeFactory.Node.ChildrenAsList' cannot be used with type arguments

I have also tried this:

Comments = node.ChildrenAsList.Add("comments").ToList()

which returned this error:

The best overloaded method match for 'System.Collections.Generic.List<umbraco.interfaces.INode>.Add(umbraco.interfaces.INode)' has some invalid arguments

This is my BlogPosts model:

public class BlogPosts
{
    public string Title { get; set; }
    public string BodyText { get; set; }
    public string PublishDate { get; set; }
    public string Author { get; set; }
    public string Image { get; set; }
    public List<BlogComment> Comments { get; set; }
}

public class BlogComment
{
    public string Comment { get; set; }
    public string CommentDate { get; set; }
}

This is an example of the Umbraco backoffice page: Image

I've searched throughout stackoverflow and google for anything which refers to calling data from a childNode into a list but the list type here is INode, when using this:

Comments = node.ChildrenAsList

it returns this error:

Cannot implicitly convert type 'System.Collections.Generic.List<umbraco.interfaces.INode>' to 'System.Collections.Generic.List<UmbracoBlogsExportPackage.Models.BlogComment>'

Solution

Okay then :-)

First of all, .Add() tries to add something to a collection, so that won't work here.
Second, I think selecting Content as Nodes is a bit backwards, so I would try not to do that.
Third, IEnumerable have a Cast() method that I think might work here. I can't really test it, though.

Again, this is very untested, but maybe try something like this? Obviously I don't know the Comment DocType alias, so remember to change that bit :-)

public List<BlogPosts> getPostList()
{
    var contentType = UmbracoContext.Current.Application.Services.ContentTypeService
        .GetContentType("umbNewsItem");
    var contentService = UmbracoContext.Current.Application.Services.ContentService;
    var nodes = contentService.GetContentOfContentType(contentType.Id);

    return nodes.Select(node => new BlogPosts()
    {
        Title = node.GetValue("title").ToNullSafeString(),
        BodyText = node.GetValue("bodyText").ToNullSafeString(),
        PublishDate = node.GetValue("publishDate").ToNullSafeString(),
        Author = node.GetValue("author").ToNullSafeString(),
        Image = node.GetValue("image").ToNullSafeString(),
        //This is where I want to grab the blog comments content
        Comments = contentService.GetChildren(node.Id).Where(x => x.ContentType.Alias == "Comment").Cast<BlogComment>().ToList()
    }).ToList();
}