//function for using the userInput text box to search for parts
$scope.findMeta = function () {
 
  //reset the text property of the play button to be blank
  $scope.view.wdg.playButton.text='';
  //
  //set the toPlay object for the play button to be undefined
  $scope.view.wdg.playButton.toPlay = undefined;
  //
  //set a variable for comparing the user input to the value of the partno application parameter
  var searchNum = $scope.app.params.partno;
  
  //
  // instead of using metadata from just the picked part, use metadata from the whole model. If resolved, proceed
  PTC.Metadata.fromId('quadcopter')
                      .then ( (metadata) => {

  //
  //set a variable for comparing the user input to the value of the partno application parameter
  var searchNum = $scope.app.params.partno;

  //
  // instead of using metadata from just the picked part, use metadata from the whole model. If resolved, proceed
  PTC.Metadata.fromId('quadcopter')
    .then((metadata) => {
        //
        // set a variable named options. this variable will become an array of ID paths that fit the input text.
        // 'like' will look for a partial text match to what is typed in. use 'same' to get an exact match 
        var options = metadata.find('partNumber').like(searchNum).getSelected();

        //
        // if the text input leads to a part number so that there is an entry in the options array
        if (options != undefined && options.length > 0) {
            //
            // set an empty array called ID. This array will house the parts that contain the entered part number
            var identifiers = []
            //
            // for each entry in the options array, push that value with 'quadcopter-' at the beginning into the ID array 
            options.forEach(function (i) {
                identifiers.push('quadcopter-' + i)
            }) //end forEach

            //
            // highlight each object in the identifiers array with the shader
            $scope.hilite(identifiers, true)

            //
            // function for removing the highlight
            var removeHilite = function (refitems) {
                //
                // return the hilite function with a value of false to the given part(s)
                return function () {
                    $scope.hilite(refitems, false)
                } // end of return function
            } // end of turning off hilite

            //
            // remove the highlight of the selected part(s) after 3000 ms
            $timeout(removeHilite(identifiers), 3000)

          } //end if statement 
    }) // end .then

      //catch statement if the promise of having a part with metadata is not met
      .catch((err) => { console.log('metadata extraction failed with reason : ' + err) })
} // end findMeta function