Created
January 1, 2016 14:38
-
-
Save ChrisBeeley/49974c2c98376a6261f8 to your computer and use it in GitHub Desktop.
Sending messages to and from client and server using JavaScript/ Shiny
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
<script type="text/javascript"> | |
// Shiny function to receive messages | |
Shiny.addCustomMessageHandler("sendMessage", | |
function(message) { | |
// call this before modifying the DOM | |
Shiny.unbindAll(); | |
/* delete the dropdown if it already | |
exists which it will the second | |
time this function is called */ | |
// get the dropdown and assign to element | |
var element = document.getElementById('mySelect'); | |
// if it already exists delete it | |
if (element !== null) | |
{ | |
element.parentNode.removeChild(element); | |
} | |
// Create empty array to store the options | |
var theNumbers = []; | |
// add ascending numbers up to the | |
// value of the message | |
for (var i = 1; i <= message; i++) { | |
theNumbers.push(i); | |
} | |
// grab the div ready to write to it | |
var theDiv = document.getElementById("output"); | |
// create a new dropdown | |
var selectList = document.createElement("select"); | |
// give it a name and write it to the div | |
selectList.setAttribute("id", "mySelect"); | |
theDiv.appendChild(selectList); | |
// add the options | |
for (var n = 0; n < theNumbers.length; n++) { | |
var option = document.createElement("option"); | |
option.setAttribute("value", theNumbers[n]); | |
option.text = theNumbers[n]; | |
selectList.appendChild(option); | |
} | |
// add an onchange function to call shinyRules | |
// every time this input changes | |
selectList.onchange = shinyRules; | |
// add class to style nicely in Bootstrap | |
selectList.className += "form-control"; | |
// call this when you've finished modifying the DOM | |
Shiny.bindAll(); | |
}); | |
shinyRules = function(){ | |
// define text array and pick random element | |
var textArray = ['JavaScript Rules!', 'Shiny Rules!']; | |
var randomNumber = Math.floor(Math.random()*textArray.length); | |
// whenever this input changes send a message to the server | |
Shiny.onInputChange("JsMessage", textArray[randomNumber]); | |
} | |
</script> |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
################################################### | |
#### Running JavaScript on the page - server.R #### | |
################################################### | |
library(shiny) | |
shinyServer(function(input, output, session) { | |
output$randomNumber = renderText({ | |
theNumber = sample(1:input$pickNumber, 1) | |
session$sendCustomMessage(type = 'sendMessage', | |
message = theNumber) | |
return(theNumber) | |
}) | |
output$theMessage = renderText({ | |
return(input$JsMessage) | |
}) | |
}) |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
############################################### | |
#### Running JavaScript on the page - ui.R #### | |
############################################### | |
library(shiny) # load Shiny at the top of both files | |
shinyUI(fluidPage( # flexible layout function | |
h4(HTML("Think of a number:</br>Does Shiny or JavaScript rule?")), | |
sidebarLayout( | |
sidebarPanel( # sidebar configuration | |
sliderInput("pickNumber", "Pick a number", | |
min = 1, max = 10, value = 5), | |
tags$div(id = "output") # tags$XX for holding dropdown | |
), | |
mainPanel( | |
textOutput("randomNumber"), | |
hr(), | |
textOutput("theMessage"), | |
includeHTML("dropdownDepend.js") # include JS file | |
) | |
) | |
)) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
ya i gest created it