Russ, S. and. (2021). Online Learning Accessibility During the Covid-19 Pandemic. In Proceedings of the 18th International Cross-Disciplinary Conference on Web Accessibility. Retrieved from https://par.nsf.gov/biblio/10223571
Error message
Warning: Undefined array key "bibcite_url" in vo_base_refresh_preprocess_bibcite_reference() (line 393 of themes/custom/vo_base_refresh/vo_base_refresh.theme).
vo_base_refresh_preprocess_bibcite_reference() call_user_func_array() (Line: 261) Drupal\Core\Theme\ThemeManager->render() (Line: 491) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 1204) Drupal\views\Plugin\views\field\FieldPluginBase->advancedRender() (Line: 238) template_preprocess_views_view_field() call_user_func_array() (Line: 261) Drupal\Core\Theme\ThemeManager->render() (Line: 491) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 1796) Drupal\views\Plugin\views\field\FieldPluginBase->theme() (Line: 769) Drupal\views\Plugin\views\style\StylePluginBase->elementPreRenderRow() call_user_func_array() (Line: 113) Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 875) Drupal\Core\Render\Renderer->doCallback() (Line: 432) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 708) Drupal\views\Plugin\views\style\StylePluginBase->renderFields() (Line: 574) Drupal\views\Plugin\views\style\StylePluginBase->renderGrouping() (Line: 462) Drupal\views\Plugin\views\style\StylePluginBase->render() (Line: 2177) Drupal\views\Plugin\views\display\DisplayPluginBase->render() (Line: 1593) Drupal\views\ViewExecutable->render() (Line: 201) Drupal\views\Plugin\views\display\Page->execute() (Line: 1690) Drupal\views\ViewExecutable->executeDisplay() (Line: 81) Drupal\views\Element\View::preRenderViewElement() call_user_func_array() (Line: 113) Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 875) Drupal\Core\Render\Renderer->doCallback() (Line: 432) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 238) Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 638) Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 231) Drupal\Core\Render\MainContent\HtmlRenderer->prepare() (Line: 128) Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse() (Line: 90) Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray() call_user_func() (Line: 111) Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch() (Line: 186) Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76) Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53) Drupal\Core\StackMiddleware\Session->handle() (Line: 48) Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28) Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32) Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 201) Drupal\page_cache\StackMiddleware\PageCache->fetch() (Line: 138) Drupal\page_cache\StackMiddleware\PageCache->lookup() (Line: 87) Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 50) Drupal\ban\BanMiddleware->handle() (Line: 48) Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51) Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36) Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51) Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 741) Drupal\Core\DrupalKernel->handle() (Line: 19)Warning: Trying to access array offset on null in vo_base_refresh_preprocess_bibcite_reference() (line 393 of themes/custom/vo_base_refresh/vo_base_refresh.theme).
vo_base_refresh_preprocess_bibcite_reference() call_user_func_array() (Line: 261) Drupal\Core\Theme\ThemeManager->render() (Line: 491) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 1204) Drupal\views\Plugin\views\field\FieldPluginBase->advancedRender() (Line: 238) template_preprocess_views_view_field() call_user_func_array() (Line: 261) Drupal\Core\Theme\ThemeManager->render() (Line: 491) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 1796) Drupal\views\Plugin\views\field\FieldPluginBase->theme() (Line: 769) Drupal\views\Plugin\views\style\StylePluginBase->elementPreRenderRow() call_user_func_array() (Line: 113) Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 875) Drupal\Core\Render\Renderer->doCallback() (Line: 432) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 708) Drupal\views\Plugin\views\style\StylePluginBase->renderFields() (Line: 574) Drupal\views\Plugin\views\style\StylePluginBase->renderGrouping() (Line: 462) Drupal\views\Plugin\views\style\StylePluginBase->render() (Line: 2177) Drupal\views\Plugin\views\display\DisplayPluginBase->render() (Line: 1593) Drupal\views\ViewExecutable->render() (Line: 201) Drupal\views\Plugin\views\display\Page->execute() (Line: 1690) Drupal\views\ViewExecutable->executeDisplay() (Line: 81) Drupal\views\Element\View::preRenderViewElement() call_user_func_array() (Line: 113) Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 875) Drupal\Core\Render\Renderer->doCallback() (Line: 432) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 238) Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 638) Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 231) Drupal\Core\Render\MainContent\HtmlRenderer->prepare() (Line: 128) Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse() (Line: 90) Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray() call_user_func() (Line: 111) Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch() (Line: 186) Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76) Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53) Drupal\Core\StackMiddleware\Session->handle() (Line: 48) Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28) Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32) Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 201) Drupal\page_cache\StackMiddleware\PageCache->fetch() (Line: 138) Drupal\page_cache\StackMiddleware\PageCache->lookup() (Line: 87) Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 50) Drupal\ban\BanMiddleware->handle() (Line: 48) Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51) Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36) Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51) Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 741) Drupal\Core\DrupalKernel->handle() (Line: 19)Warning: Trying to access array offset on null in vo_base_refresh_preprocess_bibcite_reference() (line 393 of themes/custom/vo_base_refresh/vo_base_refresh.theme).
