在 node/express 中解析布尔查询字符串参数的正确方法

Question

I'm waiting for something like the following from the front end

....?isUpdated=true

so I did something like this in code (as I'm processing only isUpdated=true , false need to be ignored)

var isUpdated = (req.query.isUpdated === 'true')

but it seems bit odd to me.

How to do this in proper way? I mean to parse a Boolean parameter from the query string.

Answer 1

Docs if you are using query-string

const queryString = require('query-string');

queryString.parse('foo=true', {parseBooleans: true});
//=> {foo: true}

Answer 2

我使用这对线：

let test = (value).toString().trim().toLowerCase(); let result = !((test === 'false') || (test === '0') || (test === ''));

Answer 3

Here is my generic solution for getting a query params as a boolean:

const isTrue = Boolean((req.query.myParam || "").replace(/\s*(false|null|undefined|0)\s*/i, ""))

It converts the query param into a string which is then cleaned by suppressing any falsy string. Any resulting non-empty string will be true .

Answer 4

You can use qs package

A little code to parse int and booleans

qs.parse(request.querystring, {
      decoder(str, decoder, charset) {
            const strWithoutPlus = str.replace(/\+/g, ' ');
            if (charset === 'iso-8859-1') {
              // unescape never throws, no try...catch needed:
              return strWithoutPlus.replace(/%[0-9a-f]{2}/gi, unescape);
            }

            if (/^(\d+|\d*\.\d+)$/.test(str)) {
              return parseFloat(str)
            }

            const keywords = {
              true: true,
              false: false,
              null: null,
              undefined,
            }
            if (str in keywords) {
              return keywords[str]
            }

            // utf-8
            try {
              return decodeURIComponent(strWithoutPlus);
            } catch (e) {
              return strWithoutPlus;
            }
          }
})

Answer 5

The only thing I would change about your approach is to make it case insensitive:

var isUpdated = ((req.query.isUpdated+'').toLowerCase() === 'true')

You could make this a utility function as well if you like:

function queryParamToBool(value) {
  return ((value+'').toLowerCase() === 'true')
}
var isUpdated = queryParamToBool(req.query.isUpdated)

Answer 6

var myBoolean = (req.query.myParam === undefined || req.query.myParam.toLowerCase() === 'false' ? false : true)

Answer 7

With some ideas from previous answers, I ended up using this function to consider undefined values as well

const parseBool = (params) => {
 return !(
   params === "false" ||
   params === "0" ||
   params === "" ||
   params === undefined
 );
};