In this tutorial we will look at how to create a github style markdown editor with preview button. Github’s markdown editor is used to edit the README.md file. This file contains getting started information about the github repository.
Using EpicEditor
EpicEditor is a JavaScript Library which can embed a mardown editor in an webpage. In this tutorial we will build a Github style markdown tool using EpicEditor.
Download EpicEditor and place it in your demo project. This is how my demo project looks
You can write content using GitHub-flavored Markdown syntax(https://github.github.com/gfm/). Admired by thousands, LightPaper is a powerful markdown editor with features such as Multi-Tabs, Folder Navigator, Distraction Free Mode, Quick Open, Live Preview, Full GFM Support, Math rendering etc. GitHub Markdown CSS demo. Multiple paragraphs in a list items: It's best to indent the paragraphs four spaces You can get away with three, but it can. Markdown editors are intuitive and lightweight text-to-HTML conversion tools for web content writers. You can use them to format lists, headers, and for emphasis. We took a deep dive into markdown.
-index.html
--epiceditor
--themes
--preview
-preview-dark.css
-github.css
-bartik.css
--editor
-epic-dark.css
-epic-light.css
--base
-epiceditor.css
--js
-epiceditor.min.js
-epiceditor.js
Create a Sample Editor
Here is the code for a sample markdown editor like Github style. With just 62 lines of code we created a editor like github’s.
<html>
<head>
<title>Github Style Markdown Editing Preview</title>
<scripttype='text/javascript'src='epiceditor/js/epiceditor.min.js'></script>
</head>
<body>
<buttononclick='preview();'>Preview</button>
<buttononclick='edit();'>Edit</button>
<divid='epiceditor'style='width: 600px; height: 600px; border: 2px solid black'></div>
<br>
<buttononclick='commit();'>Commit Change to Server</button>
<scripttype='text/javascript'>
var opts = {
container: 'epiceditor',
theme: {
base: '/themes/base/epiceditor.css',
editor: '/themes/editor/epic-light.css'
},
clientSideStorage: true,
file: {
name: 'README.md', //name of local file to open. Its not a real file but just localStorage item.
autoSave: 100 //saves the editor data into the local file every 100ms.
},
button: {
preview: false,
fullscreen: false,
bar: false
}
};
var editor = new EpicEditor(opts);
editor.load();
editor.importFile('README.md','#Last Commited Content'); //load file data from server for the last commit.
editor.preview();
function commit()
{
var theContent_html = editor.exportFile('README.md', 'html');
var theContent_md = editor.exportFile('README.md', 'text');
alert(theContent_md);
alert(theContent_html);
//here send data to server to update the file on server side.
}
function preview()
{
editor.preview();
}
function edit()
{
editor.edit();
}
</script>
</body>
</html>
Most of the code above is self explanatory.
A editor represents one file at a time. A file name (here it is README.md) is assigned to the editor. The markdown is stored/updated locally every 100ms. When user clicks the commit button you can retrieve the markdown of the file and send to server.
Whenever page is loaded you can retrieve the markdown of the file from server and load it into the local file using importFile
function. Now the editor will show the server version of the file.
Working with Markdown files in Visual Studio Code is simple, straightforward, and fun. Besides VS Code's basic editing, there are a number of Markdown specific features that will help you be more productive.
Markdown extensions
In addition to the functionality VS Code provides out of the box, you can install an extension for greater functionality.
Tip: Click on an extension tile above to read the description and reviews to decide which extension is best for you. See more in the Marketplace.
Markdown preview
VS Code supports Markdown files out of the box. You just start writing Markdown text, save the file with the .md extension and then you can toggle the visualization of the editor between the code and the preview of the Markdown file; obviously, you can also open an existing Markdown file and start working with it. To switch between views, press ⇧⌘V (Windows, Linux Ctrl+Shift+V) in the editor. You can view the preview side-by-side (⌘K V (Windows, Linux Ctrl+K V)) with the file you are editing and see changes reflected in real-time as you edit.
Here is an example with a very simple file.
