add onExit handler, fix task polling, cleanup

lms/static/coffee/src/instructor_dashboard/analytics.coffee

@@ -8,10 +8,10 @@ std_ajax_err = -> window.InstructorDashboard.util.std_ajax_err.apply this, argum
 
 
 class ProfileDistributionWidget
-  constructor: ({@$container, @feature, title, @endpoint}) ->
+  constructor: ({@$container, @feature, @title, @endpoint}) ->
     # render template
     template_params =
-      title: title
+      title: @title
       feature: @feature
       endpoint: @endpoint
     template_html = $("#profile-distribution-widget-template").html()

lms/static/coffee/src/instructor_dashboard/instructor_dashboard.coffee

@@ -33,10 +33,13 @@ CSS_INSTRUCTOR_NAV = 'instructor-nav'
 # prefix for deep-linking
 HASH_LINK_PREFIX = '#view-'
 
+$active_section = null
 
 # helper class for queueing and fault isolation.
 # Will execute functions marked by waiter.after only after all functions marked by
 # waiter.waitFor have been called.
+# To guarantee this functionality, waitFor and after must be called
+# before the functions passed to waitFor are called.
 class SafeWaiter
   constructor: ->
     @after_handlers = []
@@ -87,8 +90,9 @@ setup_instructor_dashboard = (idash_content) =>
   # clickable section titles
   $links = idash_content.find(".#{CSS_INSTRUCTOR_NAV}").find('a')
 
-  for link in ($ link for link in $links)
-    link.click (e) ->
+  # attach link click handlers
+  $links.each (i, link) ->
+    $(link).click (e) ->
       e.preventDefault()
 
       # deactivate all link & section styles
@@ -97,11 +101,11 @@ setup_instructor_dashboard = (idash_content) =>
 
       # discover section paired to link
       section_name = $(this).data 'section'
-      section = idash_content.find "##{section_name}"
+      $section = idash_content.find "##{section_name}"
 
       # activate link & section styling
       $(this).addClass CSS_ACTIVE_SECTION
-      section.addClass CSS_ACTIVE_SECTION
+      $section.addClass CSS_ACTIVE_SECTION
 
       # tracking
       analytics.pageview "instructor_section:#{section_name}"
@@ -111,7 +115,12 @@ setup_instructor_dashboard = (idash_content) =>
       location.hash = "#{HASH_LINK_PREFIX}#{section_name}"
 
       sections_have_loaded.after ->
-        section.data('wrapper')?.onClickTitle?()
+        $section.data('wrapper')?.onClickTitle?()
+
+      # call onExit handler if exiting a section to a different section.
+      unless $section.is $active_section
+        $active_section?.data('wrapper')?.onExit?()
+      $active_section = $section
 
       # TODO enable onExit handler
 
@@ -137,15 +146,25 @@ setup_instructor_dashboard = (idash_content) =>
 
 # enable sections
 setup_instructor_dashboard_sections = (idash_content) ->
-  # see fault isolation NOTE at top of file.
-  # If an error thrown in one section, it will not stop other sections from exectuing.
-  plantTimeout 0, sections_have_loaded.waitFor ->
-    new window.InstructorDashboard.sections.CourseInfo   idash_content.find ".#{CSS_IDASH_SECTION}#course_info"
-  plantTimeout 0, sections_have_loaded.waitFor ->
-    new window.InstructorDashboard.sections.DataDownload idash_content.find ".#{CSS_IDASH_SECTION}#data_download"
-  plantTimeout 0, sections_have_loaded.waitFor ->
-    new window.InstructorDashboard.sections.Membership   idash_content.find ".#{CSS_IDASH_SECTION}#membership"
-  plantTimeout 0, sections_have_loaded.waitFor ->
-    new window.InstructorDashboard.sections.StudentAdmin idash_content.find ".#{CSS_IDASH_SECTION}#student_admin"
-  plantTimeout 0, sections_have_loaded.waitFor ->
-    new window.InstructorDashboard.sections.Analytics    idash_content.find ".#{CSS_IDASH_SECTION}#analytics"
+  sections_to_initialize = [
+    constructor: window.InstructorDashboard.sections.CourseInfo
+    $element: idash_content.find ".#{CSS_IDASH_SECTION}#course_info"
+  ,
+    constructor: window.InstructorDashboard.sections.DataDownload
+    $element: idash_content.find ".#{CSS_IDASH_SECTION}#data_download"
+  ,
+    constructor: window.InstructorDashboard.sections.Membership
+    $element: idash_content.find ".#{CSS_IDASH_SECTION}#membership"
+  ,
+    constructor: window.InstructorDashboard.sections.StudentAdmin
+    $element: idash_content.find ".#{CSS_IDASH_SECTION}#student_admin"
+  ,
+    constructor: window.InstructorDashboard.sections.Analytics
+    $element: idash_content.find ".#{CSS_IDASH_SECTION}#analytics"
+  ]
+
+  sections_to_initialize.map ({constructor, $element}) ->
+    # See fault isolation NOTE at top of file.
+    # If an error is thrown in one section, it will not stop other sections from exectuing.
+    plantTimeout 0, sections_have_loaded.waitFor ->
+      new constructor $element

