Uncaught ReferenceError: Shiny is not defined - r

Question

This question is related application loading without css. I checked the java script console and get issues
Uncaught ReferenceError: Shiny is not defined
at (index):21
Uncaught ReferenceError: shinyjs is not defined
at (index):39
The script at index 21 in source:
`<script>Shiny.addCustomMessageHandler('shinyjs-show', function(params) { shinyjs.debugMessage('shinyjs: calling function "show" with parameters:'); shinyjs.debugMessage(params); shinyjs.show(params);})`;
The application is running on shiny-server on CentOs 6.

Answer 1

Make sure you call shinyjs::useShinyjs() somewhere within the session running the app.
Normally you would include this as part of the shiny UI.
But if the UI was created inside a package, then it might call useShinyjs when the package is built or installed and not in the session where the app is running.

Answer 2

That is probably the issue (referring to your comment).
As indicated here, install your packages with:
sudo su - -c "R -e \"install.packages('shiny', repos='http://cran.rstudio.com/')\""
This is because your apps will be ran by a user called shiny, user which probably cannot access the package shiny because you installed it as another user.

Answer 3

The problem is probably, because you run the code before Shiny object is created by shiny. If you look at the code of shiny it have this:
$(function() {
// Init Shiny a little later than document ready, so user code can
// run first (i.e. to register bindings)
setTimeout(initShiny, 1);
});
init_shiny.js#L511
you can use this function that I'm using:
var shinyReady = (function() {
var callbacks = $.Callbacks();
$(function() {
setTimeout(function() {
callbacks.fire();
callbacks = null;
}, 100); // this probably can be 2 since shiny use 1
});
return function(callback) {
if (callbacks) {
callbacks.add(callback);
} else {
callback();
}
};
})();
shinyReady(function() {
// your code that use Shiny object
});