How to use pouchdb-utils - 10 common examples

function finishBatch() {
    if (currentBatch.error) {
      throw new Error('There was a problem getting docs.');
    }
    result.last_seq = last_seq = currentBatch.seq;
    var outResult = clone(result);
    if (changedDocs.length) {
      outResult.docs = changedDocs;
      // Attach 'pending' property if server supports it (CouchDB 2.0+)
      /* istanbul ignore if */
      if (typeof currentBatch.pending === 'number') {
        outResult.pending = currentBatch.pending;
        delete currentBatch.pending;
      }
      returnValue.emit('change', outResult);
    }
    writingCheckpoint = true;
    return checkpointer.writeCheckpoint(currentBatch.seq,
        session).then(function () {
      writingCheckpoint = false;
      /* istanbul ignore if */
      if (returnValue.cancelled) {

AbstractPouchDB.prototype.changes = function (opts, callback) {
  if (typeof opts === 'function') {
    callback = opts;
    opts = {};
  }
  return new Changes(this, opts, callback);
};

AbstractPouchDB.prototype.close = adapterFun('close', function (callback) {
  this._closed = true;
  this.emit('closed');
  return this._close(callback);
});

AbstractPouchDB.prototype.info = adapterFun('info', function (callback) {
  var self = this;
  this._info(function (err, info) {
    if (err) {
      return callback(err);
    }
    // assume we know better than the adapter, unless it informs us
    info.db_name = info.db_name || self.name;
    info.auto_compaction = !!(self.auto_compaction && self.type() !== 'http');
    info.adapter = self.type();
    callback(null, info);
  });
});

AbstractPouchDB.prototype.id = adapterFun('id', function (callback) {
  return this._id(callback);
});

var self = this;
  var usePrefix = 'use_prefix' in self ? self.use_prefix : true;

  function destroyDb() {
    // call destroy method of the particular adaptor
    self._destroy(opts, function (err, resp) {
      if (err) {
        return callback(err);
      }
      self._destroyed = true;
      self.emit('destroyed');
      callback(null, resp || { 'ok': true });
    });
  }

  if (isRemote(self)) {
    // no need to check for dependent DBs if it's a remote DB
    return destroyDb();
  }

  self.get('_local/_pouch_dependentDbs', function (err, localDoc) {
    if (err) {
      /* istanbul ignore if */
      if (err.status !== 404) {
        return callback(err);
      } else { // no dependencies
        return destroyDb();
      }
    }
    var dependentDbs = localDoc.dependentDbs;
    var PouchDB = self.constructor;
    var deletedMap = Object.keys(dependentDbs).map(function (name) {

doc.views[viewName] = {
      map: {
        fields: mergeObjects(requestDef.index.fields)
      },
      reduce: '_count',
      options: {
        def: originalIndexDef
      }
    };

    return doc;
  }

  db.constructor.emit('debug', ['find', 'creating index', ddocId]);

  return upsert(db, ddocId, updateDdoc).then(function () {
    if (hasInvalidLanguage) {
      throw new Error('invalid language for ddoc with id "' +
      ddocId +
      '" (should be "query")');
    }
  }).then(function () {
    // kick off a build
    // TODO: abstract-pouchdb-mapreduce should support auto-updating
    // TODO: should also use update_after, but pouchdb/pouchdb#3415 blocks me
    var signature = ddocName + '/' + viewName;
    return abstractMapper(db).query.call(db, signature, {
      limit: 0,
      reduce: false
    }).then(function () {
      return {
        id: ddocId,

//   Mobile/9B206 Safari/7534.48.3
  // Firefox for iOS UA:
  //   Mozilla/5.0 (iPhone; CPU iPhone OS 8_3 like Mac OS X) AppleWebKit/600.1.4
  //   (KHTML, like Gecko) FxiOS/1.0 Mobile/12F69 Safari/600.1.4

