zaki-yama/exportDialog.html

## exportDialog.html
<!DOCTYPE html>
<html>
  <head>
    <base target="_top">
  </head>
  <body>
    <form id="form">
      <select name="repos">
        <? for (var i = 0; i < repos.length; i++) { ?>
        <option value="<?= repos[i] ?>"><?= repos[i] ?></option>
        <? } ?>
      </select>
      <input type="button" value="Export" onclick="google.script.run.export(this.parentNode)" />
    </form>
  </body>
</html>

## main.js
var CLIENT_ID = 'YOUR_CLIENT_ID',
    CLIENT_SECRET = 'YOUR_CLIENT_SECRET',
    USERNAME = 'YOUR_GITHUB_USERNAME';

var ISSUE_PROPERTIES = ['number', 'title', 'url'];

function onOpen() {
  SpreadsheetApp.getUi()
    .createMenu('GitHub')
    .addItem('Authorize', 'openAuthDialog')
    .addItem('Export', 'openExportDialog')
    .addToUi();
}

function openAuthDialog() {
  var gitHubService = getGitHubService();
  if (gitHubService.hasAccess()) {
    Browser.msgBox('Already autherized');
  } else {
    var authorizationUrl = gitHubService.getAuthorizationUrl();
    var template = HtmlService.createTemplate(
        '<a href="<?= authorizationUrl ?>" target="_blank">Authorize</a>');
    template.authorizationUrl = authorizationUrl;
    var page = template.evaluate();

    SpreadsheetApp.getUi()
      .showModalDialog(page, 'Authorize');
  }
}

function openExportDialog() {
  var repos = getRepos();

  var template = HtmlService.createTemplateFromFile('exportDialog');
  template.repos = repos;
  var page = template.evaluate();

  SpreadsheetApp.getUi()
    .showModalDialog(page, 'Export');
}

//////////////////////////////////////////////////////////////

function getGitHubService() {
  // Create a new service with the given name. The name will be used when
  // persisting the authorized token, so ensure it is unique within the
  // scope of the property store.
  return OAuth2.createService('GitHub')
      // Set the endpoint URLs, which are the same for all GitHub services.
      .setAuthorizationBaseUrl('https://github.com/login/oauth/authorize')
      .setTokenUrl('https://github.com/login/oauth/access_token')

      // Set the client ID and secret, from
      //   GitHub Settings > Applications > Developer applications
      .setClientId(CLIENT_ID)
      .setClientSecret(CLIENT_SECRET)

      // Set the name of the callback function in the script referenced
      // above that should be invoked to complete the OAuth flow.
      .setCallbackFunction('authCallback')

      // Set the property store where authorized tokens should be persisted.
      .setPropertyStore(PropertiesService.getUserProperties())
}

function authCallback(request) {
  var gitHubService = getGitHubService();
  var isAuthorized = gitHubService.handleCallback(request);
  if (isAuthorized) {
    return HtmlService.createHtmlOutput('Success! You can close this tab.');
  } else {
    return HtmlService.createHtmlOutput('Denied. You can close this tab');
  }
}

function clearService() {
  OAuth2.createService('GitHub')
  .setPropertyStore(PropertiesService.getUserProperties())
  .reset();
}

// Reusable function to generate a callback URL, assuming the script has been published as a
// web app (necessary to obtain the URL programmatically). If the script has not been published
// as a web app, set `var url` in the first line to the URL of your script project (which
// cannot be obtained programmatically).
function getCallbackURL(callbackFunction) {
  var url = ScriptApp.getService().getUrl();      // Ends in /exec (for a web app)
  url = url.slice(0, -4) + 'usercallback?state='; // Change /exec to /usercallback
  var stateToken = ScriptApp.newStateToken()
    .withMethod(callbackFunction)
    .withTimeout(120)
    .createToken();
  Logger.log(url + stateToken);
}

////////////////////////////////////////////////////

function getRepos() {
  var gitHubService = getGitHubService();
  var response = UrlFetchApp.fetch('https://api.github.com/users/' + USERNAME + '/repos?per_page=100', {
    headers: {
      Authorization: 'Bearer ' + gitHubService.getAccessToken()
    }
  });
  var repos = [];
  response = JSON.parse(response);
  for (var i = 0; i < response.length; i++) {
    repos.push(response[i].name);
  }
  return repos;
}

function export(form) {
  var issues = getIssues(form.repos);
  var values = [];
  for (var i = 0; i < issues.length; i++) {
    var issue = issues[i];
    var value = [];
    for (var j = 0; j < ISSUE_PROPERTIES.length; j++) {
      value.push(issue[ISSUE_PROPERTIES[j]]);
    }
    values.push(value);
  }
  Logger.log(values);
  var sheet = SpreadsheetApp.getActiveSheet();
  sheet.getRange(1, 1, values.length, values[0].length).setValues(values);
}

