59 error handling simpler

[gogonzo]

closes #59 Please compare with #61

• when eval_code fails then returns error condition of class (s3) c("quosure.error", "try-error", "error", "condition")
• needed to register S3 method for [[.quosure.error as S4 couldn't dispatch on the quosure.error like other methods (probably it's handled internally which has priority). Class try-error needed to make validate stop. Go to shiny:::isTruthy to see when validate interrupts the reactive.
• I'm not happy that req(<quosure.error>) in q8 doesn't return error like in q13

---

example

ui <- fluidPage(
  fluidRow(
    column(6, h1("Code")),
    column(6, h1("Output"))
  ),
  fluidRow(
    column(6, verbatimTextOutput("q1_code")),
    column(6, verbatimTextOutput("q1_output"))
  ),
  fluidRow(
    column(6, verbatimTextOutput("q2_code")),
    column(6, verbatimTextOutput("q2_output"))
  ),
  fluidRow(
    column(6, verbatimTextOutput("q3_code")),
    column(6, verbatimTextOutput("q3_output"))
  ),
  fluidRow(
    column(6, verbatimTextOutput("q4_code")),
    column(6, verbatimTextOutput("q4_output"))
  ),
  fluidRow(
    column(6, verbatimTextOutput("q5_code")),
    column(6, verbatimTextOutput("q5_output"))
  ),
  fluidRow(
    column(6, verbatimTextOutput("q6_code")),
    column(6, verbatimTextOutput("q6_output"))
  ),
  fluidRow(
    column(6, verbatimTextOutput("q7_code")),
    column(6, verbatimTextOutput("q7_output"))
  ),
  fluidRow(
    column(6, verbatimTextOutput("q8_code")),
    column(6, verbatimTextOutput("q8_output"))
  ),
  fluidRow(
    column(6, verbatimTextOutput("q9_code")),
    column(6, verbatimTextOutput("q9_output"))
  ),
  fluidRow(
    column(6, verbatimTextOutput("q10_code")),
    column(6, verbatimTextOutput("q10_output"))
  ),
  fluidRow(
    column(6, verbatimTextOutput("q11_code")),
    column(6, verbatimTextOutput("q11_output"))
  ),
  fluidRow(
    column(6, verbatimTextOutput("q12_code")),
    column(6, verbatimTextOutput("q12_output"))
  ),
  fluidRow(
    column(6, verbatimTextOutput("q13_code")),
    column(6, verbatimTextOutput("q13_output"))
  )
)

server <- function(input, output, session) {
  q1 <- reactive({
    new_quosure() %>%
    eval_code(code = 'stop("Error message details")')
  })

  output$q1_code <- reactive(
    'q1 <- reactive(new_quosure() %>%
      eval_code(stop("Error message details")))'
  )

  output$q1_output <- renderPrint(q1())

  q2 <- reactive({
    new_quosure() %>%
      eval_code(code = "x <- 0")
  })


  output$q2_code <- reactive(
    'q2 <- reactive(new_quosure() %>%
      eval_code("x <- 0")'
  )

  output$q2_output <- renderPrint(q2())

  q3 <- reactive({
    validate(need(q1(), "q1 is not valid"))
    "hello"
  })

  output$q3_code <- reactive(
    'q3 <- reactive({
    validate(need(q1(), "q1 is not valid"))
    "hello"
    })'
  )

  output$q3_output <- renderPrint(q3())

  q4 <- reactive({
    validate(need(q2(), "q2 is not valid"))
    "hello"
  })


  output$q4_code <- reactive(
    'q4 <- reactive({
     validate(need(q2(), "q2 is not valid"))
    "hello"
    })'
  )

  output$q4_output <- renderPrint(q4())

  q5 <- reactive({
    q1()[["x"]]
  })

  # Note case q2()[["not_valid"]] handled by teal.code issue #57

  output$q5_code <- reactive(
    'q5 <- reactive(q1()[["x"]])'
  )

  output$q5_output <- renderPrint({
    q5()
  })


  q6 <- reactive({
    eval_code(q2(), "w <- y * x")
  })


  output$q6_code <- reactive(
    'q6 <- reactive(eval_code(q2(), "w <- y * x"))'
  )

  output$q6_output <- renderPrint(q6())

  q7 <- reactive({
    eval_code(q1(), "w <- 10")
  })


  output$q7_code <- reactive(
    'q7 <- reactive(eval_code(q1(), "w <- 10")'
  )

  output$q7_output <- renderPrint(q7())

  q8 <- reactive({
    req(q1())
    "hello"
  })


