AppeX and JavaScript Support Enhancements in Cincom Smalltalk

The 25th Annual European
Smalltalk User Group ConferenceSeptember 4, 2017
AppeX and JavaScript
Support Enhancements in
Cincom Smalltalk™
Speaker: Vladimir K. Degen

Proprietary & Confidential
A Bargain
Two talks in one!
• Generic JavaScript code management in Smalltalk,
(a segue)
• JavaScript evaluation and web automation from within
Smalltalk.
@cincomsmalltalk #ESUG17

A Misconception
• Lots of developers, Smalltalkers included, want to get
involved in web development.
• They might think that Smalltalk and JavaScript don’t go
together well, or that the mindsets are incompatible.
• Nothing could be further from the truth!

Actually, 
Smalltalk and JavaScript 
go together like…
Beer and Bratwurst
Lox and Cream Cheese
Chocolate and Peanut
Butter

A Little Recap of AppeX
• AppeX manages your JavaScript code versioning
• It allows you to build client-side JavaScript in an Object
Oriented manner.
• In practical terms, this means defining JavaScript “classes”, and
creating “instance” methods on them.
• Take a quick look at the IDE to give a baseline for this
presentation

More Recap of AppeX
[Open the IDE, show senders/implementers etc.]
• What you write in the JavaScript function template is the JavaScript  
you get in the web browser!
• Developing in AppeX is good way to hone your JavaScript skills while
leveraging the Smalltalk IDE.
• See 3 previous ESUG presentations on AppeX, including
https://www.slideshare.net/esug/2014-0817esug2014appe-x

Some Subtleties, but only Briefly
• Up until EcmaScript6, JavaScript did not have a standard for class
hierarchies and method inheritance.
• Thus many products, including AppeX have implemented their own
class hierarchy inheritance frameworks.
• AppeX emphasizes the ApplicationClient as a delivery mechanism
of the JavaScript to the web client, with other JavaScript delivered
as external libraries.
• However the external libraries lose out on the code management
tools of AppeX.

Ok, a Bit of the Inheritance Hierarchy
JavascriptCode
JavascriptObject GenericJavascript
JavascriptArray,etc ApplicationClient JavascriptClosure
This talk

And a Couple More Subtleties
• With GenericJavascript, we are easing the process of delivering
JavaScript in any form.
• And this JavaScript can be completely managed within AppeX.
• This opens up further the possibility of easily porting sophisticated
web application code to and from AppeX,  
and also to use AppeX to produce applications in any 
software design style that you wish.

GenericJavascript
• GenericJavascript just means code that will be displayed and
executed as written.
• The code in “initialize” will be delivered to the client as is and
executed immediately.
• The functions will appear as global functions on the client.
• Since the code is in the IDE , you get syntax highlighting, senders and
implementers and code version management.
• The markup in the comments below is so Smalltalk can parse it.

GenericJavascript – Code1
// <startContents: #{AppeX.HelloScript}>
function say(aString) {
var myDiv;
myDiv = document.createElement("div");
myDiv.innerHTML = aString;
document.body.appendChild(myDiv);
}
function sayHello(){
say('Hello from sayHello');
}

GenericJavascript – Code 2
// <startInitialize: #{AppeX.HelloScript}>
document.body = document.body ||
document.createElement("body");
sayHello();
// <endContents: #{AppeX.HelloScript}>

GenericJavascript

JavascriptClosure
• A subclass of GenericJavascript which avoids creating globals.
• With JavascriptClosure, you get in addition that your code is
encapsulated in functions.
• That is, you get method and data encapsulation.
• You can also make private methods, though this is still work in
progress.
• You do *not* get class hierarchy inheritance

JavascriptClosure – Code 1
This is how it looks like in JavaScript:
Object.defineProperty(AppeX.PersonClosure.prototype,'say
Goodbye',
{value: function sayGoodbye(){
this.say('Goodbye', this.getIsWhispering());
},
enumerable: false, writable: true
});

JavascriptClosure - Function

JavascriptClosure - Initialization

Application on the Server for the JavascriptClosure

JavaScript Closures and Generic JavaScript Scripts
• Note that the file based serving still works for these.
• However, cannot just parse and file in random JavaScript.
• We produce the code in a certain format (i.e. annotated with
comments) and file it in and parse it using the same format.

