Just a reminder; before you guys start implementing one or another template language, could we have [VOTE] for one of the variants, have [PROPOSAL], or at least [SUMMARY]? :)
Here, I just want to comment that I find way more intuitive and user friendly following constructs:
if(<test>) ----------
example:
<div do="if(count(cart/item) == 0)">
<div t:if="cart/item"> and <div t:unless="cart/item"> for conditions.
Your cart is empty <div>
forEach(<sequence>) -------------------
example:
<table> <tr do="forEach(cart/item)">
<tr t:forEach="cart/item"> or <tr t:forEach="item in cart/item"> for iterators.
<td>${index}</td> <td>${description}</td> <td>${price}</td> </tr> </table>
for(var=<name>,begin=<expr>,end=<expr>,step=<expr>) ---------------------------------------------------
Is it necessary? Current jxtg does not have it (IIRC).
context=<expr> --------------
Set the current evaluation context for expressions.
example:
<table do="context=/shopping/cart">
<table t:for="/shopping/cart"> or t:context, or some such.
... and the rest is similar. I also feel that expressions like "if();context();let();for();etc;etc;etc" are too complicated for what is necessary in Cocoon Templates.
Vadim
... </table>
let(<name>=<expr>,...,<name>=<expr>) ------------------------------------
Define a number of variables for the current context. Observe that this not is a set operation it just defines the content of the variable $<name> in the current context, it doesn't intoduce any possibilities to have side effects.
example:
<h1 do="let(greeting=concat('Hello', user)> The value of greeting is ${$greeting} <h1>
macro(<name>,<param-name>,...,<param-name>) -------------------------------------------
example:
<table do="macro(mytable,list,td-class)"> <tr do="forEach($list)"> <td class="${$class}">${item}</td> </tr> </table>
We also need an evalBody as in JXTG. And maybe we should have a possibilty to give a name space to the macro name.
eval(<name>,context=<expr>,<param-name>=<expr>,...,<param-name>=<expr>) -----------------------------------------------------------------------
Evaluates the named macro in either the curent context or the excplictliy chosen, with a number of forma parameters. The containing element is replaced by the result of the evaluation. And the content of the the containing element is available in the macro through "evalBody".
example:
<table do="eval(mytable,list=carts,class='checked-out')"/>
We could maybe even have the synatax:
<table do="mytable(list=carts,class='checked-out')"/>
for user defined macros.
replace(<expr>) ---------------
Replaces the containing element with the result of the expression, useful for inserting DOM etc from the flow layer.
example:
<div do="replace(.)"/>
content(<expr>) ---------------
Like replace but replaces only the content.
attributes(<name>=<expr>,...,<name>=<expr>) -------------------------------------------
Inserts an attribute.
Several directives ------------------
So, how do we handle multiple directives for one element? We could handle the TAL example above like:
<p do="let(x=/a/long/path/from/the/root;if(x);content(x/txt);attributes(class=x/class)">
Ex Text </p>
The idea is that when the leftmost directive is executed it has the ability to access the result of executing the directive sequence right of it in its current context. It will be the rightmost directive that has direct access to the containing element with evaluated attributes and body.
The corresponding tag based template expression would be (in pseudo jx):
<jx:let name="x" value="/a/long/path/from/the/root"> <jx:if test="x"> <jx:content select="x/txt"> <jx:attribute name="class" value="x/class"> <p>Ex Text</p> </jx:attribute> </jx:content> </jx:if> <jx:let>
The jx:attribute and jx:content returns the patched variant of its respectively body. Not particulary natural constructions in a tag based template language, but hopefully it explains the direcive combination construction.
<snip/>
