code-chunk.md

• Code Chunk (Beta)
  • Format
  • Options
  • Commands & Keyboard Shortcust
  • Macro
  • Demo
  • Showcases
  • Limitations

Code Chunk (Beta)

Changes might happen in the future.
To enable code chunk highlighting, install language-gfm-enhanced package and disable the language-gfm package.

Markdown Preview Enhanced allows you to render code output into documents.

```{bash}
ls .
```

```{node}
var date = Date.now()
console.log(date.toString())
```   

Format

You can configure code chunk options in format of {lang opt1:value1, opt2:value2, ...}

lang
The grammar that the code block should highlight.
It should be put at the most front.

Options

cmd
The command to run.
If cmd is not provided, then lang will be regarded as command.

eg:

	```{python cmd:"/usr/local/bin/python3"}
	print("This will run python3 program")
	```

output
html, text, png, none

defines how to render code output.
html will append output as html.
text will append output to a pre block.
png will append output as base64 image.
none will hide the output.

eg:

```{gnuplot output:"html"}
set terminal svg
set title "Simple Plots" font ",20"
set key left box
set samples 50
set style data points

plot [-10:10] sin(x),atan(x),cos(atan(x))
```

args
args that append to command. eg:

```{python args:["-v"]}
print("Verbose will be printed first")
```

```{erd args:["-f", "svg", "-i"], output:"html"}
	# output svg format and append as html result.
```

stdin
if stdin is set to true, then the code will be passed as stdin instead of as file.

hide
hide will hide code chunk but only leave the output visible. default: false
eg:

```{python hide:true}
print('you can see this output message, but not this code')
```

id
id will be automatically generated to track the running result.
Please Do Not modify it.

Commands & Keyboard Shortcust

run and all buttons are removed in version 0.8.8. So you need to use keyboard instead. nvm I put those buttons back.

• Markdown Preview Enhanced: Run Code Chunk or shift-enter
  execute single code chunk where your cursor is at.
• Markdown Preview Enhanced: Run All Code Chunks or ctrl-shift-enter
  execute all code chunks.

Macro

• input_file
  input_file is automatically generated under the same directory of your markdown file and will be deleted after running code that is copied to input_file.
  By default, it is appended at the very end of program arguments.
  However, you can set the position of input_file in your args option by {input_file} macro. eg:

```{program args:["-i", "{input_file}", "-o", "./output.png"]}
...your code here
```

Demo

This demo shows you how to render entity-relation diagram by using erd library.

```{erd output:"html", args:["-i", "{input_file}", "-f", "svg"], id:"ithhv4z4"}

[Person]
*name
height
weight
+birth_location_id

[Location]
*id
city
state
country

Person *--1 Location
```

{erd output:"html", args:["-i", "{input_file}", "-f", "svg"], id:"ithhv4z4"}

• erd the program that we are using. (you need to have the program installed first)
• output:"html" we will append the running result as html.
• args field shows the arguments that we will use.
• id is a unique identifier automatically generated, you don't need to care about it.

Then we can click the run button at the preview to run our code.

Showcases

bash

python matplotlib 3d plot with png output

gnuplot with svg output

Limitations

• Doesn't work with ebook yet.
• Might be buggy when usingpandoc document export