[Seaside][ShoreComponents] DatePicker discussion

[Avi Bryant]

On Sep 24, 2005, at 6:32 AM, Michel Bany wrote:

> I ported the Shore date picker widget to VisualWorks and I wanted
> to discuss some of the difficulties I had.

Thanks; it's great to see discussions of the problems people are  
running into.  Consider this an open call for similar such stories :)

>
> 1) The Shore date picker is based upon the Squeak version of the Date
> class. The VisualWorks version of the Date is somewhat incompatible
> and I had to convert the VisualWork Date objects to Squeak.Date  
> objects
> (for those who do not know, the VisualWorks version of Seaside  
> includes
> a port of the Squeak chronology subsystem in a different namespace).

In which ways are the Date objects incompatible?  Rather than  
maintaining Squeak.Date, can we come up with a common protocol that  
can easily be implemented with a few extensions on either side, so  
that at least basic date code is interoperable between Squeak and VW?

> 2) Addding to the onclick attribute. Currently, coding something  
> like this
>    html attributes at: 'onclick' put: 'some javascript'.
>    html attributes at: 'onclick' put: 'some more javascript'.
> generates the onclick attribute twice in the html tag, making the  
> response
> uncompliant to xhtml.
<snip>
> Therefore I had the idea to implement this
>    html attributes at: 'onclick' append: 'some javascript'.
>    html attributes at: 'onclick' append: 'some more javascript'.
> The implementation is equivalent to at:put: when the attribute was
> never used before. It concatenates the old value with the argument,
> inserting a semi-colon otherwise.
> In my opinion, a lot of thinking is still needed there.

This makes sense.  It's very useful for the 'class' attribute as  
well, although without the semicolon separators.  The Canvas   
implementation has an #onClick: method that I will adapt to use  
this.  Perhaps we should add one to HtmlRenderer as well.

> 3) Even with the above issue somewhat solved with at:append: we need
> a technique for telling the date picker component that we want to
> append something to the onclick attribute of the calendar cells.  
> The problem
> is that sometimes we want to submit the form, sometimes we do not  
> want that.

<snip>
>
> My suggestion is to add a notification in #openTag: before opening  
> the html tag
>
> openTag: aString
>    TagNotification raiseRenderer: self tagName: aString.
>    self document openTag: aString attributes: self attributes.
>    attributeBuffer := nil.

I'm concerned about the performance implications of signalling a  
notification on every single openTag:.  At least in Squeak, I think  
that will add a ton of overhead.

If you give your elements ids, couldn't you do something like this?   
(Not sure if my JS is correct here).

html datePickerOn: #dateScheduled of: self.
html script: 'document.getElementById("someElement").onclick =  
function() {....}'.

Avi