HackMD/public/docs/features.md

# Features

## Introduction

<i class="fa fa-file-text"></i> **CodiMD** is a real-time, multi-platform collaborative markdown note editor.
This means that you can write notes with other people on your **desktop**, **tablet** or even on the **phone**.
You can sign-in via multiple auth providers like **Facebook**, **Twitter**, **GitHub** and many more on the [_homepage_](/).

If you experience any _issues_, feel free to report it on [**GitHub**](https://github.com/codimd/server/issues).
Or meet us on [**Matrix.org**](https://riot.im/app/#/room/#codimd:matrix.org) for dev-talk and interactive help.
**Thank you very much!**

## Workspace

### Modes

#### Desktop & Tablet

<i class="fa fa-eye fa-fw"></i> View: See only the result.
<i class="fa fa-columns fa-fw"></i> Both: See editor and result at the same time.
<i class="fa fa-pencil fa-fw"></i> Edit: See only the editor.

#### Mobile

<i class="fa fa-eye fa-fw"></i> View: See only the result.
<i class="fa fa-pencil fa-fw"></i> Edit: See only the editor.

### Night Mode

When you are tired of a white screen and like a night mode, click on the little moon <i class="fa fa-moon-o"></i> and turn on the night view of CodiMD.

The editor view, which is in night mode by default, can also be toggled between night and day view using the the little sun<i class="fa fa-sun-o fa-fw"></i>.

### Image Upload

You can upload an image simply by clicking on the upload button <i class="fa fa-upload"></i>.
Alternatively, you can **drag-n-drop** an image into the editor. Even **pasting** images is possible!
This will automatically upload the image to **[imgur](http://imgur.com)**, **[Amazon S3](https://aws.amazon.com/s3/)**, **[Minio](https://minio.io)** or the **local filesystem** (depending on the instance's configuration), nothing to worry about. :tada:

![imgur](https://i.imgur.com/9cgQVqD.png)

### Share Notes

If you want to share an **editable** note, just copy the URL.
If you want to share a **read-only** note, simply press the publish button <i class="fa fa-share-square-o"></i> and copy the URL.

### Save a Note

Currently, you can save to **Dropbox** <i class="fa fa-dropbox"></i> (depending on the instance's configuration) or save a Markdown <i class="fa fa-file-text"></i>, HTML or raw HTML <i class="fa fa-file-code-o"></i> file locally.

### Import Notes

Similarly to the _save_ feature, you can also import a Markdown file from **Dropbox** <i class="fa fa-dropbox"></i> (depending on the instance's configuration), or import content from your **clipboard** <i class="fa fa-clipboard"></i>, which can parse some HTML. :smiley:

### Permissions

It is possible to change the access permission of a note through the little button on the top right of the view.
There are four possible options:

|                              |Owner read/write|Signed-in read|Signed-in write|Guest read|Guest write|
|:-----------------------------|:--------------:|:------------:|:-------------:|:--------:|:---------:|
|<span class="text-nowrap"><i class="fa fa-leaf fa-fw"></i> **Freely**</span>|✔|✔|✔|✔|✔|
|<span class="text-nowrap"><i class="fa fa-pencil fa-fw"></i> **Editable**</span>|✔|✔|✔|✔|✖|
|<span class="text-nowrap"><i class="fa fa-id-card fa-fw"></i> **Limited**</span>|✔|✔|✔|✖|✖|
|<span class="text-nowrap"><i class="fa fa-lock fa-fw"></i> **Locked**</span>|✔|✔|✖|✔|✖|
|<span class="text-nowrap"><i class="fa fa-umbrella fa-fw"></i> **Protected**</span>|✔|✔|✖|✖|✖|
|<span class="text-nowrap"><i class="fa fa-hand-stop-o fa-fw"></i> **Private**</span>|✔|✖|✖|✖|✖|

**Only the owner of the note can change the note's permissions.**

### Embed a Note

Notes can be embedded as follows:

```xml
<iframe width="100%" height="500" src="https://demo.codimd.io/features" frameborder="0"></iframe>
```

### [Slide Mode](./slide-example)

You can use a special syntax to organize your note into slides.
After that, you can use the **[Slide Mode](./slide-example)** <i class="fa fa-tv"></i> to make a presentation.
Visit the above link for details.

