Highland-json

JSON encoding for Highland.js stream.

!Build Status

This JSON encoder not only encoding stream of objects, but also encode streams recursively. You can pass a stream of stream of number, and it will return an array of array of number.

Install

``
npm install highland-json
`

Usage

$3

`javascript

import _ from 'highland';
import {stringify} from 'highland-json';

const input = [
{ a : "b", b : "c" },
{ a : [1, 2, 3] },
[ 1, 2, 3 ],
[ { a : "b", b : "c" } ]
];

_(input)
.through(stringify)
.toArray(results => {
let result = results.join('');

// result === input
});
`

$3


`javascript

import _ from 'highland';
import {stringify} from 'highland-json';

const input = [
{ a : "b", b : "c" },
_([ 1, 2, 3 ]),
_([ {
a : "b",
b : _([4, 5, 6])
}
])
];

_(input)
.through(stringify)
.toArray(results => {
let result = results.join('');
/*
result === [
{ "a" : "b", "b" : "c" },
[ 1, 2, 3 ],
[ {
"a" : "b",
"b" : [4, 5, 6]
} ]
];*/
});
`



$3

stringifyObj accepts a stream of [key, value] array.

`javascript

import _ from 'highland';
import {stringifyObj} from 'highland-json';

/ Key value pair /
const input = [
['a', 'b'],
['c', 'd'],
['e', ['f', 'g', 'h']]
]

_(input)
.through(stringifyObj)
.toArray(results => {
let result = results.join('');
/*
result === {
"a": "b",
"c": "d",
"e": ["f", "g", "h"]
} */
};
`

$3

stringifyObj also accepts stream of single object, the object will be encoded as an object ({}), please only pass one object to the stream. If the stream is given more than one object, it will output something like {"a":1}{"a":2}, which is not a valid JSON. Use stringifyfor that case.

`javascript

import _ from 'highland';
import {stringifyObj} from 'highland-json';

/ Key value pair /
const input = {
a: "b",
c: "d",
e: ["f", "g", "h"]
}

_(input)
.through(stringifyObj)
.toArray(results => {
let result = results.join('');
/*
result === {
"a": "b",
"c": "d",
"e": ["f", "g", "h"]
} */
};
`

$3

Remember to pass through stringifyObj when you are encoding objects.

`javascript
const input = {
a : _([
_([1, 2, 3]),
_([4, 5, 6])
]),
b : _([{
c: _([{
d: 'e',
f: 'g'
}]).through(stringifyObj),
h: _([{
i: 'j',
k: 'l'
}]).through(stringifyObj)
}
]).through(stringifyObj)
};

_([input])
.through(stringifyObj)
.toArray(results => {
let result = JSON.parse(results.join(''));
/*
result === {
a : [[1,2,3], [4,5,6]],
b : {
c : {d:'e', f:'g'},
h : {i:'j', k:'l'}
}
} */
});
`

$3

In case if you want to use a custom stringify function.

`javascript
import _ from 'highland';
import {stringify} from 'highland-json';

const input = ['a', 'b', 'c'];
const customStringify = (val, stream)=> JSON.stringify(val + '1');

_(input)
.through(stringify({stringify: customStringify}))
.toArray(results => {
let result = results.join('');
// result === ['a1', 'b1', 'c1']
});
`

`javascript
const input = {
nums: _([1, 2, 3]),
strings: _(['a', 'b', 'c']),
};

const customStringify = (val, stream)=> {
if (stream === input.nums) {
return JSON.stringify(val * 10);
}
if (stream === input.strings) {
return JSON.stringify(val + '1');
}
throw new Error("Unreachable");
};

_([input])
.through(stringifyObj({stringify: customStringify}))
.toArray(results => {
const result = JSON.parse(results.join(''));
/*
result === {
nums: [10, 20, 30],
strings: ['a1', 'b1', 'c1'],
};
*/
});
``