Google Apps Script

Google Apps Script
Developer(s) Google
Initial release 2009 [1]
Development status Active
Written in JavaScript
Operating system Cross-platform
Type Web application framework, Scripting language
Website http://code.google.com/googleapps/appsscript/index.html

Google Apps Script is a cloud based scripting language for light-weight application development in the Google Apps platform. It is based on JavaScript,[2] however instead of running on the client, it gets executed in the Google Cloud. Google Apps Script essentially provides easy ways to automate tasks across Google products and third party services.[3]

Contents

Benefits

  1. Based on JavaScript-like syntax. Easy to learn.
  2. Under the hood, Google Apps Script uses the Google Web Toolkit (GWT) to create and display user interface elements.[4] GWT is easy to learn, and completely abstracts the complexity of AJAX/HTML from the developer.
  3. Cloud based debugger for debugging App Scripts in the web browser.
  4. It can be used to create simple tools for an organization's internal consumption.
  5. It can be used to perform simple system administration tasks.

Limitations

  1. Currently Google Apps Script does not allow connection to internal (behind-the-firewall) corporate databases, which is key to building business apps. Similarly, lack of other connectivity, such as LDAP connectivity, limits the level to which GAS can be used in the enterprise.
  2. There is no way to share scripts i.e. a new instance has be created for each use.[5] This creates overhead when it is time to update a script, since each instance has to be update manually.
  3. UI Widgets in Google Apps Script lack support for displaying HTML formatted content.[6] This severely limits the formatting of text displayed in a Google Apps Script app.
  4. GAS does not allow to use client side javascript, which limits enormously the data-validation, and overloads the server.

Example

The following code demonstrate use of Google Apps Script UI Services and DocList Services to display contents of a Google Docs Collection in Tree format.

Notice the use of JavaScript-like syntax and the use of Google Web Toolkit widgets.

function doGet(e){   
  var app = UiApp.createApplication();
  var scrollPanel = app.createScrollPanel(); // Scroll Panel is a Google Web Toolkit Widget
  tree = app.createTree(); // Tree is a Google Web Toolkit Widget
  tree.addItem(buildTree(app, "Enterprise 2.0 - Saqib"));
  scrollPanel.add(tree);  
  scrollPanel.setHeight("500");
  app.add(scrollPanel);
  return app;
}
 
function buildTree(a, searchTerm){
  var tree = a.createTreeItem(); // TreeItem is Google Web Toolkit Widget
  tree.setText(searchTerm);
 
  // Use of the Google Apps Script DocList Service to retrieve the collections.
  var folders = DocsList.getFolder(searchTerm).getFolders(); 
  for (var i = 0; i < folders.length; i++)
      tree.addItem(buildTree(a, folders[i].getName())).setState(true, true);
 
  var files = DocsList.getFolder(searchTerm).getFiles();
  for (var i = 0; i < files.length; i++) {    
    if (files[i].getType() == "document") {
     urlBase = "https://docs.google.com/document/edit?id=";
     iconHTML = "https://docs.google.com/images/doclist/icon_7_document_list.png";
    } 
    else if (files[i].getType() == "spreadsheet") {      
      urlBase = "https://spreadsheets.google.com/ccc?key=";
      iconHTML = "https://docs.google.com/images/doclist/icon_7_spreadsheet_list.png";
    }
    else if (files[i].getType() == "presentation") {       
      urlBase = "https://docs.google.com/present/edit?id=";
      iconHTML = "https://docs.google.com/images/doclist/icon_7_presentation_list.png";
    }
    else if (files[i].getType() == "drawing") {       
      urlBase = "https://docs.google.com/drawings/edit?id=";
      iconHTML = "https://docs.google.com/images/doclist/icon_7_drawing_list.png";       
    }
    else {
      urlBase = "https://docs.google.com/fileview?id=";
      iconHTML = "https://docs.google.com/images/doclist/icon_7_generic_list.png";    
    }    
 
    var image = a.createImage(iconHTML);
    var fileLabel = a.createAnchor(files[i].getName(), urlBase+ files[i].getId());     
    var fileLabelPanel = a.createHorizontalPanel();
    fileLabelPanel.add(image);
    fileLabelPanel.add(fileLabel);     
    tree.addItem(fileLabelPanel).setState(true, true);
  }   
  return tree;   
}

References

  1. ^ Meyer, David (August 20, 2009). "Google Apps Script gets green light". CNet. http://news.cnet.com/8301-1001_3-10314002-92.html. Retrieved 26 March 2011. 
  2. ^ Kienle, Holger (May/June 2010 2010). "It's About Time to Take JavaScript (More) Seriously". IEEE Software 27 (3): 60–62. doi:10.1109/MS.2010.76. http://www.computer.org/portal/web/csdl/doi/10.1109/MS.2010.76. Retrieved 25 March 2011. 
  3. ^ Google Apps Script, Welcome to Google Apps Script
  4. ^ "Google Apps Script and the Google Web Toolkit". http://code.google.com/googleapps/appsscript/guide_user_interfaces.html#AppsScriptGWT. Retrieved 26 March 2011. 
  5. ^ "Ability to share scripts". http://code.google.com/p/google-apps-script-issues/issues/detail?id=40&sort=-stars&colspec=Stars%20Opened%20ID%20Type%20Status%20Summary%20Priority%20Component%20Owner. Retrieved 25 March 2011. 
  6. ^ "Support for HTML in UiApp". http://code.google.com/p/google-apps-script-issues/issues/detail?id=175. Retrieved 30 March 2011.