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Calling Java function from Rhino

Calling Javascript functions running inside Rhino from Java is easy enough - that after all is why Rhino was created. The thing I am having trouble establishing is this:
Context: I have a Phonegap CLI (v 6.3.3) Android project (API 19+) where I do a great deal of processing via loadable JavaScript running inside rhino
A Phonegap plugin - which I am creating at the same time as the actual Phonegap app - contains class called Storage which provides public, static, methods such as readFromFile(String fileName), writeToFile(String fileName,String data) etc.
What I want to be able to do is to call Storage.readFromFile etc from my loaded JavaScript code in Rhino.
Just how this should be done is not too clear to me. From the searches I have done thus far it involves using ScriptableObject.putProperty to pass the Java class in question, Storage in my case to JavaScript. However, how this should be done and then how it should be used at the JS end leaves me rather confused.
I would be most grateful to anyone here who might be able to point me in the right direction

Given that Rhino has less than 100 followers here it should perhaps come as little surprise that this question was not answered. In the mean time I have managed to find the solution myself and it turns out to be very simple. I share it below for the benefit of anyone else running into this thread.
My Storage class is very simple. It goes something like this
public class Storage
{
public static boolean haveFile(){}
public static boolean readFromFile(String fname){}
...
}
When I call Javascript from Java via Rhino I simply pass a new instance of the Storage class as the last of my function parameters
Context rhino = Context.enter();
Object[] functionParams = new Object[] {"Other parameters",new Storage()};
rhino.setOptimizationLevel(-1);
try
{
Scriptable scope = rhino.initStandardObjects();
String rhinoLog = "var log = Packages.io.vec.ScriptAPI.log;";
String code = /*Javascript code here* as shown separately below/;
rhino.evaluateString(scope, rhinoLog + code, "ScriptAPI", 1, null);
Function function = (Function) scope.get("jsFunction", scope);
Object jsResult = function.call(rhino,scope,scope,functionParams);
}
where the Javascript code is
function jsFunction(a,s)
{
//a - or a,b,c etc - here will be the "other" parameters
//s - will be the instance of the Java side Storage class passed above
//now you can do things like
s.writeToFile('fileName','fileData');
var fd = s.readFromFile('fileName');
s.dropFile('fileName');
...
}

How to parse and load javascript object?

I have one js files . I load it using other javascrupt file using eval() function. I have seen eval is slow and with some other limtation. Since i need to store my JS file object in cache and use it anytime i need after apllication starts. I dont want to do eval() everytime.
Is there anyway to do it in simple way.
var evalObj;
if(evalObj) {
console.log('eval object already evaluated');
_myfunctionInJSFile_(layouts.FormatDate(startTime), threadName, level, categoryName, message);
}
else {
evalObj = eval(fs.readFileSync('./myJSFile', 'utf8'));
console.log('re evaluating object ..' );
_myfunctionInJSFile_(layouts.FormatDate(startTime), threadName, level,message);
}
myJSFile
var _sigmaAlarmHandler_ =function(args)
{
var args = Array.prototype.slice.call(arguments);
args.unshift();
console.log('Alarm : ', args);
}
Either the conditional eval is not working.

In node.js you can simple require your js-file:
var obj = require('./myJSFile');
obj.foo();
./myJSFile.js:
exports.foo = function() {
console.log('foo');
}
This file becomes a module with exported functions, that you need.
It loads once, then every require reuse already loaded module.

If it is not commonjs-compliant (i.e. using module.exports will not work), then you can run it in its own vm:
var vm = require('vm');
vm.runInNewContext(jscode,{/*globalvars*/});
where the second parameter is an object with global vars made available in the context in which the jscode is run. So if the second param is, say, {a:1,b:"foo"} then your jscode will run with the global variable a set to 1 and the global variable b set to "foo".
The jscode itself is a string that you load from a file or elsewhere.
Think of vm.runInNewContext() as "practice safe eval". Well, relatively safe, you can still do some dangerous stuff if you pass in particular vars, like process or file etc.
I used this for the declarative part of cansecurity http://github.com/deitch/cansecurity for nodejs
You can view the sample in the file lib/declarative.js
Here is the API for vm http://nodejs.org/api/vm.html
There are options to run in the same context, etc. But that is very risky.
When you actually run the code, using your example above:
_myfunctionInJSFile_(layouts.FormatDate(startTime), threadName, level,message);
you are looking to pass in 4 params: startTime, threadName, level, message and execute the function. The issue is that you cannot run the function on the current context. You need the function to be defined and run in the file. So you should have something like:
vm.runInNewContext(jscode,{startTime:layouts.FormatDate(startTime),threadName:threadName,level:level,message:message});
And then the jscode should look like
function _myfunctionInJSFile(startTime,threadName,level,message) {
// do whatever you need to do
}
// EXECUTE IT - the above vars are set by the global context provide in vm.runInNewContext
_myfunctionInJSFile(startTime,threadName,level,message);
If you prefer to define the function and have it loaded and run in this context, then just use the commonjs format.

