How to use the pickBy function from ramda

Find comprehensive JavaScript ramda.pickBy code examples handpicked from public code repositorys.

ramda.pickBy is a Ramda.js function that returns a new object with all properties from a source object that satisfy a given predicate function.

datasets.js

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// It removes prefix from all the key of an object
const removePrefix = curry((prefix, obj) => compose(reduce((acc, key) => assoc(key.replace(prefix, ''), obj[key], acc), {}), keys)(obj));


const pickFrameFields = (frame, obj) => compose(
  removePrefix(`${frame.def.from}!`),
  pickBy(compose(startsWith(`${frame.def.from}!`), nthArg(1)))
)(obj);


const makeHierarchy = reduce((result, item) => {
  const dataset = new Dataset(pickFrameFields(Dataset, item)).with({ lastEntity: item.lastEntity });

pick.js

GitHub: htunkhainglynn/react-learning-repo

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const pickAll = R.pickAll(['a', 'e', 'f']); // => {a: 1, e: undefined, f: undefined}
console.log('pickBy', pickAll(obj));


// pickBy is similar to filer the object 
const isEven = (val, key) => val % 2 === 0;
const pickBy = R.pickBy(isEven);
console.log('is even pickBy', pickBy(obj));

+ 131 other calls in file

How does ramda.pickBy work?

ramda.pickBy works by taking a source object and a predicate function as input, and returning a new object containing only the properties from the source object that satisfy the predicate function. When called with a predicate function, ramda.pickBy applies the predicate function to each property of the source object. If the predicate function returns true for a given property, that property is included in the output object. Otherwise, the property is excluded. The resulting object has the same keys as the input object, but contains only the properties that satisfied the predicate function. Some key features of ramda.pickBy include: The predicate function can be any function that returns a boolean value. The predicate function is called with two arguments: the value of the current property and its key. The resulting object is a new object, and the original object is not modified. Note that ramda.pickBy is part of the Ramda.js library, which provides a set of utility functions for working with functional programming concepts in JavaScript. Ramda.js functions are designed to be composable and to encourage a functional programming style of programming, with a focus on immutability and pure functions.

OrderJobService.js

GitHub: waltermitch/Trukt-Backend

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{
    dispatcherGuid: dispatcher
};

// remove and check for undefineds
const cleaned = R.pickBy((it) => it !== undefined, payload);

if (Object.keys(cleaned).length === 0)
    throw new MissingDataError('Missing Update Values');

cmr.js

GitHub: NASA-IMPACT/nncpp-cumulus-deploy

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function enhancedRequestError(error) {
  const errors = extractErrors(error).join(", ");
  const message = [error.message, errors].filter(Boolean).join(": ");
  const { code, config, name, response = {} } = error;
  const props = R.pickBy(isNotMissing, {
    code,
    config,
    name,
    response: R.omit(['config', 'request'], response),

+ 2 other calls in file

Ai Example

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const R = require("ramda");

const data = {
  name: "John",
  age: 25,
  email: "john@example.com",
  isAdmin: true,
};

const result = R.pickBy((value, key) => key !== "isAdmin", data);

console.log(result);
// Output:
// { name: 'John', age: 25, email: 'john@example.com' }

In this example, we first import the Ramda.js library, and define an object data containing some sample data with properties such as name, age, email, and isAdmin. We then use the R.pickBy function to create a new object containing only the properties from data that satisfy a predicate function. In this case, the predicate function filters out the property "isAdmin", and includes all other properties. The resulting object is then printed to the console. Note that this is just a simple example, and ramda.pickBy can be used in more complex scenarios, such as filtering or transforming objects based on more complex predicates, or composing with other Ramda.js functions to create more powerful data processing pipelines.

helper.js

GitHub: vyasishanatc194/sample-node-api

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const notNull = compose(complement(isNil))
/**
 * we need to remove undefined array means not required data.
 */
const cleanData = (entity) => pickBy(notNull, entity)


module.exports = {
  cleanData
}

cyclejs-audio-driver.js

GitHub: jemmyw/cyclejs-audio-driver

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 *         on it.
 * @see R.pick, R.filter
 * @example
 *
 *      var isUpperCase = (val, key) => key.toUpperCase() === key;
 *      R.pickBy(isUpperCase, {a: 1, b: 2, A: 3, B: 4}); //=> {A: 3, B: 4}
 */
var pickBy = _curry2(function pickBy(test, obj) {
    var result = {};
    for (var prop in obj) {

+ 17 other calls in file

index.js

GitHub: ti2travel/ti2

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}) => {
  const port = portParam || process.env.PORT || 10010;
  // create the plugin instances
  const plugins = await bb.map(Object.entries(pluginsParam), async ([pluginName, Plugin]) => {
    // pass all env variables
    const pluginEnv = pickBy(
      (_val, key) => key.substring(0, `ti2_${pluginName}`.length)
        .replace('-', '_') === `ti2_${pluginName}`,
      process.env,
    );

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