Blogit

Blogit is a blog engine back-end written in Elixir. It turns a repository (by default git repository), containing markdown files into streams of blog posts, which can be queried. Blogit supports blog configuration in YAML, including blog title, path to custom styles and images, etc.

There is a front-end implementation in Phoenix, which uses Blogit - BlogitWeb. It can be forked and configured to use any repository to build custom blog.

The blog for the Sofia University Elixir course runs on Blogit.

Installation

It is available in Hex, so the package can be installed:

1. Add blogit to your list of dependencies in mix.exs:

   def deps do
     [{:blogit, "~> 1.2"}]
   end

2. Ensure blogit is started before your application:

   def application do
     [applications: [:blogit]]
   end

Configuration

An example configuration for blogit is:

config :blogit,
  repository_url: "https://github.com/ElixirCourse/blog.git",
  polling: true, poll_interval: 300, languages: ~w(en bg de)

Possible settings are:

• repository_url |> Tells Blogit the location of the repository to use to build its contents.
• polling |> Tells Blogit if it should poll the repository specified through repository_url for changes. By default it is true.
• poll_interval |> Used if polling is set to true. The polling for changes will happen on this interval of seconds. By default it is 10 seconds.
• repository_provider |> Specified a specific implementation of the Blogit.RepositoryProvider behaviour. By default it uses Blogit.RepositoryProviders.Git which works with git repositories and knows how to check for changes in them.
• configuration_file |> Path to YAML file in the repository, which contains configuration for the blog. By default it is blog.yml.
• languages |> A list of language codes. By default it is ["en"]. The first language of the list is the default and primaty language. If there are alternative languages, if post source files are created in the folder <repo-root>/posts/<lang-code>, the posts compiled from them are marked that are in the given language. They can be queried with Blogit.list_posts(language: "<lang-code>").
• max_lines_in_preview |> The maximum lines to be used from the content of the original post source to generate its preview. The preview is generated from the beginning of the content and contains maximum max_lines_in_preview lines. By default this value is 10.

Using these settings a custom blog can be created from whatever repository. It is not hard to write FTP repository provider or Ecto repository provider.

Usage

Blogit has a public interface which can be used to build a blog similar to BlogitWeb. When the application is configured and started, the following functions can be called:

• Blogit.list_posts(options)

  Returns a list of Blogit.Models.Post.Meta structs representing posts previews in the blog. The posts are sorted by their creation date, newest first.

  All the markdown files in the folder <repo-root>/posts will be transformed into Blogit.Models.Post structs and their created_at meta field will be read using the configured Blogit.RepositoryProvider.

  Post previews can be skipped using the from option, which is 0 by default. The size of the returned list is :infinity by default (meaning "return all post previews"), but it can be changed with the size option to a number. By using these two options simple paging functionality can be implemented.

  Another supported option is language. It defaults to the default language (the first one in the configured languages list). A stream of post previews for the given language will be returned.

  Examples:

  # All post previews in the default language
  post_previews = Blogit.list_posts()
  
  # The first 5 post previews in the default language
  post_previews = Blogit.list_posts(size: 5)
  
  # The second 5 post previews in the default language
  post_previews = Blogit.list_posts(size: 5, from: 5)
  
  # All post previews in Bulgarian
  post_previews = Blogit.list_posts(language: "bg")
  
  # The second 5 post previews in Bulgarian
  post_previews = Blogit.list_posts(language: "bg", size: 5, from: 5)

• Blogit.list_pinned(options)

  Returns a list of tuples. Every such tuple has the unique name of a post as first element and its title as second. These tuples are sorted by the last updated date of the posts they represent.

  All the markdown files in the source posts folder will be transformed into Blogit.Models.Post strucs and their updated_at meta field will be read using the configured Blogit.RepositoryProvider.

  Pinned posts are posts which have specified pinned: true in their meta data.

  These are special posts which should be easy to find in the front-end implementation.

  The only supported option is language. It defaults to the default language (the first one in the configured languages list). Pinned post tuples for the given language will be returned.

  Examples:

  # Pinned post tuples for the default language
  Blogit.list_pinned()
  
  # Pinned post tuples for posts in German
  Blogit.list_pinned(language: "de")

• Blogit.filter_posts(filters, options)

  Returns a list of Blogit.Models.Post.Meta structs, filtered by the given filters.

  The first argument of the function is a map of filters. This map supports zero or more of the following keys:

  • "author" - Used to filter posts by their .meta.author field.
  • "category" - Used to filter posts by their .meta.category field.
  • "tags" - Used to filter posts by their .meta.tags field. The value for this key should a string of comma separated tags ("one,two,three").
  • "year" - Used to filter posts by their .meta.year field.
  • "month" - Used to filter posts by their .meta.month field.
  • "q" - A query to filter posts by their content or title. Supports text in double quotes in order to search for phrases.

  All these keys must be strings.

  Filtered post previews can be skipped using the from option, which is 0 by default. The size of the returned list is :infinity by default (meaning "return all filtered post previews"), but it can be changed with the size option to a number. By using these two options simple paging functionality can be implemented.