I think i have found the answer for this.
Since my application is running in node js which uses v8 engine platform. When the application starts v8 engine caches all the code/configuration and can be used anytime.
Similarly in my code i will pre-load the JS code using eval and i will do it only once. So on next call i will return only the loaded JS code. Here i need to modify the code to load once.
But main point we have look is that in future if any body has similar requirement they can cache their JS codes using eval (thanks to v8 engine) and use it till your application is running.

Express/Node.js : Render custom javascript as response

In my application, I need to provide an API (something like the Google Maps javascript API), through which I can send some custom javascript (with some session and request related information) as the response. The javascript is then used to plot some graphs on the UI. I'm using Express with Jade as my templating engine. The code that I'm currently using is:
app.use('/graph',function(req, res){
//send out graph data
var var_name = req.session.var_name //fetch something from session
var graphData = fetchGraphData(req.query.graph); //function that fetches graph data
res.contentType("text/javascript");
res.render(__dirname + '/views/graph.jade', {
title: "Title", queryStr: JSON.stringify({var_name: var_name, graphData: graphData })
});
});
And the jade file:
| some_var_name = {
| initGraph : function(divId){
| //some code here
| var graphData = !{graphData}
| // do something
As a workaround, I have started each line of the jade file with |, so that jade parses the text as plain text, and doesn't add any html tags! It works fine, but is there a cleaner way to do this? The solution may or may not use Jade!

You should look into underscore templates. I think that for generating arbitrary text output it would be somewhat cleaner. Jade is purpose-built for rendering HTML.
You could also try Mustache or Handlebars.
Based on your comment, I see you'd like to keep using res.render for rendering the template. consolodate.js adds support for all major template engines to Express. Including Underscore templates, Handlebars, Mustache and Dust, mentioned by #TheHippo.

You may try to define JavaScript functions you need to send to the browser in a separate module, outside of the template, which is probably more correct way from the "concerns separation" point of view. Also if functions are defined in a separate module they can be used both in the server and in the browser.
Then you can convert the functions to strings using its toString() method either in a function that invokes the template or right inside the template, if it supports plain JavaScript which is the case with underscore, EJS and doT templates (I tried both underscore and EJS and ended up using doT which is not only the fastest but very versatile - check it out):
JS code:
// if you send the same functions you may want to convert them to strings in advance
var data = {
funcStr: func.toString();
};
res.render(view, data);
Template (doT):
<script type="text/javascript">
func = {{= it.funcStr }};
// now you can call it here if you want but I would use
// separate JavaScript files
func();
</script>
I use it to send pre-compliled templates to the browser together with the page on the first page load, but I think it can be used in your case too.
As a side question, why can't you just bundle all these functions in a separate JavaScript module and load them as normal script file?

You can use https://www.npmjs.com/package/rendercustomjs package, it works fine but in ejs templating

Appcelerator titanium - passing js variables

I am new to JS and Appcelerator titanium. I am trying to implement the MVC model to my app, but I have a problem accessing the data in the model:
in the model.js:
var my_val;
then in file1.js, I modified the value of my_val:
Ti.include("model.js");
my_val=5;
then in another file file2.js:
Ti.include("model.js");
T.API.info(my_val); // the value I always get is "undefined"
why is file2.js not detecting the change file1.js has done to my_val? Is there anyway to make it work?

take a look at my blog posting regarding this particular problem.
blog.clearlyinnovative.com
you want to include both files in your app.js and add the variable to your namespace; this is cleaner and doesn't pollute the global scope.
var myApp = {};
Ti.include("model.js");
Ti.include("file2.js");
in model.js do something like this
var myApp.model = {};
myApp.model.my_val = 100;
in file2.js do something like this; no need to incude model.js again, the value was set in your own namespace and is clearly defined
Ti.API.info(myApp.model.my_val);

If you want to get this functionality done use Titanium Properties so that you can get/set your variable as per requirement.Do something like this in your app.js
// initialize your variable, you can update it as well with your custom value
Titanium.App.Properties.setInt('my_value', 0);
You can get this value any where you want like this:
var myValue = Titanium.App.Properties.getInt('my_value');

This is because what the statement
Ti.include('model.js');
does is to just sort of 'copy-paste' the code in your 'model.js' file into the other two files. All the variables in 'model.js' will be available to the file in which you included 'model.js'. But this only means that a copy of the variable my_val is made available to 'file2.js' not a variable that is common to all files that have the Ti.include('model.js') line!Including a file in another is pretty much the same as typing out the lines of the first file into the second but it in no way connects all files that include a common file!
So maybe instead of
Ti.include('model.js');
Ti.API.info(my_val);
you can this try this seeing as you have already included 'model.js' in 'file1.js??'
Ti.include('file1.js');
Ti.API.info(my_val);
OR you can always go with Muhammad Zeeshan's advice and check out Ti.App.Properties. Good Luck! :)

How to get texts from Resx to be used in Javascript?

We are building large ASP.NET applications for the intranet use in multiple languages/cultures. We utilize the Globalization with RESX files and use GetResourceText on the server side to get the localized texts.
Lately we are doing more and more client side logic with JQuery.
How do I get the RESX texts to be used in Javascript?
e.g. texts used for validation, dynamic messages etc.
All our Javascripts are in .JS files, we do not want to mix HTML in the ASPX page and Javascript blocks.
Thanks for your help.

