Question

I have some JS from an external JS file that I want to insert inside of a JS function in the HTML file. I can not touch the JS script in the HTML file, so I am wondering if this method can be done.

Here is the JS I want to insert inside of the JS function in the HTML file.

// FIRST JS TO INSERT
if (OS == "mobile"){
        killVideoPlayer();
    }

// SECOND JS TO INSERT
if (OS == "mobile"){ 
        loadHtmlFiveVideo();
        if (!document.all){
            flvPlayerLoaded = false;
        }
    }else {
        loadVideoPlayer();
    }

Then I want to insert it into here.

<script>
function mediaTypeCheck() {
if (bsiCompleteArray[arrayIndex].mediaType == "video") {
// INSERT FIRST JS HERE
    document.getElementById("bsi-video-wrap").style.display = "block";
    document.getElementById('pngBsi').style.display = "block";
    document.getElementById("frame_photo").style.display = "none";
    document.getElementById("relativeFrame").style.display = "block";
    document.getElementById("buy-me-photo-button-bsi").style.display = "none";
// INSTER SECOND JS HERE    
    loadVideoPlayer();
} 
if (bsiCompleteArray[arrayIndex].mediaType == "photo") {
    killVideoPlayer();
    document.getElementById("bsi-video-wrap").style.display = "none";
    document.getElementById('pngBsi').style.display = "block";
    document.getElementById("relativeFrame").style.display = "block";
    document.getElementById("frame_photo").style.display = "block";
    document.getElementById("buy-me-photo-button-bsi").style.display = "block";
    if (!document.all){
        flvPlayerLoaded = false;
    }   
}   
}
</script>

Thank you!

Answer 1

In JavaScript, you can overwrite variables with new values at any time, including functions.

By the looks of it, you could replace the mediaTypeCheck function with one of your own that does what you need and then calls the original function.

E.g.

(function(){
  // keep track of the original mediaTypeCheck 
  var old_function = mediaTypeCheck;
  // overwrite mediaTypeCheck with your wrapper function
  mediaTypeCheck = function() {
    if ( conditions ) {
      // do whatever you need to, then ...
    }
    return old_function();
  };
})();

The above can be loaded from any script, so long as it happens after the mediaTypeCheck function is defined.