lms/static/coffee/src/instructor_dashboard/student_admin.coffee

@@ -6,6 +6,8 @@
 plantTimeout = -> window.InstructorDashboard.util.plantTimeout.apply this, arguments
 plantInterval = -> window.InstructorDashboard.util.plantInterval.apply this, arguments
 std_ajax_err = -> window.InstructorDashboard.util.std_ajax_err.apply this, arguments
+load_IntervalManager = -> window.InstructorDashboard.util.IntervalManager
+
 
 # wrap window.confirm
 # display `msg`
@@ -102,8 +104,13 @@ class StudentAdmin
     @$request_response_error_all    = @$section.find ".course-specific-container .request-response-error"
 
     # start polling for task list
+    # if the list is in the DOM
     if @$table_running_tasks.length > 0
-      @start_refresh_running_task_poll_loop()
+      # reload every 20 seconds.
+      TASK_LIST_POLL_INTERVAL = 20000
+      @reload_running_tasks_list()
+      @task_poller = new (load_IntervalManager()) TASK_LIST_POLL_INTERVAL, =>
+        @reload_running_tasks_list()
 
     # attach click handlers
 
@@ -255,7 +262,6 @@ class StudentAdmin
           create_task_list_table @$table_task_history_all, data.tasks
         error: std_ajax_err => @$request_response_error_all.text "Error listing task history for this student and problem."
 
-
   reload_running_tasks_list: =>
     list_endpoint = @$table_running_tasks.data 'endpoint'
     $.ajax
@@ -264,12 +270,6 @@ class StudentAdmin
       success: (data) => create_task_list_table @$table_running_tasks, data.tasks
       error: std_ajax_err => console.warn "error listing all instructor tasks"
 
-  start_refresh_running_task_poll_loop: ->
-    @reload_running_tasks_list()
-    if @$section.hasClass 'active-section'
-      # poll every 20 seconds
-      plantTimeout 20000, => @start_refresh_running_task_poll_loop()
-
   # wraps a function, but first clear the error displays
   clear_errors_then: (cb) ->
     @$request_response_error_single.empty()
@@ -278,14 +278,10 @@ class StudentAdmin
       cb?.apply this, arguments
 
   # handler for when the section title is clicked.
-  onClickTitle: ->
-    if @$table_running_tasks.length > 0
-      @start_refresh_running_task_poll_loop()
+  onClickTitle: -> @task_poller?.start()
 
   # handler for when the section is closed
-  # not working yet.
-  # onExit: ->
-  #   clearInterval @reload_running_task_list_slot
+  onExit: -> @task_poller?.stop()
 
 
 # export for use

lms/static/coffee/src/instructor_dashboard/util.coffee

@@ -5,6 +5,7 @@
 plantTimeout = (ms, cb) -> setTimeout cb, ms
 plantInterval = (ms, cb) -> setInterval cb, ms
 
+
 # standard ajax error wrapper
 #
 # wraps a `handler` function so that first
@@ -16,6 +17,26 @@ std_ajax_err = (handler) -> (jqXHR, textStatus, errorThrown) ->
   handler.apply this, arguments
 
 
+# Helper class for managing the execution of interval tasks.
+# Handles pausing and restarting.
+class IntervalManager
+  # Create a manager which will call `fn`
+  # after a call to .start every `ms` milliseconds.
+  constructor: (@ms, @fn) ->
+    @intervalID = null
+
+  # Start or restart firing every `ms` milliseconds.
+  # Soes not fire immediately.
+  start: ->
+    if @intervalID is null
+      @intervalID = setInterval @fn, @ms
+
+  # Pause firing.
+  stop: ->
+    clearInterval @intervalID
+    @intervalID = null
+
+
 # export for use
 # create parent namespaces if they do not already exist.
 # abort if underscore can not be found.
@@ -25,3 +46,4 @@ if _?
     plantTimeout: plantTimeout
     plantInterval: plantInterval
     std_ajax_err: std_ajax_err
+    IntervalManager: IntervalManager