Unfortunately, in an external JS file the server side code is not being processed by the server. However I have seen a workaround where you can set your translated values in hidden fields on the page - this way your javascript will be able to read the values in.
For example:
<%-- This goes into your page --%>
<input type="hidden" id="translatedField" name="translatedField" value="<%=Resources.Resources.translatedText %>" />
and use this inside your javascript file:
// This is the js file
$(document).ready(function() {
alert($("#translatedField").attr("value"));
});
You will be able to separate the values and still see it in your external JS file.
There is also another workaround that creates a .aspx file that only outputs Javascript instead of HTML. Check out the link below:
Using server side method in an external JavaScript file

Always separate functionality from human readable strings.
If you're creating jQuery-plugins you should be able to pass an array of localized strings as parameter when you call your different jQuery functions. The array could be defined as inline javascript directly on the page calling the different jQuery plugins or you could load the from external resource in the format /scripts/localization/strings.js?ci=en-US and register a Generic ASP.Net Handler in web.config that would respond to scripts/localization/strings.js
The DatePicker control is a fine example of how to localize text for the jQuery datepick control - this js file is dynamically created from resource files (resx) and when included on a page it will make sure the calendar control will have danish text.

Create a HttpHandler (.ashx file), and return JSON with your text resource strings.
You may also "publish" it to global namespace, i.e.
Response.Write("window.Resources=");
Response.Write((new JavaScriptSerializer()).Serialize(strings));
set up HTML like:
<script src="Resx.ashx?lang=en-US" />
<button class="LogoutButtonResourceId OtherButtonClasses">(generic logout text)</button>
<a href="#"><span class="SomeLinkTextResourceId OtherClasses">
(generic link text)
</span></a>
and apply texts like this:
$(document).ready(function() {
for(var resId in Resources){
$("."+resId).html(Resources[resId]);
}
});

If you don't want to use ASP.NET to generate your main JavaScript, here are two other options:
Use ASP.NET to generate a script file that contains variable-to-string assignments, such as var mystring = 'my value';. Your main script would then reference the localized text with variables names rather than as embedded values. If that's still too "dirty" for you, you could encode the strings as JSON rather than as variable assignments, using an HttpHandler rather than straight .aspx.
Have your JavaScript code issue an Ajax call to retrieve an array or list of localized strings from the server. The server-side part of the call would retrieve the text from your resx files.

Have you considered using $.ajax in combination with ASP.NET WebMethods? It's hard to suggest a more concrete solution to this problem without understanding how your JavaScript/jQuery would consume/process the resources. I assume that they're organized into logical groups (or could be) where you could return several resource strings that belong on a single page.
Assuming that, you could write a very simple C# class -- or use a Dictionary<string, string> -- to return data from your ASP.NET WebMethod. The results would look something like:
[WebMethod]
public Dictionary<string, string> GetPageResources(string currentPage)
{
// ... Organizational stuff goes here.
}
I always separate out my AJAX calls into separate .js files/objects; that would look like:
function GetPageResources (page, callback)
$.ajax({ // Setup the AJAX call to your WebMethod
data: "{ 'currentPage':'" + page + "' }",
url: /Ajax/Resources.asmx/GetPageResources, // Or similar.
success: function (result) { // To be replaced with .done in jQuery 1.8
callback(result.d);
}
});
Then, in the .js executed on the page, you should be able to consume that data like:
// Whatever first executes when you load a page and its JS files
// -- I assume that you aren't using something like $(document).ready(function () {});
GetPageResources(document.location, SetPageResources);
function SetPageResources(resources) {
for (currentResource in resources) {
$("#" + currentResource.Key).html(currentResource.Value);
}
}

I know it's to late but want share my experience in this task)
I use AjaxMin. It can insert resx key values into js file on build event.
It's not common way but it keeps html without unneeded script blocks and can be done during minification process if you have it.
It works like this:
ajaxmin.exe test.js -RES:Strings resource.resx -o test.min.js
Also you need to do the same for ech locale if you have many.
Syntax to write resource keys in js (and also css) is written here:
Js localization
Css localization

How about injecting it as part of a javascript control initialization? what i do is as follows:
I have a self-contained javascript control - call it CRMControl, which has an init method called setupCRMControl, to which i pass a settings object. When i initialize it, i pass an object containing all the resources i need inside javascript as follows:
CRMControl.setupCRMControl({
numOfCRMs: 3,
maxNumOfItems: 10,
// then i pass a resources object with the strings i need inside
Resources: {
Cancel: '#Resources.Cancel',
Done: '#Resources.Done',
Title: '#Resources.Title'
}
});
Then, inside this javascript control:
var crmSettings = {};
this.setupCRMControl(settings) {
crmSettings = settings;
};
and whenever i want to show a resource, i say (for example, show an alert saying 'Done'):
alert(crmSettings.Resources.Done);
You can call it "R" to make it shorter or something, but this is my approach. Maybe this may not work if you have a whole bunch of strings, but for manageable cases, this may work.