class Webby::Resources::DB - webby-0.9.4 Documentation

# class Webby::Resources::DB

A rudimentary “database” for holding resource objects and finding them. The database is held in a Ruby hash keyed by the directories in the content folder.

### Public Class Methods

new click to toggle source

Create a new resources database object. This is used to store resources and to find them by their attributes.

    # File lib/webby/resources/db.rb, line 15
    def initialize
      @db = Hash.new {|h,k| h[k] = []}
    end

### Public Instance Methods

<<( page )
Alias for: add
add( resource ) → resource click to toggle source

Add the given resource to the database. It will not be added a second time if it already exists in the database.

    # File lib/webby/resources/db.rb, line 25
    def add( page )
      ary = @db[page.directory]

      # make sure we don't duplicate pages
      ary.delete page if ary.include? page
      ary << page

      page
    end

Also aliased as: <<
children( page, opts = {} ) → array click to toggle source

Returns an array of resources that are children of the given page resource. A child is any resource that exists in a subdirectory of the page’s directory.

#### Options¶ ↑

:sorty_by<Symbol>

  The attribute to sort by

:reverse<Boolean>

  Reverse the order of the results

    # File lib/webby/resources/db.rb, line 209
    def children( page, opts = {} )
      rgxp = Regexp.new "\\A#{page.directory}/[^/]+"

      keys = @db.keys.find_all {|k| rgxp =~ k}
      ary  = keys.map {|k| @db[k]}
      ary.flatten!

      return ary unless opts.has_key? :sort_by

      m = opts[:sort_by]
      ary.sort! {|a,b| a.__send__(m) <=> b.__send__(m)}
      ary.reverse! if opts[:reverse]
      ary
    end

clear → self click to toggle source

Removes all resources from the database.

    # File lib/webby/resources/db.rb, line 41
    def clear
      @db.clear
      self
    end

each {|resource| block} click to toggle source

Iterate over each resource in the database and pass it to the given block.

    # File lib/webby/resources/db.rb, line 52
    def each( &block )
      keys = @db.keys.sort
      keys.each do |k|
        @db[k].sort.each(&block)
      end
      self
    end

find( limit = nil, opts = {} ) → resource or nil click to toggle source
find( limit = nil, opts = {} ) {|resource| block} → resource or nil

Find a specific resource or collection of resources in the pages database. The first resource found will be returned if the limit is nil. If the limit is an integer, then up to that number of resources will be returned as an array. If the limit is :all, then all resources matching the given attributes will be returned.

Resources can be found using any combination of attributes by passing them in as options to the `find` method. This will used simple equality comparison to find the resource or resources.

If the :include option is given as :all then all resources that match the finder criteria will be returned in an array. If none are found, an empty array will be returned. If the :include option is given as an integer then the first n resources found will be returned. Otherwise, or if the :include option is not given, the first resource found will be returned

For more complex finders, a block should be supplied. The usage follows that of of the Enumerable#find or Enumerable#find_all methods, depending on the limit. The method will return the first resource or all resources, respectively, for which the block returns true.

#### Options¶ ↑

:in_directory<String>

  The directory to search.

:recursive<Boolean>

  Whether or not to recurse into subdirectories

:sort_by<Symbol>

  Sort results using the given attribute

:reverse<Boolean>

  Reverse the order of the search results

#### Examples¶ ↑

    # find the "index" resource in the "foo/bar" directory
    @pages.find( :filename => 'index', :in_directory => 'foo/bar' )

    # find all resources under the "foo/bar" directory recursively
    @pages.find( :all, :in_directory => 'foo/bar', :recursive => true )

    # find the resource named "widgets" whose color is "blue"
    @pages.find( :name => 'widgets', :color => 'blue' )

    # find all resources created in the past week
    @pages.find( :all ) do |resource|
      resource.created_at > Time.now - (7 * 24 * 3600)
    end

    # File lib/webby/resources/db.rb, line 111
    def find( *args, &block )
      opts = Hash === args.last ? args.pop : {}

      limit = args.shift
      limit = opts.delete(:limit) if opts.has_key?(:limit)
      sort_by = opts.delete(:sort_by)
      reverse = opts.delete(:reverse)

      # figure out which directories to search through and whether to recurse
      # into directories or not
      search = if (dir = opts.delete(:in_directory))
        dir = dir.sub(/^\//, '')
        strategy = if opts.delete(:recursive)
          rgxp = dir.empty? ? '.*' : Regexp.escape(dir)
          lambda { |key| key =~ /^#{rgxp}(\/.*)?$/ }
        else
          lambda { |key| key == dir }
        end
        matching_keys = @db.keys.select(&strategy)
        raise RuntimeError, "unknown directory '#{dir}'" if matching_keys.empty?
        matching_keys.map { |key| @db[key] }.flatten
      else
        self
      end

      # construct a search block if one was not supplied by the user
      block ||= lambda do |page|
        found = true
        opts.each do |key, value|
          found &&= page.__send__(key.to_sym) == value
          break if not found
        end
        found
      end

      # search through the directories for the desired pages
      ary = []
      search.each do |page|
        ary << page if block.call(page)
      end

      # sort the search results if the user gave an attribute to sort by
      if sort_by
        m = sort_by.to_sym
        ary.delete_if {|p| p.__send__(m).nil?}
        reverse ?
            ary.sort! {|a,b| b.__send__(m) <=> a.__send__(m)} :
            ary.sort! {|a,b| a.__send__(m) <=> b.__send__(m)}
      end

      # limit the search results
      case limit
      when :all, 'all'
        ary
      when Integer
        ary.slice(0,limit)
      else
        ary.first
      end
    end

parent_of( resource ) → resource or nil click to toggle source

Returns the parent page of the given resource or nil if the resource is at the root of the directory structure. The parent is the “index” page of the current directory or the next directory up the chain.

    # File lib/webby/resources/db.rb, line 231
    def parent_of( page )
      dir = page.directory

      loop do
        if @db.has_key? dir
          parent = @db[dir].find {|p| p.filename == 'index'}
          return parent unless parent.nil? or parent == page
        end

        break if dir.empty?
        dir = ::File.dirname(dir)
        dir = '' if dir == '.'
      end

      return
    end

siblings( page, opts = {} ) → array click to toggle source

Returns an array of resources that are siblings of the given page resource. A sibling is any resource that is in the same directory as the page.

#### Options¶ ↑

:sorty_by<Symbol>

  The attribute to sort by

:reverse<Boolean>

  Reverse the order of the results

    # File lib/webby/resources/db.rb, line 185
    def siblings( page, opts = {} )
      ary = @db[page.directory].dup
      ary.delete page
      return ary unless opts.has_key? :sort_by

      m = opts[:sort_by]
      ary.sort! {|a,b| a.__send__(m) <=> b.__send__(m)}
      ary.reverse! if opts[:reverse]
      ary
    end