@graffy/client/esm/httpClient.js

Graffy client library for the browser.

import { encodeUrl, serialize, deserialize, makePath } from '@graffy/common';
import { makeStream } from '@graffy/stream';

function getOptionsParam(options) {
  if (!options) return '';
  return encodeURIComponent(serialize(options));
}

export default ((baseUrl, {
  getOptions = () => {},
  watch,
  connInfoPath = '/connection'
} = {}) => store => {
  connInfoPath = makePath(connInfoPath);
  store.onWrite(connInfoPath, ({
    url
  }) => {
    baseUrl = url;
    return {
      url
    };
  });
  store.onRead(connInfoPath, () => ({
    url: baseUrl
  }));
  store.on('read', (query, options) => {
    if (!fetch) throw Error('client.fetch.unavailable');
    const optionsParam = getOptionsParam(getOptions('read', options));
    const url = baseUrl + "?q=" + encodeUrl(query) + "&opts=" + optionsParam;
    return fetch(url).then(res => {
      if (res.status === 200) return res.json();
      return res.text().then(message => {
        throw Error('server.' + message);
      });
    });
  });
  store.on('watch', (query, options) => {
    if (watch === 'none') throw Error('client.no_watch');

    if (watch === 'hang') {
      return makeStream(push => {
        push(undefined);
      });
    }

    if (!EventSource) throw Error('client.sse.unavailable');
    const optionsParam = getOptionsParam(getOptions('watch', options));
    const url = baseUrl + "?q=" + encodeUrl(query) + "&opts=" + optionsParam;
    const source = new EventSource(url);
    return makeStream((push, end) => {
      source.onmessage = ({
        data
      }) => {
        push(deserialize(data));
      };

      source.onerror = e => {
        end(Error('client.sse.transport: ' + e.message));
      };

      source.addEventListener('graffyerror', e => {
        end(Error('server.' + e.data));
      });
      return () => {
        source.close();
      };
    });
  });
  store.on('write', (change, options) => {
    if (!fetch) throw Error('client.fetch.unavailable');
    const optionsParam = getOptionsParam(getOptions('write', options));
    const url = baseUrl + "?opts=" + optionsParam;
    return fetch(url, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json'
      },
      body: serialize(change)
    }).then(res => {
      if (res.status === 200) return res.json();
      return res.text().then(message => {
        throw Error('server.' + message);
      });
    });
  });
});