  output$q8_code <- reactive(
    'q8 <- reactive({
      req(q1())
      "hello"
    })'
  )

  output$q8_output <- renderPrint(q8())


  q9 <- reactive({
    join(q2(), q7()) %>% get_var("x")
  })


  output$q9_code <- reactive(
    'q9 <- reactive({
      join(q2(), q7()) %>% get_var("x")
    })'
  )

  output$q9_output <- renderPrint(q9())

  q10 <- reactive({
    join(q2(), q7()) %>% get_code()
  })


  output$q10_code <- reactive(
    'q10 <- reactive({
      join(q2(), q7()) %>% get_code()
    })'
  )

  output$q10_output <- renderPrint(q10())


  q11 <- reactive({
    new_quosure() %>%
      eval_code("x <- 0") %>%
      eval_code("y <- 0") %>%
      eval_code("w <- u * x") %>%
      eval_code("v <- x") %>%
      get_code()
  })


  output$q11_code <- reactive(
    'q11 <- reactive({
      new_quosure() %>%
      eval_code("x <- 0") %>%
      eval_code("y <- 0") %>%
      eval_code("w <- u * x") %>%
      eval_code("v <- x") %>%
      get_code()
    })'
  )

  output$q11_output <- renderPrint(q11())


  q12_a <- reactive({
    validate(need(1 > 4, "Error: 1 is less than 4"))
    new_quosure() %>% eval_code("x <- 1")
  })

  q12_b <- reactive({
    get_code(q12_a())
  })

  output$q12_code <- reactive(
    'q12_a <- reactive({
      validate(need(1 > 4, "Error: 1 is less than 4"))
      new_quosure() %>% eval_code("x <- 1")
    })

    q12_b <- reactive({
      get_code(q12_a())
    })
    '
  )

  output$q12_output <- renderPrint(q12_b())

  q13a <- reactive(stop("error in the reactive"))
  q13b <- reactive({
    req(q13a())
    "hello"
  })
  output$q13_code <- reactive(
    'q13a <- reactive(stop("error in the reactive"))
    q13b <- reactive({
      req(q13a())
      "hello"
    })
    '
  )
  output$q13_output <- renderPrint(q13b())
}

runApp(shinyApp(ui, server))

[nikolas-burkoff]

A few minor comments, I'll look in detail tomorrow

[nikolas-burkoff]

Would you also handle validation so that the css for validation gets used in the app compare these:

and you could have an S3 method for print.quosure.error to print the message out without having the <quosure.error: ...> but I sort of like that as it signposts clearly there's a problem with the quosures

[gogonzo]

and you could have an S3 method for print.quosure.error to print the message out without having the <quosure.error: ...> but I sort of like that as it signposts clearly there's a problem with the quosures

Initially I wanted quosure to return red error as it's an error and not the restricted-input-choice. I also like that it returns <quosure.error ...>. If I make quosure.error.print I'd probably just turn it red

[nikolas-burkoff]

So this is a little more realistic for teal at the moment buttons 1 and 2 do nothing when clicked on - I think we should change teal.widgets to output the trace / validation error when you click on them

Edit these are fixed here

library(teal.code)
library(magrittr)
library(teal.widgets)
library(shiny)

ui <- fluidPage(
  verbatim_popup_ui("rcode_1", "Show R code 1"),
  verbatim_popup_ui("rcode_2", "Show R code 2"),
  verbatim_popup_ui("rcode_3", "Show R code 3")
)

server <- function(input, output, session) {
  # invalid due to code error
  q_1 <- reactive(new_quosure() %>%
    eval_code("x <- 1") %>%
    eval_code("y <- x * w"))


  verbatim_popup_srv(
    id = "rcode_1",
    verbatim_content = reactive(get_code(q_1())),
    title = "rcode_1"
  )

  # invalid due to validate
  q_2 <- reactive({
    validate(need(1 > 4, "1 is less than 4"))
    new_quosure() %>%
      eval_code("x <- 1") %>%
      eval_code("y <- x * 1")
  })

  verbatim_popup_srv(
    id = "rcode_2",
    verbatim_content = reactive(get_code(q_2())),
    title = "rcode_2"
  )

  #valid
  q_3 <- reactive(new_quosure() %>%
    eval_code("x <- 1") %>%
    eval_code("y <- x * 1"))

  verbatim_popup_srv(
    id = "rcode_3",
    verbatim_content = reactive(get_code(q_3())),
    title = "rcode_3"
  )
}

shinyApp(ui, server)