Create simple cross-browser textarea editor

This tutorial will help you create simple cross-browser textarea editor you can use on any of your HTML forms. View the sample.

The main DHTML methods used in this cross-browser textarea editor are:

• execCommand.
  This method  executes a command on the current document, current selection, or the given range.
• getElementById
  Returns a reference to the first object with the specified value of the ID attribute.

Commands used to specify an action to take on the given object:

• Bold
  Toggles the current selection between bold and nonbold.
• Underline
  Toggles the current selection between underlined and not underlined.
• Italic
  Toggles the current selection between italic and nonitalic.
• JustifyCenter
  Centers the format block in which the current selection is located.
• JustifyLeft
  Left-justifies the format block in which the current selection is located.
• JustifyRight
  Right-justifies the format block in which the current selection is located.
• Indent
  Increases the indent of the selected text by one indentation increment.
• Outdent
  Decreases by one increment the indentation of the format block in which the current selection is located.
• Undo
  Undo the step
• Redo
  Redo the step

Main DHTML properties used:

• innerHTML
  Sets or retrieves the HTML between the start and end tags of the object.
• designMode
  Sets or retrieves a value that indicates whether the document can be edited.

Download the button images here.

CSS File

.editorbuttons {
	list-style: none;
	margin: 0px;
	padding: 0px;
}
.editorbuttons li {
	float: left;
}
.editorbuttons li img {
	border:none;
}
.editorbody{clear:both; float:none;}

HTML File

 

 

 

 

 

 

 

 

 

 

Shift+Enter for single line spacing


< script language= "JavaScript" type= "text/javascript"  >

< /script >
< script language= "JavaScript" type= "text/javascript" >
    //this calles displayEditor function. Parametars are (textarea name, ,default text, textarea  width, textarea  height)
    displayEditor('content', 'Default Text', 600, 300);	
//-->
< /script >

 

JavaScript File

See comments for details

//First initiate some variables

var isEditable= false;
var isIE;
var isGecko;
var isSafari;
var isKonqueror;
var browser = navigator.userAgent.toLowerCase();

function initiateEditor() {
 //check what browser is in use

 isIE = ((browser.indexOf("msie") != -1) && (browser.indexOf("opera") == -1) && (browser.indexOf("webtv") == -1)); 
 isGecko = (browser.indexOf("gecko") != -1);
 isSafari = (browser.indexOf("safari") != -1);
 isKonqueror = (browser.indexOf("konqueror") != -1);
 
 //enable designMode if the browser is not safari or konqueror.
 if (document.getElementById && document.designMode && !isSafari && !isKonqueror) {
   isEditable= true;
 }
}
//Javascript function dislpayEditor will create the textarea. 

function displayEditor(editor, html, width, height) {
   if(isEditable){
       document.writeln('');
//create a hidden field that will hold everything that is typed in the textarea
       document.writeln('');
//assign html (textarea value) to hiddeneditor 
      document.getElementById('hidden' + editor).value = html;
//call function designer
      designer(editor, html);
   }else{
     document.writeln('< textarea name="' + editor + '" id="' + editor + '" cols="39" rows="10">' + html + '');
   }
}

//this is designer function that enables designMode and writes defalut text to the text area
function designer(editor, html) {
     var mainContent= "< html id=" + editor + ">< head >< /head >< body >" + html + "< /body >" ;
//assign the frame(textarea) to the edit variable using that frames id
     var edit = document.getElementById(editor).contentWindow.document;
//write the content to the textarea
      edit.write(mainContent);
	  edit.close();
//enable the designMode	
      edit.designMode =  "On" ;
	  document.getElementById(editor).contentDocument.designMode = "on";
}

//To execute command we will use javascript function editorCommand. 
function editorCommand(editor, command, option) {
// first we assign the content of the textarea to the variable mainField
    var mainField;
	mainField = document.getElementById(editor).contentWindow;
 // then we will use execCommand to execute the option on the textarea making sure the textarea stays in focus
   try {
          mainField.focus();
          mainField.document.execCommand(command, false, option);
          mainField.focus();
    } catch (e) { }
}

function updateEditor(editor) {
	if (!isEditable) return;
//assign the value of the textarea to the hidden field. 
	var hiddenField = document.getElementById('hidden' + editor);
	if (hiddenField.value == null) hiddenField.value = "";
		hiddenField.value = document.getElementById(editor).contentWindow.document.body.innerHTML;
}

PHP File

Most important part of the PHP code is the phpSafe function. This function makes sure that quotes are displayed appropriatly. See comments for details.

// from the form we are getting the hidden field value and sending it to the phpSafe function
$hiddencontent = phpSafe($_REQUEST['hiddencontent']);
function phpSafe($strText) {
 //removes backslash created by php from the string
    $tmpString = $strText;
    $tmpString = str_replace(chr(92), "", $tmpString); 
    return $tmpString;
}
echo $hiddencontent;

• MSDN library
• Mozilla Editor

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