function getIssues(repo) {
  var gitHubService = getGitHubService();
  var response = UrlFetchApp.fetch('https://api.github.com/repos/' + USERNAME + '/' + repo + '/issues?per_page=100', {
    headers: {
      Authorization: 'Bearer ' + gitHubService.getAccessToken()
    }
  });
  return JSON.parse(response);
}
	<!DOCTYPE html>
	<html>
	<head>
	<base target="_top">
	</head>
	<body>
	<form id="form">
	<select name="repos">
	<? for (var i = 0; i < repos.length; i++) { ?>
	<option value="<?= repos[i] ?>"><?= repos[i] ?></option>
	<? } ?>
	</select>
	<input type="button" value="Export" onclick="google.script.run.export(this.parentNode)" />
	</form>
	</body>
	</html>
	var CLIENT_ID = 'YOUR_CLIENT_ID',
	CLIENT_SECRET = 'YOUR_CLIENT_SECRET',
	USERNAME = 'YOUR_GITHUB_USERNAME';

	var ISSUE_PROPERTIES = ['number', 'title', 'url'];

	function onOpen() {
	SpreadsheetApp.getUi()
	.createMenu('GitHub')
	.addItem('Authorize', 'openAuthDialog')
	.addItem('Export', 'openExportDialog')
	.addToUi();
	}

	function openAuthDialog() {
	var gitHubService = getGitHubService();
	if (gitHubService.hasAccess()) {
	Browser.msgBox('Already autherized');
	} else {
	var authorizationUrl = gitHubService.getAuthorizationUrl();
	var template = HtmlService.createTemplate(
	'<a href="<?= authorizationUrl ?>" target="_blank">Authorize</a>');
	template.authorizationUrl = authorizationUrl;
	var page = template.evaluate();

	SpreadsheetApp.getUi()
	.showModalDialog(page, 'Authorize');
	}
	}

	function openExportDialog() {
	var repos = getRepos();

	var template = HtmlService.createTemplateFromFile('exportDialog');
	template.repos = repos;
	var page = template.evaluate();

	SpreadsheetApp.getUi()
	.showModalDialog(page, 'Export');
	}

	//////////////////////////////////////////////////////////////

	function getGitHubService() {
	// Create a new service with the given name. The name will be used when
	// persisting the authorized token, so ensure it is unique within the
	// scope of the property store.
	return OAuth2.createService('GitHub')
	// Set the endpoint URLs, which are the same for all GitHub services.
	.setAuthorizationBaseUrl('https://github.com/login/oauth/authorize')
	.setTokenUrl('https://github.com/login/oauth/access_token')

	// Set the client ID and secret, from
	// GitHub Settings > Applications > Developer applications
	.setClientId(CLIENT_ID)
	.setClientSecret(CLIENT_SECRET)

	// Set the name of the callback function in the script referenced
	// above that should be invoked to complete the OAuth flow.
	.setCallbackFunction('authCallback')

	// Set the property store where authorized tokens should be persisted.
	.setPropertyStore(PropertiesService.getUserProperties())
	}

	function authCallback(request) {
	var gitHubService = getGitHubService();
	var isAuthorized = gitHubService.handleCallback(request);
	if (isAuthorized) {
	return HtmlService.createHtmlOutput('Success! You can close this tab.');
	} else {
	return HtmlService.createHtmlOutput('Denied. You can close this tab');
	}
	}

	function clearService() {
	OAuth2.createService('GitHub')
	.setPropertyStore(PropertiesService.getUserProperties())
	.reset();
	}

	// Reusable function to generate a callback URL, assuming the script has been published as a
	// web app (necessary to obtain the URL programmatically). If the script has not been published
	// as a web app, set `var url` in the first line to the URL of your script project (which
	// cannot be obtained programmatically).
	function getCallbackURL(callbackFunction) {
	var url = ScriptApp.getService().getUrl(); // Ends in /exec (for a web app)
	url = url.slice(0, -4) + 'usercallback?state='; // Change /exec to /usercallback
	var stateToken = ScriptApp.newStateToken()
	.withMethod(callbackFunction)
	.withTimeout(120)
	.createToken();
	Logger.log(url + stateToken);
	}

	////////////////////////////////////////////////////

	function getRepos() {
	var gitHubService = getGitHubService();
	var response = UrlFetchApp.fetch('https://api.github.com/users/' + USERNAME + '/repos?per_page=100', {
	headers: {
	Authorization: 'Bearer ' + gitHubService.getAccessToken()
	}
	});
	var repos = [];
	response = JSON.parse(response);
	for (var i = 0; i < response.length; i++) {
	repos.push(response[i].name);
	}
	return repos;
	}

	function export(form) {
	var issues = getIssues(form.repos);
	var values = [];
	for (var i = 0; i < issues.length; i++) {
	var issue = issues[i];
	var value = [];
	for (var j = 0; j < ISSUE_PROPERTIES.length; j++) {
	value.push(issue[ISSUE_PROPERTIES[j]]);
	}
	values.push(value);
	}
	Logger.log(values);
	var sheet = SpreadsheetApp.getActiveSheet();
	sheet.getRange(1, 1, values.length, values[0].length).setValues(values);
	}

	function getIssues(repo) {
	var gitHubService = getGitHubService();
	var response = UrlFetchApp.fetch('https://api.github.com/repos/' + USERNAME + '/' + repo + '/issues?per_page=100', {
	headers: {
	Authorization: 'Bearer ' + gitHubService.getAccessToken()
	}
	});
	return JSON.parse(response);
	}