DoubleU23/tailored-keymapping

map objectKeys with given keyMap

tailored-keymapping

map objectKeys with given keyMap

Usage

npm install tailored-keymapping --save

import TailoredKeymapping from 'tailored-keymapping'

// define keymap
const keymap = {
    'test': {
        'oldKey':   'newKey'
    ,   'foo':      'bar'
    ,   'abc':      'xyz'
        /**
         * custom mapping function
         *  called after mapping loop
         * @param  {object} data - mapped data object
         * @return {any} newValue - new value of the keyName
         * @return {array} [newKey,newValue] - new key/value pair
         */
    ,   'keyName': function(data) {
            return ['newKey', newValue]
            // return newValue; // to use original keyname ('keyName')
        }
    }
}

// create instance
const keyMapping = new TailoredKeymapping(keymap)

// overwrite keymap after initialisation if needed
keyMapping.setKeymap(otherKeymap)

// process data with given options
let mappedData = keyMapping.map(dataToMap, {
       'keymapTree':        'test' // || ['sub', 'subsub']
    ,  'onlyMappedVars':    true
        /**
         * callback function
         *  mutate data after mapping
         * @param  {object} dataMapped   - mapped data object (after custom functions)
         * @param  {object} dataOriginal - mapped data object (after custom functions)
         * @return {object} newData - mutated data object
         */
    ,   callback: function(data) {
            data.dynamicVar = data.foo + data.abc;
            return data;
        }
     )

// you can also rely on default options and just pass a callback function
mappedData = keyMapping.map(payload, (data)=>newData)

default options

{
    onlyMappedVars: false   // drop old keys?
,   keymapTree:     ''      // keymaps subtree to use
,   callback:       null    // mutate data after mapping
}

Examples

import KeyMapping from 'tailored-keymapping'
// create instance with keyMap
const keyMapping = new KeyMapping({foo: 'bar'})

// basic flat keymap
let dataMapped = keyMapping.map({foo: 'foo_content'})
console.log(dataMapped) // => {bar: 'foo_content', foo: 'foo_content'}

// basic deep keymap
keyMapping.setKeymap({sub: {subsub: {foo: 'bar'}}})
dataMapped = keyMapping.map(
    {foo: 'foo_content'}
,   {   keymapTree: ['sub', 'subsub']
    ,   onlyMappedVars: true
    }
)
console.log(dataMapped) // => {bar: 'foo_content'}

// custom functions
keyMapping.setKeymap({
    'newKey': (data) => data.foo+'-'+data.bar
})
dataMapped = keyMapping.map(
    {foo: 'foo', bar: 'bar'} // data2map
,   {onlyMappedVars: true}  // options or callback
)
console.log(datMapped) // => {newKey: 'foo-bar'}

for more examples have a look at the mocha tests

Roadmap

• 0.2.0 - finish basic tests
• 0.1.6 - remove lodash dependecy (?)
• 0.1.45 - added travis build hook
• 0.1.44 - fixxed bug (mappedKey > originalKey)
• 0.1.41 - added callback tests
• 0.1.4 - added tests
• 0.1.2 - dist folder is new entrypoint

TBD

• assert.throws doesn't fail on wrong Error msg (@tests: 'select wrong subtree')
• keymap handling in constructor !?

Bugs

if you find a bug, please report them @Issues