Field API
The Field API CRUD functions have been removed.
Documentation
Files Affected
hook_field_formatter_info() has been removed.
Documentation
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hook_field_formatter_view() has been removed.
Documentation
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hook_field_info() has been removed.
Documentation
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hook_field_instance_settings_form() has been removed.
Documentation
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hook_field_is_empty() has been removed.
Documentation
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hook_field_presave() has been removed.
Documentation
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hook_field_schema() has been removed.
Documentation
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hook_field_settings_form() has been removed.
Documentation
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hook_field_validate() has been removed.
Documentation
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hook_field_widget_form() has been removed.
Documentation
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hook_field_widget_info() has been removed.
Documentation
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Form API
form_error() is now a method of FormStateInterface.
Documentation
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Info File
Module info files' core key must have a value of 8.x.
Documentation
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Info files must contain a type key.
Documentation
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Many common dependencies have moved into core.
Documentation
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Modules no longer declare classes in their info file.
Documentation
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Miscellaneous
Classes must be PSR-4 compliant.
Documentation
The core token API is now a service.
Documentation
Files Affected
Many common functions, shared variables, and constants have been renamed.
Documentation
Automated web tests must be in a PSR-4 namespace, and unit tests must be converted to PHPUnit.
Documentation
Rendering
drupal_add_js() has been removed.
Documentation
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System
l() has been removed.
Documentation
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url() has been removed.
Documentation
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hook_init() has been removed.
Documentation
Files Affected