r flexdashboard issue with arules reactive input - shinydashboard

Question

I'm trying to create a flexdashboard with results from the r arules apriori function, so to display associated relations for specific items selected from the pull down menu in the markdown dashboard. When I create function outside the markdown environment I'm able successfully feed the new product item to the apriori function without problem and the graph changes as expected when I change item. When I replace the function variable with the reactive function name I get an error message saying no rules "Error: x contains 0 rules!"
Using the provided Grocery data, I'm want to the reactive input to feed the selected variable either "whole milk" or "sugar" and output the rules for the the specified variable and create a graph. I'm new to dashboards so I don't know if need to use a different function than the "reactive".
Below is the markdown code I'm having trouble feeding a new variables into the aproiri function.
---
title: "Grocery_Test"
output:
flexdashboard::flex_dashboard:
storyboard: true
social: menu
source_code: embed
runtime: shiny
---
```{r global, include=FALSE}
library(plotly)
library(flexdashboard)
library(htmlwidgets)
library(htmltools)
library(knitr)
library(arules)
library(arulesViz)
library(igraph)
library(datasets)
data(Groceries)
```Inputs {.sidebar}
-----------------------------------------------------------------------
```{r}
selectInput("Product","Product", c("whole milk","sugar"))
```
###Associated Product
```{r}
product <- reactive({input$product})
renderPlot({
#product<-"whole milk"
rules <- apriori (data=Groceries
,parameter=list (supp=0.001,conf = 0.15,maxlen=3)
,appearance = list(default="rhs",lhs=Product())
,control = list (verbose=F))
rules_conf <- sort (rules, by=c("confidence"), decreasing=TRUE) # 'high-confidence' rules.
redundant <- which (colSums (is.subset (rules_conf, rules_conf)) > 1) # get redundant rules in vector
rules_conf <- rules_conf[-redundant] # remove redundant rules
plot(rules_conf, method="graph",measure = "confidence", shading = "lift"
,control = list(engine="htmlwidget"))
})
```