Chrome Web Store: new way to publish Google Apps Script

Apps Script developers that wished to share their work with a larger audience have traditionally turned to the Script Gallery, which allows other users to copy and install the script into their own spreadsheets. While appropriate for custom functions and spreadsheet extensions, it didn't fit well when distributing more complex functionality and apps.

In this blog post we'll be highlighting a newer way to distribute your scripts: deploying them as a web app and publishing them to the Chrome Web Store. Compared to the Script Gallery, the Chrome Web Store has some distinct advantages for developers:

• Automatic updates - Change your code, do some testing, and publish a new version to update the app for all users instantly.
• More information - Detailed descriptions, promotional images, ratings, and reviews lead tocompelling listings.
• Greater discoverability - Visit the Chrome Web Store site to learn about the benefits.

Looking through the Script Gallery we believe there are many scripts that would be a great fit for the Chrome Web Store and would benefit from the advantages listed above. Some aspects of a good candidate script are:

• Custom UI - Users interact with your script through a custom user interface, not via custom spreadsheet functions or onEdit triggers.
• Background processing - Your script uses time-based triggers to do work in the background and doesn't require that the Google Spreadsheet is open.
• Not primarily about Google Spreadsheets - Your script's main focus isn't spreadsheets and you utilize a variety of services to provide separate functionality.

A great example of such a script is Gmail Meter, which was first launched in the Script Gallery but has since been published to Chrome Web Store. Now users can install and run the script without needing to create a spreadsheet, see script code, or set up triggers. It may take a little work to update a spreadsheet-based script to use the web app model, and some common tasks are:

• Implement doGet() - Instead of showing your custom UI on the spreadsheet with Spreadsheet.show(), put the same code into the doGet() method and return the finalUiInstance or HtmlOutput object.
• Deploy as a web app - Configure your script to run as a web app, which will assign it a unique URL. In most cases you'll want the web app to run as the user so that it can access their services.
• Remove references to active spreadsheet - When published as a web app there is no active spreadsheet, so if your script needs access to a spreadsheet then you'll need to use SpreadsheetApp.openById() instead. You can use the DocsList service or theDocsListDialog UI widget to help users locate the desired spreadsheet.
• Handle multiple users - When published as a web app users access the same copy of the script, so you may need to change the way you organize data to avoid conflicts.UserProperties work well for small settings, and when using ScriptDb make the user's login ID or email address part of the objects so that you can filter for them later.

Publishing to the Chrome Web Store only takes a few clicks, and we provide instructions for the process in our documentation. We hope that you are inspired to take your scripts to the next level, and if you have any questions along the way feel free to reach out to us on StackOverflow or Google+.

By Eric Koleda
Ref: http://googleappsdeveloper.blogspot.com/2012/09/expand-your-reach-with-web-apps.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+GoogleAppsDeveloperBlog+%28Google+Apps+Developer+Blog%29