contenteditable：保存和恢復插入位置

Question

下面的函數會使插入符號移回開頭。在函數被調用後，我會如何讓它保持在同一個位置？

function highlightText() { 
      var mystring = document.getElementById("writeArea").textContent; 
      mystring = mystring.replace(/function/g , "<span class=\"func\">function</span>"); 
      document.getElementById("writeArea").innerHTML = mystring; 
     } 

CONTENTEDITABLE聲明：

<div class="codeArea" id="writeArea" contenteditable="true"> <p> edit me! </p> </div> 

Answer 1

使用selectionStart來獲取和設置插入符的位置：

document.getElementById("writeArea").onkeyup = highlightText(this); 
 
function highlightText(o) { 
 
    var mystring = document.getElementById("writeArea").textContent, 
 
    caretPosition = o.selectionStart; 
 
    mystring = mystring.replace(/function/g , "<span class=\"func\">function</span>"); 
 
    document.getElementById("writeArea").innerHTML = mystring; 
 
    document.getElementById("writeArea").selectionStart = caretPosition; 
 
}

<div class="codeArea" id="writeArea" contenteditable="true"> <p> edit me! </p> </div>