Undefined Component - Stack Trace Debugging?

Question

I'm fairly new to magento2 and trying to fix a broken extension.

I'm having a lot of trouble with stack traces, I'm not sure if it's just the way magento is or if it's because of reflection making it more abstract, but just by reading the stack I'm not able to figure out which file an error takes place in.

Example: If i go to the catalog and try to add a new product of the type this extension provides (it's a gift card extension),

It throws an error and dies.

The stack trace looks like this.

a:4:{i:0;s:112:"The requested component ("giftcard_price_selector") is not found. Before using, you must add the implementation.";i:1;s:8841:"#0 /path/to/magento/install/vendor/magento/module-ui/Model/Manager.php(207): Magento\Framework\View\Element\UiComponent\Config\Provider\Component\Definition->getComponentData('giftcard_price_...')
#1 /path/to/magento/install/vendor/magento/framework/View/Element/UiComponentFactory.php(187): Magento\Ui\Model\Manager->createRawComponentData('giftcard_price_...')
#2 /path/to/magento/install/vendor/magento/module-ui/Component/Form/Field.php(82): Magento\Framework\View\Element\UiComponentFactory->create('giftcard_price_...', 'giftcard_price_...', Array)
#3 /path/to/magento/install/vendor/magento/framework/View/Layout/Generator/UiComponent.php(148): Magento\Ui\Component\Form\Field->prepare()
#4 /path/to/magento/install/vendor/magento/framework/View/Layout/Generator/UiComponent.php(145): Magento\Framework\View\Layout\Generator\UiComponent->prepareComponent(Object(Magento\Ui\Component\Form\Field))
#5 /path/to/magento/install/vendor/magento/framework/View/Layout/Generator/UiComponent.php(145): Magento\Framework\View\Layout\Generator\UiComponent->prepareComponent(Object(Magento\Ui\Component\Container))
#6 /path/to/magento/install/vendor/magento/framework/View/Layout/Generator/UiComponent.php(145): Magento\Framework\View\Layout\Generator\UiComponent->prepareComponent(Object(Magento\Ui\Component\Form\Fieldset))
#7 /path/to/magento/install/vendor/magento/framework/View/Layout/Generator/UiComponent.php(126): Magento\Framework\View\Layout\Generator\UiComponent->prepareComponent(Object(Magento\Ui\Component\Form))
#8 /path/to/magento/install/vendor/magento/framework/View/Layout/Generator/UiComponent.php(93): Magento\Framework\View\Layout\Generator\UiComponent->generateComponent(Object(Magento\Framework\View\Layout\Data\Structure), 'product_form', Array, Object(Magento\Framework\View\Layout\Interceptor))
#9 /path/to/magento/install/vendor/magento/framework/View/Layout/GeneratorPool.php(86): Magento\Framework\View\Layout\Generator\UiComponent->process(Object(Magento\Framework\View\Layout\Reader\Context), Object(Magento\Framework\View\Layout\Generator\Context))
#10 /path/to/magento/install/vendor/magento/framework/View/Layout.php(327): Magento\Framework\View\Layout\GeneratorPool->process(Object(Magento\Framework\View\Layout\Reader\Context), Object(Magento\Framework\View\Layout\Generator\Context))
#11 /path/to/magento/install/vendor/magento/framework/View/Layout/Builder.php(129): Magento\Framework\View\Layout->generateElements()
#12 /path/to/magento/install/vendor/magento/framework/View/Page/Builder.php(55): Magento\Framework\View\Layout\Builder->generateLayoutBlocks()
#13 /path/to/magento/install/vendor/magento/framework/View/Layout/Builder.php(65): Magento\Framework\View\Page\Builder->generateLayoutBlocks()
#14 /path/to/magento/install/vendor/magento/framework/View/Layout.php(244): Magento\Framework\View\Layout\Builder->build()
#15 /path/to/magento/install/vendor/magento/framework/View/Layout.php(859): Magento\Framework\View\Layout->build()
#16 /path/to/magento/install/vendor/magento/module-backend/Model/View/Result/Page.php(59): Magento\Framework\View\Layout->getBlock('menu')
#17 /path/to/magento/install/vendor/magento/module-catalog/Controller/Adminhtml/Product/NewAction.php(71): Magento\Backend\Model\View\Result\Page->setActiveMenu('Magento_Catalog...')
#18 /path/to/magento/install/vendor/magento/framework/App/Action/Action.php(102): Magento\Catalog\Controller\Adminhtml\Product\NewAction->execute()
#19 /path/to/magento/install/vendor/magento/module-backend/App/AbstractAction.php(226): Magento\Framework\App\Action\Action->dispatch(Object(Magento\Framework\App\Request\Http))
#20 /path/to/magento/install/vendor/magento/framework/Interception/Interceptor.php(74): Magento\Backend\App\AbstractAction->dispatch(Object(Magento\Framework\App\Request\Http))
#21 /path/to/magento/install/vendor/magento/framework/Interception/Chain/Chain.php(70): Magento\Catalog\Controller\Adminhtml\Product\NewAction\Interceptor->___callParent('dispatch', Array)
#22 /path/to/magento/install/vendor/magento/framework/Interception/Chain/Chain.php(63): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Catalog...', 'dispatch', Object(Magento\Catalog\Controller\Adminhtml\Product\NewAction\Interceptor), Array, 'adminAuthentica...')
#23 /path/to/magento/install/vendor/magento/module-backend/App/Action/Plugin/Authentication.php(143): Magento\Framework\Interception\Chain\Chain->Magento\Framework\Interception\Chain\{closure}(Object(Magento\Framework\App\Request\Http))
#24 /path/to/magento/install/vendor/magento/framework/Interception/Chain/Chain.php(67): Magento\Backend\App\Action\Plugin\Authentication->aroundDispatch(Object(Magento\Catalog\Controller\Adminhtml\Product\NewAction\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#25 /path/to/magento/install/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Catalog...', 'dispatch', Object(Magento\Catalog\Controller\Adminhtml\Product\NewAction\Interceptor), Array, 'adminMassaction...')
#26 /path/to/magento/install/vendor/magento/module-backend/App/Action/Plugin/MassactionKey.php(33): Magento\Catalog\Controller\Adminhtml\Product\NewAction\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))
#27 /path/to/magento/install/vendor/magento/framework/Interception/Interceptor.php(142): Magento\Backend\App\Action\Plugin\MassactionKey->aroundDispatch(Object(Magento\Catalog\Controller\Adminhtml\Product\NewAction\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#28 /path/to/magento/install/var/generation/Magento/Catalog/Controller/Adminhtml/Product/NewAction/Interceptor.php(26): Magento\Catalog\Controller\Adminhtml\Product\NewAction\Interceptor->___callPlugins('dispatch', Array, Array)
#29 /path/to/magento/install/vendor/magento/framework/App/FrontController.php(55): Magento\Catalog\Controller\Adminhtml\Product\NewAction\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#30 /path/to/magento/install/vendor/magento/framework/Interception/Interceptor.php(74): Magento\Framework\App\FrontController->dispatch(Object(Magento\Framework\App\Request\Http))
#31 /path/to/magento/install/vendor/magento/framework/Interception/Chain/Chain.php(70): Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', Array)
#32 /path/to/magento/install/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Framework\Interception\Chain\Chain->invokeNext('Magento\\Framewo...', 'dispatch', Object(Magento\Framework\App\FrontController\Interceptor), Array, 'install')
#33 /path/to/magento/install/vendor/magento/framework/Module/Plugin/DbStatusValidator.php(69): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception\{closure}(Object(Magento\Framework\App\Request\Http))
#34 /path/to/magento/install/vendor/magento/framework/Interception/Interceptor.php(142): Magento\Framework\Module\Plugin\DbStatusValidator->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#35 /path/to/magento/install/var/generation/Magento/Framework/App/FrontController/Interceptor.php(26): Magento\Framework\App\FrontController\Interceptor->___callPlugins('dispatch', Array, Array)
#36 /path/to/magento/install/vendor/magento/framework/App/Http.php(135): Magento\Framework\App\FrontController\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#37 /path/to/magento/install/vendor/magento/framework/App/Bootstrap.php(258): Magento\Framework\App\Http->launch()
#38 /path/to/magento/install/index.php(39): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http))

