CodeMirror 3 Indent All Lines / Autoformat
Problem
You have created an instance of a CodeMirror and initialized it with some text and would like to correct its indentation or you would like to give the user the option to 'autoformat' the text entered.
Solution
Iterate over all lines in the editor and indent them individually:
var e = CodeMirror.fromTextArea(textarea.get(0), {});
for (var i=0;i<e.lineCount();i++) { e.indentLine(i); }
This should indent all lines in your editor nicely:
Note that in CodeMirror 2 there was an autoformatter add-in which is not officially supported for CodeMirror 3.