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<img alt="qs" src="./logos/banner_default.png" width="800" /> | |
</p> | |
# qs <sup>[![Version Badge][npm-version-svg]][package-url]</sup> | |
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[![coverage][codecov-image]][codecov-url] | |
[![License][license-image]][license-url] | |
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[](https://bestpractices.coreinfrastructure.org/projects/9058) | |
[![npm badge][npm-badge-png]][package-url] | |
A querystring parsing and stringifying library with some added security. | |
Lead Maintainer: [Jordan Harband](https://github.com/ljharb) | |
The **qs** module was originally created and maintained by [TJ Holowaychuk](https://github.com/visionmedia/node-querystring). | |
## Usage | |
```javascript | |
var qs = require('qs'); | |
var assert = require('assert'); | |
var obj = qs.parse('a=c'); | |
assert.deepEqual(obj, { a: 'c' }); | |
var str = qs.stringify(obj); | |
assert.equal(str, 'a=c'); | |
``` | |
### Parsing Objects | |
[](#preventEval) | |
```javascript | |
qs.parse(string, [options]); | |
``` | |
**qs** allows you to create nested objects within your query strings, by surrounding the name of sub-keys with square brackets `[]`. | |
For example, the string `'foo[bar]=baz'` converts to: | |
```javascript | |
assert.deepEqual(qs.parse('foo[bar]=baz'), { | |
foo: { | |
bar: 'baz' | |
} | |
}); | |
``` | |
When using the `plainObjects` option the parsed value is returned as a null object, created via `{ __proto__: null }` and as such you should be aware that prototype methods will not exist on it and a user may set those names to whatever value they like: | |
```javascript | |
var nullObject = qs.parse('a[hasOwnProperty]=b', { plainObjects: true }); | |
assert.deepEqual(nullObject, { a: { hasOwnProperty: 'b' } }); | |
``` | |
By default parameters that would overwrite properties on the object prototype are ignored, if you wish to keep the data from those fields either use `plainObjects` as mentioned above, or set `allowPrototypes` to `true` which will allow user input to overwrite those properties. | |
*WARNING* It is generally a bad idea to enable this option as it can cause problems when attempting to use the properties that have been overwritten. | |
Always be careful with this option. | |
```javascript | |
var protoObject = qs.parse('a[hasOwnProperty]=b', { allowPrototypes: true }); | |
assert.deepEqual(protoObject, { a: { hasOwnProperty: 'b' } }); | |
``` | |
URI encoded strings work too: | |
```javascript | |
assert.deepEqual(qs.parse('a%5Bb%5D=c'), { | |
a: { b: 'c' } | |
}); | |
``` | |
You can also nest your objects, like `'foo[bar][baz]=foobarbaz'`: | |
```javascript | |
assert.deepEqual(qs.parse('foo[bar][baz]=foobarbaz'), { | |
foo: { | |
bar: { | |
baz: 'foobarbaz' | |
} | |
} | |
}); | |
``` | |
By default, when nesting objects **qs** will only parse up to 5 children deep. | |
This means if you attempt to parse a string like `'a[b][c][d][e][f][g][h][i]=j'` your resulting object will be: | |
```javascript | |
var expected = { | |
a: { | |
b: { | |
c: { | |
d: { | |
e: { | |
f: { | |
'[g][h][i]': 'j' | |
} | |
} | |
} | |
} | |
} | |
} | |
}; | |
var string = 'a[b][c][d][e][f][g][h][i]=j'; | |
assert.deepEqual(qs.parse(string), expected); | |
``` | |
This depth can be overridden by passing a `depth` option to `qs.parse(string, [options])`: | |
```javascript | |
var deep = qs.parse('a[b][c][d][e][f][g][h][i]=j', { depth: 1 }); | |
assert.deepEqual(deep, { a: { b: { '[c][d][e][f][g][h][i]': 'j' } } }); | |
``` | |
You can configure **qs** to throw an error when parsing nested input beyond this depth using the `strictDepth` option (defaulted to false): | |
```javascript | |
try { | |
qs.parse('a[b][c][d][e][f][g][h][i]=j', { depth: 1, strictDepth: true }); | |
} catch (err) { | |
