在集合中使用模糊匹配查找对象

Question

我有一个类似于这样的集合：

const collection = [
    {
        name: 'THIS_ITEM',
        conditions: {
            oneCondition: false,
            anotherCondition: false,
            yourCondition: false,
            myCondition: false
        }
    }, {
        name: 'THAT_ITEM',
        conditions: {
            oneCondition: false,
            anotherCondition: false,
            yourCondition: true,
            myCondition: false
        }
    }, {
        name: 'THOSE_ITEMS',
        conditions: {
            oneCondition: true,
            anotherCondition: false,
            yourCondition: null,
            myCondition: false
        }
    }
];

...然后是一个长这样的对象：

const condition = {
    oneCondition: true,
    anotherCondition: false,
    yourCondition: true,
    myCondition: false
};

我正在尝试将“condition”对象与“collection”中的嵌套“conditions”对象进行匹配，以找到匹配项，从而检索匹配条目中的“name”属性。

让我感到困惑的是，“conditions”属性可以具有“模糊”值。我的意思是，如果源“collection”中的任何属性设置为“true”或“false”，则它们必须与“condition”中的值完全匹配。但是，如果源“collection”中的属性具有“null”值，则可以匹配“true”或“false”中的任何一个。

例如：

以下内容将匹配：

const condition = {
    oneCondition: true,
    anotherCondition: false,
    yourCondition: true,
    myCondition: false
};

const collection = [
    …
    }, {
        name: 'THOSE_ITEMS',
        conditions: {
            oneCondition: true,
            anotherCondition: false,
            yourCondition: null,
            myCondition: false
        }
    }
];

这些不会：

const condition = {
    oneCondition: true,
    anotherCondition: false,
    yourCondition: true,
    myCondition: false
};

const collection = [
    …
    }, {
        name: 'THAT_ITEM',
        conditions: {
            oneCondition: false,
            anotherCondition: false,
            yourCondition: true,
            myCondition: false
        }
    }, {
    …
];

有什么建议吗？我在使用Lodash，但似乎无法想象出不含有冗长和嵌套的解决方案。

- Brandon Durham

Answer 1

你可以使用 Array#filter 和 Array#every 来设置条件，并通过测试 null 值作为通配符。

var collection = [{ name: 'THIS_ITEM', conditions: { oneCondition: false, anotherCondition: false, yourCondition: false, myCondition: false } }, { name: 'THAT_ITEM', conditions: { oneCondition: false, anotherCondition: false, yourCondition: true, myCondition: false } }, { name: 'THOSE_ITEMS', conditions: { oneCondition: true, anotherCondition: false, yourCondition: null, myCondition: false } }],
    condition = { oneCondition: true, anotherCondition: false, yourCondition: true, myCondition: false },
    result = collection.filter(o =>
        Object.keys(condition).every(k =>
            o.conditions[k] === null || o.conditions[k] === condition[k]
        )
    );

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

- Nina Scholz

Answer 2

你可以使用 lodash#filter，配合 lodash#isMatch 和 lodash#omitBy，匹配一个不包含任何 null 值的集合对象的条件。

const result = _.filter(collection, v => 
  _.isMatch(condition, _.omitBy(v.conditions, _.isNull))
);

const collection = [
    {
        name: 'THIS_ITEM',
        conditions: {
            oneCondition: false,
            anotherCondition: false,
            yourCondition: false,
            myCondition: false
        }
    }, {
        name: 'THAT_ITEM',
        conditions: {
            oneCondition: false,
            anotherCondition: false,
            yourCondition: true,
            myCondition: false
        }
    }, {
        name: 'THOSE_ITEMS',
        conditions: {
            oneCondition: true,
            anotherCondition: false,
            yourCondition: null,
            myCondition: false
        }
    }
];

const condition = {
    oneCondition: true,
    anotherCondition: false,
    yourCondition: true,
    myCondition: false
};

const result = _.filter(collection, v => 
  _.isMatch(condition, _.omitBy(v.conditions, _.isNull))
);


console.log(result);

body > div { min-height: 100%; top: 0; }

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.js"></script>

- ryeballar

Answer 3

您可以使用lodash的_.isMatchWith()函数来过滤收集数据：

const condition = {"oneCondition":true,"anotherCondition":false,"yourCondition":true,"myCondition":false};
const collection = [{"name":"1","conditions":{"oneCondition":true,"anotherCondition":false,"yourCondition":true,"myCondition":false}},{"name":"2","conditions":{"oneCondition":true,"anotherCondition":false,"yourCondition":false,"myCondition":false}},{"name":"3","conditions":{"oneCondition":true,"anotherCondition":false,"yourCondition":null,"myCondition":false}}];

const result = collection.filter(({ conditions }) => 
  _.isMatchWith(condition, conditions, (objValue, othValue) => 
    objValue === null || othValue === null || objValue === othValue) // if at least one of the values is null or they are equal
);

console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

- Ori Drori

Answer 4

您可以使用lodash的组合.filter(), .every()和.isEqual()方法来循环遍历collection并仅过滤与您的对象具有相同条件的项目：

_.filter(collection, function(c) {
  return _.every(_.keys(condition), function(currentKey) {
    return c.conditions[currentKey] === null ||
      _.isEqual(c.conditions[currentKey], condition[currentKey]);
  });
});

演示：

const collection = [{
  name: 'THIS_ITEM',
  conditions: {
    oneCondition: false,
    anotherCondition: false,
    yourCondition: false,
    myCondition: false
  }
}, {
  name: 'THAT_ITEM',
  conditions: {
    oneCondition: false,
    anotherCondition: false,
    yourCondition: true,
    myCondition: false
  }
}, {
  name: 'THOSE_ITEMS',
  conditions: {
    oneCondition: true,
    anotherCondition: false,
    yourCondition: null,
    myCondition: false
  }
}];

const condition = {
  oneCondition: true,
  anotherCondition: false,
  yourCondition: true,
  myCondition: false
};




var result = _.filter(collection, function(c) {
  return _.every(_.keys(condition), function(currentKey) {
    return c.conditions[currentKey] === null ||
      _.isEqual(c.conditions[currentKey], condition[currentKey]);
  });
});

console.log(result);

.as-console-wrapper {
  max-height: 100% !important;
  top: 0;
}

<script src="http://underscorejs.org/underscore-min.js"></script>

- cнŝdk