ShowEmotionsController.js

({
    showEmotion : function(component, event, helper) {
        var toneAnalyzeResponse = component.get( "v.toneAnalyzeResponse" );
        
        var standardTones = [ "joy", "sadness", "anger", "fear" ];
        
        var emotion;
        for( var i = 0; i <= standardTones.length - 1; i++ ) {
            if( toneAnalyzeResponse.indexOf( standardTones[i] ) !== -1 ) {
                emotion = standardTones[i];
                break;
            }
        }
        
        helper.getGiphyImage( 
            emotion,
            function( gifUrl ) {
                component.set( "v.gifUrl", gifUrl );
                component.set( "v.detectedEmotion", emotion );
            }
        );
    }
})