---
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.
< em style = "color: red" > red text< / em >
\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}
< span style = "color: red" > red text< / span >
```
### 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:
{width=10em}
To prevent this, add a backslash at the end of the line with the image:
{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 `<head>` . This would
normally not work, because the entire document is wrapped with `<main>` . 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 `<head>` ^[This is taken directly from [KaTeX's docs ](https://katex.org/docs/browser.html )]:
```html
< link rel = 'stylesheet' href = 'https://cdn.jsdelivr.net/npm/katex@0.16.4/dist/katex.min.css' integrity = 'sha384-vKruj+a13U8yHIkAyGgK1J3ArTLzrFGBbBc0tDp4ad/EyewESeXE/Iv67Aj8gKZ0' crossorigin = 'anonymous' >
```
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.
