RMarkdown - Having The Title (text Heading Before A Table) Be Conditional

I have an R Markdown that is parameterized. Basically, I'm filtering a dataframe by a 'case_id' field and outputting a table of those filtered results. I render the RMarkdown docum

Solution 1:

You can do this by wrapping the table heading in appropriate if statements.

   ---
    title: "My Title"
    output: 
      html_document:
    params:
       case: case
    ---

    ```{r setup, include=FALSE}
    knitr::opts_chunk$set(echo = TRUE)
    ```

    ```{r warning = FALSE, echo = FALSE, fig.height=10, fig.width=6}
    data <- read.csv(text="case_id,event,group,start,end,color,line.color
                           3,event_1,Project,2020-06-15,2020-10-15,#ffffff,#FF0000
                           3,event_1,Meetings,2020-07-30,2020-07-30,#ffffff,#0000ff
                           5,event_1,Meetings,2020-08-30,2020-08-30,#ffffff,#FF0000
                           5,event_1,Meetings,2020-08-30,2020-08-30,#ffffff,#FF0000
                           5,event_1,Meetings,2020-08-30,2020-08-30,#ffffff,#FF0000
                           9,event_1,Meetings,2017-01-15,2017-01-15,#ffffff,#FF0000")
    data$case_id <- as.numeric(data$case_id)
    param_check <- any(params$case==data$case_id)
    if (param_check) {
        
       #Filter PDMP by the selected case
        data.filtered <- data %>%
                            filter(params$case==case_id)
        
        data.filtered <- data.filtered %>%
          filter(!is.na(start)&!is.na(end))
        
        pdmp_numRows <- nrow(data.filtered)
        
    }
    ```

    `r  if (param_check) { if (pdmp_numRows > 0) {"# My Table"} }`

    ```{r warning = FALSE, echo = FALSE, fig.height=10, fig.width=6}
    if(param_check) {    
      if (pdmp_numRows>0) { 
    
        #Print table of prescriptions
            data.filtered %>%
          arrange(start)%>%
          kable() %>%  kable_styling(bootstrap_options = "striped","condensed", font_size = 12)
        
      }
      
    }
    
    
    ```

Solution 2:

First load your csv into a data.frame then put the title in a chunk that'll get evaluated only when there are cases that have the provided id:

---
title: "My Title"
output: 
  html_document:
params:
   case: case

---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
data <- read.csv(text="case_id,event,group,start,end,color,line.color
                       3,event_1,Project,2020-06-15,2020-10-15,#ffffff,#FF0000
                       3,event_1,Meetings,2020-07-30,2020-07-30,#ffffff,#0000ff
                       5,event_1,Meetings,2020-08-30,2020-08-30,#ffffff,#FF0000
                       5,event_1,Meetings,2020-08-30,2020-08-30,#ffffff,#FF0000
                       5,event_1,Meetings,2020-08-30,2020-08-30,#ffffff,#FF0000
                       9,event_1,Meetings,2017-01-15,2017-01-15,#ffffff,#FF0000")
data$case_id <- as.numeric(data$case_id)
```

```{r, eval=any(params$case==data$case_id), results='asis'}
print("## My Table")
```