10.3 Iteration E3: Finishing the Cart 10.1 Iteration E1: Creating a Smarter Cart
Log errors and show them on the screen.
Rescue error: log, flash, and redirect.
edit app/controllers/carts_controller.rb
class CartsController < ApplicationController
before_action :set_cart, only: [:show, :edit, :update, :destroy]
rescue_from ActiveRecord::RecordNotFound, with: :invalid_cart
# GET /carts
# ...
private
# ...
def invalid_cart
logger.error "Attempt to access invalid cart #{params[:id]}"
redirect_to store_url, notice: 'Invalid cart'
end
end
Reproduce the error.
get /carts/wibble
get http://localhost:3000/
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Invalid cart
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Inspect the log.
tail -25 log/development.log
ActiveRecord::RecordNotFound (Couldn't find Cart with 'id'=wibble):
app/controllers/carts_controller.rb:67:in `set_cart'
Rendered /home/rubys/git/rails/actionpack/lib/action_dispatch/middleware/templates/rescues/_source.erb (0.6ms)
Rendered /home/rubys/git/rails/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (0.7ms)
Rendered /home/rubys/git/rails/actionpack/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (0.7ms)
Rendered /home/rubys/git/rails/actionpack/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/layout (8.2ms)
Started GET "/carts/wibble" for 127.0.0.1 at 2014-11-18 09:41:05 -0500
Processing by CartsController#show as HTML
Parameters: {"id"=>"wibble"}
Cart Load (0.1ms) SELECT "carts".* FROM "carts" WHERE "carts"."id" = ? LIMIT 1 [["id", 0]]
Attempt to access invalid cart wibble
Redirected to http://localhost:3000/
Completed 302 Found in 3ms (ActiveRecord: 0.4ms)
Started GET "/" for 127.0.0.1 at 2014-11-18 09:41:05 -0500
Processing by StoreController#index as HTML
Product Load (0.2ms) SELECT "products".* FROM "products" ORDER BY "products"."updated_at" DESC LIMIT 1
Product Load (0.1ms) SELECT "products".* FROM "products" ORDER BY "products"."title" ASC
Rendered store/index.html.erb within layouts/application (5.8ms)
Completed 200 OK in 55ms (Views: 52.3ms | ActiveRecord: 0.5ms)
Limit access to product_id
edit app/controllers/line_items_controller.rb
# Never trust parameters from the scary internet, only allow the white
# list through.
def line_item_params
params.require(:line_item).permit(:product_id)
end
rake test:controllers
Run options: --seed 4099
# Running:
......................
Finished in 0.268097s, 82.0598 runs/s, 164.1195 assertions/s.
22 runs, 44 assertions, 0 failures, 0 errors, 0 skips
Inspect the log.
grep -B 8 -A 7 "Unpermitted parameter" log/test.log
(0.0ms) begin transaction
-----------------------------------------------------
LineItemsControllerTest: test_should_update_line_item
-----------------------------------------------------
LineItem Load (0.0ms) SELECT "line_items".* FROM "line_items" WHERE "line_items"."id" = ? LIMIT 1 [["id", 980190962]]
Processing by LineItemsController#update as HTML
Parameters: {"line_item"=>{"cart_id"=>nil, "product_id"=>nil}, "id"=>"980190962"}
LineItem Load (0.0ms) SELECT "line_items".* FROM "line_items" WHERE "line_items"."id" = ? LIMIT 1 [["id", 980190962]]
Unpermitted parameters: cart_id
(0.0ms) SAVEPOINT active_record_1
(0.0ms) RELEASE SAVEPOINT active_record_1
Redirected to http://test.host/line_items/980190962
Completed 302 Found in 1ms (ActiveRecord: 0.1ms)
(0.0ms) rollback transaction
edit test/controllers/line_items_controller_test.rb
test "should update line_item" do
patch :update, id: @line_item, line_item: { product_id: @line_item.product_id }
assert_redirected_to line_item_path(assigns(:line_item))
end
rake log:clear LOGS=test
rake test:controllers
Run options: --seed 65066
# Running:
......................
Finished in 0.278179s, 79.0858 runs/s, 158.1715 assertions/s.
22 runs, 44 assertions, 0 failures, 0 errors, 0 skips
grep "Unpermitted parameters" log/test.log | wc -l
0
10.3 Iteration E3: Finishing the Cart 10.1 Iteration E1: Creating a Smarter Cart