text: var mongoose = require('mongoose'),
      Schema = mongoose.Schema;
  var ArticleSchema = new Schema({
      title: {
          type: String,
          default: '',
          trim: true,
          required: '请输入文章标题'
      },
      content: {
          type: String,
          default: '',
          trim: true,
          required: '请输入文章内容'
      },
      category:{
          type: String,
          trim: true,
          default: ''
      },
      isGood:{
          type: Boolean,
          default: false
      },
      author:{
          type: String,
          default: '',
          trim: true
      },
      source:{
          type: String,
          default: '',
          trim: true
      },
      creator: {
          type: Schema.ObjectId,
          ref: 'User'
      },
      created: {
          type: Date,
          default: Date.now
      }
  });
  mongoose.model('Article', ArticleSchema);