Add CommunityMember.

Allow multiple organizers per community.  There is now just 1 leader of an community.

Allow stepping up if there's no organizer.

Add ability to remove memberships.

app/abilities/ability.rb

@@ -19,6 +19,7 @@ def initialize(user)
       can :index, ChangesetComment
       can [:index, :show], Community
       can [:index], CommunityLink
+      can [:index], CommunityMember
       can [:confirm, :confirm_resend, :confirm_email], :confirmation
       can [:index, :rss, :show], DiaryEntry
       can :index, DiaryComment
@@ -49,9 +50,17 @@ def initialize(user)
         can [:create], DiaryComment
         can [:make_friend, :remove_friend], Friendship
         can [:new, :create, :reply, :show, :inbox, :outbox, :muted, :mark, :unmute, :destroy], Message
-        can [:create, :new], Community
-        can [:edit, :update], Community, { :organizer_id => user.id }
-        can [:edit, :create, :destroy, :new, :update], CommunityLink, { :community => { :organizer_id => user.id } }
+        user_is_community_organizer = {
+          :community_members => {
+            :user_id => user.id,
+            :role => CommunityMember::Roles::ORGANIZER
+          }
+        }
+        can [:create, :new, :step_up], Community
+        can [:edit, :update], Community, user_is_community_organizer
+        can [:edit, :create, :destroy, :new, :update], CommunityLink, { :community => user_is_community_organizer }
+        can [:create], CommunityMember, { :user_id => user.id }
+        can [:destroy, :edit, :update], CommunityMember, { :community => user_is_community_organizer }
         can [:close, :reopen], Note
         can [:show, :edit, :update], :preference
         can [:edit, :update], :profile

app/assets/stylesheets/common.scss

@@ -802,6 +802,37 @@ img.user_thumbnail_tiny {
   object-fit: contain;
 }
 
+.user_card {
+  @extend .card;
+  width: 100px;
+  display: inline-block;
+  > img {
+    @extend .card-img-top;
+  }
+  > div {
+    @extend .card-body;
+    /*
+    Some display_names are long and break the uniform display of user cards.
+    For now, hide the overflow.  This does make some user names ambiguous.
+    TODO: Fix this.
+    */
+    overflow: hidden;
+    white-space: nowrap;
+    padding: 0.5rem;  /* override bootstrap's 1.25rem */
+    > h5 {
+      @extend .card-title;
+      font-size: 0.9rem;  /* override bootstrap's 1.25 rem */
+    }
+  }
+}
+
+
+/* Rules for geo microformats */
+
+abbr.geo {
+  border-bottom: none;
+}
+
 /* General styles for action lists / subnavs */
 
 nav.secondary-actions {

app/controllers/communities_controller.rb

@@ -4,35 +4,48 @@ class CommunitiesController < ApplicationController
   layout "site"
   before_action :authorize_web
 
-  before_action :set_community, :only => [:edit, :show, :update]
+  before_action :set_community, :only => [:edit, :show, :step_up, :update]
 
   helper_method :recent_changesets
 
   load_and_authorize_resource :except => [:create, :new]
   authorize_resource
 
   def index
+    @critical_mass = 2
     display_name = params[:user_display_name]
     if display_name
       @user = User.active.find_by(:display_name => display_name)
       if @user
         @title = t ".title", :display_name => @user.display_name
-        @communities_organized = @user.communities_organized
+        @communities_leading = @user.communities_lead
       else
         render_unknown_user display_name
         return
       end
     elsif current_user
       @title = t ".title", :display_name => current_user.display_name
-      @communities_organized = current_user.communities_organized
+      @communities_leading = current_user.communities_lead
     end
 
-    @all_communities = Community.order(:name)
+    # Only list out communities that have at least n members in order to mitigate spam.  In order to get
+    # a community listed, the organizer must find n members and give them the link to the page manually.
+    @all_communities = Community
+                       .joins(:community_members)
+                       .group("communities.id")
+                       .having("COUNT(communities.id) > #{@critical_mass}")
+
+    @my_communities = current_user ? current_user.communities : []
   end
 
   # GET /communities/mycity
   # GET /communities/mycity.json
-  def show; end
+  def show
+    # for existing or new member
+    @current_user_membership = CommunityMember.find_or_initialize_by(
+      :community => @community, :user_id => current_user&.id
+    )
+  end
 
   def new
     @title = t ".title"
@@ -43,8 +56,8 @@ def edit; end
 
   def create
     @community = Community.new(community_params)
-    @community.organizer = current_user
-    if @community.save
+    @community.leader = current_user
+    if @community.save && add_first_organizer
       redirect_to @community, :notice => t(".success")
     else
       render "new"
@@ -60,8 +73,34 @@ def update
     end
   end
 