assert(err instanceof RangeError); | |
assert.strictEqual(err.message, 'Input depth exceeded depth option of 1 and strictDepth is true'); | |
} | |
``` | |
The depth limit helps mitigate abuse when **qs** is used to parse user input, and it is recommended to keep it a reasonably small number. The strictDepth option adds a layer of protection by throwing an error when the limit is exceeded, allowing you to catch and handle such cases. | |
For similar reasons, by default **qs** will only parse up to 1000 parameters. This can be overridden by passing a `parameterLimit` option: | |
```javascript | |
var limited = qs.parse('a=b&c=d', { parameterLimit: 1 }); | |
assert.deepEqual(limited, { a: 'b' }); | |
``` | |
If you want an error to be thrown whenever the a limit is exceeded (eg, `parameterLimit`, `arrayLimit`), set the `throwOnLimitExceeded` option to `true`. This option will generate a descriptive error if the query string exceeds a configured limit. | |
```javascript | |
try { | |
qs.parse('a=1&b=2&c=3&d=4', { parameterLimit: 3, throwOnLimitExceeded: true }); | |
} catch (err) { | |
assert(err instanceof Error); | |
assert.strictEqual(err.message, 'Parameter limit exceeded. Only 3 parameters allowed.'); | |
} | |
``` | |
When `throwOnLimitExceeded` is set to `false` (default), **qs** will parse up to the specified `parameterLimit` and ignore the rest without throwing an error. | |
To bypass the leading question mark, use `ignoreQueryPrefix`: | |
```javascript | |
var prefixed = qs.parse('?a=b&c=d', { ignoreQueryPrefix: true }); | |
assert.deepEqual(prefixed, { a: 'b', c: 'd' }); | |
``` | |
An optional delimiter can also be passed: | |
```javascript | |
var delimited = qs.parse('a=b;c=d', { delimiter: ';' }); | |
assert.deepEqual(delimited, { a: 'b', c: 'd' }); | |
``` | |
Delimiters can be a regular expression too: | |
```javascript | |
var regexed = qs.parse('a=b;c=d,e=f', { delimiter: /[;,]/ }); | |
assert.deepEqual(regexed, { a: 'b', c: 'd', e: 'f' }); | |
``` | |
Option `allowDots` can be used to enable dot notation: | |
```javascript | |
var withDots = qs.parse('a.b=c', { allowDots: true }); | |
assert.deepEqual(withDots, { a: { b: 'c' } }); | |
``` | |
Option `decodeDotInKeys` can be used to decode dots in keys | |
Note: it implies `allowDots`, so `parse` will error if you set `decodeDotInKeys` to `true`, and `allowDots` to `false`. | |
```javascript | |
var withDots = qs.parse('name%252Eobj.first=John&name%252Eobj.last=Doe', { decodeDotInKeys: true }); | |
assert.deepEqual(withDots, { 'name.obj': { first: 'John', last: 'Doe' }}); | |
``` | |
Option `allowEmptyArrays` can be used to allowing empty array values in object | |
```javascript | |
var withEmptyArrays = qs.parse('foo[]&bar=baz', { allowEmptyArrays: true }); | |
assert.deepEqual(withEmptyArrays, { foo: [], bar: 'baz' }); | |
``` | |
Option `duplicates` can be used to change the behavior when duplicate keys are encountered | |
```javascript | |
assert.deepEqual(qs.parse('foo=bar&foo=baz'), { foo: ['bar', 'baz'] }); | |
assert.deepEqual(qs.parse('foo=bar&foo=baz', { duplicates: 'combine' }), { foo: ['bar', 'baz'] }); | |
assert.deepEqual(qs.parse('foo=bar&foo=baz', { duplicates: 'first' }), { foo: 'bar' }); | |
assert.deepEqual(qs.parse('foo=bar&foo=baz', { duplicates: 'last' }), { foo: 'baz' }); | |
``` | |
If you have to deal with legacy browsers or services, there's also support for decoding percent-encoded octets as iso-8859-1: | |
```javascript | |
var oldCharset = qs.parse('a=%A7', { charset: 'iso-8859-1' }); | |
assert.deepEqual(oldCharset, { a: '§' }); | |
``` | |
Some services add an initial `utf8=✓` value to forms so that old Internet Explorer versions are more likely to submit the form as utf-8. | |
