Initial Extension

.gitignore

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+.DS_Store

LICENSE

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 MIT License
 
-Copyright (c) 2022 quarto-ext
+Copyright (c) 2022 RStudio, PBC.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

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-# latex-environment
+# latex-environments
+
+## Overview
+
+This is Quarto extension that enables `divs` to be output as a custom environment in LaTeX. This is useful when you'd like to share content between LaTeX and other formats, but need the content to be placed in an environment when emitting LaTeX.
+
+## Installation
+
+To install this extension in your current directory (or into the Quarto project that you're currently working in),  use the following command:
+
+```
+quarto install extension dragonstyle/latex-environments
+```
+
+## Usage
+
+Divs with a class name listed in the in the `environments` key will be emitted in LaTeX as an environment with the provided name (or the class name itself if no name is provided). All of the following are valid:
+
+```yaml
+environments: program
+
+environments:
+  - program
+
+environments: [program]
+
+environments:
+  program: program-env
+```
+
+## Example
+
+```markdown
+---
+title: Test document
+environments: [program]
+----
+
+:::{.program}
+The contents of this div will be output in a `program`
+latex environment, but will appear in HTML (and any other output 
+format as a simple div with the class `program`)
+:::
+```

_extensions/quarto-ext/latex-environments/_extension.yml

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+title: LaTeX Environments
+author: RStudio, PBC
+version: 0.1.0
+contributes:
+  filters:
+    - extension.lua

_extensions/quarto-ext/latex-environments/extension.lua

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+-- environment.lua
+-- Copyright (C) 2020 by RStudio, PBC
+
+local classEnvironments = pandoc.MetaMap({})
+
+-- helper that identifies arrays
+local function tisarray(t)
+  local i = 0
+  for _ in pairs(t) do
+    i = i + 1
+    if t[i] == nil then return false end
+  end
+  return true
+end 
+
+-- reads the environments
+local function readEnvironments(meta)
+  local env = meta['environments']
+  if env ~= nil then
+    if tisarray(env) then 
+      -- read an array of strings
+      for i,v in ipairs(env) do        
+        local value = pandoc.utils.stringify(v)
+        classEnvironments[value] = value
+      end
+    else
+      -- read key value pairs
+      for k,v in pairs(env) do
+        local key = pandoc.utils.stringify(k)
+        local value = pandoc.utils.stringify(v)
+        classEnvironments[key] = value
+      end
+    end
+  end
+end
+
+-- use the environments from metadata to 
+-- emit a custom environment for latex
+local function writeEnvironments(divEl)
+  if quarto.doc.isFormat("latex") then
+    for k,v in pairs(classEnvironments) do
+      if divEl.attr.classes:includes(k) then
+        -- process this into a latex environment
+        local beginEnv = '\\begin' .. '{' .. v .. '}'
+        local endEnv = '\n\\end{' .. v .. '}'
+
+        -- if the first and last div blocks are paragraphs then we can
+        -- bring the environment begin/end closer to the content
+        if divEl.content[1].t == "Para" and divEl.content[#divEl.content].t == "Para" then
+          table.insert(divEl.content[1].content, 1, pandoc.RawInline('tex', beginEnv .. "\n"))
+          table.insert(divEl.content[#divEl.content].content, pandoc.RawInline('tex', "\n" .. endEnv))
+        else
+          table.insert(divEl.content, 1, pandoc.RawBlock('tex', beginEnv))
+          table.insert(divEl.content, pandoc.RawBlock('tex', endEnv))
+        end
+        return divEl
+      end
+    end
+  end
+end
+
+-- Run in two passes so we process metadata 
+-- and then process the divs
+return {
+    {Meta = readEnvironments}, 
+    {Div = writeEnvironments}
+}

example.qmd

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+---
+title: Environment Example
+environments: 
+  - program
+format:
+  latex: default
+  html: default
+filters:
+  - latex-environments
+---
+
+## Overview
+
+Divs with a class name listed in the in the `environments` key will be emitted in LaTeX as an environment with the provided name (or the class name itself if no name is provided). All of the following are valid:
+
+```yaml
+environments: program
+```
+
+```yaml
+environments:
+  - program
+```
+
+```yaml
+environments:
+  program: program-env
+```
+
+## Example
+
+:::{.program}
+The contents of this div will be output in a `program`
+latex environment, but will appear in HTML (and any other output format as a simple div with the class `program`)
+:::