exception not caught in a javascript constructor in IE
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blissteria
Jan 5, 2009, 11:37:13 AM1/5/09
to Google Web Toolkit
Hi,
I have a pb related to InternetExplorer and probably GWT (but I'm not
convinced) since I have not managed to reproduce it outside of my gwt
project.
Let foo.js a javascript file containing:
function MyObject(){
throw "String Thrown";
};
In my Module.gwt.xml I add the following line to include the script
<script src="foo.js" />
Then in any java file of my application, in the click method of a
clickListener for instance, I call the function "createMyObject"
defined as:
public native void createMyObject()/*-{
new $wnd.MyObject();
}-*/;
The call of this function is surrounded by a try/catch block :
try {
createMyObject();
}
catch (Exception e){
Window.alert(e);
}
This works fine in firefox 2 and 3 but not in IE (6 and 7). In IE I
got an "exception rised but not caught" error and therefore no
alert...
What do you think of this problem?
Regards,
Blisseria.
I have a pb related to InternetExplorer and probably GWT (but I'm not
convinced) since I have not managed to reproduce it outside of my gwt
project.
Let foo.js a javascript file containing:
function MyObject(){
throw "String Thrown";
};
In my Module.gwt.xml I add the following line to include the script
<script src="foo.js" />
Then in any java file of my application, in the click method of a
clickListener for instance, I call the function "createMyObject"
defined as:
public native void createMyObject()/*-{
new $wnd.MyObject();
}-*/;
The call of this function is surrounded by a try/catch block :
try {
createMyObject();
}
catch (Exception e){
Window.alert(e);
}
This works fine in firefox 2 and 3 but not in IE (6 and 7). In IE I
got an "exception rised but not caught" error and therefore no
alert...
What do you think of this problem?
Regards,
Blisseria.
Ian Petersen
Jan 5, 2009, 11:43:04 AM1/5/09
to Google-We...@googlegroups.com
On Mon, Jan 5, 2009 at 8:37 AM, blissteria <bliss...@hotmail.com> wrote:
> Let foo.js a javascript file containing:
> function MyObject(){
> throw "String Thrown";
> };
>
> In my Module.gwt.xml I add the following line to include the script
> <script src="foo.js" />
>
> Then in any java file of my application, in the click method of a
> clickListener for instance, I call the function "createMyObject"
> defined as:
> public native void createMyObject()/*-{
> new $wnd.MyObject();
> }-*/;
>
> The call of this function is surrounded by a try/catch block :
> try {
> createMyObject();
> }
> catch (Exception e){
> Window.alert(e);
> }
>
> This works fine in firefox 2 and 3 but not in IE (6 and 7). In IE I
> got an "exception rised but not caught" error and therefore no
> alert...
>
> What do you think of this problem?
> Let foo.js a javascript file containing:
> function MyObject(){
> throw "String Thrown";
> };
>
> In my Module.gwt.xml I add the following line to include the script
> <script src="foo.js" />
>
> Then in any java file of my application, in the click method of a
> clickListener for instance, I call the function "createMyObject"
> defined as:
> public native void createMyObject()/*-{
> new $wnd.MyObject();
> }-*/;
>
> The call of this function is surrounded by a try/catch block :
> try {
> createMyObject();
> }
> catch (Exception e){
> Window.alert(e);
> }
>
> This works fine in firefox 2 and 3 but not in IE (6 and 7). In IE I
> got an "exception rised but not caught" error and therefore no
> alert...
>
> What do you think of this problem?
I'm just guessing here because I don't know how GWT maps native
Javascript "exceptions" into Java. I think your problem might be
related to the fact that you're throwing a string, not an Exception
and you're catching an Exception, not a string.
Do you have control over the script you're trying to include? Can you
modify the throw statement to call into a Java method that throws a
"real" exception? Could you factor the throw statement into a helper
function that gets substituted by a JSNI method when the script is
invoked from a GWT app?
Ian
blissteria
Jan 5, 2009, 12:02:55 PM1/5/09
to Google Web Toolkit
Thanks for the really quick answer!!!
I can modify the script I include but I'd rather not. The calls of
"throw" are already wrapped in a function therefore your solution
could be envisaged.
There is another solution that works but I do not trully understand
why. I wrap the call of "new MyObject()" in a function defined in the
foo.js file :
function wrappingMyObjectConstructor() {
try {
return new MyObject();
} catch (e) {
throw e;
}
}
and calling wrappingMyObjectConstructor in JSNI works fine in IE. This
is a hack, it works, but does anyone know how to avoid this or can
explain this?
