CODEWITHSUNDEEP
javascriptrshiny
Hamilton Blake
Hamilton Blake

Reputation: 642

Shiny and Javascript - Uncaught ReferenceError: TRUE is not defined

I have a shinyapp which has a basic login screen.

When the app loads, the "Logged" variable is FALSE. When the user successfully logs in within the session, the R login code is as follows:

X$Logged <- TRUE

At this point, in the javascript console I get warnings saying "Uncaught ReferenceError: TRUE is not defined".

I click on the link to go to the code, and the javascript code is:

(function() {
with (this) {return (X$Logged=TRUE);}
})

I am a beginner. I am assuming that firstly, this is the javascript render of my R code above, and secondly that it doesn't like it because javascript expects a lower case boolean "true".

How can I get around this? Equally, R doesn't like lower case boolean.

Upvotes: 3

Views: 4261

Answers (2)

Hamilton Blake
Hamilton Blake

Reputation: 642

Paul's and Mritunjay's answer helped me to get this fixed.

The misunderstanding was in a conditionalPanel() within my ui.R file. I had:

conditionalPanel(
condition="X$Logged=TRUE"
...
)

I spotted the single "=" instead of "==" and realised the condition within the inverted commas is JS, and not R. I therefore changed my ui.R to this:

conditionalPanel(
condition="X$Logged=true"
...
)

However, I kept upper case "TRUE" in all of my server.R logic, like this:

X$Logged <- TRUE

...and it now works.

Upvotes: 1

Paul S.
Paul S.

Reputation: 66334

How can I get around this? Equally, R doesn't like lower case boolean.

Define one in the other, e.g. as you're going to JavaScript, before your code (in the JavaScript)

var TRUE = true, FALSE = false;

Then

(function() {
    with (this) {return (X$Logged=TRUE);} // should now work
})

Alternatively, you could use bool-like things, i.e. 1 and 0 instead.

Finally, how are you doing the R to JS transformation? This well may be a bug in the framework you've used

Upvotes: 2

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