/// <summary>
/// Attempts to update the content of the supplied <see cref="BlogSnippet"/> from
/// a YAML front matter block in the supplied array of lines.
/// </summary>
/// <param name="snippet">The <see cref="BlogSnippet"/> to be updated.</param>
/// <param name="lines">An array of lines possibly containing a YAML front matter block.</param>
private void UpdateFromYamlFrontMatterBlock(BlogSnippet snippet, string[] lines)
{
var linesText = string.Join("\n", lines);
var yaml = StringUtils.ExtractString(linesText, "---", "---", returnDelimiters: true);
if (yaml != null)
{
snippet.Title = StringUtils.ExtractString(yaml, "title: ", "\n");
snippet.Abstract = StringUtils.ExtractString(yaml, "abstract: ", "\n");
snippet.Categories = StringUtils.ExtractString(yaml, "categories: ", "\n")
.Split(new char[] { ',', ' ' }, StringSplitOptions.RemoveEmptyEntries);
snippet.Keywords = StringUtils.ExtractString(yaml, "keywords: ", "\n")
.Split(new char[] { ',', ' ' }, StringSplitOptions.RemoveEmptyEntries);
if (DateTime.TryParse(StringUtils.ExtractString(yaml, "postDate: ", "\n"), out DateTime postedOn))
{
snippet.PostedOn = postedOn;
}
}
}
/// <summary>
/// Gets a collection containing <see cref="BlogSnippet"/> items for all blog posts.
/// </summary>
/// <returns>
/// A collection containing <see cref="BlogSnippet"/> items for all blog posts.
/// </returns>
private async Task <IEnumerable <BlogSnippet> > RetrieveAllAsync()
{
var snippets = new List <BlogSnippet>();
foreach (var path in GetAllPaths())
{
var snippet = new BlogSnippet
{
Url = $"/{path.Substring(path.LastIndexOf("posts")).Replace("\\", "/")}"
};
string markdown = await File.ReadAllTextAsync(path);
string[] firstLines = StringUtils.GetLines(markdown, 30); // Assume YAML front matter block is in first 30 lines
if (markdown.StartsWith("---"))
{
UpdateFromYamlFrontMatterBlock(snippet, firstLines);
}
if (string.IsNullOrEmpty(snippet.Title))
{
foreach (var line in firstLines.Take(10))
{
if (line.TrimStart().StartsWith("# "))
{
snippet.Title = line.TrimStart(new char[] { ' ', '\t', '#' });
break;
}
}
}
if (snippet.PostedOn.Equals(DateTime.MinValue))
{
snippet.PostedOn = GetPostDateFromPath(path);
}
snippets.Add(snippet);
}
return(snippets);
}