vo_base_refresh_preprocess_bibcite_reference() call_user_func_array() (Line: 261) Drupal\Core\Theme\ThemeManager->render() (Line: 491) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 1204) Drupal\views\Plugin\views\field\FieldPluginBase->advancedRender() (Line: 238) template_preprocess_views_view_field() call_user_func_array() (Line: 261) Drupal\Core\Theme\ThemeManager->render() (Line: 491) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 1796) Drupal\views\Plugin\views\field\FieldPluginBase->theme() (Line: 769) Drupal\views\Plugin\views\style\StylePluginBase->elementPreRenderRow() call_user_func_array() (Line: 113) Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 875) Drupal\Core\Render\Renderer->doCallback() (Line: 432) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 708) Drupal\views\Plugin\views\style\StylePluginBase->renderFields() (Line: 574) Drupal\views\Plugin\views\style\StylePluginBase->renderGrouping() (Line: 462) Drupal\views\Plugin\views\style\StylePluginBase->render() (Line: 2177) Drupal\views\Plugin\views\display\DisplayPluginBase->render() (Line: 1593) Drupal\views\ViewExecutable->render() (Line: 201) Drupal\views\Plugin\views\display\Page->execute() (Line: 1690) Drupal\views\ViewExecutable->executeDisplay() (Line: 81) Drupal\views\Element\View::preRenderViewElement() call_user_func_array() (Line: 113) Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 875) Drupal\Core\Render\Renderer->doCallback() (Line: 432) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 238) Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 638) Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 231) Drupal\Core\Render\MainContent\HtmlRenderer->prepare() (Line: 128) Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse() (Line: 90) Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray() call_user_func() (Line: 111) Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch() (Line: 186) Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76) Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53) Drupal\Core\StackMiddleware\Session->handle() (Line: 48) Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28) Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32) Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 201) Drupal\page_cache\StackMiddleware\PageCache->fetch() (Line: 138) Drupal\page_cache\StackMiddleware\PageCache->lookup() (Line: 87) Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 50) Drupal\ban\BanMiddleware->handle() (Line: 48) Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51) Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36) Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51) Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 741) Drupal\Core\DrupalKernel->handle() (Line: 19)Warning: Trying to access array offset on null in vo_base_refresh_preprocess_bibcite_reference() (line 393 of themes/custom/vo_base_refresh/vo_base_refresh.theme).
