rstudio/shiny

Add support for ifelse logic in conditionalPanel

Open

#843 opened on May 22, 2015

View on GitHub
 (3 comments) (4 reactions) (0 assignees)R (5,649 stars) (1,890 forks)batch import
Difficulty: IntermediateEffort: LowHelp WantedPriority: LowType: Enhancement :bulb:

Description

Many times I want to do something along the lines of

conditionalPanel("input.test", "yep"),
conditionalPanel("!input.test", "nope")

Some syntactic sugar here would be awesome :) Hopefully the above could be translated into

conditionalPanel("input.test", iftrue = "yep", iffalse = "nope")

(clearly I'm not great at naming arguments)

Contributor guide

Tech stack
None
Domain
frontend
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Basic understanding of Shiny's conditionalPanelFamiliarity with R package development
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
This issue requests adding an ifelse like syntax to conditionalPanel. The implementation would involve modifying the conditionalPanel function in Shiny's R source, likely in R/conditionalpanel.R or similar. Look for existing similar patterns (e.g., tabPanel arguments) and ensure backward compatibility. There is no linked PR or maintainer comment, so the approach is open. Consider using ellipsis or named arguments to support iftrue and iffalse.