The view function receives a list of arguments. Each argument
corresponds to the Data or rendered ewc tuple.
On Nov 9, 2007 8:07 AM, David King <[EMAIL PROTECTED]> wrote:
>
> > You can currently do what you wanted to do without changing ErlyWeb.
> > To make your examples work, I would do the following:
> > [{data, "SomeString"},
> > {ewc,...},
> > {data, [<<"Some">,["IO","List"]]}]
>
> Does the view function then receive it as three arguments, like:
>
> <%@ view_function([FirstString, RenderedEwc, TheIOList]) %>
>
> Or is the view function called three times, once with each argument?
>
>
>
>
> >
> > or even better:
> >
> > [{data, {"SomeString", [<<"Some">,["IO","List"]]}},
> > {ewc,...}]
> >
> > (The second option shows how to combine multiple data elements under a
> > single 'data' tuple.)
> >
> > The rule of thumb is that you can return either a single tuple or a
> > list of tuples. If the tuple is {data, Data}, the view function gets
> > only Data in place of the tuple. If the tuple is {ewc,...}, the view
> > function gets the rendered component in its place. For (nested) lists
> > of tuples, the transformation applies to each element in the list.
> >
> > Yariv
> >
> >
> > On Nov 8, 2007 11:21 PM, David King <[EMAIL PROTECTED]> wrote:
> >>
> >>> To further refine my question: is there any way to pass in a mix of
> >>> IOlists and rendered {ewc} tuples to a view function? Can we turn
> >>> {data} into this?
> >>
> >> Sorry about all of the list traffic. I did figure out how to do this,
> >> sort of. I added this ewc clause to erlyweb.erl (I'm running 0.6.2,
> >> but I'm sure this hasn't changed substantially):
> >>
> >> ewc({edata, EwcsAndLists}, AppData) when is_list(EwcsAndLists) ->
> >> Rendered=lists:map(fun(EwcOrData) ->
> >> case EwcOrData of
> >> Ewc when is_tuple(Ewc) and (element
> >> (1,Ewc) =:= ewc) ->
> >> render_subcomponent(Ewc,AppData);
> >> Data ->
> >> Data
> >> end
> >> end, EwcsAndLists),
> >> {response,[{rendered,Rendered}]};
> >>
> >> It effectively adds a new response from controller functions, called
> >> 'edata', that can be used like this:
> >>
> >> {edata, [ "Title",
> >> {ewc, post, post_list, [A, Posts ]}]}.
> >>
> >> That is, such that {ewc}s and iolists can be mixed. It doesn't
> >> traverse deep lists though, I suppose that could be added but it
> >> might be hard to tell an IO-list from a list of {ewc}s without
> >> actually traversing it. (Deep lists would be useful for my app, but
> >> that's an exercise for another day)
> >>
> >> Is there any chance that we can get this in the main distribution?
> >> It's pretty simple and shouldn't break anyone's existing apps. I'd
> >> like to avoid having to maintain my own version :)
> >>
> >>
> >>
> >>>
> >>> On 08 Nov 2007, at 20:22, David King wrote:
> >>>
> >>>>
> >>>> What is the difference between returning this:
> >>>>
> >>>> ["SomeString",
> >>>> {ewc,...},
> >>>> [<<"Some">,["IO","List"]]]
> >>>>
> >>>> And this:
> >>>>
> >>>> {data,["SomeString",
> >>>> {ewc,...},
> >>>> [<<"Some">,["IO","List"]]]}
> >>>>
> >>>> (Other than that the latter doesn't work.) In either case, a view
> >>>> function like this should work:
> >>>>
> >>>> <%@ view([FirstString,RenderedComponent,SomeOtherString]) %>
> >>>> ...
> >>>>
> >>>> The problem is that I can't always just return a {data} tuple or a
> >>>> [{ewc}] list, I have to differentiate between one that includes
> >>>> rendered components and one that doesn't, and I worry that the
> >>>> "detection" between the two may fail when I mix them (for instance,
> >>>> maybe I want to render a page with a title and a list of items; the
> >>>> title is a literal string, but the items are rendered {ewc}s). Am I
> >>>> missing an overarching design that requires a difference between
> >>>> passing a view function a list of rendered components and a list of
> >>>> iolists? Is there any way that we can get {data} to look at its
> >>>> arguments and see if they are {ewc}s, and render them just like it
> >>>> would if I returned a [{ewc}], so that I can always return a
> >>>> {data}?
> >>>>
> >>>>
> >>>
> >>>
> >>
> >>>
> >>
> >
> >
>
> >
>
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