Make R/Shiny/ggplot2 linegraph using 3 variables--date, state_territory, and discrete variable

Question

my data frame is tableau_jh_df [first 4 lines shown]:

date province_state number_of_cases
1 2020-01-22 Alabama 0
2 2020-01-22 Alaska 0
3 2020-01-22 Arizona 0

Based on user selection of province_state from Shiny control, I want to plot a line graph of total number_of_cases by week using ggplot2. What I am getting so far is all of the cases regardless of which province_state is selected. Here is my code and the graph:

# ui
fluidRow(
        column(3,
               selectInput("state_terr", "Choose a State/Territory:",
                           list("Alabama", "Alaska", "Arizona" [,...etc]  
# server
output$plot <- renderPlot({
    min_date <- as.Date("2020-01-20")
    max_date <- NA
    ggplot(tableau_jh_df, aes(date, number_of_cases, col = input$state_terr,
                              group = 1)) +
    geom_line() +
    labs(x = "Date", y = "Number of Cases") +
    theme(axis.text.x = element_text(angle = 45),
          axis.text.y = element_text(angle = 90))  

Number of Cases by Date

Answer 1

You have to filter your dataset according to the chosen state or province. Using filter from dplyr try this:

ggplot(filter(tableau_jh_df, province_state == input$state_terr), 
       aes(date, number_of_cases, col = input$state_terr, group = 1)) +
    geom_line() +
    labs(x = "Date", y = "Number of Cases") +
    theme(axis.text.x = element_text(angle = 45),
          axis.text.y = element_text(angle = 90))

BTW: col = input$state_terr has no effect on the color of the line if that was your intention.