[Seaside-dev] submitFormNamed: weirdness

[Michel Bany]

Hi Michael,

I do not quite understand your description of the weirdness. My  
understanding is that the POST is the result of submitting the form,   
while the GET is the result of a redirect generated by the handling  
of the POST by Seaside.

The behavior of #submitFormNamed: has been completely reworked (lr. 
441 & lr.446). You may want to try the following fixes to WAAnchorTag  
and see it they fix the weirdness:

1. Add an instance variable named 'callbackKey'

2. Add method #handlerForForm:

handlerForForm: formName
	^ 'submitFormTriggeringCallback('''
			, formName displayString
			, ''', '''
			, callbackKey displayString
			, ''', "href" ); return false;'

3. Change method #submitFormNamed:

submitFormNamed: aString
	callbackKey isNil
		ifTrue:
			[self error: '#submitFormNamed: should be sent after #callback:'].
	self onClick: (self handlerForForm: aString)

HTH
Michel



On Nov 26, 2007, at 8:38 PM, Michael Lucas-Smith wrote:

> Hi All,
>
> Just recently I hit a weird bug with anchor's submitting forms..  
> specifically using #submitFormNamed:
>
> If you do something like:
>
> html anchor
>    callback: [self save];
>    submitFormNamed: 'form';
>    with: 'Save'.
>
> You'll have the web browser fire off a POST followed immediately by  
> a GET on two separate connections making it impossible for Seaside  
> to know which should be processed first. Often the GET will finish  
> first, causing the browser to redirect to a different page and  
> cancel the POST command - which may or may not have run yet.
>
> I saw this appear in the form of a bad demo at OCSTUG where the  
> POST submits the form and the GET writes to the database. However,  
> depending on timing, the write to the database would have empty  
> values.
>
> If you use #ignoreURL to put a 'return false' on the end of the  
> onclick you quickly discover that the anchor's callback is never  
> run.. which is puzzling when I found this thread: http:// 
> www.nabble.com/Anchor-with-submit-and-callback-t2648056.html from  
> 2006 describing how submitFormNamed: should preserve the action id  
> of the previously setup callback. This code doesn't exist in  
> Seaside 2.8 final.
>
> Right now a workable hack is:
>
> html anchor
>    callback: [self save];
>    submitFormNamed: 'form';
>    onClick: 'window.location = this.href';
>    ignoreURL;
>    with: 'Save'
>
> Which is just ugly as :) and it does mean the browser is still very  
> likely to terminate the second POST connection on the server side  
> which is likely to raise a "Client disconnect" sort of exception  
> (which is probably caught by the server - however, that's sort of  
> besides the point).
>
> Cheers,
> Michael
>
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