Additionally, the server can check the value against wrong encodings of the checkmark character and detect that a query string or `application/x-www-form-urlencoded` body was *not* sent as utf-8, eg. if the form had an `accept-charset` parameter or the containing page had a different character set. | |
**qs** supports this mechanism via the `charsetSentinel` option. | |
If specified, the `utf8` parameter will be omitted from the returned object. | |
It will be used to switch to `iso-8859-1`/`utf-8` mode depending on how the checkmark is encoded. | |
**Important**: When you specify both the `charset` option and the `charsetSentinel` option, the `charset` will be overridden when the request contains a `utf8` parameter from which the actual charset can be deduced. | |
In that sense the `charset` will behave as the default charset rather than the authoritative charset. | |
```javascript | |
var detectedAsUtf8 = qs.parse('utf8=%E2%9C%93&a=%C3%B8', { | |
charset: 'iso-8859-1', | |
charsetSentinel: true | |
}); | |
assert.deepEqual(detectedAsUtf8, { a: 'ø' }); | |
// Browsers encode the checkmark as ✓ when submitting as iso-8859-1: | |
var detectedAsIso8859_1 = qs.parse('utf8=%26%2310003%3B&a=%F8', { | |
charset: 'utf-8', | |
charsetSentinel: true | |
}); | |
assert.deepEqual(detectedAsIso8859_1, { a: 'ø' }); | |
``` | |
If you want to decode the `&#...;` syntax to the actual character, you can specify the `interpretNumericEntities` option as well: | |
```javascript | |
var detectedAsIso8859_1 = qs.parse('a=%26%239786%3B', { | |
charset: 'iso-8859-1', | |
interpretNumericEntities: true | |
}); | |
assert.deepEqual(detectedAsIso8859_1, { a: '☺' }); | |
``` | |
It also works when the charset has been detected in `charsetSentinel` mode. | |
### Parsing Arrays | |
**qs** can also parse arrays using a similar `[]` notation: | |
```javascript | |
var withArray = qs.parse('a[]=b&a[]=c'); | |
assert.deepEqual(withArray, { a: ['b', 'c'] }); | |
``` | |
You may specify an index as well: | |
```javascript | |
var withIndexes = qs.parse('a[1]=c&a[0]=b'); | |
assert.deepEqual(withIndexes, { a: ['b', 'c'] }); | |
``` | |
Note that the only difference between an index in an array and a key in an object is that the value between the brackets must be a number to create an array. | |
When creating arrays with specific indices, **qs** will compact a sparse array to only the existing values preserving their order: | |
```javascript | |
var noSparse = qs.parse('a[1]=b&a[15]=c'); | |
assert.deepEqual(noSparse, { a: ['b', 'c'] }); | |
``` | |
You may also use `allowSparse` option to parse sparse arrays: | |
```javascript | |
var sparseArray = qs.parse('a[1]=2&a[3]=5', { allowSparse: true }); | |
assert.deepEqual(sparseArray, { a: [, '2', , '5'] }); | |
``` | |
Note that an empty string is also a value, and will be preserved: | |
```javascript | |
var withEmptyString = qs.parse('a[]=&a[]=b'); | |
assert.deepEqual(withEmptyString, { a: ['', 'b'] }); | |
var withIndexedEmptyString = qs.parse('a[0]=b&a[1]=&a[2]=c'); | |
assert.deepEqual(withIndexedEmptyString, { a: ['b', '', 'c'] }); | |
``` | |
**qs** will also limit specifying indices in an array to a maximum index of `20`. | |
Any array members with an index of greater than `20` will instead be converted to an object with the index as the key. | |
This is needed to handle cases when someone sent, for example, `a[999999999]` and it will take significant time to iterate over this huge array. | |
```javascript | |
var withMaxIndex = qs.parse('a[100]=b'); | |
assert.deepEqual(withMaxIndex, { a: { '100': 'b' } }); | |
``` | |
This limit can be overridden by passing an `arrayLimit` option: | |
```javascript | |
var withArrayLimit = qs.parse('a[1]=b', { arrayLimit: 0 }); | |
assert.deepEqual(withArrayLimit, { a: { '1': 'b' } }); | |
``` | |
If you want to throw an error whenever the array limit is exceeded, set the `throwOnLimitExceeded` option to `true`. This option will generate a descriptive error if the query string exceeds a configured limit. | |
