--- language: en highlight-style: native --- # Formátítko 2.0 A python program based on [pandoc](https://pandoc.org/) and its python library [panflute](http://scorreia.com/software/panflute) for converting from markdown to TeX and HTML with added fancy features like image processing, python-based macros and much more. ## Requirements This project requires `panflute 2.3.0` that itself requires `pandoc 3.0`. If the version of `pandoc` doesn't match, very weird things can happen. ImageMagick and Inkscape are used for image processing. Nodejs is used for KaTeX. ## Usage ``` usage: formatitko [-h] [-l IMG_LOOKUP_DIRS [IMG_LOOKUP_DIRS ...]] [-p IMG_PUBLIC_DIR] [-c IMG_CACHE_DIR] [-i IMG_WEB_PATH] [-w OUTPUT_HTML] [-t OUTPUT_TEX] [-m OUTPUT_MD] [-j OUTPUT_JSON] [--katex-server] [-k KATEX_SOCKET] [--debug] input_filename positional arguments: input_filename The markdown file to process. options: -h, --help show this help message and exit -l IMG_LOOKUP_DIRS [IMG_LOOKUP_DIRS ...], --img-lookup-dirs IMG_LOOKUP_DIRS [IMG_LOOKUP_DIRS ...] Image lookup directories. When processing images, the program will try to find the image in them first. Always looks for images in the same folder as the markdown file. (default: []) -p IMG_PUBLIC_DIR, --img-public-dir IMG_PUBLIC_DIR Directory to put processed images into. The program will overwrite images, whose dependencies are newer. (default: public) -c IMG_CACHE_DIR, --img-cache-dir IMG_CACHE_DIR Directory to cache processed images and intermediate products. The program will overwrite files, whose dependencies are newer. (default: cache) -i IMG_WEB_PATH, --img-web-path IMG_WEB_PATH Path where the processed images are available on the website. (default: /) -w OUTPUT_HTML, --output-html OUTPUT_HTML The HTML file (for Web) to write into. (default: None) -t OUTPUT_TEX, --output-tex OUTPUT_TEX The TEX file to write into. (default: None) -m OUTPUT_MD, --output-md OUTPUT_MD The Markdown file to write into. (Uses pandoc to generate markdown) (default: None) -j OUTPUT_JSON, --output-json OUTPUT_JSON The JSON file to dump the pandoc-compatible AST into. (default: None) --katex-server Starts a KaTeX server and prints the socket filename onto stdout. Useful for running formatitko many times without starting the KaTeX server each time. (default: False) -k KATEX_SOCKET, --katex-socket KATEX_SOCKET The KaTeX server socket filename obtained by running with `--katex-server`. (default: None) --debug ``` ## Format Formátítko uses all the default pandoc markdown extensions except for definition lists and citations. It also adds its own custom features. ## Features ### Hiding and showing elements based on flags Flags can be set in the Front Matter or with python code. Then, elements with the `if` attribute will only be shown if the flag is set to True and elements with the `ifn` attribute will only be show if the flag is not set to True. **Example:** ```markdown {.group} --- flags: foo: true --- [This will be shown]{if=foo} [This will not be shown]{if=bar} [This will be shown]{ifn=bar} ``` ### Including other files There are two ways of including files. #### Importing The first is importing, which only takes the state (defined commands, metadata, etc.) from the file and any content is omitted. This is useful for creating libraries of commands. There are three types of imports: ##### Python Module (the default) ```markdown [#ksp_formatitko as ksp]{} ``` or ```markdown [#ksp_formatitko]{} ``` with an optional `type=module` in the curly brackets, tries to import a python module as a set of formatitko commands. See below for more details about commands. ##### JSON Metadata [#test/test.json]{type=metadata key=orgs} This will import metadata from a JSON file. THe optional `key` argument sets the key under which the whole JSON file will be placed. Dictionaries are merged, others overwritten. #### Partials Partials are the very opposite of imports, they have their own context, which inherits everything from the context they're included in, but gets reset after the file ends. :::{partial=test/empty.md} ::: If the `untrusted` attribute is set to True, the partial and all its children will not be able to define commands or run inline blocks (but it will be able to run commands defined in the parent). ^[Please don't trust this for any security though, we're playing with *eval* fire, this will never be secure.] You can also import raw HTML and TeX if you set the `type` attribute of the partial to `tex` or `html`. ### Groups Groups are pieces of markdown with their own sandboxed context, in other words, inline partials. Syntax-wise they are pandoc Divs with the `.group` class. All attributes of the Div will be passed down as metadata to the group. ::: {.group lang=cs} OOOoo český mód ::: If you want to have more fancy metadata, that can only be specified in a front matter, you can use the following syntax: ```markdown {.group} --- lang: cs --- OOOoo český mód ``` If you need to nest groups or have code blocks inside groups, you can increase the amount of backticks around the outer block: ````markdown {.group} ```go fmt.Pritln("owo") ``` ```` Note however, that when this syntax is used, pandoc is executed for each of these blocks which could get slow. Using divs is preferred. Groups and partials are also enclosed in `\begingroup` and `\endgroup` in the output TeX. ### Raw HTML and TeX ^[This is a pandoc feature] If raw HTML or TeX is included in the markdown file, it will automagically pop out into the respective output file. red text \vskip1em This has the advantage and disadvantage of being very *"automagic"*, which means that for instance markdown inside HTML will still get interpreted as markdown. It is however very very unreliable, so in most cases, you should use explicit raw blocks with the unnamed attribute set to either `html` or `tex`. ^[Still a pandoc feature.] ``` {=html} red text ``` ### Running python code Formátítko allows you to run Python code directly from your MD file. Any `python` code block with the class `run` will be executed. #### Command environment The commands will be executed as functions with the following signature: ```python def command(element: Command, context: Context) -> list[Element]: ``` some global variables may be available, and are defined in `command_env.py`: ```python import panflute as pf import formatitko.elements as fe from formatitko.util import import_md_list from formatitko.util import parse_string from formatitko.context import Context from formatitko.command import Command from panflute import Element ``` ##### `element` parameter The `element` parameter holds the element the command is currently being executed on. In the case of running python blocks directly, it is probably not interesting but will get interesting later. ##### `context` parameter You can access the current context using the `context` parameter. The context provides read/write access to the FrontMatter metadata. The context has the following methods: `context.get_metadata(key: str, simple: bool=True, immediate: bool=False)` - `key`: The key of the metadatum you want to get. Separate child keys with dots: `ctx.get_metadata("flags.foo")` - `simple`: Whether to use python's simple builtin types or panflute's MetaValues. MetaValues can contain formatted text, simple values loose all formatting. - `immediate`: Only get metadatum from the current context, not from its parents. `context.set_metadata(key: str, value)` - `key`: The key of the metadatum you want to get. Separate child keys with dots: `ctx.get_metadata("flags.foo")` - `value`: Any value you want to assign to the metadatum `context.unset_metadata(key: str)` Delete the metadatum in the current context and allow it to inherit the value from the parent context. - `key`: The key of the metadatum you want to get. Separate child keys with dots: `ctx.get_metadata("flags.foo")` Helper functions for flags exist which work the same as for metadata: `context.is_flag_set(flag: str) -> bool` `context.set_flag(flag: str, val: bool)` `context.unset_flag(flag: str)` There are also other useful functions, which you can see for yourself in `context.py`. > **WARNING**: Writing to metadata should **only** be done **at the beginning** > of the document or a group (before any printable content). Writing to metadata > in other places in the document might cause undefined behaviour (mostly some > elements might behave as if the metadata was set elsewhere). ##### Return value The function **must** return a list of valid Elements. This list may be empty. These elements will be placed in the document in the location where the command was invoked. The `parse_string` function might be useful, it turns a simple string into a list of panflute's `Str`s and `Space`s (without any formatting). If you want to use markdown in your function output, you have to convert it yourself using `import_md` but beware this calls pandoc, is potentially slow and is discouraged. **Examples:** ````markdown {.group} --- title: Foo --- ```python {.run} return [ pf.Para(pf.Emph(pf.Str("wooo"))), pf.Para(*parse_string("The title of this file is: " + context.get_metadata("title"))) ] ``` ```` ```python {.run} return [pf.Strong(*parse_string("Hello world!"))] ``` ### Defining and running commands Code blocks can be also saved and executed later. Defining is done using the `define` attribute: **Example:** ```python {define=commandname} return [pf.Str("foo")] ``` If you try to define the same command twice, you will get an error. To redefine a command, use the `define` attribute instead of `redefine`. ### Running defined commands There are multiple ways of running commands. There is the shorthand way: [!commandname]{} Or using the `c` attribute on a span or a div (new: or a codeblock!): [Some content]{c=commandname} :::{c=commandname} Some content ::: ```python {define=bash} import subprocess c = subprocess.run(["bash", "-c", element.text], stdout=subprocess.PIPE, check=True, encoding="utf-8") return [pf.Para(pf.Str(c.stdout))] ``` ```bash {c=bash} cat /etc/hostname ``` To access the content or attributes of the div or span the command has been called on, the `element` variable