# module ExtractsPath

Module providing methods for dealing with separating a tree-ish string and a file path string when combined in a request parameter

### Public Instance Methods

assign_ref_vars() click to toggle source

Assigns common instance variables for views working with Git tree-ish objects

Assignments are:

- @id - A string representing the joined ref and path

- @ref - A string representing the ref (e.g., the branch, tag, or commit SHA)

- @path - A string representing the filesystem path

- @commit - A CommitDecorator representing the commit from the given ref

- @tree - A TreeDecorator representing the tree at the given ref/path

If the :id parameter appears to be requesting a specific response format, that will be handled as well.

Automatically renders `not_found!` if a valid tree path could not be resolved (e.g., when a user inserts an invalid path or ref).

    # File lib/extracts_path.rb, line 94
    def assign_ref_vars
      # Handle formats embedded in the id
      if params[:id].ends_with?('.atom')
        params[:id].gsub!(%r\.atom$/, '')
        request.format = :atom
      end

      @ref, @path = extract_ref(params[:id])

      @id = File.join(@ref, @path)

      @commit = CommitDecorator.decorate(@project.commit(@ref))

      @tree = Tree.new(@commit.tree, @project, @ref, @path)
      @tree = TreeDecorator.new(@tree)

      raise InvalidPathError if @tree.invalid?
    rescue NoMethodError, InvalidPathError
      not_found!
    end

extract_ref(input) click to toggle source

Given a string containing both a Git tree-ish, such as a branch or tag, and a filesystem path joined by forward slashes, attempts to separate the two.

Expects a @project instance variable to contain the active project. This is used to check the input against a list of valid repository refs.

Examples

    # No @project available
    extract_ref('master')
    # => ['', '']

    extract_ref('master')
    # => ['master', '']

    extract_ref("f4b14494ef6abf3d144c28e4af0c20143383e062/CHANGELOG")
    # => ['f4b14494ef6abf3d144c28e4af0c20143383e062', 'CHANGELOG']

    extract_ref("v2.0.0/README.md")
    # => ['v2.0.0', 'README.md']

    extract_ref('issues/1234/app/models/project.rb')
    # => ['issues/1234', 'app/models/project.rb']

    # Given an invalid branch, we fall back to just splitting on the first slash
    extract_ref('non/existent/branch/README.md')
    # => ['non', 'existent/branch/README.md']

Returns an Array where the first value is the tree-ish and the second is the path

    # File lib/extracts_path.rb, line 45
    def extract_ref(input)
      pair = ['', '']

      return pair unless @project

      if input.match(%r^([[:alnum:]]{40})(.+)/)
        # If the ref appears to be a SHA, we're done, just split the string
        pair = $~.captures
      else
        # Otherwise, attempt to detect the ref using a list of the project's
        # branches and tags

        # Append a trailing slash if we only get a ref and no file path
        id = input
        id += '/' unless id.ends_with?('/')

        valid_refs = @project.ref_names
        valid_refs.select! { |v| id.start_with?("#{v}/") }

        if valid_refs.length != 1
          # No exact ref match, so just try our best
          pair = id.match(%r([^\/]+)(.*)/).captures
        else
          # Partition the string into the ref and the path, ignoring the empty first value
          pair = id.partition(valid_refs.first)[1..-1]
        end
      end

      # Remove ending slashes from path
      pair[1].gsub!(%r^\/|\/$/, '')

      pair
    end