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diff --git a/docs/change_log/release-3.0.md b/docs/change_log/release-3.0.md new file mode 100644 index 0000000..85a5d27 --- /dev/null +++ b/docs/change_log/release-3.0.md @@ -0,0 +1,206 @@ +title: Release Notes for v3.0 + +# Python-Markdown 3.0 Release Notes + +We are pleased to release Python-Markdown 3.0 which adds a few new features and +fixes various bugs and deprecates various old features. See the list of changes +below for details. + +Python-Markdown version 3.0 supports Python versions 2.7, 3.4, 3.5, 3.6, 3.7, +PyPy and PyPy3. + +## Backwards-incompatible changes + +### `enable_attributes` keyword deprecated + +The `enable_attributes` keyword is deprecated in version 3.0 and will be +ignored. Previously the keyword was `True` by default and enabled an +undocumented way to define attributes on document elements. The feature has been +removed from version 3.0. As most users did not use the undocumented feature, it +should not affect most users. For the few who did use the feature, it can be +enabled by using the [Legacy Attributes](../extensions/legacy_attr.md) +extension. + +### `smart_emphasis` keyword and `smart_strong` extension deprecated + +The `smart_emphasis` keyword is deprecated in version 3.0 and will be ignored. +Previously the keyword was `True` by default and caused the parser to ignore +middle-word emphasis. Additionally, the optional `smart_strong` extension +provided the same behavior for strong emphasis. Both of those features are now +part of the default behavior, and the [Legacy +Emphasis](../extensions/legacy_em.md) extension is available to disable that +behavior. + +### `output_formats` simplified to `html` and `xhtml`. + +The `output_formats` keyword now only accepts two options: `html` and `xhtml` +Note that if `(x)html1`, `(x)html4` or `(x)html5` are passed in, the number is +stripped and ignored. + +### `safe_mode` and `html_replacement_text` keywords deprecated + +Both `safe_mode` and the associated `html_replacement_text` keywords are +deprecated in version 3.0 and will be ignored. The so-called "safe mode" was +never actually "safe" which has resulted in many people having a false sense of +security when using it. As an alternative, the developers of Python-Markdown +recommend that any untrusted content be passed through an HTML sanitizer (like +[Bleach]) after being converted to HTML by markdown. In fact, [Bleach Whitelist] +provides a curated list of tags, attributes, and styles suitable for filtering +user-provided HTML using bleach. + +If your code previously looked like this: + +```python +html = markdown.markdown(text, safe_mode=True) +``` + +Then it is recommended that you change your code to read something like this: + +```python +import bleach +from bleach_whitelist import markdown_tags, markdown_attrs +html = bleach.clean(markdown.markdown(text), markdown_tags, markdown_attrs) +``` + +If you are not interested in sanitizing untrusted text, but simply desire to +escape raw HTML, then that can be accomplished through an extension which +removes HTML parsing: + +```python +from markdown.extensions import Extension + +class EscapeHtml(Extension): + def extendMarkdown(self, md): + md.preprocessors.deregister('html_block') + md.inlinePatterns.deregister('html') + +html = markdown.markdown(text, extensions=[EscapeHtml()]) +``` + +As the HTML would not be parsed with the above Extension, then the serializer +will escape the raw HTML, which is exactly what happened in previous versions +with `safe_mode="escape"`. + +[Bleach]: https://bleach.readthedocs.io/ +[Bleach Whitelist]: https://github.com/yourcelf/bleach-whitelist + +### Positional arguments deprecated + +Positional arguments on the `markdown.Markdown()` class are deprecated as are +all except the `text` argument on the `markdown.markdown()` wrapper function. +Using positional arguments will raise an error. Only keyword arguments should be +used. For example, if your code previously looked like this: + +```python +html = markdown.markdown(text, [SomeExtension()]) +``` + +Then it is recommended that you change it to read something like this: + +```python +html = markdown.markdown(text, extensions=[SomeExtension()]) +``` + +!!! Note + This change is being made as a result of deprecating `"safe_mode"` as the + `safe_mode` argument was one of the positional arguments. When that argument + is removed, the two arguments following it will no longer be at the correct + position. It is recommended that you always use keywords when they are + supported for this reason. + +### Extension name behavior has changed + +In previous versions of Python-Markdown, the built-in extensions received +special status and did not require