To switch the editor into slide mode, set the [document type](./yaml-metadata#type) to `slide`.

## View

### Autogenerated Table of Contents

You can look at the bottom right section of the view area, there is a _ToC_ button <i class="fa fa-bars"></i>.
Pressing that button will show you a current _Table of Contents_, and will highlight which section you're at.
ToCs support up to **three header levels**.

### Permalink

Every header will automatically add a permalink on the right side.
You can hover and click <i class="fa fa-chain"></i> to anchor on it.

## Edit

### Editor Modes

You can look in the bottom right section of the editor area, there you'll find a button with `SUBLIME` on it.
When you click it, you can select 3 editor modes, which will also define your shortcut keys:

- [Sublime](https://codemirror.net/demo/sublime.html) (default)
- [Emacs](https://codemirror.net/demo/emacs.html)
- [Vim](https://codemirror.net/demo/vim.html)

### Auto-Complete

This editor provides full auto-complete hints in markdown.

- Emojis: type `:` to show hints.
- Code blocks: type ` ``` `, followed by another character to show syntax highlighting suggestions.
- Headers: type `#` to show hint.
- Referrals: type `[]` to show hint.
- Externals: type `{}` to show hint.
- Images: type `!` to show hint.

### Title

The first **level 1 heading** (e.g. `# Title`) will be used as the note title.

### Tags

Using tags as follows, the specified tags will show in your **history**.

###### tags: `features` `cool` `updated`

### [YAML Metadata](./yaml-metadata)

You can provide advanced note information to set the browser behavior (visit above link for details):

- robots: set web robots meta
- lang: set browser language
- dir: set text direction
- breaks: set to use line breaks
- GA: set to use Google Analytics
- disqus: set to use Disqus
- slideOptions: setup slide mode options

### Table of Contents

Use the syntax `[TOC]` to embed a table of contents into your note.

[TOC]

### Emoji

You can type any emoji like this :smile: :smiley: :cry: :wink:

> See full emoji list [here](http://www.emoji-cheat-sheet.com/).

### ToDo List

- [ ] ToDos
  - [x] Buy some salad
  - [ ] Brush teeth
  - [x] Drink some water
  - [ ] **Click my box** and see the source code, if you're allowed to edit!

### Code Block

We support many programming languages, use the auto complete function to see the entire list.

```javascript=
var s = "JavaScript syntax highlighting";
alert(s);
function $initHighlight(block, cls) {
  try {
    if (cls.search(/\bno\-highlight\b/) != -1)
      return process(block, true, 0x0F) +
             ' class=""';
  } catch (e) {
    /* handle exception */
  }
  for (var i = 0 / 2; i < classes.length; i++) {
    if (checkCondition(classes[i]) === undefined)
      return /\d+[\s/]/g;
  }
}
```

If you want **line numbers**, type `=` after specifying the code block languagues.
Also, you can specify the start line number.
Like below, the line number starts from 101:

```javascript=101
var s = "JavaScript syntax highlighting";
alert(s);
function $initHighlight(block, cls) {
  try {
    if (cls.search(/\bno\-highlight\b/) != -1)
      return process(block, true, 0x0F) +
             ' class=""';
  } catch (e) {
    /* handle exception */
  }
  for (var i = 0 / 2; i < classes.length; i++) {
    if (checkCondition(classes[i]) === undefined)
      return /\d+[\s/]/g;
  }
}
```

Or you might want to continue the previous code block's line number, use `=+`:

```javascript=+
var s = "JavaScript syntax highlighting";
alert(s);
```

Somtimes you have a super long text without breaks. It's time to use `!` to wrap your code:

```!
When you’re a carpenter making a beautiful chest of drawers, you’re not going to use a piece of plywood on the back.
```

