实用jquery扩展收集（1）：在光标处插入内容 和 获取textarea选中的值

1 $.fn.extend({
2         insertAtCursor : function(myValue) {
3             var $t = $(this)[0];
4             if (document.selection) {
5                 this.focus();
6                 sel = document.selection.createRange();
7                 sel.text = myValue;
8                 this.focus();
9             } else if ($t.selectionStart || $t.selectionStart == '0') {
10                 var startPos = $t.selectionStart;
11                 var endPos = $t.selectionEnd;
12                 var scrollTop = $t.scrollTop;
13                 $t.value = $t.value.substring(0, startPos) + myValue + $t.value.substring(endPos, $t.value.length);
14                 this.focus();
15                 $t.selectionStart = startPos + myValue.length;
16                 $t.selectionEnd = startPos + myValue.length;
17                 $t.scrollTop = scrollTop;
18             } else {
19                 this.value += myValue;
20                 this.focus();
21             }
22         }
23     });

1 $.fn.selection = function(){
2         var s,e,range,stored_range;
3         if(this[0].selectionStart == undefined){
4             var selection=document.selection;
5             if (this[0].tagName.toLowerCase() != "textarea") {
6                 var val = this.val();
7                 range = selection.createRange().duplicate();
8                 range.moveEnd("character", val.length);
9                 s = (range.text == "" ? val.length:val.lastIndexOf(range.text));
10                 range = selection.createRange().duplicate();
11                 range.moveStart("character", -val.length);
12                 e = range.text.length;
13             }else {
14                 range = selection.createRange(),
15                 stored_range = range.duplicate();
16                 stored_range.moveToElementText(this[0]);
17                 stored_range.setEndPoint('EndToEnd', range);
18                 s = stored_range.text.length - range.text.length;
19                 e = s + range.text.length;
20             }
21         }else{
22             s=this[0].selectionStart,
23             e=this[0].selectionEnd;
24         }
25         var te=this[0].value.substring(s,e);
26         return {start:s,end:e,text:te};
27     };