View source for E1826 Add student view for instructor

== Introduction ==
=== Background ===

The navigation for an instructor follows the below structure.
* Home
* Manage...
** Users
** Questionnaires
** Courses
** ''Assignments''
** Impersonate User
** Anonymized View
* Survey Deployments
* ''Assignments''
* Course Evaluation
* Profile
* Contact Us

And that for a student follows the below structure.
* Home
* Assignments
* Pending Surveys
* Profile
* Contact Us

For an instructor, the menu item 'Assignments' is present in 2 places - in the main menu as 'Assignments' and in the sub-menu as 'Manage.../Assignments' (''italicized'' above). This could potentially be confusing. 'Manage.../Assignments' sub-menu item allows the instructor to create/edit assignments. The menu item 'Assignments' allows an instructor to participate in assignments. This is typically something that the instructor wants to do in a student role and hence there needs to be a '''student view''' for instructors to act as students without impersonating them and thus reducing confusion. The same needs to be implemented for admin and super admin as well.

=== Problem statement ===
Create a '''student view''' for instructors so that they can perform student operations without impersonating them. When an instructor logs in, he/she is in the default view with corresponding menu items (with the exception of the 'Assignments' menu item). There should be an option to switch to and revert back from the student view. When in student view, an instructor is presented with the student menu as listed above.

== Implementation ==
=== expertiza/app/views/shared/_navigation.html.erb ===
This file is shared between all views and is responsible for rendering all the elements in the top-most part of the web page. (i.e Displaying the menu items, the logout button etc.)

In order to switch between '''instructor view''' and '''student view''', the following code was added. When the user is in '''instructor view''', there is a link named "Switch to Student View" to switch to '''student view''' and when the user is in '''student view''', 'here is a link named "Revert to Instructor View" to switch back to the '''instructor view'''.
 <% if session[:user].role.instructor? %>
                  <% if session.key?(:student_view) %>
                      <%= link_to "Revert to Instructor View", {controller: "instructor", action: "revert_to_instructor_view"},
                                  method: :post, :style => "color: white" %>
                  <% else %>
                      <%= link_to "Switch to Student View", {controller: "instructor", action: "set_student_view"},
                                  method: :post, :style => "color: white" %>
                  <% end %>
              <% end %>

=== expertiza/app/controllers/instructor_controller.rb ===

A new instructor_controller.rb file has been added. This controller currently contains the actions to switch to student view and revert back to instructor view.
<pre>
class InstructorController < ApplicationController
  # check to see if the current action is allowed
  def action_allowed?
    # only an instructor is allowed to perform all the actions in
    # this controller
    return true if session[:user].role.instructor?
  end

  # sets student_view in session object and redirects to
  # student_task/list after updating hidden_menu_items
  def set_student_view
    session[:student_view] = true
    MenuItemsHelper.update_hidden_menu_items_for_student_view(session)
    redirect_to controller: 'student_task', action: 'list'
  end

  # destroys student_view in session object and redirects to
  # tree_display/list after updating hidden_menu_items
  def revert_to_instructor_view
    session.delete(:student_view)
    MenuItemsHelper.update_hidden_menu_items_for_instructor_view(session)
    redirect_to controller: 'tree_display', action: 'list'
  end
end
</pre>

=== expertiza/config/routes.rb ===

New post methods are added in ''config/routes.rb''. The routes are directed to the instructor controller's ''set_student_view'' and ''revert_to_instructor_view'' actions.

<pre>
  resources :instructor, only: [] do
    collection do
      post  :set_student_view
      post  :revert_to_instructor_view
    end
  end

</pre>

== Manual UI Testing ==

The user needs to log-in as an instructor to view this functionality.

1. Login as an instructor. Enter 'instructor6' as username and 'password' as password.

2. Click on '''Open Student View''' below username to switch to student view.


[[File:default_view.png]]


3. Click on '''Close Student View''' below username to come back to default view.


[[File:student_view.png]]

== Automated Test Plan ==
1. '''Check whether ''Assignments'' and ''Course Evaluation'' are hidden when in instructor view.'''  
This test case is to check if the menu items ''Assignments'' and ''Course Evaluation'' are hidden when an instructor is in instructor view. The following lines can be added to a spec/features file:

<pre>
it " can display relevant menu items after login as an admin/instructor/TA", js: true do
    create(:instructor)
    login_as 'instructor6'
    visit '/tree_display/list'
    expect(page).to have_current_path('/tree_display/list')
    expect(page).to have_content('Manage content')
    expect(page).to have_content('Survey Deployments')
    expect(page).not_to have_content('Assignments')
    expect(page).not_to have_content('Course Evaluation')
end
</pre>

2. '''Check whether ''Manage content'' and ''Survey Deployments'' are hidden in student view.'''
This test case is to check if the menu items ''Manage content'' and ''Survey Deployments'' are hidden when the instructor switches to student view. The following lines are to be added:

<pre>
it "can display relevant menu items when switching to student view", js: true do
    create(:instructor)
    login_as 'instructor6'
    visit '/tree_display/list'
    click_link 'Swtich to Student View'
    expect(page).to have_current_path('/student_task/list')
    expect(page).to have_content('Assignments')
    expect(page).to have_content('Course Evaluation')
    expect(page).not_to have_content('Manage content')
    expect(page).not_to have_content('Survey Deployments')
end
</pre>

== External Links ==
# Link to forked repository [[https://github.com/akshayravichandran/expertiza]]
# Link to screen cast [[https://youtu.be/lRZT4q7YDLA]]

==References==

Expertiza
* https://expertiza.ncsu.edu/ 

Expertiza Github
* https://github.com/expertiza/expertiza

Expertiza Documentation
* http://wiki.expertiza.ncsu.edu/index.php/Expertiza_documentation

RSpec Documentation
* http://rspec.info/documentation/