LiveResource updated API

gistfile1.txt

-- VALUE

import { JsonValueInterest, LiveResource } from 'liveresource';

class TimeValueInterest extends JsonValueInterest {
  transform(obj) {
    return obj.time;
  }
}

// Automatic start
const timeValueResource = new LiveResource("http://test.liveresource.org/test", {
  interest: TimeValueInterest
});

timeValueResource.on('value', (data) => {
  console.log(data);
});

// Manual start
const timeValueManualStartResource = new LiveResource({interest: TimeValueInterest});
fetch("http://test.liveresource.org/test")
  .then((response) => {
    const json = response.json();
    console.log(json.time);
    timeValueManualStartResource.start(response.headers);
  });

timeValueManualStartResource.on('value', (data) => {
  console.log(data);
});


-- CHANGES

import { JsonChangesInterest, LiveResource } from 'liveresource';

class TimeChangesInterest extends JsonChangesInterest {
  transform(obj) {
    // Format is "+xx"
    const change = obj['time:change'] || "+0";
    let c = change.trim();
    let sign = "+";
    let value = 0;
    if (c.charAt(0) === "+" || c.charAt(0) === "-") {
      sign = c.charAt(0);
      c = c.substring(1);
    }
    value = parseInt(c, 10);
    return { sign, value };
  }
}

let currentTime = 0;
const timeChangesResource = new LiveResource({interest: TimeChangesInterest});

fetch("http://test.liveresource.org/test")
  .then((response) => {
    const json = response.json();
    currentTime = json.time;
    console.log(currentTime);
    timeChangesResource.start(response.headers);
  });

timeChangesResource.on('changes', (data) => {
  const multiplier = (data.sign === "+") ? 1 : -1;
  currentTime += multiplier * data.value;
  console.log(currentTime);
});

--

LiveResource

constructor

new LiveResource(url, options) or new LiveRsource(options);

if the first parameter is a string, then it's treated the same as {url}
and merged in with the rest of the options

if url is provided, then in the case of a ValueParser an initial fetch
will be performed that will also trigger a value event and then automatically
call start() with the headers return from that fetch.

if url is not provided, then it's necessary for caller to to call start()
at a later time and pass in a set of headers to begin the process.

options:

interest  - a class or instance of a class that is an Interest.
            If omitted, JsonValueInterest is the default.

start(headers)

starts LiveResource process with the passed-in headers.