Tip: You can also right-click on the editor Tab and select Open Preview (⇧⌘V (Windows, Linux Ctrl+Shift+V)) or use the Command Palette (⇧⌘P (Windows, Linux Ctrl+Shift+P)) to run the Markdown: Open Preview to the Side command (⌘K V (Windows, Linux Ctrl+K V)).
Dynamic previews and preview locking
By default, Markdown previews automatically update to preview the currently active Markdown file:
You can lock a Markdown preview using the Markdown: Toggle Preview Locking command to keep it locked to its current Markdown document. Locked previews are indicated by [Preview] in the title:
Editor and preview synchronization
VS Code automatically synchronizes the Markdown editor and the preview panes. Scroll the Markdown preview and the editor is scrolled to match the preview's viewport. Scroll the Markdown editor and the preview is scrolled to match its viewport:
You can disable scroll synchronization using the markdown.preview.scrollPreviewWithEditor
and markdown.preview.scrollEditorWithPreview
settings.
The currently selected line in the editor is indicated in the Markdown preview by a light gray bar in the left margin:
Additionally, double clicking an element in the Markdown preview will automatically open the editor for the file and scroll to the line nearest the clicked element.
Outline view
The Outline view is a separate section in the bottom of the File Explorer. When expanded, it will show the symbol tree of the currently active editor. For Markdown files, the symbol tree is the Markdown file's header hierarchy.
The Outline view is a great way to review your document's header structure and outline.
Extending the Markdown preview
Extensions can contribute custom styles and scripts to the Markdown preview to change its appearance and add new functionality. Here's a set of example extensions that customize the preview:
Using your own CSS
You can also use your own CSS in the Markdown preview with the 'markdown.styles': []
setting. This lists URLs for style sheets to load in the Markdown preview. These stylesheets can either be https
URLs, or relative paths to local files in the current workspace.
For example, to load a stylesheet called Style.css
at the root of your current workspace, use File > Preferences > Settings to bring up the workspace settings.json
file and make this update:
Keep trailing whitespace in order to create line breaks
To create hard line breaks, Markdown requires two or more spaces at the end of a line. Depending on your user or workspace settings, VS Code may be configured to remove trailing whitespace. In order to keep trailing whitespace in Markdown files only, you can add these lines to your settings.json
:
Markdown preview security
For security reasons, VS Code restricts the content displayed in the Markdown preview. This includes disabling script execution and only allowing resources to be loaded over https
.
When the Markdown preview blocks content on a page, an alert popup is shown in the top right corner of the preview window:
You can change what content is allowed in the Markdown preview by clicking on this popup or running the Markdown: Change preview security settings command in any Markdown file:
The Markdown preview security settings apply to all files in the workspace.
Here are the details about each of these security levels:
Strict
This is the default setting. Only loads trusted content and disables script execution. Blocks http
images.
It is strongly recommended that you keep Strict
security enabled unless you have a very good reason to change it AND you trust all markdown files in the workspace.
Allow insecure content
Keeps scripts disabled but allows content to be loaded over http
.
Disable
Disables additional security in the preview window. This allows script execution and also allows content to be loaded over http
.
Snippets for Markdown
There are several built-in Markdown snippets included in VS Code - press ⌃Space (Windows, Linux Ctrl+Space) (Trigger Suggest) and you get a context specific list of suggestions.
Tip: You can add in your own User Defined Snippets for Markdown. Take a look at User Defined Snippets to find out how.
Compiling Markdown into HTML
VS Code integrates with Markdown compilers through the integrated task runner. We can use this to compile .md
files into .html
files. Let's walk through compiling a simple Markdown document.
Step 1: Install a Markdown compiler
For this walkthrough, we use the popular Node.js module, markdown-it.
Note: There are many Markdown compilers to choose from beyond markdown-it. Pick the one that best suits your needs and environment.
Step 2: Create a simple MD file
Open VS Code on an empty folder and create a sample.md
file.
Note: You can open a folder with VS Code by either selecting the folder with File > Open Folder or navigating to the folder and typing 'code .' at the command line.
Place the following source code in that file:
Step 3: Create tasks.json
The next step is to set up the task configuration file tasks.json
. To do this, run Terminal > Configure Tasks and click Create tasks.json file from templates. VS Code then presents a list of possible tasks.json
templates to choose from. Select Others since we want to run an external command.