the full path to be provided. Additionally, +third party extensions whose name started with `"mdx_"` received the same +special treatment. This is no longer the case. + +Support has been added for extensions to define an [entry +point](../extensions/api.md#entry_point). An entry point is a string name which +can be used to point to an `Extension` class. The built-in extensions now have +entry points which match the old short names. And any third-party extensions +which define entry points can now get the same behavior. See the documentation +for each specific extension to find the assigned name. + +If an extension does not define an entry point, then the full path to the +extension must be used. See the [documentation](../reference.md#extensions) for +a full explanation of the current behavior. + +### Extension configuration as part of extension name deprecated + +The previously documented method of appending the extension configuration +options as a string to the extension name is deprecated and will raise an error. +The [`extension_configs`](../reference.md#extension_configs) keyword should be +used instead. See the [documentation](../reference.md#extension_configs) for a +full explanation of the current behavior. + +### HeaderId extension deprecated + +The HeaderId Extension is deprecated and will raise an error if specified. Use +the [Table of Contents](../extensions/toc.md) Extension instead, which offers +most of the features of the HeaderId Extension and more (support for meta data +is missing). + +Extension authors who have been using the `slugify` and `unique` functions +defined in the HeaderId Extension should note that those functions are now +defined in the Table of Contents extension and should adjust their import +statements accordingly (`from markdown.extensions.toc import slugify, unique`). + +### Homegrown `OrderedDict` has been replaced with a purpose-built `Registry` + +All processors and patterns now get "registered" to a +[Registry](../extensions/api.md#registry). A backwards compatible shim is +included so that existing simple extensions should continue to work. +A `DeprecationWarning` will be raised for any code which calls the old API. + +### Markdown class instance references. + +Previously, instances of the `Markdown` class were represented as any one of +`md`, `md_instance`, or `markdown`. This inconsistency made it difficult when +developing extensions, or just maintaining the existing code. Now, all instances +are consistently represented as `md`. + +The old attributes on class instances still exist, but raise a +`DeprecationWarning` when accessed. Also on classes where the instance was +optional, the attribute always exists now and is simply `None` if no instance +was provided (previously the attribute would not exist). + +### `markdown.util.isBlockLevel` deprecated + +The `markdown.util.isBlockLevel` function is deprecated and will raise a +`DeprecationWarning`. Instead, extensions should use the `isBlockLevel` method +of the `Markdown` class instance. Additionally, a list of block level elements +is defined in the `block_level_elements` attribute of the `Markdown` class which +extensions can access to alter the list of elements which are treated as block +level elements. + +### `md_globals` keyword deprecated from extension API + +Previously, the `extendMarkdown` method of a `markdown.extensions.Extension` +subclasses accepted an `md_globals` keyword, which contained the value returned +by Python's `globals()` built-in function. As all of the configuration is now +held within the `Markdown` class instance, access to the globals is no longer +necessary and any extensions which expect the keyword will raise a +`DeprecationWarning`. A future release will raise an error. + +### Added new, more flexible `InlineProcessor` class + +A new `InlineProcessor` class handles inline processing much better and allows +for more flexibility. The new `InlineProcessor` classes no longer utilize +unnecessary pretext and post-text captures. New class can accept the buffer that +is being worked on and manually process the text without regular expressions and +return new replacement bounds. This helps us to handle links in a better way and +handle nested brackets and logic that is too much for regular expression. + +## New features + +The following new features have been included in the release: + +* A new [testing framework](../test_tools.md) is included as a part of the + Markdown library, which can also be used by third party extensions. + +* A new `toc_depth` parameter has been added to the + [Table of Contents Extension](../extensions/toc.md). + +* Additional CSS class names can be appended to + [Admonitions](../extensions/admonition.md). |