I want to save a javascript code as store function via Java API. The problem is that I don't know how to convert String (type 2) to code (type 13). I know that in PHP it's possible:
new mongo.Code("function myFunction() { return 123; }").
So is there any way to save stored function via Java API?
It's very similar in Java:
final Code code = new Code("function myFunction() { return 123; }");
Related
I need to check for fullscreen support with my Go WASM Canvas project, before switching to fullscreen mode. I have the following code so far:
var fullscreenFunc js.Value
var fullscreenNotSupported bool
set with the following logic:
fullscreenFunc = app.Get("requestFullscreen")
if fullscreenFunc.IsUndefined() {
fullscreenFunc = app.Get("mozRequestFullScreen")
if fullscreenFunc.IsUndefined() {
fullscreenFunc = app.Get("webkitRequestFullscreen")
if fullscreenFunc.IsUndefined() {
fullscreenFunc = app.Get("msRequestFullscreen")
if fullscreenFunc.IsUndefined() {
fullscreenNotSupported = true
println("Fullscreen not supported")
}
}
}
}
I was expecting to be able to call the correct function with js.Invoke, but I see no way to tell the Invoke upon which object the call should be made. My 'app' value is being interpreted just as a param.
func Fullscreen(app js.Value) {
if fullscreenNotSupported {
return
}
fullscreenFunc.Invoke(app)
}
resulting in:
panic: JavaScript error: 'mozRequestFullScreen' called on an object that does not implement interface Element.
So am I correct in my thinking that the only way I can call the correct method, is not to store the Function, but to store a string of the function name, and then 'invoke' / 'call' it using the following approach?
app.Call(fullscreenFunctionNameString)
It feels like I misunderstood the purpose of Invoke. Is it only for js.Global() type calls?
[edit] Using 'Call', at least it seems possible to derive the function name without having to repeat the above browser specifics:
fullscreenFunctionName = fullscreenFunc.Get("name").String()
app.Call(fullscreenFunctionNameString)
It doesn't answer the question, but is probably of help to someone trying to do the same.
The arguments to invoke get turned into arguments for the javascript function it wraps. Since those fullscreen functions don't need any arguments, I think you might just need to change:
fullscreenFunc.Invoke(app)
To:
fullscreenFunc.Invoke()
...assuming app is the same JS element in both places. If not your Call solution is probably your best bet.
I'm trying to use callMethod() from a method executed on the server.
In this case, I should be able to call it in synchronous mode. However, through trial and error I have found that in this context (i.e. on the server), the method requires three parameters rather than the two mentioned in the docs.
It requires
the first parameter to be a string
the second parameter to be an array
the third parameter to be an object
I've tried quite a few combinations with these parameters but nothing seems to work. At the same time, Wakanda doesn't throw an error as long as the parameters are in the correct form.
Any ideas would be more than welcome.
TIA
Let's suppose we have two variable, one containing the name of the dataClass and the second the name of the dataClass's method :
var myDataClass = "User";
var myMethod = "addUser";
To use the dataClass 'User' and call the method 'addUser' you can do it this way :
var currentClass = ds.dataClasses[myDataClass];
currentClass[myMethod]()
The method callMethod() is a clientSide method, it should be used on prototyper Js files.
try to use it on a button.click event :
button1.click = function button1_click (event)
{
ds.User.callMethod({method:"method1", onSuccess:myFunction, onError:failure});
function myFunction(){
return true;
}
function failure(){
return false;
}
};
To call method in a serverSide js File in a synchronous mode, you can just make the call in this manner :
var test = ds.User.method1();
I am using jscript for scripting in Testcomplete.
I have a function
function A()
{
return someobjReference ; //this variable contains a reference
}
function B()
{
}
I need to use the object reference(someobjReference ) in function B().How can i do that?
Thanks !
The JScript language used in TestComplete is the JavaScript language implementation from Microsoft. You can find a lot of information on JavaScript language in Internet or in printed books.
As for your question, you can do this in the following manner:
function B()
{
var objRef = A();
// use objRef, for example:
// Log.Message(objRef.Name);
}
OK, I have a function in C++ that I need to call from JavaScript, and one of the parameters is a JavaScript object. The JavaScript looks like this:
var message = {
fieldA: 42,
fieldB: "moo"
};
myObj.send(message, function (err) { console.log("Result: " + err); });
In the send() routine I need to call a native function in another C library that may block. All functions in this library may block so I've been using uv_queue_work extensively.