This generates a tasks.json
file in your workspace .vscode
folder with the following content:
To use markdown-it to compile the Markdown file, change the contents as follows:
Tip: While the sample is there to help with common configuration settings, IntelliSense is available for the tasks.json
file as well to help you along. Use ⌃Space (Windows, Linux Ctrl+Space) to see the available settings.
Step 4: Run the Build Task
Since in more complex environments there can be more than one build task we prompt you to pick the task to execute after pressing ⇧⌘B (Windows, Linux Ctrl+Shift+B) (Run Build Task). In addition, we allow you to scan the output for compile problems. Since we only want to convert the Markdown file to HTML select Never scan the build output from the presented list.
At this point, you should see an additional file show up in the file list sample.html
.
If you want to make the Compile Markdown task the default build task to run execute Configure Default Build Task from the global Terminal menu and select Compile Markdown from the presented list. The final tasks.json
file will then look like this:
Automating Markdown compilation
Let's take things a little further and automate Markdown compilation with VS Code. We can do so with the same task runner integration as before, but with a few modifications.
Step 1: Install Gulp and some plug-ins
We use Gulp to create a task that automates Markdown compilation. We also use the gulp-markdown plug-in to make things a little easier.
We need to install gulp both globally (-g
switch) and locally:
Note: gulp-markdown-it is a Gulp plug-in for the markdown-it module we were using before. There are many other Gulp Markdown plug-ins you can use, as well as plug-ins for Grunt.
You can test that your gulp installation was successful by typing gulp -v
. You should see a version displayed for both the global (CLI) and local installations.
Step 2: Create a simple Gulp task
Open VS Code on the same folder from before (contains sample.md
and tasks.json
under the .vscode
folder), and create gulpfile.js
at the root.
Place the following source code in that file:
Github Markdown Definition List
What is happening here?
- We are watching for changes to any Markdown file in our workspace, i.e. the current folder open in VS Code.
- We take the set of Markdown files that have changed, and run them through our Markdown compiler, i.e.
gulp-markdown-it
. - We now have a set of HTML files, each named respectively after their original Markdown file. We then put these files in the same directory.
Step 3: Run the gulp default Task
To complete the tasks integration with VS Code, we will need to modify the task configuration from before to run the default Gulp task we just created. You can either delete the tasks.json
file or empty it only keeping the 'version': '2.0.0'
property. Now execute Run Task from the global Terminal menu. Observe that you are presented with a picker listing the tasks defined in the gulp file. Select gulp: default to start the task. We allow you to scan the output for compile problems. Since we only want to convert the Markdown file to HTML select Never scan the build output from the presented list. At this point, if you create and/or modify other Markdown files, you see the respective HTML files generated and/or changes reflected on save. You can also enable Auto Save to make things even more streamlined.
If you want to make the gulp: default task the default build task executed when pressing ⇧⌘B (Windows, Linux Ctrl+Shift+B) run Configure Default Build Task from the global Terminal menu and select gulp: default from the presented list. The final tasks.json
file will then look like this:
Step 4: Terminate the gulp default Task
The gulp: default task runs in the background and watches for file changes to Markdown files. If you want to stop the task, you can use the Terminate Task from the global Terminal menu.
Next steps
Read on to find out about:
- CSS, SCSS, and Less - Want to edit your CSS? VS Code has great support for CSS, SCSS, and Less editing.
Common questions
Github Markdown List Inside Table
Is there spell checking?
Not installed with VS Code but there are spell checking extensions. Check the VS Code Marketplace to look for useful extensions to help with your workflow.
Does VS Code support GitHub Flavored Markdown?
Github Markdown List Sublist
No, VS Code targets the CommonMark Markdown specification using the markdown-it library. GitHub is moving toward the CommonMark specification which you can read about in this update.
In the walkthrough above, I didn't find the Configure Task command in the Command Palette?
You may have opened a file in VS Code rather than a folder. You can open a folder by either selecting the folder with File > Open Folder or navigating to the folder and typing 'code .' at the command line.