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updating documentation with the example

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This commit is contained in:
Danny Yoo 2011-07-11 22:22:09 -04:00
parent e4c91b3917
commit a01da31310
2 changed files with 84 additions and 11 deletions
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89
scribblings/manual.scrbl
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@ -153,7 +153,7 @@ and if this does appear, then Whalesong should be installed successfully.
@subsection{Running Whalesong}
@subsection{Making Standalone @tt{.xhtml} files with Whalesong}
Let's try making a simple, standalone executable. At the moment, the
program must be written in the base language of @racket[(planet
@ -234,19 +234,90 @@ web browser, we should see a pale, green page with some output.
@;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@section{Extended example}
@subsection{Using Whalesong functions from JavaScript}
@;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(This example needs to use modules. It should also show how we can use the
other command-line options to compress the javascript, and how to
use @tt{get-javascript} and @tt{get-runtime}, to allow the user to
build a customized html file.)
Whalesong also allows functions defined from Racket to be used from
JavaScript. As an example, we can take the boring @tt{factorial}
function and define it in a module called @filepath{factorial.rkt}:
@filebox["factorial.rkt"]{
@verbatim|{
#lang planet dyoo/whalesong
(provide fact)
(define (fact x)
(cond
[(= x 0)
1]
[else
(* x (fact (sub1 x)))]))
}|}
Instead of creating a standalone @tt{.xhtml}, we can use @tt{whalesong} to
get us the module's code. From the command-line:
@verbatim|{
$ whalesong get-javascript factorial.rkt > factorial.js
$ ls -l factorial.js
-rw-r--r-- 1 dyoo dyoo 27421 2011-07-11 22:02 factorial.js
}|
This file does require some runtime support not included in
@filepath{factorial.js}; let's generate the @tt{runtime.js} and save
it as well. At the command-line:
@verbatim|{
$ whalesong get-runtime > runtime.js
$ ls -l runtime.js
-rw-r--r-- 1 dyoo dyoo 544322 2011-07-11 22:12 runtime.js
}|
Now that we have these, let's write an @filepath{index.html} that uses
the @racket[fact] function that we @racket[provide]ed from
@filepath{factorial.rkt}.
@filebox["index.html"]{
@verbatim|{
<!DOCTYPE html>
<html>
<head>
<script src="runtime.js"></script>
<script src="fact.js"></script>
<script>
// Each module compiled with 'whalesong get-runtime' is treated as a
// main module. invokeMains() will invoke them.
plt.runtime.invokeMains();
plt.runtime.ready(function() {
// Grab the definition of 'fact'...
var myFactClosure = plt.runtime.lookupInMains('fact');
// Make it available as a JavaScript function...
var myFact = plt.baselib.functions.asJavaScriptFunction(
myFactClosure);
// And call it!
myFact(function(v) {
$('#answer').text(v.toString());
},
function(err) {
$('#answer').text(err.message).css("color", "red");
},
10000
// "one-billion-dollars"
);
});
</script>
</head>
<body>
The factorial of 10000 is <span id="answer">being computed</span>.
</body>
</html>
}|
}
Replacing the @racket[10000] with @racket["one-billion-dollars"] should
reliably produce a proper error message.
@;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

6
tests/coersing/index.html
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@ -16,9 +16,11 @@ plt.runtime.ready(function() {
$('#answer').text(v.toString());
},
function(err) {
$('#answer').text(err.message);
$('#answer').text(err.message).css("color", "red");
},
10000);
10000
// "one-billion-dollars"
);
});
</script>
</head>