### Blockquote Tags

> Using the syntax below to specifiy your **name, time and color** to vary the blockquotes.
> [name=ChengHan Wu] [time=Sun, Jun 28, 2015 9:59 PM] [color=#907bf7]
> > Even support nested blockquotes!
> > [name=Max Mustermann] [time=Sun, Jun 28, 2015 9:47 PM] [color=red]

### Externals

#### YouTube

{%youtube aqz-KE-bpKQ %}

#### Vimeo

{%vimeo 124148255 %}

#### Gist

{%gist schacon/4277%}

#### SlideShare

{%slideshare briansolis/26-disruptive-technology-trends-2016-2018-56796196 %}

#### PDF

**Caution: this might be blocked by your browser if not using an `https` URL.**
{%pdf https://papers.nips.cc/paper/5346-sequence-to-sequence-learning-with-neural-networks.pdf %}

### MathJax

You can render *LaTeX* mathematical expressions using **MathJax**, as on [math.stackexchange.com](http://math.stackexchange.com/):

The *Gamma function* satisfying $\Gamma(n) = (n-1)!\quad\forall n\in\mathbb N$ is via the Euler integral

$$
x = {-b \pm \sqrt{b^2-4ac} \over 2a}.
$$

$$
\Gamma(z) = \int_0^\infty t^{z-1}e^{-t}dt\,.
$$

> More information about **LaTeX** mathematical expressions [here](http://meta.math.stackexchange.com/questions/5020/mathjax-basic-tutorial-and-quick-reference).

### Diagrams

#### UML Sequence Diagrams

You can render sequence diagrams like this:

```sequence
Alice->Bob: Hello Bob, how are you?
Note right of Bob: Bob thinks
Bob-->Alice: I am good thanks!
Note left of Alice: Alice responds
Alice->Bob: Where have you been?
```

More information about **sequence diagrams** syntax [here](http://bramp.github.io/js-sequence-diagrams/).

#### Flow Charts

Flow charts can be specified like this:

```flow
st=>start: Start
e=>end: End
op=>operation: My Operation
op2=>operation: lalala
cond=>condition: Yes or No?

st->op->op2->cond
cond(yes)->e
cond(no)->op2
```

More information about **flow charts** syntax [here](http://adrai.github.io/flowchart.js/).

#### Graphviz

```graphviz
digraph hierarchy {
  nodesep=1.0 // Increases the separation between nodes

  node [color=Red,fontname=Courier,shape=box] // All nodes will this shape and colour
  edge [color=Blue, style=dashed] // All the lines look like this

  Headteacher->{Deputy1 Deputy2 BusinessManager}
  Deputy1->{Teacher1 Teacher2}
  BusinessManager->ITManager
  {rank=same;ITManager Teacher1 Teacher2} // Put them on the same level
}
```

More information about **graphviz** syntax [here](http://www.tonyballantyne.com/graphs.html)

#### Mermaid

```mermaid
gantt
  title A Gantt Diagram

  section Section
  A task: a1, 2014-01-01, 30d
  Another task: after a1, 20d
  
  section Another
  Task in sec: 2014-01-12, 12d
  Another task: 24d
```

More information about **mermaid** syntax [here](http://knsv.github.io/mermaid)

#### Abc Music Notation

```abc
X:1
T:Speed the Plough
M:4/4
C:Trad.
K:G
|:GABc dedB|dedB dedB|c2ec B2dB|c2A2 A2BA|
GABc dedB|dedB dedB|c2ec B2dB|A2F2 G4:|
|:g2gf gdBd|g2f2 e2d2|c2ec B2dB|c2A2 A2df|
g2gf g2Bd|g2f2 e2d2|c2ec B2dB|A2F2 G4:|
```

More information about **abc** syntax [here](http://abcnotation.com/learn)

### Alert Area

:::success
Yes :tada:
:::

:::info
This is a message :mega:
:::

:::warning
Watch out :zap:
:::

:::danger
Oh No! :fire:
:::

### Typography

#### Headers

``` markdown
# h1 Heading
## h2 Heading
### h3 Heading
#### h4 Heading
##### h5 Heading
###### h6 Heading
```

#### Horizontal Rules

___

---

***

#### Typographic Replacements

Enable typographer option to see result.

