Get selected / highlighted text with code mirror from text area not working

Question

On my text area with codemirror I am trying to be able to select/ highlight text and then be able to click on my bold button and should wrap the bold tags around it.

I have looked at

SO Question 1 , SO Question 2

But does not seem to work with code mirror.

My Question is: With codemirror How could I grab the selected text and then make sure when I click on the bold button it wraps the text correctly?

Codepen Code View

Codepen Full View

Script

var editor = document.getElementById('text-editor');
var string = grabed_text();

    $("#text-editor").each(function (i) {
        editor = CodeMirror.fromTextArea(this, {
            lineNumbers: true,
            mode: 'html'
        });

        $('button').click(function(){

          var val = $(this).data('val');


          switch(val){
            case 'bold': editor.replaceSelection('<b>' + string + '</b>');
            break;
           }
        });
    });

function grabed_text() {

}    

HTML

<div class="container">

<div class="row">

<div class="col-lg-12 col-md-12 col-sm-12 col-xs-12">
<div class="panel panel-default"  onLoad="text_editor();">
<div class="panel-heading">
<button type="button" data-val="bold" class="btn btn-default">Bold</button>
</div>
<div class="panel-body">
<textarea id="text-editor" name="text-editor" class="form-control"></textarea>
</div>
</div>
</div>

</div>

<div class="row">

<div class="col-lg-12 col-md-12 col-sm-12 col-xs-12">
<div id="question-iframe"></div>
</div>

</div>

</div>

Answer 1

Issue in your code is in the switch case where you're handling bold button.

 case 'bold': 
      editor.replaceSelection('<b>' + string + '</b>');
      break;

Here you're replacing the current selection by wrapping <b> tags around string variable but it's not defined anywhere. Ideally it should reflect the current selection from your editor. So I suggest you change your code like below.

  // inside your click handler
  var val = $(this).data('val');
  var string = editor.getSelection();

  switch(val){
     case 'bold': { 
               editor.replaceSelection('<b>' + string + '</b>');
            break;
          }
  }

Here's a Pen with the above changes.