问筛选闪亮的selectizeInput并在数据集中没有满足输入的观察时显示空白图

EN

---
title: "test"
output: 
  flexdashboard::flex_dashboard:
    theme: bootstrap
runtime: shiny
---

```{r setup, include=FALSE}

```{r global, include=FALSE}

                           as.Date("2018-06-30"), 

                           "days"),

                sex = sample(c("male", "female"), 181, replace=TRUE),

                lang = sample(c("english", "spanish"), 181, replace=TRUE),

                age = sample(20:35, 181, replace=TRUE))

Sidebar {.sidebar}
=====================================

```{r}

Page 1
=====================================

```{r}

mutate(new = 1) %>%

arrange(date) %>%

filter(if(is.null(input$foo)) (new==1) else (lang %in% input$foo)) %>%

select(date, new) %>%

tibbletime::collapse_by("1 week", side = "start", clean = TRUE) %>%

group_by(date) %>%

mutate(total = sum(new, na.rm = TRUE)) %>%

distinct(date, .keep_all = TRUE) %>%

ungroup() %>%

# expand matrix to include weeks without data

complete(

  date = seq(date[1], date[length(date)], by = "1 week"),

  fill = list(total = 0)

)

totals <- totals()

xts(totals, order.by = totals$date)

dyRangeSelector() %>%

dyOptions(useDataTimezone = FALSE,

          stepPlot = TRUE,

          drawGrid = FALSE,

          fillGraph = TRUE)