GitHub Repo Searches

gistfile1.js

var _ = require('lodash');
var github = require('octonode');

var Rx = require('rx');

// repos :: Search -> Options -> Observable Data
// callback style is converted to Promise and then to Observable
function repos(search, options) {
  return Rx.Observable.fromPromise(new Promise(function (resolve, reject) {
    search.repos(options, function (err, body, header) {
      if (err)
        reject(err);
      else
        resolve({body: body, header: header});
    });
  }));
}

// nextPage :: Options {page: Num} -> Options {page: Num}
function nextPage(options) {
  options = _.clone(options);
  options.page = options.page ? options.page + 1 : 2;
  return options;
}

// parseLink :: String -> Link {<Rel>:<Url>}
function parseLink(text) {
  var links = _.map(text.split(','), function (part) {
    var match = part.trim().match(/<(.*)>; rel=\"(.*)\"/);
    return [ match[2], match[1] ];
  });
  return _.zipObject(links);
}

// reposAll :: Search -> Options -> Observable Data
// using concatMap
// function reposAll(search, options) {
//   return repos(search, options).concatMap(
//     function (data) {
//       var current = Rx.Observable.return(data);
//       var links = utils.parseLink(data.header.link);
//       if (links.next) {
//         return current.concat(reposAll(search, nextPage(options)));
//       } else {
//         return current;
//       }
//     }
//   );
// }

// reposAll :: Search -> Options -> Observable Data
// using expand
// function reposAll(search, options) {
//   return repos(search, options).expand(
//     function (data) {
//       var links = utils.parseLink(data.header.link);
//       if (links.next) {
//         return repos(search, nextPage(options));
//       } else {
//         return Rx.Observable.empty();
//       }
//     }
//   );
// }

// reposAll :: Search -> Options -> Observable Data
function reposAll(search, options) {
  return Rx.Observable.create(function (observer) {
    var disposed = false;

    function onNext(items) {
      //var i = 0, len = items.length;
      // for (; i < len && !disposed; i++)
      //   observer.onNext(items[i]);
      if (!disposed)
        observer.onNext(items);
    }
    function onError(err) {
      if (!disposed)
        observer.onError(err);
    }
    function onCompleted() {
      if (!disposed)
        observer.onCompleted();
    }

    var callback = function (err, body, header) {
      if (err) {
        onError(err);
      } else {
        onNext({body: body, header: header});
        var links = utils.parseLink(header.link);
        if (links.next && !disposed) {
          search.repos(nextPage(options), callback);
        } else {
          onCompleted();
        }
      }
    };
    search.repos(options, callback);
    return function () {
      disposed = true;
    };
  });
}

var client = github.client();
var search = client.search();

var source = reposAll(search, {
  q: 'android in:name,description,readme created:2015-01-01..2015-01-31',
  per_page: 100
})
// we can flatten the results as an Observable of Repo
.concatMap(function(data) {  
  return Rx.Observable.from(data.body.items);
});

source.take(100).subscribe(function onNext(repo) {
  console.log(repo.full_name);
});

reposAll 은 3가지 버전이 있다. expand()를 이용한 것(두번째)이 가장 간단하다. 3번째 버전은 Observable을 직접 만든 것. 첫번째 버전은 concatMap()을 이용한 것이다.