(c) (C) (r) (R) (tm) (TM) (p) (P) +-

test.. test... test..... test?..... test!....

!!!!!! ???? ,,

Remarkable -- awesome

"Smartypants, double quotes"

'Smartypants, single quotes'

#### Emphasis

**This is bold text**

__This is bold text__

*This is italic text*

_This is italic text_

~~Deleted text~~

lu~lala~

Superscript: 19^th^

Subscript: H~2~O

++Inserted text++

==Marked text==

#### Blockquotes

> Blockquotes can also be nested...
>> ...by using additional greater-than signs right next to each other...
> > > ...or with spaces between arrows.

#### Lists

##### Unordered

+ Create a list by starting a line with `+`, `-`, or `*`
+ Sub-lists are made by indenting 2 spaces:
  - Marker character change forces new list start:
    * Ac tristique libero volutpat at
    + Facilisis in pretium nisl aliquet
    - Nulla volutpat aliquam velit
+ Very easy!

##### Ordered

1. Lorem ipsum dolor sit amet
2. Consectetur adipiscing elit
3. Aenean commodo ligula eget dolor

1. **You can use sequential numbers...**
1. **...or keep all the numbers as `1.`**
1. Aenean massa
2. Cum sociis natoque penatibus
3. Magnis dis parturient montes
4. Nascetur ridiculus mus
1. Donec quam felis

Start numbering with offset:

57. foo
1. bar

#### Code

Inline `code`

Indented code

    // Some comments
    line 1 of code
    line 2 of code
    line 3 of code

Block code "fences"

```
Sample text here...
```

Syntax highlighting

``` js
var foo = function (bar) {
  return bar++;
};

console.log(foo(5));
```

#### Tables

| Option | Description |
| ------ | ----------- |
| data   | path to data files to supply the data that will be passed into templates. |
| engine | engine to be used for processing templates. Handlebars is the default. |
| ext    | extension to be used for dest files. |

Right aligned columns

| Option | Description |
| ------:| -----------:|
| data   | path to data files to supply the data that will be passed into templates. |
| engine | engine to be used for processing templates. Handlebars is the default. |
| ext    | extension to be used for dest files. |

Left aligned columns

| Option | Description |
|:------ |:----------- |
| data   | path to data files to supply the data that will be passed into templates. |
| engine | engine to be used for processing templates. Handlebars is the default. |
| ext    | extension to be used for dest files. |

Center aligned columns

| Option | Description |
|:------:|:-----------:|
| data   | path to data files to supply the data that will be passed into templates. |
| engine | engine to be used for processing templates. Handlebars is the default. |
| ext    | extension to be used for dest files. |

#### Links

[link text](https://demo.codimd.org)
[link with title](https://nodeca.github.io/pica/demo/ "title text!")
Autoconverted link https://github.com/nodeca/pica

#### Images

![Minion](https://octodex.github.com/images/minion.png)

With a title:
![Stormtroopocat](https://octodex.github.com/images/stormtroopocat.jpg "The Stormtroopocat")

Like links, images also have a footnote style syntax with a reference later in the document defining the URL location:
![Dojocat][dojoref]

[dojoref]: https://octodex.github.com/images/dojocat.jpg  "The Dojocat"

Show the image with given size:
![Minion](https://octodex.github.com/images/minion.png =200x200)

#### Footnotes

Footnote 1 link[^first].
Footnote 2 link[^second].
Inline footnote^[Text of inline footnote] definition.
Duplicated footnote reference[^second].

[^first]: Footnote **can have markup**
    and multiple paragraphs.
[^second]: Footnote text.

#### Definition Lists

Term 1

:   Definition 1
with lazy continuation.

Term 2 with *inline markup*

:   Definition 2

        { some code, part of Definition 2 }

    Third paragraph of definition 2.

_Compact style:_

Term 1
  ~ Definition 1

Term 2
  ~ Definition 2a
  ~ Definition 2b

#### Abbreviations

This is an HTML abbreviation example.
It converts "HTML", but keeps intact partial entries like "xxxHTMLyyy" and so on.

*[HTML]: Hyper Text Markup Language