On Mon, Jun 12, 2017 at 5:29 AM, sebb <seb...@gmail.com> wrote:
> On 12 June 2017 at 03:36, Sam Ruby <ru...@intertwingly.net> wrote:
>> On Sun, Jun 11, 2017 at 7:16 PM, sebb <seb...@gmail.com> wrote:
>>> On 11 June 2017 at 00:14, Sam Ruby <ru...@intertwingly.net> wrote:
>>>> On Sat, Jun 10, 2017 at 6:39 PM, sebb <seb...@gmail.com> wrote:
>>>>> On 10 June 2017 at 23:20, Sam Ruby <ru...@intertwingly.net> wrote:
>>>>>> On Sat, Jun 10, 2017 at 6:15 PM, sebb <seb...@gmail.com> wrote:
>>>>>>> On 10 June 2017 at 17:22, Sam Ruby <ru...@intertwingly.net> wrote:
>>>>>>>> On Sat, Jun 10, 2017 at 12:05 PM, sebb <seb...@gmail.com> wrote:
>>>>>>>>> On 10 June 2017 at 16:58, Sam Ruby <ru...@intertwingly.net> wrote:
>>>>>>>>>> On Sat, Jun 10, 2017 at 11:48 AM, sebb <seb...@gmail.com> wrote:
>>>>>>>>>>> On 10 June 2017 at 15:57, Sam Ruby <ru...@intertwingly.net> wrote:
>>>>>>>>>>>> On Sat, Jun 10, 2017 at 10:27 AM, sebb <seb...@gmail.com> wrote:
>>
>> [snip]
>>
>>>>>
>>>>> I don't know where to start with ExecJS.
>>>>
>>>> Neither do I.
>>>>
>>>>> But it ought to be possible to use window.onerror or similar in the
>>>>> generated code to catch/display the error to the user.
>>>>
>>>> There is no window object on the server.
>>>>
>>>>> Or wrap the generated JS in try/catch.
>>>>
>>>> And do what?
>>>
>>> Display err.stack
>>>
>>> for example:
>>>
>>> try {
>>> ...
>>> } catch(err) {
>>> alert(err.stack);
>>> console.log(err.stack);
>>> etc.
>>> }
>>>
>>> However I've no idea how to add that to the generated code.
>>>
>>> It might be worth seeing what the following gives:
>>>
>>> rescue ExecJS::ProgramError => e
>>> Wunderbar.error e.inspect
>>>
>>> It may be that the error object has more info embedded.
>>
>> With no window object on the server, there is no window.alert. There
>> is no console object on the server either. Lets try this the other
>> way. I've included a sample program below with no dependencies other
>> than execjs:
>>
>> require 'execjs'
>>
>> source = %{
>> function test () {
>> try {
>> var x = null;
>> x.y();
>> } catch(err) {
>> alert(err.stack);
>> console.log(err.stack);
>> }
>> }
>> }
>>
>> context = ExecJS.compile(source);
>> context.call("test()");
>
> Running that with ruby fails with the error:
>
> test ((execjs):7:7): ReferenceError: alert is not defined
> (ExecJS::ProgramError)
>
> However the generated app.js file contains code of the form:
>
> .catch(function(error) {
> alert(errror);
> jQuery("#confirm").modal("hide");
> self.setState({disabled: false})
>
> which *does* use alert.
That code is contained within logic that is known to only run on the client.
> Though why it uses errror instead of error is unclear.
Clearly a typo on my part. I've pushed a fix. Good catch!
> I don't know how the alert gets added to the generated js, but if that
> could be updated to change the alert and/or wrap the code in a
> try/catch block it might solve the issue.
If you look at the fix I just pushed, you will see the code that gets
translated into the code mentioned above.
As to adding another try/catch block: again the question is do what
within that try/catch block? On the client, you get a nice traceback
in your console. On the server, there is no access to an alert or
console.log function.
> ==
>
> As to improving the server code reporting, it looks as though it may
> be sufficient to add
>
> Wunderbar.error e.backtrace
Getting a stack traceback of the ruby stack will only tell you that
you are calling render. At most, it will help you identify which page
the error occurred on, information that already is in the server log.
There would be value in showing a javascript traceback, but to date
I've not figured out a way to do that. If you experiment with the
smalls script I provided and find a way to show the javascript
traceback with that code, I would be very interested.
> after
>
> https://github.com/rubys/wunderbar/blob/master/lib/wunderbar/react.rb#L133
>
>> - Sam Ruby
- Sam Ruby
