[英]How do I filter nested array of objects on multiple conditions?
下面是對象的示例數組。 我希望根據criteriaType
, id
和source
過濾這個。 如果input.source
匹配,則應過濾掉父對象。 此外,所有過濾條件都是可選的。
[{
"id": "9be6c6299cca48f597fe71bc99c37b2f",
"caption": "caption1",
"criteriaType": "type2",
"input": [
{
"id_1": "66be4486ffd3431eb60e6ea6326158fe",
"criteriaId": "9be6c6299cca48f597fe71bc99c37b2f",
"source": "type1",
},
{
"id_1": "1ecdf410b3314865be2b52ca9b4c8539",
"criteriaId": "9be6c6299cca48f597fe71bc99c37b2f",
"source": "type2",
}
]
},
{
"id": "b83b3f081a7b45e087183740b12faf3a",
"caption": "caption1",
"criteriaType": "type1",
"input": [
{
"id_1": "f46da7ffa859425e922bdbb701cfcf88",
"criteriaId": "b83b3f081a7b45e087183740b12faf3a",
"source": "type3",
},
{
"id_1": "abb87219db254d108a1e0f774f88dfb6",
"criteriaId": "b83b3f081a7b45e087183740b12faf3a",
"source": "type1",
}
]
},
{
"id": "fe5b071a2d8a4a9da61bbd81b9271e31",
"caption": "caption1",
"criteriaType": "type1",
"input": [
{
"id_1": "7ea1b85e4dbc44e8b37d1110b565a081",
"criteriaId": "fe5b071a2d8a4a9da61bbd81b9271e31",
"source": "type3",
},
{
"id_1": "c5f943b61f674265b8237bb560cbed03",
"criteriaId": "fe5b071a2d8a4a9da61bbd81b9271e31",
"source": "type3",
}
]
}]
我只能通過criteriaType
& id
實現過濾。 但是我也無法按source
過濾以確保在沒有input.source匹配的情況下不返回父級。
var json = <<array of objects>> ;
const {objectId: id, ctype: criteriaType, inputSource: source } = param; // getting the the params
json = ctype ? json.filter(({criteriaType}) => criteriaType === ctype ): json;
json = (objectId ? json.filter(({id}) => id === objectId ): json)
.map (({id, caption, criteriaType, input }) => {
//some manipulation
return { //results after manipulation}
})
幫幫我! 提前致謝。 我不確定我們是否可以鏈接過濾器來實現它。
尋找與esLint兼容的代碼
有幾種方法可以解決這個問題。 你可以在純JS中實現這個,我推薦Lodash :
1)Lodash 過濾器
``` javascript
var users = [
{ 'user': 'barney', 'age': 36, 'active': true },
{ 'user': 'fred', 'age': 40, 'active': false }
];
_.filter(users, function(o) { return !o.active; });
// => objects for ['fred']
// The `_.matches` iteratee shorthand.
_.filter(users, { 'age': 36, 'active': true });
// => objects for ['barney']
// The `_.matchesProperty` iteratee shorthand.
_.filter(users, ['active', false]);
// => objects for ['fred']
// The `_.property` iteratee shorthand.
_.filter(users, 'active');
// => objects for ['barney']
```
2)JavaScript ES5 過濾器()
``` javascript
var words = ['spray', 'limit', 'elite', 'exuberant', 'destruction', 'present'];
var result = words
.filter(word => word.length > 6)
.filter(word => word.length < 8);
console.log(result);
// expected output: Array ["present"]
```
2) MapReduce
MapReduce是我最喜歡使用集合/集合的工具之一。
您在上面的代碼中使用了map()
。 訣竅可能是將map
更改為reduce
。
使用map
,您可以獲得1-1的收集項目比例。
使用reduce
,您可以為輸入中的每個項目生成任意數量的項目。 例如
``` javascript
var stuff = ['couch', 'chair', 'desk'];
var hasFiveLetters = stuff.reduce((total, item) => {
if (item.length === 5) total.push(item); // add to total any items you like
return total; // don't forget to return total!