```javascript | |
try { | |
qs.parse('a[1]=b', { arrayLimit: 0, throwOnLimitExceeded: true }); | |
} catch (err) { | |
assert(err instanceof Error); | |
assert.strictEqual(err.message, 'Array limit exceeded. Only 0 elements allowed in an array.'); | |
} | |
``` | |
When `throwOnLimitExceeded` is set to `false` (default), **qs** will parse up to the specified `arrayLimit` and if the limit is exceeded, the array will instead be converted to an object with the index as the key | |
To disable array parsing entirely, set `parseArrays` to `false`. | |
```javascript | |
var noParsingArrays = qs.parse('a[]=b', { parseArrays: false }); | |
assert.deepEqual(noParsingArrays, { a: { '0': 'b' } }); | |
``` | |
If you mix notations, **qs** will merge the two items into an object: | |
```javascript | |
var mixedNotation = qs.parse('a[0]=b&a[b]=c'); | |
assert.deepEqual(mixedNotation, { a: { '0': 'b', b: 'c' } }); | |
``` | |
You can also create arrays of objects: | |
```javascript | |
var arraysOfObjects = qs.parse('a[][b]=c'); | |
assert.deepEqual(arraysOfObjects, { a: [{ b: 'c' }] }); | |
``` | |
Some people use comma to join array, **qs** can parse it: | |
```javascript | |
var arraysOfObjects = qs.parse('a=b,c', { comma: true }) | |
assert.deepEqual(arraysOfObjects, { a: ['b', 'c'] }) | |
``` | |
(_this cannot convert nested objects, such as `a={b:1},{c:d}`_) | |
### Parsing primitive/scalar values (numbers, booleans, null, etc) | |
By default, all values are parsed as strings. | |
This behavior will not change and is explained in [issue #91](https://github.com/ljharb/qs/issues/91). | |
```javascript | |
var primitiveValues = qs.parse('a=15&b=true&c=null'); | |
assert.deepEqual(primitiveValues, { a: '15', b: 'true', c: 'null' }); | |
``` | |
If you wish to auto-convert values which look like numbers, booleans, and other values into their primitive counterparts, you can use the [query-types Express JS middleware](https://github.com/xpepermint/query-types) which will auto-convert all request query parameters. | |
### Stringifying | |
[](#preventEval) | |
```javascript | |
qs.stringify(object, [options]); | |
``` | |
When stringifying, **qs** by default URI encodes output. Objects are stringified as you would expect: | |
```javascript | |
assert.equal(qs.stringify({ a: 'b' }), 'a=b'); | |
assert.equal(qs.stringify({ a: { b: 'c' } }), 'a%5Bb%5D=c'); | |
``` | |
This encoding can be disabled by setting the `encode` option to `false`: | |
```javascript | |
var unencoded = qs.stringify({ a: { b: 'c' } }, { encode: false }); | |
assert.equal(unencoded, 'a[b]=c'); | |
``` | |
Encoding can be disabled for keys by setting the `encodeValuesOnly` option to `true`: | |
```javascript | |
var encodedValues = qs.stringify( | |
{ a: 'b', c: ['d', 'e=f'], f: [['g'], ['h']] }, | |
{ encodeValuesOnly: true } | |
); | |
assert.equal(encodedValues,'a=b&c[0]=d&c[1]=e%3Df&f[0][0]=g&f[1][0]=h'); | |
``` | |
This encoding can also be replaced by a custom encoding method set as `encoder` option: | |
```javascript | |
var encoded = qs.stringify({ a: { b: 'c' } }, { encoder: function (str) { | |
// Passed in values `a`, `b`, `c` | |
return // Return encoded string | |
}}) | |
``` | |
_(Note: the `encoder` option does not apply if `encode` is `false`)_ | |
Analogue to the `encoder` there is a `decoder` option for `parse` to override decoding of properties and values: | |
```javascript | |
var decoded = qs.parse('x=z', { decoder: function (str) { | |
// Passed in values `x`, `z` | |
return // Return decoded string | |
}}) | |
``` | |
You can encode keys and values using different logic by using the type argument provided to the encoder: | |
```javascript | |
var encoded = qs.stringify({ a: { b: 'c' } }, { encoder: function (str, defaultEncoder, charset, type) { | |
if (type === 'key') { | |
return // Encoded key | |