JavascriptClosure and GenericJavascript - 1
• One advantage comes in how you can more naturally view and perhaps
reuse your code when the view is restricted to the single method, but
the methods are listed and grouped.
• The Smalltalk tools based browsers and code separation aids in
understandability of JavaScript as well as it does for Smalltalk.

• Suppose that you had a bunch of JavaScript Code that was kind of
complex and maybe not optimally written. Obviously not your own
code. Might’ve been your coworkers or just something you got from the
web.

JavaScript Closure and Generic JavaScript - 2
• Putting your JavaScript into AppeX helps you to rationalize it.  
You are strongly encouraged by the tools to at least identify your
functions, the scopes of your variables, your objects, in order to get the
benefit of the tools.

• You could dump all your code into a big GenericJavascript,  
but that might not buy you much. So you can do this to get  
your application working then refactor from there.
• AppeX encourages an iterative development style.

On to the JSAutomator/JSEvaluator
• JSEvaluator uses whatever web browser is available on the
server to evaluate JavaScript from within the AppeX IDE.
• Development only, not run-time.

Evaluating JavaScript in Smalltalk (sort of)
• Start the JSEvaluator Server
• Here are a few expressions that you might try in a workspace,
and comparing with the result when the JavaScript is evaluated in
a web browser console:
JSEvaluator evaluateJavaScript: '"a" + "c"'. "ac"
JSEvaluator evaluateJavaScript: ' 1 2 '. "Error"
JSEvaluator evaluateJavaScript:‘JSON.stringify(window.location);'.

A More Practical Example, the Beautifier
• To try out JavaScript formatting using the open source
library jsbeautifier (http://jsbeautifier.org/):
a) Make a change to a JavaScript method in the  
refactoring browser
b)Try Menu...Edit...Format to observe the results.
• Conclusion:We have some ideas for useful external
JavaScript libraries, perhaps you have others.

Before Beautifying

After Beautifying

Website Automation
• We have a lot of web application examples that we want to retest,
naturally, during internal releases.
• We created the JSAutomator, build upon the JSEvaluator.
• A test (or automation) script is injected into the application to be
tested.
• The injected JavaScript exercises the web application's functionality
and sends results back to the Smalltalk server.

Non-Intrusive Testing
• One goal was to have a completely non-intrusive testing mechanism
that does not require one modify the “tested” application in any way,
whether the application is external or internal.
• The JSAutomator uses a couple of techniques to achieve this goal.

Injecting Code
• Ideally the JSAutomator just adds its own code libraries  
(very easy when dealing with AppeX applications).
• Or:The Hammer
Inserting script tags at the end of the initial HTML document, and
then including the JSAutomator libraries.
• The downloaded code uses a couple of techniques to manipulate
the client browser, such as function wrapping and setTimeout.

Waiting for Results
• Ultimately, Smalltalk waits upon the “promise” or expected
results from the client browser.
• Internally, we’ve created a bunch of SUnit tests for our
examples. I’d like to show you a couple of those now.

Demos
Order of display:
• First an AppeX example opened and exercised manually:
HelloLocalized.
• Then automated.
• Finally, all of them automated.

Conclusions
• GenericJavascript increases flexibility of coding different types of
applications in AppeX while leveraging the Smalltalk IDE.
• GenericJavascript is used in the JSEvaluator, and hence the
JSAutomator.
• The JSAutomator framework has already proven useful to us for
regression testing of web applications.
• We hope you have fun with these new AppeX tools and capabilities.

Contact Us
Suzanne Fortman  
Director of Smalltalk Global Operations 
sfortman@cincom.com 
@SuzCST (Twitter)
Arden Thomas  
Product Manager 
athomas@cincom.com 
@ArdenTCST (Twitter)
Vladimir Degen 
vdegen@cincom.com

AppeX and JavaScript Support Enhancements in Cincom Smalltalk

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