In order to be compatible with IE and FF we have to use the following methods:
<textarea id="runcode24456"><!doctype html> <title>dom contains method by Masaki </title> <meta charset= "utf-8"/> <meta na Me= "keywords" content= dom contains method by Masaki/> <meta name= "description" content= "Dom contains method by Masaki"/> <script type= "Text/javascript" > if (!! Window.find) {HTMLElement.prototype.contains = function (b) {return this.comparedocumentposition (b)-> 0}} WI Ndow.onload = function () {var A = document.getElementById (' parent '), B = document.getElementById (' child '); Alert (A.contains (B)); Alert (B.contains (A)); } </script> <p >contains method </p> <div id= "parent" > <p> <strong id= "Child" >conta Ins method </strong> </p> </div></textarea>
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However, Firefox supports the Comparedocumentposition () method, which is the method developed by the Web, standard browsers support, but the practicality is very poor, so no one to use, not spread. It uses the same form as contains, but returns not a Boolean, but a very strange number, which is summed up in the following way:
| Bits |
number |
meaning |
| 000000 |
0 |
element consistent |
| 000001 |
1 |
node in a different document (or one outside the document) |
| 000010 |
2 |
node B before node A |
| 000100 |
4 |
Node A in Before Node B |
| 001000 |
8 |
Node B contains node A |
| 010000 |
|
node A contains node B |
| 100000 |
|
Private use of browser |
<textarea id="runcode16170"><!doctype html> <title>dom contains method by Masaki </title> <meta charset= "Utf-8"/> <meta N Ame= "keywords" content= dom contains method by Masaki/> <meta name= "description" content= "Dom contains method by Masaki"/> <script type= "Text/javascript" > window.onload = function () {var A = document.getElementById (' parent '), B = doc Ument.getelementbyid (' child '); Alert (A.comparedocumentposition (B));//b is not connected to a, b after a, B is contained 4+16 = alert (B.comparedocumentposition (a)),//a is not connected to B, A in front of B, A contains b 2+8 = ten} </script> <p >comparedocumentposition method </p> <div id= "parent" > <p > <strong id= "Child" > This example please run in a standard browser. </strong> </p> </div></textarea>
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PPK gives the following solutions.
Copy Code code as follows:
if (window. Node && node.prototype &&! Node.prototype.contains) {
Node.prototype.contains = function (ARG) {
Return!! (This.comparedocumentposition (ARG) & 16)
}
}
I got a shorter one:
Copy Code code as follows:
if (!! Window.find) {
HTMLElement.prototype.contains = function (B) {
Return This.comparedocumentposition (B)-> 0
}
}
<textarea id="runcode88957"><!doctype html> <title>dom contains method by Masaki </title> <meta charset= "Utf-8"/> <meta N Ame= "keywords" content= dom contains method by Masaki/> <meta name= "description" content= "Dom contains method by Masaki"/> <script type= "Text/javascript" > if (!! Window.find) {HTMLElement.prototype.contains = function (b) {return this.comparedocumentposition (b)-> 0}} WI Ndow.onload = function () {var A = document.getElementById (' parent '), B = document.getElementById (' child '); Alert (A.contains (B)); Alert (B.contains (A)); } </script> <p >contains method </p> <div id= "parent" > <p> <strong id= "Child" >contai ns method </strong> </p> </div></textarea>
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Copy Code code as follows:
2011.9.24 by Masaki
var contains = function (root, EL) {
if (root.comparedocumentposition)
return root = = = El | | !! (Root.comparedocumentposition (EL) & 16);
if (root.contains && el.nodetype = 1) {
Return Root.contains (EL) && root!== el;
}
while ((el = El.parentnode))
if (el = = root) return true;
return false;
}
