R/chat.R

In skranz/shinyChatQuiz: Shiny app for online lecture support with chat and quizzes

chat.example = function() {
  restore.point.options(display.restore.point = TRUE)
  library(shinyEvents)

  app = eventsApp()
  app$glob$app.counter = 0
  init.chat.globals(app)
  app$ui = fluidPage(
    quizchat.headers(),
    push.js.headers(),
    p("Chat Example"),
    chat.ui(),
    simpleButton("testBtn","Add Random Text")
  )
  eventHandler("chatSendEvent",fun =  function(value, ..., app=getApp()) {
    add.chat.entry(msg=value,app=app)
  })
  buttonHandler("testBtn", function(...){
    add.chat.entry(msg="This is just a long, or not so long test message.")
  })
  appInitHandler(function(..., app) {
    init.chat.app.instance(app)
  })
  viewApp(app)
}

init.chat.app.instance = function(app) {
  glob = app$glob
  app$msg.counter = 0
  color = glob$colors[ (app$idnum-1 %% length(glob$colors))+1 ]
  app$msg.entry = c(idnum=as.character(app$idnum), msg="", user=app$user, initials=app$initials,time="", color=color)

  app$push.past.secs = glob$push.past.secs

  observeEvent(glob$rv.msg.counter(), {
    insert.newest.chat.entries()
  })
}


initials.colors = function() {
  #library(RColorBrewer)
  #glueformula::varnames_snippet(c(brewer.pal(12,"Set3"),brewer.pal(8,"Accent"),brewer.pal(9,"Pastel1"), brewer.pal(8,"Pastel2")))

  c("#8DD3C7", "#FFFFB3", "#BEBADA", "#FB8072", "#80B1D3", "#FDB462", "#B3DE69", "#FCCDE5", "#D9D9D9", "#BC80BD", "#CCEBC5", "#FFED6F", "#7FC97F", "#BEAED4", "#FDC086", "#FFFF99", "#386CB0", "#F0027F", "#BF5B17", "#666666", "#FBB4AE", "#B3CDE3", "#CCEBC5", "#DECBE4", "#FED9A6", "#FFFFCC", "#E5D8BD", "#FDDAEC", "#F2F2F2", "#B3E2CD", "#FDCDAC", "#CBD5E8", "#F4CAE4", "#E6F5C9", "#FFF2AE", "#F1E2CC", "#CCCCCC")
}


chat.ui = function(user=app$user, is.admin=app$is.admin, show.username=TRUE, change.user.btn = TRUE, app=getApp()) {
  restore.point("chat.ui")
   html = paste0('<div id="chat-outer" class="col-md-5">
    <div class="panel panel-primary">
        <div class="panel-heading">

            <span style="margin-right: 1em">
              Chat
            </span>
            ', if (is.admin)  paste0('<span style="margin-left: 0px">
            <button class="btn btn-qc btn-xs" id="pause-chat-btn"
       style="margin-left: 0em;">Pause chat</button>
              <button class="btn btn-qc btn-xs" id="restart-chat-btn"
       style="margin-left: 5px; margin-right: 5px;', if (!isTRUE(app$glob$pause.chat)) 'display: none', '">Restart chat</button>
            <span>'),'
            ' , if (show.username) paste0('<br><span id="chat-user-header">',user,'</span>'),'

        </div>
        <div id="chat-body" class="panel-body" style="height: 20em">
            <ul id="chat-ul" class="chat">
              ',inner.chat.entries(max.entries = if(is.admin) 500 else 10),'
            </ul>
        </div>
        <div class="panel-footer">
            <div class="input-group">
                <input id="chat-input" type="text" class="form-control input-sm" placeholder="Type your message here..." />
                <span class="input-group-btn">
                    <button class="btn btn-qc btn-sm" id="btn-chat-send">
                        Send</button>
                </span>
            </div>
        </div>
    </div>
', if (change.user.btn) '<button id="changeUserBtn" style="" type="button" class="btn btn-default action-button ">Nutzernamen ändern</button>',
'</div>')

   if (change.user.btn) {
     buttonHandler("changeUserBtn",change.user.name)
   }


   HTML(html)
}

inner.chat.entries = function(max.entries=20, app=getApp()) {
  restore.point("inner.chat.entries")
  glob = app$glob
  n = glob$msg.counter
  if (n < 1) return(NULL)
  rows = max(1,(n-max.entries)+1):n
  msg.mat = glob$msg.mat


  paste0(collapse="\n",'<li class="left clearfix">
    <span class="circle pull-left" style="background-color: ',msg.mat[rows,"color"],';"><span class="initials">',msg.mat[rows,"initials"],'</span></span>
    <div class="chat-body clearfix">
    <div class="header">
    <strong class="primary-font">',msg.mat[rows,"user"],'</strong> <small class="pull-right text-muted">
    <span class="glyphicon glyphicon-time"></span>',msg.mat[rows,"time"],'</small>
    </div>
    <p>',msg.mat[rows,"msg"],'</p>
    </div>
    </li>
  ')
}

