不能从sails.js填充的对象中删除数组

Question

不能更改delete或library对象的books属性值。

Library.findOne(12).populate('books').populate('createdBy').exec(
    function(err,library) {
        delete library.createdBy;
        //worked
        delete library.name;
        //worked
        delete library.books;
        //no effect
        library.books = [];
        //worked
        library.books = [{a:'any val'}];
        //just like library.books=[]
        console.log(library);
    });

我的library for books和createdBy的模型是这样的

createdBy: {
    model: "createdBy"
},
books: {
    collection: "books",
    via: "library",
    dominant: true
}

我不知道这里发生了什么。

Answer 1

delete library.books;不起作用，因为关联不是模型对象中的字段。关联实际上存在于associations对象中，读/写操作通过自定义getter/setter完成。你可以在waterline/model/lib/internalMethods/defineasassociations .js#L109:

中看到更多关于此行为的信息。

Define.prototype.buildHasManyProperty = function(collection) {
  var self = this;
  // Attach to a non-enumerable property
  this.proto.associations[collection] = new Association();
  // Attach getter and setter to the model
  Object.defineProperty(this.proto, collection, {
    set: function(val) { self.proto.associations[collection]._setValue(val); },
    get: function() { return self.proto.associations[collection]._getValue(); },
    enumerable: true,
    configurable: true
  });
};

希望对你有帮助。

这会引起问题吗?这可以通过一开始就不填充关联来避免。执行model.toObject()或model.toJSON()，然后删除关联字段也应该工作。