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function debug in Drupal 8

Same name and namespace in other branches
  1. 7 includes/ \debug()
  2. 9 core/includes/ \debug()

Outputs debug information.

The debug information is passed on to trigger_error() after being converted to a string using _drupal_debug_message().


$data: Data to be output.

$label: Label to prefix the data.

$print_r: Flag to switch between print_r() and var_export() for data conversion to string. Set $print_r to FALSE to use var_export() instead of print_r(). Passing recursive data structures to var_export() will generate an error.

8 calls to debug()
AssertPageCacheContextsAndTagsTrait::assertCacheContexts in core/modules/system/src/Tests/Cache/AssertPageCacheContextsAndTagsTrait.php
Ensures that some cache contexts are present in the current response.
AssertPageCacheContextsAndTagsTrait::assertCacheMaxAge in core/modules/system/src/Tests/Cache/AssertPageCacheContextsAndTagsTrait.php
Asserts the max age header.
AssertPageCacheContextsAndTagsTrait::debugCacheTags in core/modules/system/src/Tests/Cache/AssertPageCacheContextsAndTagsTrait.php
Provides debug information for cache tags.
EntityCacheTagsTestBase::verifyRenderCache in core/modules/system/src/Tests/Entity/EntityCacheTagsTestBase.php
Verify that a given render cache entry exists, with the correct cache tags.
EntityCacheTagsTestBase::verifyRenderCache in core/modules/system/tests/src/Functional/Entity/EntityCacheTagsTestBase.php
Verify that a given render cache entry exists, with the correct cache tags.

... See full list

7 string references to 'debug'
ErrorTest::providerTestGetLastCaller in core/tests/Drupal/Tests/Core/Utility/ErrorTest.php
Data provider for testGetLastCaller.
PhpUnitTestRunner::summarizeResults in core/lib/Drupal/Core/Test/PhpUnitTestRunner.php
Tallies test results per test class.
PhpUnitTestRunnerTest::providerTestSummarizeResults in core/tests/Drupal/Tests/Core/Test/PhpUnitTestRunnerTest.php
SimpletestDeprecationTest::testDeprecatedPhpUnitFunctions in core/modules/simpletest/tests/src/Kernel/SimpletestDeprecationTest.php
@expectedDeprecation simpletest_phpunit_xml_filepath is deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. Use \Drupal\Core\Test\PhpUnitTestRunner::xmlLogFilepath() instead. See @expectedDeprecation…
TestBase::error in core/modules/simpletest/src/TestBase.php
Fire an error assertion.

... See full list


core/includes/, line 1127
Common functions that many Drupal modules will need to reference.


function debug($data, $label = NULL, $print_r = TRUE) {

  // Print $data contents to string.
  $string = Html::escape($print_r ? print_r($data, TRUE) : var_export($data, TRUE));

  // Display values with pre-formatting to increase readability.
  $string = '<pre>' . $string . '</pre>';
  trigger_error(trim($label ? "{$label}: {$string}" : $string));