} else if (type === 'value') { | |
return // Encoded value | |
} | |
}}) | |
``` | |
The type argument is also provided to the decoder: | |
```javascript | |
var decoded = qs.parse('x=z', { decoder: function (str, defaultDecoder, charset, type) { | |
if (type === 'key') { | |
return // Decoded key | |
} else if (type === 'value') { | |
return // Decoded value | |
} | |
}}) | |
``` | |
Examples beyond this point will be shown as though the output is not URI encoded for clarity. | |
Please note that the return values in these cases *will* be URI encoded during real usage. | |
When arrays are stringified, they follow the `arrayFormat` option, which defaults to `indices`: | |
```javascript | |
qs.stringify({ a: ['b', 'c', 'd'] }); | |
// 'a[0]=b&a[1]=c&a[2]=d' | |
``` | |
You may override this by setting the `indices` option to `false`, or to be more explicit, the `arrayFormat` option to `repeat`: | |
```javascript | |
qs.stringify({ a: ['b', 'c', 'd'] }, { indices: false }); | |
// 'a=b&a=c&a=d' | |
``` | |
You may use the `arrayFormat` option to specify the format of the output array: | |
```javascript | |
qs.stringify({ a: ['b', 'c'] }, { arrayFormat: 'indices' }) | |
// 'a[0]=b&a[1]=c' | |
qs.stringify({ a: ['b', 'c'] }, { arrayFormat: 'brackets' }) | |
// 'a[]=b&a[]=c' | |
qs.stringify({ a: ['b', 'c'] }, { arrayFormat: 'repeat' }) | |
// 'a=b&a=c' | |
qs.stringify({ a: ['b', 'c'] }, { arrayFormat: 'comma' }) | |
// 'a=b,c' | |
``` | |
Note: when using `arrayFormat` set to `'comma'`, you can also pass the `commaRoundTrip` option set to `true` or `false`, to append `[]` on single-item arrays, so that they can round trip through a parse. | |
When objects are stringified, by default they use bracket notation: | |
```javascript | |
qs.stringify({ a: { b: { c: 'd', e: 'f' } } }); | |
// 'a[b][c]=d&a[b][e]=f' | |
``` | |
You may override this to use dot notation by setting the `allowDots` option to `true`: | |
```javascript | |
qs.stringify({ a: { b: { c: 'd', e: 'f' } } }, { allowDots: true }); | |
// 'a.b.c=d&a.b.e=f' | |
``` | |
You may encode the dot notation in the keys of object with option `encodeDotInKeys` by setting it to `true`: | |
Note: it implies `allowDots`, so `stringify` will error if you set `decodeDotInKeys` to `true`, and `allowDots` to `false`. | |
Caveat: when `encodeValuesOnly` is `true` as well as `encodeDotInKeys`, only dots in keys and nothing else will be encoded. | |
```javascript | |
qs.stringify({ "name.obj": { "first": "John", "last": "Doe" } }, { allowDots: true, encodeDotInKeys: true }) | |
// 'name%252Eobj.first=John&name%252Eobj.last=Doe' | |
``` | |
You may allow empty array values by setting the `allowEmptyArrays` option to `true`: | |
```javascript | |
qs.stringify({ foo: [], bar: 'baz' }, { allowEmptyArrays: true }); | |
// 'foo[]&bar=baz' | |
``` | |
Empty strings and null values will omit the value, but the equals sign (=) remains in place: | |
```javascript | |
assert.equal(qs.stringify({ a: '' }), 'a='); | |
``` | |
Key with no values (such as an empty object or array) will return nothing: | |
```javascript | |
assert.equal(qs.stringify({ a: [] }), ''); | |
assert.equal(qs.stringify({ a: {} }), ''); | |
assert.equal(qs.stringify({ a: [{}] }), ''); | |
assert.equal(qs.stringify({ a: { b: []} }), ''); | |
assert.equal(qs.stringify({ a: { b: {}} }), ''); | |
``` | |
Properties that are set to `undefined` will be omitted entirely: | |
```javascript | |
assert.equal(qs.stringify({ a: null, b: undefined }), 'a='); | |
``` | |
The query string may optionally be prepended with a question mark: | |
```javascript | |
assert.equal(qs.stringify({ a: 'b', c: 'd' }, { addQueryPrefix: true }), '?a=b&c=d'); | |
``` | |
The delimiter may be overridden with stringify as well: | |
```javascript | |
assert.equal(qs.stringify({ a: 'b', c: 'd' }, { delimiter: ';' }), 'a=b;c=d'); | |
