/* This script and many more are available free online at
The JavaScript Source :: http://javascript.internet.com
Created by: Robin Winslow :: http://www.robinwinslow.me.uk */

// Find and select all text in the document that matches the "value" of the element passed
// If no element if passed, it will attempt to use the value of "this"
// Only works in a browser that supports the "window.getSelection" method, as other selection methods don't support multiple selectionsz
function performMultiSearch(elem,searchElem) {
   // set up variables
   var searchString; // Will hold the text to search for
   var theSelection; // Will hold the document's selection object
   var textNodes; // Will hold all the text nodes in the document

   // Set it to search the entire document if we haven't been given an element to search
   if(!searchElem || typeof(searchElem) == 'undefined') searchElem = document.body;

   // Get the string to search for
   if(elem && elem.value) searchString = elem.value;
   else if(this && this.value) searchString = this.value;

   // Get all the text nodes in the document
   textNodes = findTypeNodes(searchElem,3);

   // Get the selection object
   if(window.getSelection) theSelection = window.getSelection(); // firefox
   else { // some other browser - doesn't support multiple selections at once
       alert("sorry this searching method isn't supported by your browser");
       return;
   }

   // Empty the selection
   theSelection.removeAllRanges(); // We want to empty the selection regardless of whether we're selecting anything

   if(searchString.length > 0) { // make sure the string isn't empty, or it'll crash.
       // Search all text nodes
       for(var i = 0; i < textNodes.length; i++) {
           // Create a regular expression object to do the searching
           var reSearch = new RegExp(searchString,'gmi'); // Set it to 'g' - global (finds all instances), 'm' - multiline (searches more than one line), 'i' - case insensitive
           var stringToSearch = textNodes[i].textContent;
           while(reSearch(stringToSearch)) { // While there are occurrences of the searchString
               // Add the new selection range
               var thisRange = document.createRange();
               thisRange.setStart(textNodes[i],reSearch.lastIndex - searchString.length); // Start node and index of the selection range
               thisRange.setEnd(textNodes[i],reSearch.lastIndex); //  End node and index of the selection
               theSelection.addRange(thisRange); // Add the node to the document's current selection
           }
       }
   }

   return;
}

// Will find and select the first instance of the value of the passed element, then when called again will moves on to the next instance
// If no element passed it will try to get the value from "this"
function performSingleSearch(elem,searchElem) {
   // set up variables
   var searchString; // Will hold the text to search for
   var theSelection; // Will hold the document's selection object
   var textNodes; // Will hold all the text nodes in the document

   // Set it to search the entire document if we haven't been given an element to search
   if(!searchElem || typeof(searchElem) == 'undefined') searchElem = document.body;

   // Get the string to search for
   if(elem && elem.value) searchString = elem.value;
   else if(this && this.value) searchString = this.value;

   if(searchString && searchString.length > 0) { // make sure the string isn't empty, or it'll crash.
       if(window.getSelection) { // Firefox
           // Get the selection
           theSelection = window.getSelection();

           // Get all the text nodes in the document
           textNodes = findTypeNodes(searchElem,3);

           // If there's already a selection, and it's the string we're searching for
           var searchMatch = new RegExp(searchString,'i');
           if(theSelection.rangeCount == 1 && searchMatch(theSelection.getRangeAt(0).toString())) {
               var currentRange = theSelection.getRangeAt(0);
               theSelection.removeAllRanges();

               var newRange = null;

