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):在光标处插入值

 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     });

(2):获取textarea选中的值

 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     };