contenteditable：保存和恢复插入符号位置

Question

下面的函数使插入符号移回开头。调用函数后如何让它保持在同一个位置？

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

Contenteditable 声明：

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

Answer 1

使用selectionStart 获取和设置插入符号的位置：

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>