vo_base_refresh_preprocess_bibcite_reference() call_user_func_array() (Line: 261) Drupal\Core\Theme\ThemeManager->render() (Line: 491) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 1204) Drupal\views\Plugin\views\field\FieldPluginBase->advancedRender() (Line: 238) template_preprocess_views_view_field() call_user_func_array() (Line: 261) Drupal\Core\Theme\ThemeManager->render() (Line: 491) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 1796) Drupal\views\Plugin\views\field\FieldPluginBase->theme() (Line: 769) Drupal\views\Plugin\views\style\StylePluginBase->elementPreRenderRow() call_user_func_array() (Line: 113) Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 875) Drupal\Core\Render\Renderer->doCallback() (Line: 432) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 708) Drupal\views\Plugin\views\style\StylePluginBase->renderFields() (Line: 574) Drupal\views\Plugin\views\style\StylePluginBase->renderGrouping() (Line: 462) Drupal\views\Plugin\views\style\StylePluginBase->render() (Line: 2177) Drupal\views\Plugin\views\display\DisplayPluginBase->render() (Line: 1593) Drupal\views\ViewExecutable->render() (Line: 201) Drupal\views\Plugin\views\display\Page->execute() (Line: 1690) Drupal\views\ViewExecutable->executeDisplay() (Line: 81) Drupal\views\Element\View::preRenderViewElement() call_user_func_array() (Line: 113) Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 875) Drupal\Core\Render\Renderer->doCallback() (Line: 432) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 238) Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 638) Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 231) Drupal\Core\Render\MainContent\HtmlRenderer->prepare() (Line: 128) Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse() (Line: 90) Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray() call_user_func() (Line: 111) Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch() (Line: 186) Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76) Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53) Drupal\Core\StackMiddleware\Session->handle() (Line: 48) Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28) Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32) Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 201) Drupal\page_cache\StackMiddleware\PageCache->fetch() (Line: 138) Drupal\page_cache\StackMiddleware\PageCache->lookup() (Line: 87) Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 50) Drupal\ban\BanMiddleware->handle() (Line: 48) Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51) Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36) Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51) Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 741) Drupal\Core\DrupalKernel->handle() (Line: 19)Deprecated function: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in Drupal\Component\Utility\UrlHelper::isValid() (line 452 of core/lib/Drupal/Component/Utility/UrlHelper.php).
Drupal\Component\Utility\UrlHelper::isValid() (Line: 395) vo_base_refresh_preprocess_bibcite_reference() call_user_func_array() (Line: 261) Drupal\Core\Theme\ThemeManager->render() (Line: 491) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 1204) Drupal\views\Plugin\views\field\FieldPluginBase->advancedRender() (Line: 238) template_preprocess_views_view_field() call_user_func_array() (Line: 261) Drupal\Core\Theme\ThemeManager->render() (Line: 491) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 1796) Drupal\views\Plugin\views\field\FieldPluginBase->theme() (Line: 769) Drupal\views\Plugin\views\style\StylePluginBase->elementPreRenderRow() call_user_func_array() (Line: 113) Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 875) Drupal\Core\Render\Renderer->doCallback() (Line: 432) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 708) Drupal\views\Plugin\views\style\StylePluginBase->renderFields() (Line: 574) Drupal\views\Plugin\views\style\StylePluginBase->renderGrouping() (Line: 462) Drupal\views\Plugin\views\style\StylePluginBase->render() (Line: 2177) Drupal\views\Plugin\views\display\DisplayPluginBase->render() (Line: 1593) Drupal\views\ViewExecutable->render() (Line: 201) Drupal\views\Plugin\views\display\Page->execute() (Line: 1690) Drupal\views\ViewExecutable->executeDisplay() (Line: 81) Drupal\views\Element\View::preRenderViewElement() call_user_func_array() (Line: 113) Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 875) Drupal\Core\Render\Renderer->doCallback() (Line: 432) Drupal\Core\Render\Renderer->doRender() (Line: 248) Drupal\Core\Render\Renderer->render() (Line: 238) Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 638) Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 231) Drupal\Core\Render\MainContent\HtmlRenderer->prepare() (Line: 128) Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse() (Line: 90) Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray() call_user_func() (Line: 111) Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch() (Line: 186) Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76) Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53) Drupal\Core\StackMiddleware\Session->handle() (Line: 48) Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28) Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32) Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 201) Drupal\page_cache\StackMiddleware\PageCache->fetch() (Line: 138) Drupal\page_cache\StackMiddleware\PageCache->lookup() (Line: 87) Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 50) Drupal\ban\BanMiddleware->handle() (Line: 48) Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51) Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36) Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51) Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 741) Drupal\Core\DrupalKernel->handle() (Line: 19)