+  def step_up
+    message = nil
+    if @community.organizers.empty?
+      if @community.member?(current_user)
+        message = t ".you_have_stepped_up"
+        add_first_organizer
+      else
+        message = t ".only_members_can_step_up"
+      end
+    else
+      message = t ".already_has_organizer"
+    end
+    redirect_to @community, :notice => message
+  end
+
   private
 
+  def add_first_organizer
+    membership = CommunityMember.new(
+      {
+        :community_id => @community.id,
+        :user_id => current_user.id,
+        :role => CommunityMember::Roles::ORGANIZER
+      }
+    )
+    membership.save
+  end
+
   def recent_changesets
     bbox = @community.bbox.to_scaled
     Changeset
@@ -72,6 +111,9 @@ def recent_changesets
 
   def set_community
     @community = Community.friendly.find(params[:id])
+  rescue ActiveRecord::RecordNotFound
+    @not_found_community = params[:id]
+    render "no_such_community", :status => :not_found
   end
 
   def community_params

app/controllers/community_members_controller.rb

@@ -0,0 +1,68 @@
+class CommunityMembersController < ApplicationController
+  layout "site"
+  before_action :authorize_web
+  before_action :set_community_member, :only => [:destroy, :edit, :update]
+  load_and_authorize_resource :except => [:create]
+  authorize_resource
+
+  def index
+    @community = Community.friendly.find(params[:community_id])
+    @roles = CommunityMember::Roles::ALL_ROLES.map(&:pluralize)
+  rescue ActiveRecord::RecordNotFound
+    @not_found_community = params[:community_id]
+    render :template => "communities/no_such_community", :status => :not_found
+  end
+
+  def edit; end
+
+  def create
+    # membership = CommunityMember.new(create_params)
+    # If there's no given user, default to the current_user.
+    membership = CommunityMember.new(create_params.reverse_merge!(:user_id => current_user.id))
+    membership.role = CommunityMember::Roles::MEMBER
+    if membership.save
+      redirect_to community_path(membership.community), :notice => t(".success")
+    else
+      # There are 2 reasons we may get here.
+      # 1. database failure / disk full
+      # 2. the community does not exist
+      # Either way, sending the user to the communities list page is ok.
+      redirect_to communities_path, :alert => t(".failure")
+    end
+  end
+
+  def update
+    if @community_member.update(update_params)
+      redirect_to @community_member.community, :notice => t(".success")
+    else
+      flash.now[:alert] = t(".failure")
+      render :edit
+    end
+  end
+
+  def destroy
+    issues = @community_member.can_be_deleted
+    if issues.empty? && @community_member.destroy
+      redirect_to @community_member.community, :notice => t(".success")
+    else
+      issues = issues.map { |i| t("activerecord.errors.models.community_member.#{i}") }
+      issues = issues.to_sentence.capitalize
+      flash[:error] = "#{t('.failure')} #{issues}."
+      redirect_to community_community_members_path(@community_member.community)
+    end
+  end
+
+  private
+
+  def set_community_member
+    @community_member = CommunityMember.find(params[:id])
+  end
+
+  def create_params
+    params.require(:community_member).permit(:community_id, :user_id)
+  end
+
+  def update_params
+    params.require(:community_member).permit(:role)
+  end
+end

app/models/community.rb

@@ -5,7 +5,7 @@
 #  id           :bigint(8)        not null, primary key
 #  name         :string           not null
 #  description  :text             not null
-#  organizer_id :bigint(8)        not null
+#  leader_id    :bigint(8)        not null
 #  slug         :string           not null
 #  location     :string           not null
 #  latitude     :float            not null
@@ -27,14 +27,19 @@
 #  fk_rails_...  (organizer_id => users.id)
 #
 
-# At this time a community has one organizer.  The first organizer is
-# the user that created the community.
+# At this time a community has one leader.  The leader of a community starts out
+# being the user that created the community.  The creator of a community also
+# is an organizer member.
 
 class Community < ApplicationRecord
   extend FriendlyId
   friendly_id :name, :use => :slugged
 
