[Feature Request]: Improve messages on input validation

[llrs-roche]

Feature description

One user reported on internal forum this error. If one uses a character instead of a data.frame on the value_choices for paramcd the user gets a cryptic message Warning: Error in template_forest_tte: Assertion on 'obj_var_name' failed: Must have length 1. and the app is not usable.

This could be an issue on value_choices that needs to validate the input and provide more informative warnings/error message but I also think this should be handled here (and other arguments checked).

reproducible example

library(nestcolor)
library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union
library("teal.modules.clinical")
#> Loading required package: teal
#> Loading required package: shiny
#> Loading required package: teal.data
#> Loading required package: teal.code
#> Loading required package: teal.slice
#> Registered S3 method overwritten by 'teal':
#>   method        from      
#>   c.teal_slices teal.slice
#> 
#> You are using teal version 0.15.2.9103
#> 
#> Attaching package: 'teal'
#> The following objects are masked from 'package:teal.slice':
#> 
#>     as.teal_slices, teal_slices
#> Loading required package: teal.transform
#> Loading required package: tern
#> Loading required package: rtables
#> Loading required package: formatters
#> 
#> Attaching package: 'formatters'
#> The following object is masked from 'package:base':
#> 
#>     %||%
#> Loading required package: magrittr
#> 
#> Attaching package: 'rtables'
#> The following object is masked from 'package:utils':
#> 
#>     str
#> Registered S3 method overwritten by 'tern':
#>   method   from 
#>   tidy.glm broom

data <- teal_data()
data <- within(data, {
  ADSL <- tmc_ex_adsl
  ADTTE <- tmc_ex_adtte
  ADSL$RACE <- droplevels(ADSL$RACE) %>% with_label("Race")
})
join_keys(data) <- default_cdisc_join_keys[names(data)]

ADSL <- data[["ADSL"]]
ADTTE <- data[["ADTTE"]]

arm_ref_comp <- list(
  ARM = list(
    ref = "B: Placebo",
    comp = c("A: Drug X", "C: Combination")
  ),
  ARMCD = list(
    ref = "ARM B",
    comp = c("ARM A", "ARM C")
  )
)

app <- init(
  data = data,
  modules = modules(
    tm_g_forest_tte(
      label = "Forest Survival",
      dataname = "ADTTE",
      arm_var = choices_selected(
        variable_choices(ADSL, c("ARM", "ARMCD")),
        "ARMCD"
      ),
      arm_ref_comp = arm_ref_comp,
      paramcd = choices_selected(
        value_choices("ADTTE", "PARAMCD", "PARAM"),
        "OS"
      ),
      subgroup_var = choices_selected(
        variable_choices(ADSL, names(ADSL)),
        c("BMRKR2", "SEX")
      ),
      strata_var = choices_selected(
        variable_choices(ADSL, c("STRATA1", "STRATA2")),
        "STRATA2"
      )
    )
  )
)
#> Initializing tm_g_forest_tte
#> Initializing reporter_previewer_module
if (interactive()) {
  shinyApp(app$ui, app$server)
}

^{Created on 2025-01-21 with reprex v2.1.1}

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