is available, which contains the `panflute` representation of the element. **Example:** ```python {define=index} return [element.content[int(element.attributes["i"])]] ``` [Pick the third element from this span]{c=index i=2} ### Direct metadata print Metadata can be printed directly using a shorthand. The advantage of this is it keeps the formatting from the metadatum's definition ```markdown {.group} --- a: b: some text with **strong** --- [$a.b]{} ``` ### Syntax highlighting Formátítko uses [pygments](https://pygments.org/) to highlight syntax in code blocks. To turn it off for a single block, don't specify a language or set the `highlight` attribute to `False`. You can also set the metadatum `highlight` to `false` in the FrontMatter to disable it in a given Group. To change the [highlighting style](https://pygments.org/styles/), you have to set the `highlight-style` metadatum or the `style` attribute directly on the element. **Examples:** ```python print("cool") ``` ```python {style=manni} print("freezing") ``` ```zsh {highlight=False} ./formatitko.py README.md ``` ### Language awareness Formátítko is language aware, this means that the `lang` metadatum is somewhat special. (It is also special for pandoc) ### NBSP Formátítko automatically inserts no-break spaces according to its sorta smart rules. (See the `whitespace.py` file for more info) These rules **depend on the chosen language**. (`cs` has some additional rules) To insert a literal no-break space, you can either insert the unicode no-break space or use the html escape. Enforcing a breakable space is not as painless, you should insert a​ zero-width space beside the normal​ space. ### Smart quotes Quotes get automatically converted to the slanted ones according to the current language. **Examples:** ::: {.group lang=cs} "Uvozovky se v českém testu píší 'jinak' než v angličtině." ::: "In Czech texts, quotes are written 'differently' than in English" ### Math Math blocks get automatically converted to HTML using $Ka\TeX$ and fall out unchanged into TeX output. To make KaTeX as consistent with TeX as possible, the `\begingroup` and `\endgroup` that are produced by [Groups](#groups) are also emulated in the KaTeX environment, so macro definitions should be isolated as you expect. ### Images #### Figures Pandoc's [implicit figures](https://pandoc.org/MANUAL.html#extension-implicit_figures) are enabled, so images which are alone in a paragraph are automatically converted to figures: ![A single pixel image, wow!](test/1px.png "This is the alt text shown to screen readers (it defaults to the caption)"){width=10em} To prevent this, add a backslash at the end of the line with the image: ![A single pixel image, wow!](test/1px.png "This is the alt text shown to screen readers"){width=10em}\ #### Image gathering Images are automatically searched for in the directory where each markdown file is (including partials) and also in directories listed in the `--lookup-dirs` command line parameter. After processing, they're all put into the folder specified with `--public-dir`. Formátítko also does dependency management, which means that all images will be regenerated only when their dependencies are newer. #### Image processing Images are automatically processed so that they can be successfully used in both output formats. This includes generating multiple sizes and providing a [srcset](https://developer.mozilla.org/en-US/docs/Learn/HTML/Multimedia_and_embedding/Responsive_images). To customize this, the `file-width`, `file-height`, `file-dpi`, `file-quality` and `no-srcset` attributes are available. All but the last one should be integers. Processing also includes Asymptote images -- you can simply include an asymptote program as an image and formátítko handles the rest for you. #### Content headers and footers If you want formatitko to generate fully formed html files for you, you might want to add a HTML partial with the starting tags and ``. This would normally not work, because the entire document is wrapped with `
`. Using the special `.header_content` and `.footer_content` classes of divs, you can append content to a header and footer, which are popped to the output before and after the document. :::: {.header_content} ::: {partial="test/test-top.html" type="html"} ::: :::: ## Working with the produced output ### HTML The HTML should be almost usable as-is. The styles for synstax-highlighting are added automatically. The styles for KaTeX however are not and should be added in your ``^[This is taken directly from [KaTeX's docs](https://katex.org/docs/browser.html)]: ```html ``` You can see how this is done in `test/test.md` ### TeX The TeX output is not usable as is. Many of the elements are just converted to macros, which you have to define yourself. There is an example implementation in `formatitko.tex`, which uses LuaTeX and the ucwmac package, but you should customize it to your needs (and to the context in which the output is used). ## More examples More usage examples can be found (even though a bit chaotically) in the test directory.