React Native Requires Chilkat v11.5.0+

Box: Poll User Events and Save a Checkpoint

See more Box Examples

Poll the authenticated user event stream in bounded batches. The local JSON checkpoint keeps processed event IDs and the next stream position. This single-process demonstration logs events; a production worker should commit its business action, deduplication record, and cursor transactionally and prune old IDs.

See the Box API guide for setup and the complete workflow.

React Native

import { FileAccess, HttpCurl, JsonObject, StringBuilder } from '@chilkat/react-native'

async function chilkatExample() {
  let success = false;

  // Requires Chilkat 11.5.0 or later and a previously unlocked Chilkat bundle.
  // See Global Unlock Sample.
  // Guide: Box API Guide.

  success = false;

  // Supply an unexpired token obtained with one of the Box authentication examples.
  // A token represents a particular user or service account. IDs must be accessible to it.
  const curl = new HttpCurl();
  curl.setVar('access_token', 'BOX_ACCESS_TOKEN');

  const state = new JsonObject();
  const files = new FileAccess();
  const statePath = 'qa_data/box_events_state.json';
  if (files.fileExists(statePath)) {
    success = true;
    try {
      state.loadFile(statePath);
    } catch {
      success = false;
    }
    if (!success) {
      console.log(state.lastErrorText);
      return;
    }

    if (!state.hasMember('position')) {
      console.log('Invalid checkpoint: position missing.');
      return;
    }
  } else {
    // "now" starts a new subscription. It deliberately skips historical events.
    state.updateString('position', 'now');
  }

  curl.setVar('position', state.stringOf('position'));
  const page = new JsonObject();
  const seenPath = new StringBuilder();
  let eventId = '';
  let nextPosition = '';
  let batch = 0;
  let i = 0;
  let count = 0;
  let more = true;
  while ((more) && (batch < 20)) {
    curl.clearTargetOutput('*');
    const authorizedCommand1 = new StringBuilder();
    authorizedCommand1.setString('curl -X GET "https://api.box.com/2.0/events?stream_type=all&stream_position={{position}}&limit=100" -H "Authorization: Bearer {{access_token}}"');
    const headerReplacement1 = authorizedCommand1.replace('{{access_token}}', curl.getVar('access_token'));
    success = true;
    try {
      await curl.doYourThingAsync(authorizedCommand1.getAsString());
    } catch {
      success = false;
    }
    if ((!success) || (curl.statusCode !== 200)) {
      console.log(`Box request failed. HTTP status: ${curl.statusCode}`);
      console.log(`Failure reason: ${curl.failReason}`);
      console.log(curl.responseBodyStr);
      return;
    }

    success = true;
    try {
      curl.getResponseJson(page);
    } catch {
      success = false;
    }
    if (!success) {
      console.log(curl.lastErrorText);
      return;
    }

    count = page.sizeOfArray('entries');
    i = 0;
    while (i < count) {
      page.i = i;
      eventId = page.stringOf('entries[i].event_id');
      if (eventId === '') {
        console.log('Event without an event_id; checkpoint not advanced.');
        return;
      }

      seenPath.clear();
      seenPath.append('seen.');
      seenPath.append(eventId);
      if (!state.hasMember(seenPath.getAsString())) {
        // Replace this logging with your idempotent business operation.
        // Record success only after that operation succeeds.
        console.log(`${eventId} ${page.stringOf('entries[i].event_type')} ${page.stringOf('entries[i].source.id')}`);
        state.updateBool(seenPath.getAsString(), true);
      }

      i++;
    }

    nextPosition = page.stringOf('next_stream_position');
    if (nextPosition === '') {
      console.log('Missing next_stream_position; checkpoint not advanced.');
      return;
    }

    more = (count > 0) && (nextPosition !== curl.getVar('position'));
    state.updateString('position', nextPosition);
    success = true;
    try {
      state.writeFile(statePath);
    } catch {
      success = false;
    }
    if (!success) {
      console.log(state.lastErrorText);
      return;
    }

    curl.setVar('position', nextPosition);
    batch++;
  }

  console.log('Checkpoint saved. Run again later to continue polling.');
}