Thanks
On 5 jan, 17:43, "Ian Petersen" <ispet...@gmail.com> wrote:
I can modify the script I include but I'd rather not. The calls of
"throw" are already wrapped in a function therefore your solution
could be envisaged.
There is another solution that works but I do not trully understand
why. I wrap the call of "new MyObject()" in a function defined in the
foo.js file :
function wrappingMyObjectConstructor() {
try {
return new MyObject();
} catch (e) {
throw e;
}
}
and calling wrappingMyObjectConstructor in JSNI works fine in IE. This
is a hack, it works, but does anyone know how to avoid this or can
explain this?
Thanks
On 5 jan, 17:43, "Ian Petersen" <ispet...@gmail.com> wrote:
Ian Petersen
Jan 5, 2009, 12:08:41 PM1/5/09
to Google-We...@googlegroups.com
On Mon, Jan 5, 2009 at 9:02 AM, blissteria <bliss...@hotmail.com> wrote:
> There is another solution that works but I do not trully understand
> why. I wrap the call of "new MyObject()" in a function defined in the
> foo.js file :
> function wrappingMyObjectConstructor() {
> try {
> return new MyObject();
> } catch (e) {
> throw e;
> }
> }
>
> and calling wrappingMyObjectConstructor in JSNI works fine in IE. This
> is a hack, it works, but does anyone know how to avoid this or can
> explain this?
> There is another solution that works but I do not trully understand
> why. I wrap the call of "new MyObject()" in a function defined in the
> foo.js file :
> function wrappingMyObjectConstructor() {
> try {
> return new MyObject();
> } catch (e) {
> throw e;
> }
> }
>
> and calling wrappingMyObjectConstructor in JSNI works fine in IE. This
> is a hack, it works, but does anyone know how to avoid this or can
> explain this?
You may have found a bug in GWT. If GWT can catch thrown strings in
the second case but not in the first case, then I think there's a
problem with the exception mapping between the languages. You might
want to file a bug and, if you do, try to include a really good repro
case.
Ian
blissteria
Jan 5, 2009, 11:25:30 PM1/5/09
to Google Web Toolkit
I finally managed to reproduce this pb outside of gwt. It seems to be
due to the fact the js is loaded inside an iframe (which is the case
of the js generated by gwt).
Here is a simple example to reproduce it.
######## main.html ########
<html>
<head>
<script type="text/javascript">
function MyObject(){
throw "String thrown";
};
//This function is the workaround to the pb explained in my previous
post
function wrappingMyObjectConstructor(){
try{
new MyObject();
}
catch(e){
throw(e);
}
}
</script>
</head>
<body>
<iframe src="iframe.html" width="500px" height="200px"></iframe>
</body>
</html>
######## iframe.html ########
<html>
<head>
<script type="text/javascript">
function buggy(){
try{
new parent.window.MyObject();
}
catch(e){
alert(e);
}
}
function notBuggy(){
try{
parent.window.wrappingMyObjectConstructor();
}
catch(e){
alert(e);
}
}
</script>
</head>
<body>
<a href="javascript:buggy();">buggy : constructor called directly</
a><br/>
<a href="javascript:notBuggy();">not buggy : constructor called via
wrapping function</a>
</body>
</html>
On 5 jan, 18:08, "Ian Petersen" <ispet...@gmail.com> wrote:
due to the fact the js is loaded inside an iframe (which is the case
of the js generated by gwt).
Here is a simple example to reproduce it.
######## main.html ########
<html>
<head>
<script type="text/javascript">
function MyObject(){
throw "String thrown";
};
//This function is the workaround to the pb explained in my previous
post
function wrappingMyObjectConstructor(){
try{
new MyObject();
}
catch(e){
throw(e);
}
}
</script>
</head>
<body>
<iframe src="iframe.html" width="500px" height="200px"></iframe>
</body>
</html>
######## iframe.html ########
<html>
<head>
<script type="text/javascript">
function buggy(){
try{
new parent.window.MyObject();
}
catch(e){
alert(e);
}
}
function notBuggy(){
try{
parent.window.wrappingMyObjectConstructor();
}
catch(e){
alert(e);
}
}
</script>
</head>
<body>
<a href="javascript:buggy();">buggy : constructor called directly</
a><br/>
<a href="javascript:notBuggy();">not buggy : constructor called via
wrapping function</a>
</body>
</html>
On 5 jan, 18:08, "Ian Petersen" <ispet...@gmail.com> wrote:
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