Now, from this trace, I can clearly see that some page in the extension is referencing a component called giftcard_price_selector, and if i search the source of the extension, i see it referenced in a couple of places.

My question to you is, how do i figure out which place it is?

I see that a page is adding a field, which caused magento's internal UI component factory to create a price selector (I assume this is probably a drop-down or something, I'm not really sure.) which is causing the error, but i can't seem to figure out which file it's actually happening in.

Part of this is me wanting to know the answer, but if you post an answer and could give a brief overview of how you got the answer so I can learn myself, it would be greatly appreciated

Answer 1

From what I understand, the issue should be in a layout.xml file, as that is how UiComponents are included. I would look in your module's catalog_product_new.xml file, as that corresponds to the controller name (Magento\Catalog\Controller\Adminhtml\Product\NewAction).

That file isn't actually in the stack trace, but Magento reads it from the filesystem to build the tree of layout blocks and containers. In Magento 2, each layout.xml file corresponds to a specific handle, which is a term for a set of layout instructions. Typically, the handle corresponds to a action URL (frontname/controllerFolder/actionName). In this case, the front name was catalog, the controller sub-folder was product, and the referenced controller class (which can be called the action class) was NewController, so I would look inside the view/adminhtml/layout/catalog_product_new.xml file.

Welcome to Magento. Please let me know if anything I said doesn't make sense or needs clarification.