               // Move on to the next occurrence of it by iterating through text nodes...:
               for(var i = 0; i < textNodes.length; i++) {
                   // If this text node is before the currentRange, ignore it and carry on to the next one
                   if(currentRange.comparePoint(textNodes[i],0) == -1 && currentRange.startContainer != textNodes[i]) continue;
                   // If this text node is the same as the currentRange, find the point in the currentRange
                   else if((currentRange.comparePoint(textNodes[i],0) == -1 && currentRange.startContainer == textNodes[i]) || (currentRange.comparePoint(textNodes[i],0) == 0)) {
                       // Create a regular expression object to do the searching
                       var reSearch = new RegExp(searchString,'gmi'); // Set it to 'g' - global (finds all instances), 'm' - multiline (searches more than one line), 'i' - case insensitive
                       var stringToSearch = textNodes[i].textContent;
                       while(reSearch(stringToSearch)) { // While there are occurrences of the searchString
                           // Test if the index is after the currentRange's position
                           if(reSearch.lastIndex - searchString.length > currentRange.startOffset) {
                               // This is the new search position - empty the old selection and add the new selection range
                               theSelection.removeAllRanges();
                               newRange = document.createRange();
                               newRange.setStart(textNodes[i],reSearch.lastIndex - searchString.length); // Start node and index of the selection range
                               newRange.setEnd(textNodes[i],reSearch.lastIndex); //  End node and index of the selection
                               break; // We're not interested in the other results, so break out of this while loop.
                           }
                       }
                       if(newRange) break; // If we found a new range, break out of this for loop, cos there's nothing more to do.
                       else continue; // Otherwise continue
                   }
                   // If this text node is after the current one, search to see if it has any occurrences of the searchString
                   else if(currentRange.comparePoint(textNodes[i],0) == 1) {
                       // Create a regular expression object to do the searching
                       var reSearch = new RegExp(searchString,'gmi'); // Set it to 'g' - global (finds all instances), 'm' - multiline (searches more than one line), 'i' - case insensitive
                       var stringToSearch = textNodes[i].textContent;
                       // If we had a find, use it
                       if(reSearch(stringToSearch)) {
                           // This is the new search position - empty the old selection and add the new selection range
                           theSelection.removeAllRanges();
                           newRange = document.createRange();
                           newRange.setStart(textNodes[i],reSearch.lastIndex - searchString.length); // Start node and index of the selection range
                           newRange.setEnd(textNodes[i],reSearch.lastIndex); //  End node and index of the selection
                           break; // We're not interested in the other results, so break out of this while loop.
                       } else continue;
                   }
               }

               if(newRange) {
                   theSelection.addRange(newRange); // Add the node to the document's current selection
                   // Make the new range visible
                   newRange.startContainer.parentNode.scrollIntoView(false);
                   return;
               } else performSingleSearch(elem,searchElem);
           }

           // If we don't already have a selection, just find the first instance
           else {
               // Search all text nodes
               for(var i = 0; i < textNodes.length; i++) {
                   // Create a regular expression object to do the searching
                   var reSearch = new RegExp(searchString,'gmi'); // Set it to 'g' - global (finds all instances), 'm' - multiline (searches more than one line), 'i' - case insensitive
                   var stringToSearch = textNodes[i].textContent;
                   if(reSearch(stringToSearch)) { // If there are occurrences of the searchString
                       // This is the new search position - empty the old selection and add the new selection range
                       theSelection.removeAllRanges();
                       // Add the new selection range
                       var thisRange = document.createRange();
                       thisRange.setStart(textNodes[i],reSearch.lastIndex - searchString.length); // Start node and index of the selection range
                       thisRange.setEnd(textNodes[i],reSearch.lastIndex); //  End node and index of the selection
                       theSelection.addRange(thisRange); // Add the node to the document's current selection
                       thisRange.startContainer.parentNode.scrollIntoView(false);
                       break; // We're done
                   }
               }
           }
       }
       else if(document.selection) { // Internet Explorer
           theSelection = document.selection;
           var currentRange = theSelection.createRange();

           // Create text range to cover the whole of the searchElem
           var searchRange = document.body.createTextRange();
           searchRange.moveToElementText(searchElem);

           // Empty the current selection
           theSelection.empty();
           // If this text is already selected, find the next selection
           if(currentRange && currentRange.text && currentRange.text.match(eval('/'+searchString+'/i'))) {
               // Move start position of range past this word
               currentRange.moveStart('character');
               // Move end position to end of the search element
               currentRange.setEndPoint('EndToEnd',searchRange);
               // Search again
               if(currentRange.findText(searchString)) {
                   // We have found another instance
                   currentRange.select();
                   // Set the key press event, keeping the functionality of the old one as well
                   // This is so that IE will cycle on to the next search result when you press enter, something that Firefox did already
                   var currentkeypress = document.body.onkeypress;
                   window.setTimeout(function() {
                       document.body.onkeypress = function(evt) {
                           if(!evt) evt = window.event; // for internet explorer

