CodeMirror: Code Folding Demo

Code Folding Demo

JavaScript:

​x
 
/*
 * Demonstration of code folding
 */
window.onload = function() {
  var te = document.getElementById("code");
  var sc = document.getElementById("script");
  te.value = (sc.textContent || sc.innerText || sc.innerHTML).replace(/^\s*/, "");
  sc.innerHTML = "";
  var te_html = document.getElementById("code-html");
  te_html.value = document.documentElement.innerHTML;
  var te_python = document.getElementById("code-python");
  var te_markdown = document.getElementById("code-markdown");
  te_markdown.value = "# Foo\n## Bar\n\nblah blah\n\n## Baz\n\nblah blah\n\n# Quux\n\nblah blah\n"
  var te_json = document.getElementById("code-json");
​
  window.editor = CodeMirror.fromTextArea(te, {
    mode: "javascript",
    lineNumbers: true,
    lineWrapping: true,
    extraKeys: {"Ctrl-Q": function(cm){ cm.foldCode(cm.getCursor()); }},
    foldGutter: true,
    gutters: ["CodeMirror-linenumbers", "CodeMirror-foldgutter"]
  });
  editor.foldCode(CodeMirror.Pos(13, 0));
​
  window.editor_json = CodeMirror.fromTextArea(te_json, {
    mode: {name: "javascript", json: true},
    lineNumbers: true,
    lineWrapping: true,
    extraKeys: {"Ctrl-Q": function(cm){ cm.foldCode(cm.getCursor()); }},
    foldGutter: true,
    gutters: ["CodeMirror-linenumbers", "CodeMirror-foldgutter"],
    foldOptions: {
      widget: (from, to) => {
        var count = undefined;
​
        // Get open / close token
        var startToken = '{', endToken = '}';        
        var prevLine = window.editor_json.getLine(from.line);
        if (prevLine.lastIndexOf('[') > prevLine.lastIndexOf('{')) {
          startToken = '[', endToken = ']';
        }
​
        // Get json content
        var internal = window.editor_json.getRange(from, to);
        var toParse = startToken + internal + endToken;
​
        // Get key count
        try {
          var parsed = JSON.parse(toParse);
          count = Object.keys(parsed).length;
        } catch(e) { }        
​
        return count ? `\u21A4${count}\u21A6` : '\u2194';
      }
    }
  });
  editor_json.foldCode(CodeMirror.Pos(5, 0));
​
  window.editor_html = CodeMirror.fromTextArea(te_html, {
    mode: "text/html",
    lineNumbers: true,
    lineWrapping: true,
    extraKeys: {"Ctrl-Q": function(cm){ cm.foldCode(cm.getCursor()); }},
    foldGutter: true,
    gutters: ["CodeMirror-linenumbers", "CodeMirror-foldgutter"]
  });
  editor_html.foldCode(CodeMirror.Pos(0, 0));
  editor_html.foldCode(CodeMirror.Pos(34, 0));
​
  window.editor_python = CodeMirror.fromTextArea(te_python, {
    mode: "python",
    lineNumbers: true,
    extraKeys: {"Ctrl-Q": function(cm){ cm.foldCode(cm.getCursor()); }},
    foldGutter: true,
    gutters: ["CodeMirror-linenumbers", "CodeMirror-foldgutter"]
  });
​
  window.editor_markdown = CodeMirror.fromTextArea(te_markdown, {
    mode: "markdown",
    lineNumbers: true,
    lineWrapping: true,
    extraKeys: {"Ctrl-Q": function(cm){ cm.foldCode(cm.getCursor()); }},
    foldGutter: true,
    gutters: ["CodeMirror-linenumbers", "CodeMirror-foldgutter"]
  });
};
  

HTML:

xxxxxxxxxx
 
<head>↔</head>
​
<body>
<div id="nav">↔</div>
​
<article>
  <h2>Code Folding Demo</h2>
  <form>
    <div style="max-width: 50em; margin-bottom: 1em">JavaScript:<br>
    <textarea id="code" name="code"></textarea></div>
    <div style="max-width: 50em; margin-bottom: 1em">HTML:<br>
    <textarea id="code-html" name="code-html"></textarea></div>    
    <div style="max-width: 50em; margin-bottom: 1em">JSON with custom widget:<br>
    <textarea id="code-json" name="code-json">{
  "menu": {
    "id": "file",
    "value": "File",
    "popup": {
      "menuitem": [
        {"value": "New", "onclick": "CreateNewDoc()"},
        {"value": "Open", "onclick": "OpenDoc()"},
        {"value": "Close", "onclick": "CloseDoc()"}
      ]
    }
  }
}
    </textarea></div>
    <div style="max-width: 50em">Python:<br>
    <textarea id="code-python" name="code">def foo():
  do_some_stuff()
  here
  return None
​
class Bar:
  __init__(self):
    if True:
      print("True")
    else:
      print("False")
​
  this_code_makes_no_sense():
    pass
​
# A comment</textarea></div>
    <div style="max-width: 50em">Markdown:<br>
    <textarea id="code-markdown" name="code"></textarea></div>
  </form>
  <script id="script"></script>
</article>
​
</body>

JSON with custom widget:

xxxxxxxxxx
 
{
  "menu": {
    "id": "file",
    "value": "File",
    "popup": {
      "menuitem": [↤3↦]
    }
  }
}
    

Python:

xxxxxxxxxx
 
def foo():
  do_some_stuff()
  here
  return None
​
class Bar:
  __init__(self):
    if True:
      print("True")
    else:
      print("False")
​
  this_code_makes_no_sense():
    pass
​
# A comment

Markdown:

xxxxxxxxxx
 
# Foo
## Bar
​
blah blah
​
## Baz
​
blah blah
​
# Quux
​
blah blah
​