  Another supported option is language. It defaults to the default language (the first one in the configured languages list). A stream of post previews, filtered by the given filters for the given language will be returned.

  Examples:

  # All the post previews in the default language, filtered by the given `filters`
  filters = %{"q" => "OTP", "author" => "meddle", "tags" => "ab"}
  Blogit.filter_posts(filters)
  
  # The second two post previews in German, filtered by the given `filters`
  filters = %{"q" => "OTP", "author" => "meddle", "tags" => "ab"}
  Blogit.filter_posts(filters, language: "de", from: 2, size: 2)

• Blogit.posts_by_dates(options)

  Returns a list of tuples of three elements from the given list of posts.

  The first element of a tuple is a year. The second is a month number. The third is a counter - how many posts are created during that month and that year.

  The tuples are sorted from the newest to the oldest, using the years and the months.

  Can be used for implementing an easy-to-browse view component by years/months.

  The only supported option is language. It defaults to the default language (the first one in the configured languages list). Statistics for the posts in the given language will be returned.

  Examples:

  # Statistics for the posts in the default language
  posts_by_date = Blogit.posts_by_dates()
  # [{2017, 6, 5}, {2017, 5, 1}, {2016, 5, 1}]
  
  # Statistics for the posts in Bulgarian
  posts_by_date = Blogit.posts_by_dates(language: "bg")
  # [{2017, 5, 1}, {2016, 5, 1}]

• Blogit.post_by_name(name, options)

  Returns a single post by its unique identifier - its name field. The name should be an atom. The result is in the form {:ok, post} if a post with the given name exist for the given (or default) language. The post element of that tuple is a Blogit.Models.Post struct.

  Posts have unique names, usually constructed using the file path of their source markdown file in the repository.

  If there is no post with the given name, the tuple {:error, "No post with name the-passed-name found."} is returned.

  The only supported option is language. It defaults to the default language (the first one in the configured languages list). Post with the given name in the given language will be returned if found.

  Examples:

  # A post with the name `:otp`, written in the default language
  {:ok, post} = Blogit.post_by_name(:otp)
  IO.puts post.name # :otp
  IO.puts post.meta.author # The author of the post
  IO.puts post.raw # The source markdown of the post
  
  # A post with the name `:otp`, written in Bulgarian
  {:ok, post} = Blogit.post_by_name(:otp, language: "bg")

• Blogit.configuration(options)

  Retrieves the blog configuration. The configuration is in the form of a Blogit.Models.Configuration struct.

  It contains title and sub-title of the blog, path to logo or background image (or both), path to custom CSS file, etc..

  The configuration is generated from an YAML file (by default blog.yml, stored in the root of the repository of the blog). This location can be configured through setting the :configuration_file key of the :blogit configuration.

  The only supported option is language. It defaults to the default language (the first one in the configured languages list). Configuration for the given language will be returned.

  Examples:

  # The configuration of the blog for the default language
  Blogit.configuration()
  
  # The configuration for the German part of the blog
  Blogit.configuration(language: "de")

License

The license is standard MIT license, feel free to fork Blogit and do whatever you want with it. You can also contribute to it.

Contributions

Just fork the Blogit repository and create a PR. You can also create issues with features you wish we support. You can propose style changes on the code and additional tests.

All kinds of contributions are welcome!

How to create your own blog?

Blogit has a simple Phoenix front-end application : BlogitWeb.

Follow these steps to create your own blog (read more at BlogitWeb's README):

1. Fork BlogitWeb project.

2. Modify its config/prod.exs configuration:

   config :blogit,
     repository_url: "<path-to-a-git-repository-with-your-posts>",
     polling: true, poll_interval: 300

3. Recompile the dependencies, so the configuration is updated:

   mix deps.get
   mix deps.clean
   mix deps.compile

4. Deploy it somewhere.

   BlogitWeb depends on distillery and has a little bash script in its root, called build_release.sh. Just run it and it will build a release. You can also run it like this : ./build_release.sh --upgrade in order to create updated release. Follow distillery's notes when deploying.'

   BlogitWeb has a Dockerfile.build file which can be used to make a build in Docker if you don't have Elixir installed. It has a Dockerfile too so you can try it locally.

   There is a template edeliver configuration too.

5. When it is deployed just add new markdown posts to your repository specified in the configuration and it will be published automatically.

Features to be implemented

• Pages (for example 'about me') and specific streams of posts, presented as pages.
• Slides. If we have a folder containing a specifically formated markdown (?) files, they could be turned into slides available on Blogit.
• Different front-ends for Blogit. Not only BlogtWeb. Also let's keep BlogitWeb up to date, tested and documented. For now it is a bit messy, but usable.
• Multiple source formats for posts, not only MARKDOWN.
• Additional repository providers.

Contact me

I'm Nikolay Tsvetinov (meddle) from elixir-lang.bg.

You can find me at:

• Twitter
• Github
• Gmail
• elixir-lang.bg
• My blog, implemented using Blogit