WinJS Load CSS from app folder and watch its changes

gistfile1.coffee

"ms-appdata:///local/conf/dailyPage.css".toStorageFileAsync()
  .then (cssFile) =>
    style = document.createElement("style")
    style.type = "text/css"
    readFileAsync = ->
      Windows.Storage.FileIO.readTextAsync(cssFile)
      .then (cssText) ->
        style.sheet.cssText = cssText
    readFileAsync()
    .then ->
      document.head.appendChild(style)

    # Now track the file and update the styles when the file is changed
    # Since we cannot track individual files we have to watch the whole folder
    queryOptions = new Windows.Storage.Search.QueryOptions(Windows.Storage.Search.CommonFileQuery.orderByName, [".css"])
    cssFile.getParentAsync()
    .then (folder) =>
      @fileQuery = folder.createFileQueryWithOptions(queryOptions)
      @fileQuery.addEventListener("contentschanged", readFileAsync)
      @fileQuery.getFilesAsync()
      # Part of my custom WinJS PageNavigator unload hook
      @unload["removeCssRefresher"] = ->
        @fileQuery.removeEventListener("contentschanged", readFileAsync)
        @fileQuery = null