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JavaScript implements iframe automatic height adjustment and cross-domain cross-domain between different main domain names_javascript skills

WBOYOriginal: 2016-05-16 15:13:121375browse

Everyone knows that Js has a same-origin policy, which means that iframes nested in different main domain names do not allow Js to communicate.

For example, I have a website, and I want to embed its website pages in the website. Then I can use iframe to reference the address of the third-party website.

However, the problem is that the height of the iframe is fixed and cannot be well integrated with third-party websites. For example, the third-party website uses a waterfall flow plug-in. To automatically calculate the height during rolling loading, let’s talk about cross-domain first: iframe main Domain names have different cross-domain methods. If an iframe is placed in the website A.com B.com A and references B.com, in this case, the Js in B.com cannot access A.com. Cross-domain JS must have the same origin, that is, the same main domain name, so what should we do?

We can introduce an iframe in B.com, let’s call it C for now. This iframe loads a web page in A.com. In this way, if the same source exists, the web page in the iframe in B.com can communicate with A.com. Next, as long as B and C communicate, let C communicate with A to complete the B->A communication, so that when the height of B changes, C is notified, and C notifies A to adjust the iframe height.
Communication between B and C can actually be achieved through the url address. The B.com iframe is set to hidden, and C can receive it when the src address is changed.

Stop talking nonsense and get on with the code

A.com/index.html

<html>
  <script src="{$smarty.const.STATIC_URL}/js/jquery-1.7.1.min.js"></script>
  <script>
   var test = function() {
     $('#h1').html('test');
   }
   </script>
<body>
<h1 id="h1">nba.alltosun.net</h1>
<iframe id="ifm" width="760" height="100" src="http://***.sinaapp.com/"></iframe>
</body>
</html>

B.com/index.html

<html>
<head></head>
<body>
  <h1>**.appsina.com</h1>
  <button id="button">设置高度</button>
  <div id="div" style="height:200px;display:none;"></div>
  <script src="http://nba.alltosun.net/js/jquery-1.7.1.min.js"></script>
  <script>
  $(function(){
    window.ifrH = function(e){
      var searchUrl = window.location.search;
      var b = null;
       
      var getParam = function(url, param) {
        var q = url.match(new RegExp( param + "=[^&]*")),
        n = "";
        if (q && q.length) {
          n = q[0].replace(param + "=", "");
        }
        return n;
      }
       
      var f = getParam(searchUrl,"url"),
        h = getParam(searchUrl, "ifmID"),
        k = getParam(searchUrl, "cbn"),
        g = getParam(searchUrl, "mh");
       
 
      var iframeId = 'testiframe';
      var iframe = document.getElementById(iframeId);
      var divId = 'alltosun';
       
      if (!iframe){
        var iframe = document.createElement('iframe');
        iframe.id = iframeId;
        iframe.style.display = "none";
        iframe.width = 0;
        iframe.height = 0;
        document.body.appendChild(iframe);
      }
       
      if (e && e.type == "onload" && h) {
        b.parentNode.removeChild(b);
        b = null;
      }
       
      if (!b) {
        b = document.createElement("div");
        b.id = divId;
        b.style.cssText = "clear:both;"
        document.body.appendChild(b);
      }
       
      var l = b.offsetTop + b.offsetHeight;
      iframe.src = (decodeURIComponent(f) || 
          "http://*****/test2") + "&h=" + l + "&ifmID=" + (h || "ifm") + "&cbn=test" + "&mh=" + g + "&t=" + ( (+ new Date()));
       
      if (e && e.type =="onload") {
        window.onload = null;
      }
    }
     
    window.onload = function() {
      ifrH({type: "onload"});
    }
     
    // ifrH();
    $('button').click(function(){
      $('div').show();
      ifrH();
    })
  })
  </script>
</body>
</html>

C proxy file

<script>
var search = window.location.search,
getSearchParam = function (search, key) {
  var mc = search.match (new RegExp ( key + "=([^\&]*)") ),
    ret="";
  mc && mc.length && (ret = mc[0].replace( key + "=",""));
  return ret;
},
// 参数h 
h = getSearchParam(search,"h"),
ifmID = getSearchParam(search,"ifmID"),
cbn = getSearchParam(search,"cbn"),
// 宽高
mh = getSearchParam(search,"mh") || h,
isFunction = function(fn){
  return !!fn && !fn.nodeName && fn.constructor != String 
      && fn.constructor != RegExp && fn.constructor != Array 
      && (/function/i).test(fn + "");
};
 
try{
  if(parent && parent.parent){
    ifm = parent.parent.document.getElementById(ifmID);
    ifm && mh && (ifm.height=mh);
    fn=parent.parent[cbn];
    isFunction(fn) && fn.call();
    ifm=null;
  }
}catch(ex){
  console.log(ex);
}
 
</script>

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