--- 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.py [-h] [-l IMG_LOOKUP_DIRS [IMG_LOOKUP_DIRS ...]] [-p IMG_PUBLIC_DIR] [-i IMG_WEB_PATH] [-w OUTPUT_HTML] [-t OUTPUT_TEX] 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 not overwrite existing images. (default: public) -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: output.html) -t OUTPUT_TEX, --output-tex OUTPUT_TEX The TEX file to write into. (default: output.tex) ``` ## 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. The syntax is as follows: [#test/empty.md]{} The curly braces are required for pandoc to parse the import properly and should be left empty. #### 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. They function exactly the same as partials, namely can have their own front matter. ```markdown {.group} --- language: 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") ``` ```` 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: #### Context You can access the current context using the `ctx` variable. The context provides read/write access to the FrontMatter metadata. The context has the following methods: `ctx.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. `ctx.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 `ctx.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: `ctx.is_flag_set(flag: str) -> bool` `ctx.set_flag(flag: str, val: bool)` `ctx.unset_flag(flag: str)` #### Writing output There are two modes of writing output, plaintext and element-based. Plaintext mode uses the `print(text: str)` and `println(text: str)` functions, that append text to a buffer which is then interpreted as markdown input. Element-based mode uses the `appendChild(element: pf.Element)` and `appendChildren(*elements: List[pf.Element])` functions which allow you to append `panflute` elements to a list which is then again interpreted as input. The `panflute` library is available as `pf`. When one of these functions is called, the mode is set and functions from the other mode cannot be called within the same block of code. **Examples:** ````markdown {.group} --- title: Foo --- ```python {.run} println("*wooo*") println() println("The title of this file is: " + ctx.get_metadata("title")) ``` ```` ```python {.run} appendChild(pf.Para(pf.Strong(pf.Str("foo")))) ``` ### Defining and running commands Code blocks can be also saved and executed later. Defining is done using the `define` attribute: **Example:** ```python {define=commandname} print("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: [Some content]{c=commandname} :::{c=commandname} Some content ::: 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} appendChild(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 in the **top-level document** this is to prevent the need for many inline style definitions. **Examples:** ```python print("cool") ``` ```zsh {highlight=False} ./formatitko.py README.md ``` ### Language awareness Formátítko is language aware, this means that the `language` metadatum is somewhat special. When set using the front matter, it is also popped out to TeX as a `\languagexx` macro. Currently supported values are `cs` and `en` for internal uses but can be set to anything. ### 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:** ```markdown {.group} --- language: 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`. #### 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. Keep in mind that the processing tries to be as lazy as possible, so it never overwrites any files and if it finds the right format or resolution (only judging by the filenames) in the lookup directories it will just copy that. This means that any automatic attempts at conversion can be overridden by converting the file yourself, naming it accordingly and placing it either in the public or one of the lookup directories. ## 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 ``` Also the output HTML is not intended as a standalone file but should be included as part of a larger template. (That includes a doctype, other css, etc.) ### 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).