This routine is the first time I've hit an issue and it is because of the JavaScript object. The C++ code looks like this:
struct SendMessageRequest
{
Persistent<Object> message;
Persistent<Function> callback;
int result;
};
Handle<Value> MyObj::Send(const Arguments& args)
{
HandleScope scope;
// Parameter checking done but not included here
Local<Object> message = Local<Object>::Cast(args[0]);
Local<Function> callback = Local<Function>::Cast(args[1]);
// Send data to worker thread
SendMessageRequest* request = new SendMessageRequest;
request->message = Persistent<Object>::New(message);
request->callback = Persistent<Function>::New(callback);
uv_work_t* req = new uv_work_t();
req->data = request;
uv_queue_work(uv_default_loop(), req, SendMessageWorker, SendMessageWorkerComplete);
return scope.Close(Undefined());
}
This is all fine, the problem comes when I try to access request->message in the SendMessageWorker function.
void SendMessageWorker(uv_work_t* req)
{
SendMessageRequest* request = (SendMessageRequest*)req->data;
Local<Array> names = request->message->GetPropertyNames();
// CRASH
It seems that calling methods off of request->message causes an Access Violation on a really small address (probably a NULL pointer reference somewhere in V8/node). So using request->message directly must be wrong. I know to access the callback function I need to do this:
request->callback->Call(Context::GetCurrent()->Global(), 1, argv);
Do I need to use Context::GetCurrent()->Global() in order to access methods off of the Object class that is wrapped by the Persistent template? If so how do I do that?
The code in SendMessageWorker is not executed on the JavaScript - what uv_queue_work does is execute your SendMessageWorker in a separate thread, so it can let the node.js code run as well, and when it's ready, SendMessageWorkerComplete is executed back on the JavaScript thread.
So you can't use JavaScript variables in SendMessageWorker - if you really need to, you'd have to convert them to e.g. C++ string before calling uv_queue_work.
So I've been playing around with Lift in Scala, and I've been enjoying it a lot. I might just be missing something that exists in the lift javascript library, but I haven't been able to find any way of using a scoped javascript callback. It seems that the lift way of handling callbacks is to pass the callback as function name and have lift return a JsCmd that Call()s the function.
My lift code is heavily based on this example http://demo.liftweb.net/json_more
And my javascript looks kinda like
function operation(config) {
var actions = config.actions,
action = actions.shift(),
name = config.name;
function chainAction(response) {
if (actions.length > 0) {
action = actions.shift();
action.action(name, chainAction);
}
}
action.action(name, chainAction);
}
operation({
name: "ajax",
actions: [
{ action: ajaxCall1 },
{ action: ajaxCall2 }
]
});
Where I'd want ajaxCall1 and ajaxCall2, to be AJAX calls to lift. i.e. callNoParam() in the lift example, and chainAction to be the scoped callback. Is there a way to do this in lift that I'm missing? For clarity, I have been able to get this code to call the lift function, but not to handle the callback correctly.
Thanks.
Edit
Upon reading through the lift-generated javascript code, it looks like there are indeed placeholders for success/failure callbacks. In particular, it looks like this line of lift
AllJsonHandler.is.jsCmd
is generating this line of javascript
function F86737576748N5SY25(obj) {liftAjax.lift_ajaxHandler('F86737576748N5SY25='+ encodeURIComponent(JSON.stringify(obj)), null,null);}
which references this method
lift_ajaxHandler: function(theData, theSuccess, theFailure, responseType)
But not allowing me to pass theSuccess or theFailure which look like they are being passed along into jQuery.ajax() calls. My investigation continues. If anyone has any good resources on is.jsCmd it would be appreciated.
Below is a piece of code that adds a Javascript function doCallback to the page (in #placeholder). This function will print a line to the console and then do an ajaxCall back to the server to the function commandCallback.
def addExecuteCallback(ns: NodeSeq):NodeSeq = {
val log = JsRaw("console.log('[doCallback] Generated from Lift.');").cmd &
SHtml.ajaxCall(JsRaw("commandString"), commandCallback _)._2.cmd
val f = JsCmds.Function("doCallback", List[String](), log)
("#placeholder" #> JsCmds.Script(f)).apply(ns)
}
At the end of commandCallback, you can return:
JsCmds.Run("chainAction('" + valueOfResponse + "');")