  // indexedDB is null on some UIWebViews and undefined in others
  // see: https://bugs.webkit.org/show_bug.cgi?id=137034
  if (typeof indexedDB === 'undefined' || indexedDB === null ||
      !/iP(hone|od|ad)/.test(navigator.userAgent)) {
    // definitely not WKWebView, avoid creating an unnecessary database
    return true;
  }
  // Cache the result in LocalStorage. Reason we do this is because if we
  // call openDatabase() too many times, Safari craps out in SauceLabs and
  // starts throwing DOM Exception 14s.
  var hasLS = hasLocalStorage();
  // Include user agent in the hash, so that if Safari is upgraded, we don't
  // continually think it's broken.
  var localStorageKey = '_pouch__websqldb_valid_' + navigator.userAgent;
  if (hasLS && localStorage[localStorageKey]) {
    return localStorage[localStorageKey] === '1';
  }
  var openedTestDB = canOpenTestDB();
  if (hasLS) {
    localStorage[localStorageKey] = openedTestDB ? '1' : '0';
  }
  return openedTestDB;
}

function getHost(name, opts) {
  // encode db name if opts.prefix is a url (#5574)
  if (hasUrlPrefix(opts)) {
    var dbName = opts.name.substr(opts.prefix.length);
    // Ensure prefix has a trailing slash
    var prefix = opts.prefix.replace(/\/?$/, '/');
    name = prefix + encodeURIComponent(dbName);
  }

  var uri = parseUri(name);
  if (uri.user || uri.password) {
    uri.auth = {username: uri.user, password: uri.password};
  }

  // Split the path part of the URI into parts using '/' as the delimiter
  // after removing any leading '/' and any trailing '/'
  var parts = uri.path.replace(/(^\/|\/$)/g, '').split('/');

  uri.db = parts.pop();
  // Prevent double encoding of URI component
  if (uri.db.indexOf('%') === -1) {
    uri.db = encodeURIComponent(uri.db);
  }

  uri.path = parts.join('/');

function LevelPouch(opts, callback) {
  opts = clone(opts);
  var api = this;
  var instanceId;
  var stores = {};
  var revLimit = opts.revs_limit;
  var db;
  var name = opts.name;
  // TODO: this is undocumented and unused probably
  /* istanbul ignore else */
  if (typeof opts.createIfMissing === 'undefined') {
    opts.createIfMissing = true;
  }

  var leveldown = opts.db;

  var dbStore;
  var leveldownName = functionName(leveldown);

function getDocs(src, target, diffs, state) {
  diffs = clone(diffs); // we do not need to modify this

  var resultDocs = [],
      ok = true;

  function getAllDocs() {

    var bulkGetOpts = createBulkGetOpts(diffs);

    if (!bulkGetOpts.docs.length) { // optimization: skip empty requests
      return;
    }

    return src.bulkGet(bulkGetOpts).then(function (bulkGetResponse) {
      /* istanbul ignore if */
      if (state.cancelled) {
        throw new Error('cancelled');

api._allDocs = readLock(function (opts, callback) {
    opts = clone(opts);
    countDocs(function (err, docCount) {
      /* istanbul ignore if */
      if (err) {
        return callback(err);
      }
      var readstreamOpts = {};
      var skip = opts.skip || 0;
      if (opts.startkey) {
        readstreamOpts.gte = opts.startkey;
      }
      if (opts.endkey) {
        readstreamOpts.lte = opts.endkey;
      }
      if (opts.key) {
        readstreamOpts.gte = readstreamOpts.lte = opts.key;
      }

api._allDocs = readLock(function (opts, callback) {
    opts = pouchdbUtils.clone(opts);
    countDocs(function (err, docCount) {
      /* istanbul ignore if */
      if (err) {
        return callback(err);
      }
      var readstreamOpts = {};
      var skip = opts.skip || 0;
      if (opts.startkey) {
        readstreamOpts.gte = opts.startkey;
      }
      if (opts.endkey) {
        readstreamOpts.lte = opts.endkey;
      }
      if (opts.key) {
        readstreamOpts.gte = readstreamOpts.lte = opts.key;
      }