``` | |
If you only want to override the serialization of `Date` objects, you can provide a `serializeDate` option: | |
```javascript | |
var date = new Date(7); | |
assert.equal(qs.stringify({ a: date }), 'a=1970-01-01T00:00:00.007Z'.replace(/:/g, '%3A')); | |
assert.equal( | |
qs.stringify({ a: date }, { serializeDate: function (d) { return d.getTime(); } }), | |
'a=7' | |
); | |
``` | |
You may use the `sort` option to affect the order of parameter keys: | |
```javascript | |
function alphabeticalSort(a, b) { | |
return a.localeCompare(b); | |
} | |
assert.equal(qs.stringify({ a: 'c', z: 'y', b : 'f' }, { sort: alphabeticalSort }), 'a=c&b=f&z=y'); | |
``` | |
Finally, you can use the `filter` option to restrict which keys will be included in the stringified output. | |
If you pass a function, it will be called for each key to obtain the replacement value. | |
Otherwise, if you pass an array, it will be used to select properties and array indices for stringification: | |
```javascript | |
function filterFunc(prefix, value) { | |
if (prefix == 'b') { | |
// Return an `undefined` value to omit a property. | |
return; | |
} | |
if (prefix == 'e[f]') { | |
return value.getTime(); | |
} | |
if (prefix == 'e[g][0]') { | |
return value * 2; | |
} | |
return value; | |
} | |
qs.stringify({ a: 'b', c: 'd', e: { f: new Date(123), g: [2] } }, { filter: filterFunc }); | |
// 'a=b&c=d&e[f]=123&e[g][0]=4' | |
qs.stringify({ a: 'b', c: 'd', e: 'f' }, { filter: ['a', 'e'] }); | |
// 'a=b&e=f' | |
qs.stringify({ a: ['b', 'c', 'd'], e: 'f' }, { filter: ['a', 0, 2] }); | |
// 'a[0]=b&a[2]=d' | |
``` | |
You could also use `filter` to inject custom serialization for user defined types. | |
Consider you're working with some api that expects query strings of the format for ranges: | |
``` | |
https://domain.com/endpoint?range=30...70 | |
``` | |
For which you model as: | |
```javascript | |
class Range { | |
constructor(from, to) { | |
this.from = from; | |
this.to = to; | |
} | |
} | |
``` | |
You could _inject_ a custom serializer to handle values of this type: | |
```javascript | |
qs.stringify( | |
{ | |
range: new Range(30, 70), | |
}, | |
{ | |
filter: (prefix, value) => { | |
if (value instanceof Range) { | |
return `${value.from}...${value.to}`; | |
} | |
// serialize the usual way | |
return value; | |
}, | |
} | |
); | |
// range=30...70 | |
``` | |
### Handling of `null` values | |
By default, `null` values are treated like empty strings: | |
```javascript | |
var withNull = qs.stringify({ a: null, b: '' }); | |
assert.equal(withNull, 'a=&b='); | |
``` | |
Parsing does not distinguish between parameters with and without equal signs. | |
Both are converted to empty strings. | |
```javascript | |
var equalsInsensitive = qs.parse('a&b='); | |
assert.deepEqual(equalsInsensitive, { a: '', b: '' }); | |
``` | |
To distinguish between `null` values and empty strings use the `strictNullHandling` flag. In the result string the `null` | |
values have no `=` sign: | |
```javascript | |
var strictNull = qs.stringify({ a: null, b: '' }, { strictNullHandling: true }); | |
assert.equal(strictNull, 'a&b='); | |
``` | |
To parse values without `=` back to `null` use the `strictNullHandling` flag: | |
```javascript | |
var parsedStrictNull = qs.parse('a&b=', { strictNullHandling: true }); | |
assert.deepEqual(parsedStrictNull, { a: null, b: '' }); | |
``` | |
To completely skip rendering keys with `null` values, use the `skipNulls` flag: | |
```javascript | |
var nullsSkipped = qs.stringify({ a: 'b', c: null}, { skipNulls: true }); | |
assert.equal(nullsSkipped, 'a=b'); | |
``` | |
If you're communicating with legacy systems, you can switch to `iso-8859-1` using the `charset` option: | |
```javascript | |
var iso = qs.stringify({ æ: 'æ' }, { charset: 'iso-8859-1' }); | |
assert.equal(iso, '%E6=%E6'); | |
``` | |
