A ton of stuff was done to finalize the app for use

app/controllers/mats_controller.rb

@@ -0,0 +1,93 @@
+class MatsController < ApplicationController
+  before_action :set_mat, only: [:show, :edit, :update, :destroy]
+
+  # GET /mats
+  # GET /mats.json
+  def index
+    @mats = Mat.all
+  end
+
+  # GET /mats/1
+  # GET /mats/1.json
+  def show
+  end
+
+  # GET /mats/new
+  def new
+    @mat = Mat.new
+    if params[:tournament]
+      @tournament_field = params[:tournament]
+      @tournament = Tournament.find(params[:tournament])
+    end
+  end
+
+  # GET /mats/1/edit
+  def edit
+    @tournament_field = @mat.tournament_id
+  end
+
+  # POST /mats
+  # POST /mats.json
+  def create
+    if user_signed_in?
+    else
+      redirect_to root_path
+    end
+    @mat = Mat.new(mat_params)
+    @tournament = Tournament.find(mat_params[:tournament_id])
+    respond_to do |format|
+      if @mat.save
+        format.html { redirect_to @tournament, notice: 'Mat was successfully created.' }
+        format.json { render action: 'show', status: :created, location: @mat }
+      else
+        format.html { render action: 'new' }
+        format.json { render json: @mat.errors, status: :unprocessable_entity }
+      end
+    end
+  end
+
+  # PATCH/PUT /mats/1
+  # PATCH/PUT /mats/1.json
+  def update
+    if user_signed_in?
+    else
+      redirect_to root_path
+    end
+    @tournament = Tournament.find(@mat.tournament_id)
+    respond_to do |format|
+      if @mat.update(mat_params)
+        format.html { redirect_to @tournament, notice: 'Mat was successfully updated.' }
+        format.json { head :no_content }
+      else
+        format.html { render action: 'edit' }
+        format.json { render json: @mat.errors, status: :unprocessable_entity }
+      end
+    end
+  end
+
+  # DELETE /mats/1
+  # DELETE /mats/1.json
+  def destroy
+    if user_signed_in?
+    else
+      redirect_to root_path
+    end
+    @tournament = Tournament.find(@mat.tournament_id)
+    @mat.destroy
+    respond_to do |format|
+      format.html { redirect_to @tournament }
+      format.json { head :no_content }
+    end
+  end
+
+  private
+    # Use callbacks to share common setup or constraints between actions.
+    def set_mat
+      @mat = Mat.find(params[:id])
+    end
+
+    # Never trust parameters from the scary internet, only allow the white list through.
+    def mat_params
+      params.require(:mat).permit(:name, :tournament_id)
+    end
+end