-  belongs_to :organizer, :class_name => "User"
+  # Organizers before members, a tad hacky, but works for now.
+  has_many :community_members, -> { order(:user_id) }, :inverse_of => :community
+  has_many :users, :through => :community_members # TODO: counter_cache
+
+  belongs_to :leader, :class_name => "User"
   has_many :community_links
 
   validates :name, :presence => true, :length => 1..255, :characters => true
@@ -59,6 +64,22 @@ def max_lon=(longitude)
     super(OSM.normalize_longitude(longitude))
   end
 
+  def member?(user)
+    community_members.where(:user_id => user.id).count.positive?
+  end
+
+  def members
+    community_members.where(:role => CommunityMember::Roles::MEMBER)
+  end
+
+  def organizer?(user)
+    community_members.where(:user_id => user.id, :role => CommunityMember::Roles::ORGANIZER).count.positive?
+  end
+
+  def organizers
+    community_members.where(:role => CommunityMember::Roles::ORGANIZER)
+  end
+
   def bbox
     BoundingBox.new(min_lon, min_lat, max_lon, max_lat)
   end

app/models/community_member.rb

@@ -0,0 +1,46 @@
+# == Schema Information
+#
+# Table name: community_members
+#
+#  id           :bigint(8)        not null, primary key
+#  community_id :integer          not null
+#  user_id      :integer          not null
+#  role         :string(64)       not null
+#  created_at   :datetime         not null
+#  updated_at   :datetime         not null
+#
+# Indexes
+#
+#  index_community_members_on_community_id                       (community_id)
+#  index_community_members_on_community_id_and_user_id_and_role  (community_id,user_id,role) UNIQUE
+#  index_community_members_on_user_id                            (user_id)
+#
+
+class CommunityMember < ApplicationRecord
+  module Roles
+    ORGANIZER = "organizer".freeze
+    MEMBER = "member".freeze
+    ALL_ROLES = [ORGANIZER, MEMBER].freeze
+  end
+
+  belongs_to :community
+  belongs_to :user
+
+  scope :organizers, -> { where(:role => Roles::ORGANIZER) }
+  scope :members, -> { where(:role => Roles::MEMBER) }
+
+  validates :community, :associated => true
+  validates :user, :associated => true
+  validates :role, :inclusion => { :in => Roles::ALL_ROLES }
+
+  # TODO: validate uniqueness of user's role in each community.
+
+  # We assume this user already belongs to this community.
+  def can_be_deleted
+    issues = []
+    # The user may also be an organizer under a separate membership.
+    issues.append(:is_organizer) if CommunityMember.exists?(:community_id => community_id, :user_id => user_id, :role => Roles::ORGANIZER)
+
+    issues
+  end
+end

app/models/issue.rb

@@ -87,7 +87,7 @@ def set_reported_user
                          when "User"
                            reportable
                          when "Community"
-                           reportable.organizer
+                           reportable.leader
                          when "Note"
                            reportable.author
                          else

app/models/user.rb

@@ -87,7 +87,9 @@ class User < ApplicationRecord
 
   has_many :reports
 
-  has_many :communities_organized, :class_name => "Community", :foreign_key => :organizer_id, :inverse_of => :organizer
+  has_many :communities_lead, :class_name => "Community", :foreign_key => :leader_id, :inverse_of => :leader
+  has_many :community_members
+  has_many :communities, :through => :community_members
 
   scope :visible, -> { where(:status => %w[pending active confirmed]) }
   scope :active, -> { where(:status => %w[active confirmed]) }

app/views/communities/index.html.erb

@@ -12,12 +12,15 @@
   </nav>
 <% end %>
 
-<% if @communities_organized %>
-  <%= render :partial => "index_list", :locals => { :communities => @communities_organized, :header => t(".communities_organized") } %>
+<% if @communities_leading %>
+  <%= render :partial => "index_list", :locals => { :communities => @communities_leading, :header => t(".communities_leading") } %>
 <% end %>
 
+<%= render :partial => "index_list", :locals => { :communities => @my_communities, :header => t(".my_communities") } %>
+
 <p>
   <%= t(".sorted_by") %>
+  <%= t(".critical_mass", :n => @critical_mass) %>
 </p>
 
 <%= render :partial => "index_list", :locals => { :communities => @all_communities, :header => t(".all") } %>

app/views/communities/no_such_community.html.erb

@@ -0,0 +1,8 @@
+<% content_for :heading do %>
+  <h1>
+    <%= t ".heading", :community => @not_found_community %>
+  </h1>
+<% end %>
+<p>
+  <%= t ".body", :community => @not_found_community %>
+</p>