old_contents: var mongoose = require('mongoose')
      , Schema = mongoose.Schema;
  
  //Schema for data that has been manipulated by students 
              //(output from client)
  
  var Assignment = new Schema ({
  
      //For tracking submissions and route creation
      email:              { type: String, default: ''},
      assignmentNumber:   {type: String, default: ''},
      dateCreated:        {type: String, default: ''},
      shared:             {type: Boolean, default: 'false'},//public or private
      
      //uploaded data, nodes can be x,y as in scatteplots
      //links can be any association 
      nodes: [Schema.Types.Mixed],
      links: [{ 
          to:     {type: String, default: ''},
          from:   {type: String, default: ''},
          value:  {type: String, default: ''}
      }]
      //add a before and after so that student can see changes
  })
  
  mongoose.model('Assignment', Assignment);
  
new_contents: var mongoose = require('mongoose')
      , Schema = mongoose.Schema;
  
  //Schema for data that has been manipulated by students 
              //(output from client)
  
  var Assignment = new Schema ({
  
      //For tracking submissions and route creation
      email:          { type: String, default: ''},
      assignmentID:   {type: String, default: ''},
      dateCreated:    {type: Date, default: Date.now()},
      shared:         {type: Boolean, default: 'false'},//public or private
      
      //uploaded data, nodes can be x,y as in scatteplots
      //links can be any association 
      nodes: [Schema.Types.Mixed],
      links: [{ 
          to:     {type: String, default: ''},
          from:   {type: String, default: ''},
          value:  {type: String, default: ''}
      }]
      //add a before and after so that student can see changes
  })
  
  mongoose.model('Assignment', Assignment);
  
subject: set date as default and cleanup