pause.chat = function(..., app=getApp()) {
  restore.point("pause.chat")
  if (!isTRUE(app$is.admin)) return()
  app$glob$pause.chat = TRUE
  shinyEvents::setHtmlHide("pause-chat-btn")
  shinyEvents::setHtmlShow("restart-chat-btn", display="inline")

  add.chat.entry(msg="Admin paused chat.")
}

restart.chat = function(..., app=getApp()) {
  restore.point("restart.chat")
  if (!isTRUE(app$is.admin)) return()
  app$glob$pause.chat = FALSE
  shinyEvents::setHtmlHide("restart-chat-btn")
  shinyEvents::setHtmlShow("pause-chat-btn", display="inline")
  add.chat.entry(msg="Admin restarted chat.")
}

add.chat.entry = function(msg="message", app=getApp()) {
  restore.point("add.chat.entry")

  if (!isTRUE(app$is.admin) & isTRUE(app$glob$pause.chat)) {
    return()
  }

  msg = htmlEscape(msg)
  app$msg.entry["msg"] = msg
  time = Sys.time()
  app$msg.entry["time"] = format(time,"%H:%M", tz=app$glob$tz)

  glob = app$glob
  row = glob$msg.counter+1

  # Possibly enlarge msg.mat
  n = NROW(glob$msg.mat)
  if (row+1 > n) {
    empty.mat = matrix("",nrow=n, ncol=6)
    colnames(empty.mat) = c("idnum", "msg","user", "initials","time", "color")
    glob$msg.mat = rbind(glob$msg.mat, empty.mat)
    glob$msg.time = c(glob$msg.time, rep(0L, n))
  }
  glob$msg.mat[row,] = app$msg.entry
  glob$msg.time[row] = time
  glob$msg.counter = glob$msg.counter+1
  glob$rv.msg.counter(glob$msg.counter)
}

insert.newest.chat.entries = function(app=getApp()) {
  #restore.point("insert.newest.chat.entries")

  glob = app$glob
  if (isTRUE(app$msg.counter >= glob$msg.counter))
    return()
  rows = (app$msg.counter+1):glob$msg.counter
  #restore.point("insert.newest.chat.entries2")

  for (row in rows) {
    callJS("insertChat", .args=as.list(glob$msg.mat[row,-1]))
  }
  app$msg.counter = glob$msg.counter

  # push new messages that are not older than app$push.past.secs
  if (isTRUE(glob$push.msg & app$is.admin)) {
    # Only push recent messages if some are not by yourself
    from.somebody.else = any(glob$msg.mat[rows,"idnum"] != as.character(app$idnum))
    if (!from.somebody.else) return()

    time = as.integer(Sys.time())
    past.secs = time-as.integer(glob$msg.time[1:glob$msg.counter])
    use = which(past.secs <= app$push.past.secs)
    if (length(use)>0) {
      if (length(use)>3) use = use[(length(use)-2):length(use)]
      restore.point("push.messages...")
      push.message(paste0(glob$msg.mat[use,"initials"],": ", glob$msg.mat[use,"msg"],collapse="\n---\n"))
    }
  }
}


insert.chat.entry = function(msg="message", user="user",initials="U", time=format(Sys.time(),"%H:%M", tz=app$glob$tz), color="55C1E7", app=getApp()) {
  restore.point("insert.chat")
  callJS("insertChat", .args=list(msg=msg, user=user, initials=initials, time=time, color=color))
}


change.user.name = function(..., app=getApp()) {
  lang = app$glob$lang
  input.lab = if (lang=="de") "Neuer Nutzername" else "New username"
  showModal(modalDialog(footer=NULL, easyClose=TRUE,
    textInput("userInput",input.lab, app$user),
    simpleButton("newUserOkBtn","Ok", form.ids = c("userInput")),
    simpleButton("newUserCancelBtn","Cancel"),
  ))
  buttonHandler("newUserOkBtn", function(formValues,..., app=getApp()) {
    args = list(...)
    restore.point("loginClick")
    user = formValues$userInput
    if (nchar(trimws(user))==0) {
      removeModal()
      return()
    }
    user = substring(user, 1,30)
    app$user = user
    app$initials = make.initials(user)
    app$msg.entry["user"] = user
    app$msg.entry["initials"] = app$initials
    setInnerHTML("chat-user-header", user)
    update.app.cookie()
    removeModal()
  })
  buttonHandler("newUserCancelBtn", function(...,app=getApp()) {
    removeModal()
  })
}