                           // If the selection is still what we thought it was
                           var nowRange = document.selection.createRange();
                           if(nowRange.htmlText == currentRange.htmlText) {
                               if(evt.keyCode == 13) { // If enter key pressed
                                   // Set the onkeypress back to what it was
                                   document.body.onkeypress = currentkeypress;
                                   // Perform the search
                                   performSingleSearch(elem,searchElem);
                               }
                           } else {
                               // If the selection isn't what we though, set the onkeypress back to what it was
                               document.body.onkeypress = currentkeypress;
                           }
                           // Either way, perform old onkeypress event as well
                           if(currentkeypress) currentkeypress(evt);
                       }
                   },30);
                   return true;
               } else performSingleSearch(elem,searchElem);
           } else {
               // Find the first occurrence of the searchString
               if(searchRange.findText(searchString)) {
                   // If we've found something, select it
                   searchRange.select();
                   // Set the key press event, keeping the functionality of the old one as well
                   // This is so that IE will cycle on to the next search result when you press enter, something that Firefox did already
                   var currentkeypress = document.body.onkeypress;
                   window.setTimeout(function() {
                       document.body.onkeypress = function(evt) {
                           if(!evt) evt = window.event; // for internet explorer

                           // If the selection is still what we thought it was
                           var nowRange = document.selection.createRange();
                           if(nowRange.htmlText == searchRange.htmlText) {
                               if(evt.keyCode == 13) { // If enter key pressed
                                   // Set the onkeypress back to what it was
                                   document.body.onkeypress = currentkeypress;
                                   // Perform the search
                                   performSingleSearch(elem,searchElem);
                               }
                           } else {
                               // If the selection isn't what we though, set the onkeypress back to what it was
                               document.body.onkeypress = currentkeypress;
                           }
                           // Either way, perform old onkeypress event as well
                           if(currentkeypress) currentkeypress(evt);
                       }
                   },30);

                   return true;
               } else {
                   return false;
               }
           }
       } else alert("Sorry your browser doesn't support a supported selection object");
   }
}

// Recursively find all text nodes within an element
function findTypeNodes(elem,type) {
   // Remove superfluous text nodes and merge adjacent text nodes
   elem.normalize();

   var typeNodes = new Array();
   // Search all children of this element to see which ones are the right type of node
   for(var nodeI = 0; nodeI < elem.childNodes.length; nodeI++) {
       if(elem.childNodes[nodeI].nodeType == type) typeNodes.push(elem.childNodes[nodeI]); // If it is a the right type of node, add it to the array
       else {
           // If not a the right type of node, search it in turn
           typeNodes = typeNodes.concat(findTypeNodes(elem.childNodes[nodeI],type));
       }
   }
   return typeNodes; // return the array
}

// Multiple onload function created by: Simon Willison
// http://simon.incutio.com/archive/2004/05/26/addLoadEvent
function addLoadEvent(func) {
 var oldonload = window.onload;
 if (typeof window.onload != 'function') {
   window.onload = func;
 } else {
   window.onload = function() {
     if (oldonload) {
       oldonload();
     }
     func();
   }
 }
}

addLoadEvent(function() {
 // Create a button
 var theInput = document.getElementById('searchInput');
 var theButton = document.getElementById('performSearch');
 var elementToSearch = document.body; // Use getElementById('yourIDName') to only allow search for a specific id.
 theButton.onclick = function() { // Set the onclick function
   performSingleSearch(theInput,elementToSearch);
 }
 // Also perform search on enter press
 theInput.onkeypress = function(evt) {
   if(!evt) evt = window.event; // for internet explorer
   if(evt.keyCode == 13) performSingleSearch(theInput,elementToSearch);
 }
});