# Markdown Helper
[![Gem](https://img.shields.io/gem/v/markdown_helper.svg?style=flat)](http://rubygems.org/gems/markdown_helper "View this project in Rubygems")
## Contents
- [Installation](#installation)
- [What's a Markdown Helper?](#whats-a-markdown-helper)
- [How It Works](#how-it-works)
- [Restriction: ```git``` Only](#restriction-git-only)
- [Commented or Pristine?](#commented-or-pristine)
- [File Inclusion](#file-inclusion)
- [Re-use Text](#re-use-text)
- [Include Generated Text](#include-generated-text)
- [Nest Inclusions](#nest-inclusions)
- [Merged Text Formats](#merged-text-formats)
- [Markdown](#markdown)
- [Highlighted Code Block](#highlighted-code-block)
- [Plain Code Block](#plain-code-block)
- [Comment](#comment)
- [Details](#details)
- [Pre-Formatted Text](#pre-formatted-text)
- [Usage](#usage)
- [CLI](#cli)
- [API](#api)
- [Include Descriptions](#include-descriptions)
- [Example Include Descriptions](#example-include-descriptions)
- [Page TOC](#page-toc)
- [Diagnostics](#diagnostics)
- ["Noisy" (Not Pristine)](#noisy-not-pristine)
- [Missing Includee File](#missing-includee-file)
- [Circular Inclusion](#circular-inclusion)
- [Run ```irb```](#run-irb)
- [What Should Be Next?](#what-should-be-next)
## Installation
```gem install markdown_helper```
## What's a Markdown Helper?
Class MarkdownHelper
supports:
* [File inclusion](#file-inclusion): to include text from other files, as code-block or markdown.
* [Page TOC](#page-toc): to create and insert the table of contents for a markdown page.
* [Run irb](#run-irb): to execute Ruby snippets in the Ruby interactive shell (```irb```) and include the output in markdown.
## How It Works
The markdown helper is a preprocessor that reads a markdown document (template) and writes another markdown document.
The template can contain certain instructions that call for file inclusions.
### Restriction: ```git``` Only
The helper works only in a ```git``` project: the working directory or one of ita parents must be a git directory -- one in which command ```git rev-parse --git-dir``` succeeds.
### Commented or Pristine?
By default, the output markdown has added comments that show:
* The path to the template file.
* The path to each included file.
You can suppress those comments using the pristine
option.
## File Inclusion
This markdown helper enables file inclusion in GitHub markdown.
(Actually, this README file itself is built using file inclusion.)
See all [use cases](markdown/use_cases/use_cases.md#use-cases).
### Re-use Text
Keep your markdown DRY (Don't Repeat Yourself) by re-using text. See the [use case](markdown/use_cases/include/reuse_text/use_case.md#reuse-text).
### Include Generated Text
In particular, you can include text that's built during your "readme build." See the [use case](markdown/use_cases/include/include_generated_text/use_case.md#include-generated-text).
### Nest Inclusions
You can nest inclusions. See the [use case](markdown/use_cases/include/nest_inclusions/use_case.md#nest-inclusions).
### Merged Text Formats
#### Markdown
You can include text that is to be treated simply as markdown. See the [use case](markdown/use_cases/include/include_markdown/use_case.md#include-markdown).
#### Highlighted Code Block
You can include a code block that's to be highlighted. See the [use case](markdown/use_cases/include/include_highlighted_code/use_case.md#include-highlighted-code).
#### Plain Code Block
You can also include a code block without highlighting. See the [use case](markdown/use_cases/include/include_code_block/use_case.md#include-code-block).
#### Comment
You can include text that's to become a comment in the markdown. See the [use case](markdown/use_cases/include/include_text_as_comment/use_case.md#include-text-as-comment).
#### Details
You can include text that's to become details in the markdown. See the [use case](markdown/use_cases/include/include_text_as_details/use_case.md#include-text-as-details).
### Pre-Formatted Text
You can include text that's pre-formatted. See the [use case](markdown/use_cases/include/include_text_as_pre/use_case.md#include-text-as-pre).
### Usage
#### CLI
```include.txt```:
```
Usage: markdown_helper include [options] template_file_path markdown_file_path
--pristine No comments added
--help Display help
where
* template_file_path is the path to an existing file.
* markdown_file_path is the path to a file to be created.
Typically:
* Both file types are .md.
* The template file contains file inclusion descriptions.
```
#### API
```include_usage.rb```:
```ruby
require 'markdown_helper'
template_file_path = 'highlight_ruby_template.md'
markdown_file_path = 'highlighted_ruby.md'
# Pristine.
markdown_helper = MarkdownHelper.new
markdown_helper.pristine = true
markdown_helper.include(template_file_path, markdown_file_path)
# Also pristine.
markdown_helper = MarkdownHelper.new(:pristine => true)
markdown_helper.include(template_file_path, markdown_file_path)
```
#### Include Descriptions
Specify each file inclusion at the beginning of a line via an *include description*, which has the form:
@[
*format*]\(
*relative_file_path*)
where:
* *format* (in square brackets) is one of the following:
* Highlighting mode such as [ruby]
, to include a highlighted code block. This can be any Ace mode mentioned in [GitHub Languages](https://github.com/github/linguist/blob/master/lib/linguist/languages.yml).
* [:code_block]
, to include a plain code block.
* [:markdown]
, to include text markdown (to be rendered as markdown).
* [:comment]
, to include text as a markdown comment.
* [:pre]
, to include pre-formatted text.
* [:details]
, to include text as details.
* *relative_file_path* points to the file to be included.
##### Example Include Descriptions
```include.md```:
```
@[ruby](my_ruby.rb)
@[:code_block](my_language.xyzzy)
@[:markdown](my_markdown.md)
@[:comment](my_comment.txt)
@[:pre](my_preformatted.txt)
```
#### Page TOC
You can specify the location for an automatically-generated page TOC (table of cotents). See the [use case](markdown/use_cases/include/include_page_toc/use_case.md#include-page-toc).
#### Diagnostics
##### "Noisy" (Not Pristine)
By default, the markdown helper inserts comments indicating inclusions. See the [use case](markdown/use_cases/include/include_with_added_comments/use_case.md#include-with-added-comments).
##### Missing Includee File
A missing includee file causes an exception that shows an inclusion backtrace. See the [use case](markdown/use_cases/include/diagnose_missing_includee/use_case.md#diagnose-missing-includee).
##### Circular Inclusion
A circular inclusion causes an exception that shows an inclusion backtrace. See the [use case](markdown/use_cases/include/diagnose_circular_includes/use_case.md#diagnose-circular-includes).
## Run ```irb```
* Execute Ruby snippets in the Ruby interactive shell (```irb```) and include the output in markdown. See the [use case](markdown/use_cases/run_irb/run_irb/use_case.md#run-irb).
## What Should Be Next?
I have opened some enhancement Issues in the GitHub [markdown_helper](https://github.com/BurdetteLamar/markdown_helper) project:
* [Project TOC](https://github.com/BurdetteLamar/markdown_helper/issues/37): table of contents of all markdown pages in project.
* [Partial file inclusion](https://github.com/BurdetteLamar/markdown_helper/issues/38): including only specified lines from a file (instead of the whole file).
* [Ruby-entity inclusion](https://github.com/BurdetteLamar/markdown_helper/issues/39): like file inclusion, but including a Ruby class, module, or method.
* [Pagination](https://github.com/BurdetteLamar/markdown_helper/issues/40): series of markdown pages connected by prev/next navigation links.
Feel free to comment on any of these, or to add more Issues (enhancement or otherwise).