Characters that don't exist in `iso-8859-1` will be converted to numeric entities, similar to what browsers do: | |
```javascript | |
var numeric = qs.stringify({ a: '☺' }, { charset: 'iso-8859-1' }); | |
assert.equal(numeric, 'a=%26%239786%3B'); | |
``` | |
You can use the `charsetSentinel` option to announce the character by including an `utf8=✓` parameter with the proper encoding if the checkmark, similar to what Ruby on Rails and others do when submitting forms. | |
```javascript | |
var sentinel = qs.stringify({ a: '☺' }, { charsetSentinel: true }); | |
assert.equal(sentinel, 'utf8=%E2%9C%93&a=%E2%98%BA'); | |
var isoSentinel = qs.stringify({ a: 'æ' }, { charsetSentinel: true, charset: 'iso-8859-1' }); | |
assert.equal(isoSentinel, 'utf8=%26%2310003%3B&a=%E6'); | |
``` | |
### Dealing with special character sets | |
By default the encoding and decoding of characters is done in `utf-8`, and `iso-8859-1` support is also built in via the `charset` parameter. | |
If you wish to encode querystrings to a different character set (i.e. | |
[Shift JIS](https://en.wikipedia.org/wiki/Shift_JIS)) you can use the | |
[`qs-iconv`](https://github.com/martinheidegger/qs-iconv) library: | |
```javascript | |
var encoder = require('qs-iconv/encoder')('shift_jis'); | |
var shiftJISEncoded = qs.stringify({ a: 'こんにちは!' }, { encoder: encoder }); | |
assert.equal(shiftJISEncoded, 'a=%82%B1%82%F1%82%C9%82%BF%82%CD%81I'); | |
``` | |
This also works for decoding of query strings: | |
```javascript | |
var decoder = require('qs-iconv/decoder')('shift_jis'); | |
var obj = qs.parse('a=%82%B1%82%F1%82%C9%82%BF%82%CD%81I', { decoder: decoder }); | |
assert.deepEqual(obj, { a: 'こんにちは!' }); | |
``` | |
### RFC 3986 and RFC 1738 space encoding | |
RFC3986 used as default option and encodes ' ' to *%20* which is backward compatible. | |
In the same time, output can be stringified as per RFC1738 with ' ' equal to '+'. | |
``` | |
assert.equal(qs.stringify({ a: 'b c' }), 'a=b%20c'); | |
assert.equal(qs.stringify({ a: 'b c' }, { format : 'RFC3986' }), 'a=b%20c'); | |
assert.equal(qs.stringify({ a: 'b c' }, { format : 'RFC1738' }), 'a=b+c'); | |
``` | |
## Security | |
Please email [@ljharb](https://github.com/ljharb) or see https://tidelift.com/security if you have a potential security vulnerability to report. | |
## qs for enterprise | |
Available as part of the Tidelift Subscription | |
The maintainers of qs and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. | |
Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. | |
[Learn more.](https://tidelift.com/subscription/pkg/npm-qs?utm_source=npm-qs&utm_medium=referral&utm_campaign=enterprise&utm_term=repo) | |
[package-url]: https://npmjs.org/package/qs | |
[npm-version-svg]: https://versionbadg.es/ljharb/qs.svg | |
[deps-svg]: https://david-dm.org/ljharb/qs.svg | |
[deps-url]: https://david-dm.org/ljharb/qs | |
[dev-deps-svg]: https://david-dm.org/ljharb/qs/dev-status.svg | |
[dev-deps-url]: https://david-dm.org/ljharb/qs#info=devDependencies | |
[npm-badge-png]: https://nodei.co/npm/qs.png?downloads=true&stars=true | |
[license-image]: https://img.shields.io/npm/l/qs.svg | |
[license-url]: LICENSE | |
[downloads-image]: https://img.shields.io/npm/dm/qs.svg | |
[downloads-url]: https://npm-stat.com/charts.html?package=qs | |
[codecov-image]: https://codecov.io/gh/ljharb/qs/branch/main/graphs/badge.svg | |
[codecov-url]: https://app.codecov.io/gh/ljharb/qs/ | |
[actions-image]: https://img.shields.io/endpoint?url=https://github-actions-badge-u3jn4tfpocch.runkit.sh/ljharb/qs | |
[actions-url]: https://github.com/ljharb/qs/actions | |
## Acknowledgements | |
qs logo by [NUMI](https://github.com/numi-hq/open-design): | |
[<img src="https://raw.githubusercontent.com/numi-hq/open-design/main/assets/numi-lockup.png" alt="NUMI Logo" style="width: 200px;"/>](https://numi.tech/?ref=qs) | |