Handlebars now supports subexpressions.
{{foo (bar 3)}}
Subexpressions are always evaluated as helpers; if
`3` were omitted from the above example, `bar`
would be invoked as a param-less helper, even
though a top-levell `{{bar}}` would be considered
ambiguous.
The return value of a subexpression helper is
passed in as a parameter of a parent subexpression
helper, even in string params mode. Their type,
as listed in `options.types` or `options.hashTypes`
in string params mode, is "sexpr".
The main conceptual change in the Handlebars code
is that there is a new AST.SexprNode that manages
the params/hash passed into a mustache, as well
as the logic that governs whether that mustache
is a helper invocation, property lookup, etc.
MustacheNode, which used to manage this stuff,
still exists, but only manages things like
white-space stripping and whether the mustache
is escaped or not. So, a MustacheNode _has_
a SexprNode.
The introduction of subexpressions is fully
backwards compatible, but a few things needed
to change about the compiled output of a template
in order to support subexpressions. The main one
is that the options hash is no longer stashed in
a local `options` var before being passed to
either the helper being invoked or the
`helperMissing` fallback. Rather, the options
object is inlined in these cases. This does
mean compiled template sizes will be a little
bit larger, even those that don't make use of
subexpressions, but shouldn't have any noticeable
impact on performance when actually rendering
templates as only one of these inlined objects
will actually get evaluated.
Escaped-escape mustaches ("\\{{") immediately following escaped
mustaches ("\{{") were being handled incorrectly.
Fix the lookahead to make sure yytext still contains the appropriate
slashes when we pop out of <emu> so they can be handled consistently
by the initial state.
Removes unnecessary commonjs code generated for the parser. This reduces
the size of the parse by about 700bytes and should resolve lookup issues
with browserify and other static analysis tools. See #220
Previously, the parser required at least one character of whitespace
to properly interpret empty blocks around simple inverses, which was
non-intuitive and inconsistent with empty block parsing.
Update the parser to allow empty blocks around simple inverses.
kpdecker
machty
Stanley Stuart
Daniel Marcotte
James Gorrie
Chris Broadfoot
Jean-Pierre Fiset
Yehuda Katz
Les Hill
tomhuda