Agile Web Development with Rails, Edition 5
10.3 Iteration E3: Finishing the Cart
10.1 Iteration E1: Creating a Smarter Cart
10.2 Iteration E2: Handling Errors
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_index_url, notice: 'Invalid cart'
end
end
Reproduce the error.
get /carts/wibble
You are being
redirected .
get http://localhost:3000/
Invalid cart
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Inspect the log.
tail -25 log/development.log Rendering /home/rubys/git/rails/actionpack/lib/action_dispatch/middleware/templates/rescues/diagnostics.html.erb within rescues/layout
Rendering /home/rubys/git/rails/actionpack/lib/action_dispatch/middleware/templates/rescues/_source.html.erb
Rendered /home/rubys/git/rails/actionpack/lib/action_dispatch/middleware/templates/rescues/_source.html.erb (1.8ms)
Rendering /home/rubys/git/rails/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb
Rendered /home/rubys/git/rails/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (0.9ms)
Rendering /home/rubys/git/rails/actionpack/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb
Rendered /home/rubys/git/rails/actionpack/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (0.6ms)
Rendered /home/rubys/git/rails/actionpack/lib/action_dispatch/middleware/templates/rescues/diagnostics.html.erb within rescues/layout (12.2ms)
Started GET "/carts/wibble" for 127.0.0.1 at 2017-06-03 00:41:39 -0400
Processing by CartsController#show as HTML
Parameters: {"id"=>"wibble"}
Cart Load (0.1ms) SELECT "carts".* FROM "carts" WHERE "carts"."id" = ? LIMIT ? [["id", 0], ["LIMIT", 1]]
Attempt to access invalid cart wibble
Redirected to http://localhost:3000/
Completed 302 Found in 4ms (ActiveRecord: 0.6ms)
Started GET "/" for 127.0.0.1 at 2017-06-03 00:41:39 -0400
Processing by StoreController#index as HTML
Rendering store/index.html.erb within layouts/application
Product Load (0.2ms) SELECT "products".* FROM "products" ORDER BY "products"."title" ASC
Rendered store/index.html.erb within layouts/application (9.9ms)
Completed 200 OK in 31ms (Views: 28.1ms | 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
rails test:controllers Run options: --seed 47289
# Running:
.......................
Finished in 0.634250s, 36.2633 runs/s, 55.1833 assertions/s.
23 runs, 35 assertions, 0 failures, 0 errors, 0 skips
Inspect the log.
grep -B 8 -A 7 "Unpermitted parameter" log/test.log -----------------------------------------------------
LineItemsControllerTest: test_should_update_line_item
-----------------------------------------------------
LineItem Load (0.1ms) SELECT "line_items".* FROM "line_items" WHERE "line_items"."id" = ? LIMIT ? [["id", 980190962], ["LIMIT", 1]]
Started PATCH "/line_items/980190962" for 127.0.0.1 at 2017-06-03 00:41:41 -0400
Processing by LineItemsController#update as HTML
Parameters: {"line_item"=>{"cart_id"=>"980190962", "product_id"=>"298486374"}, "id"=>"980190962"}
LineItem Load (0.0ms) SELECT "line_items".* FROM "line_items" WHERE "line_items"."id" = ? LIMIT ? [["id", 980190962], ["LIMIT", 1]]
Unpermitted parameter: cart_id
(0.0ms) SAVEPOINT active_record_1
Product Load (0.0ms) SELECT "products".* FROM "products" WHERE "products"."id" = ? LIMIT ? [["id", 298486374], ["LIMIT", 1]]
Cart Load (0.0ms) SELECT "carts".* FROM "carts" WHERE "carts"."id" = ? LIMIT ? [["id", 980190962], ["LIMIT", 1]]
(0.0ms) RELEASE SAVEPOINT active_record_1
Redirected to http://www.example.com/line_items/980190962
Completed 302 Found in 3ms (ActiveRecord: 0.1ms)
(0.0ms) rollback transaction
edit test/controllers/line_items_controller_test.rb test "should update line_item" do
patch line_item_url(@line_item),
params: { line_item: { product_id: @line_item.product_id } }
assert_redirected_to line_item_url(@line_item)
end
rake log:clear LOGS=test rails test:controllers Run options: --seed 27619
# Running:
.......................
Finished in 0.709529s, 32.4159 runs/s, 49.3285 assertions/s.
23 runs, 35 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
