Redux Saga example

weather-saga.js

import {
  call,
  put,
  takeLatest
} from 'redux-saga/effects'

import {
  UPDATE_QUERY,

  WEATHER_DATA_REQUESTED,
  WEATHER_DATA_RECEIVED,
  WEATHER_DATA_FAILED,

  store
} from './update'


/**
 * Weather search saga
 */
const getWeatherApiUrl = city => {
  city = encodeURIComponent(city);

  const query = `select item,astronomy,units from weather.forecast where woeid in (select woeid from geo.places(1) where text="${ city }") and u="c"`;
  return `https://query.yahooapis.com/v1/public/yql?q=${ escape(query) }&format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys`;
}

const httpGet = function (requestUrl) {
  return fetch(requestUrl)
          .then( response => response.json() )
          .catch( error => ({ error }) )
}

const fetchWeather = function* (action) {
  try {
    const query = store.getState().weather.query;
    const url = getWeatherApiUrl( query );

    const result = yield call( httpGet, url )

    yield put({
      type: WEATHER_DATA_RECEIVED,
      payload: {
        result: { ...result.query.results.channel.item,
          units: result.query.results.channel.units,
          astronomy: result.query.results.channel.astronomy
        }
      }
    })
  }

  catch (e) {
    yield put({
      type: WEATHER_DATA_FAILED,
      payload: { loadError: e.message }
    })
  }
}

export const searchSaga = function* () {
  yield takeLatest( WEATHER_DATA_REQUESTED, fetchWeather );
}