Re: [Webtek-devel] bug in foreach

[max d. <pro...@gm...>]

the Macro | Handler params are needed

	* to check the template-syntax during template-compile-time
	* to dont allow access to every variable within templates (i.e. you  
let the user modify templates)
	* to generate documentation

if you dont want that check, you can set the failmode="silent" property:

	<% box.get_dimensions.get_value failmode="silent" %>

in case of an runtime-error (during rendering the template) an empty- 
string is returned for this macro.

...hmmm... but this behavour is still a work in progress.

On 26.06.2008, at 17:50, Adrian Smith wrote:

> OK - Thanks for the description.
>
> I am not sure I agree/understand the difference between a Handler  
> and a Macro. I mean they could just be the same?
>
> Sometimes a Macro returns a non-string (e.g. as the input for the  
> "list" paramter of "foreach") so given that Macros return "anything"  
> - strings, lists, objects - it would make sense for attributes of  
> them (with the "." syntax) to be usable.
>
> I mean in programming languages, you can write:
> $box
> $box->get_dimensions()
> $box->get_dimensions()->get_width()
> There is no distinction where the first doesn't work at all, the  
> second only works if get_dimensions is a Macro, and the third only  
> works if get_dimensions is a Handler.
>
> But anyway - now I understand the difference (I think) - so it  
> doesn't matter too much on a practical level for me.
>
>
>
> 2008/6/16 max demmelbauer <pro...@gm...>:
> hmmm.. this is no bug, because you used the macro in a wrong way.
>
> the format of a macro is defined like:
>
> 	<% handler.handler.macro_name param1="abc" param2=" ... <% ...  
> %> ..." | filter1 | filter2 param="..." %>
>
> if you omit the handler (i.e. you want to call a macro in the  
> current page) you can write:
>
> 	<% macro_name param1="abc" param2=" ... <% ... %> ..." | filter1 |  
> filter2 param="..." %>
>
> for better understanding you can think the above macro-call is the  
> same as:
>
> 	<% actual_page.macro_name ... %>
>
> (but the handler actual_page dont exists, because it's already the  
> default)
>
>
> so to your example:
>
> i think you want to put the current iterator (which is a handler  
> obj) as a param to a macro,  like:
>
> 	sub a_macro {
> 	   my ($self, %params) = @_;
>
> 	   return $params{'iterator_obj'}->some_macro();
> 	}
>
> but this is not possible because, when you write:
>
> 	<% a_macro iterator_obj="<% xyz %>" %>
> 	
> xyz is called as a macro function for the current page (and this is  
> exactly the error-msg from your example)
>
> so, there are two solutions for this problem.
>
> 1) our solution with the self macro have done the trick (because it  
> returns the handler obj)
>
> 2) handler xyz is already defined for the current page (from the  
> foreach macro), so you can write in the macro-code:
>
> 	sub a_macro {
> 	   my ($self, %params) = @_;
>
> 	   return $self->handler($params{'handler_name'})->some_macro();
> 	}
>
> 	and in the template
>
> 	<% foreach iterator="xyz" do~q{
> 	    <% a_macro handler_name="xyz" %>
> 	} %>
>
> hmmm... i think the second solution is not as nice as the first,  
> because you have to split the logic: half in the template (the  
> handler-name) and half in macro-code (handler-obj for the handler- 
> name).. and this solution also only works in the same page, where  
> the foreach is called. so a
>
> 	<% foreach iterator="xyz" do~q{
> 	    <% parent.a_macro handler_name="xyz" %>
> 	} %>
>
> wouldn't work!
>
> so i think we should implement a general macro which returns the obj  
> of the current handler (like your self macro). what would you think  
> is the right name for such an macro?
>
> is
>
> sub self :Macro { ... } a good name?
>
> i think its ok, so we should implement this in WebTek/Handler.pm
>
> lg. max.
>
>
> On 15.06.2008, at 13:49, Adrian Smith wrote:
>
>> I just searched for ages for this bug!
>>
>> <% foreach list="...." iterator="xyz" do~q{
>>    <% a_macro param="<% xyz %>" %>
>> } %>
>>
>> This doesn't work, producing the error:
>>
>> macro_error : MyApp::Page::MyPage=HASH(0x227f904) has no macro 'xyz'
>>
>> If I implement the following method in class Xyz:
>>
>> sub self :Macro {
>>    my $self = shift;
>>    return $self;
>> }
>>
>> and then put the following in the template:
>>
>> <% foreach list="...." iterator="xyz" do~q{
>>    <% a_macro param="<% xyz.self %>" %>
>> } %>
>>
>> Then it works fine
>
>