}, []); // initialize total to []
console.log(hasFiveLetters); // ['couch', 'chair'];
```
要求是過濾器是可選的,並且不會返回任何源匹配的父項https://jsfiddle.net/cpk18dt4/9/
評論在代碼中。 希望它能解釋這個功能的作用。
const fnFilter = (criteriaType, id, source) => {
let result = oData;
if (criteriaType) { // it can be null (optional)
result = result.filter(d => d.criteriaType === criteriaType);
}
if (id) { // it can be null (optional)
result = result.filter(d => d.id === id);
}
if (source) { // it can be null (optional)
result = result.filter(d => {
const inputs = d.input.filter(inp => inp.source === source);
// If none of the input.source match, the parent object should be filtered out
if (inputs.length === 0) {
return false;
}
d.input = inputs;
return true;
});
}
return result;
};
可以使用Lodash查找和過濾器。 與需要匹配的第一次匹配的Filter相比,在嵌套數組中查找會更快。
json = ctype ? _.filter(json, function(o) {
return o.criteriaType === ctype;
}) || json;
json = objectId ? _.filter(json, function(o) {
return o.id === objectId;
}) || json;
json = source ? _.filter(json, function(o) {
return _.find(o.input, function(input_object) {
return input_object.source === source;
});
}) || json;
嘗試這個:
var obj = [{ "id": "9be6c6299cca48f597fe71bc99c37b2f", "caption": "caption1", "criteriaType": "type2", "input": [ { "id_1": "66be4486ffd3431eb60e6ea6326158fe", "criteriaId": "9be6c6299cca48f597fe71bc99c37b2f", "source": "type1", }, { "id_1": "1ecdf410b3314865be2b52ca9b4c8539", "criteriaId": "9be6c6299cca48f597fe71bc99c37b2f", "source": "type2", } ] }, { "id": "b83b3f081a7b45e087183740b12faf3a", "caption": "caption1", "criteriaType": "type1", "input": [ { "id_1": "f46da7ffa859425e922bdbb701cfcf88", "criteriaId": "b83b3f081a7b45e087183740b12faf3a", "source": "type3", }, { "id_1": "abb87219db254d108a1e0f774f88dfb6", "criteriaId": "b83b3f081a7b45e087183740b12faf3a", "source": "type1", } ] }, { "id": "fe5b071a2d8a4a9da61bbd81b9271e31", "caption": "caption1", "criteriaType": "type1", "input": [ { "id_1": "7ea1b85e4dbc44e8b37d1110b565a081", "criteriaId": "fe5b071a2d8a4a9da61bbd81b9271e31", "source": "type3", }, { "id_1": "c5f943b61f674265b8237bb560cbed03", "criteriaId": "fe5b071a2d8a4a9da61bbd81b9271e31", "source": "type3", } ] }]; function filterObj(obj, column, value){ var newArray = obj.filter(function (el) { if(el[column]){ return el[column] == value; }else{ for(var key in el.input){ if(typeof(el.input[key] == "object")){ var item = el.input[key]; if(item[column] == value){return item;} } } } }); return newArray; } console.log(filterObj(obj, 'caption','caption1')); console.log(filterObj(obj, 'criteriaId','fe5b071a2d8a4a9da61bbd81b9271e31')); console.log(filterObj(obj, 'id_1','1ecdf410b3314865be2b52ca9b4c8539'));
// if field has a value, filter on it, else return original json
const having = (json, field, val) =>
val ? json.filter(j => j[field] === val) : json
const filterBySource = (json, source) => {
if (!source) return json
return json.filter(
j => j.input.length > 0 && j.input.some(input => input.source === source)
)
}
function search(json, params = {}) {
const { objectId: id, ctype: criteriaType, inputSource: source } = params
// if no filters, return the whole json
if (!(id || criteriaType || source)) return json
let result
result = having(json, 'id', id)
result = having(result, 'criteriaType', criteriaType)
return filterBySource(result, source)
}
const params = {
objectId: 'fe5b071a2d8a4a9da61bbd81b9271e31',
ctype: 'type1',
inputSource: 'type3'
}
search(json, params).map(({ id, caption, criteriaType, input }) => {
// do something with filtered json
})
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