Because the default content of a t-call is compiled before the block of
the t-call is created, the default content can sometimes incorrectly be
treated as though it is at the root of the template. This causes various
issues, in the case of a t-if, the default content will just replace the
t-call entirely when truthy, and when falsy the template will not return
anything, leading to a crash. Similar things occur with t-foreach and
t-out with a default content.
This commit fixes that by moving the block creation for the t-call ahead
of the compilation of the default content. In doing so, it makes the
context attribute "preventRoot" obsolete: the purpose of this attribute
is to somehow make the code aware that the root of the template will be
defined later, but because it wasn't propagated everywhere properly it
caused this issue. Now that the root already exists before we compile
the default content, we don't need it anymore.
Before this commit, doing `t-out="null"` would crash, since the
safeOutput function would assume that it is a block, thanks to the fact
that `typeof null === 'object'`.
We handle here the null value just as if it was undefined: it outputs an
empty string.
The t-out directive is compiled internally into a LazyValue, which
represents a value that may or may not be created sometimes in the
future. It can also be reused more than once, and this is where there
may be an issue: if a component is contained in the lazyvalue, it needs
a unique key (coming from the t-foreach) to be properly indexed in the
parent children map. However, the LazyValue does not keep the key
information, so it is not able to provide it to its content.
The fix is then quite clear: the LazyValue class should store the key
information, and provides it to its content. This allows the LazyValue
to be used multiple times, in any place in a template.
closes#1270
Before this commit, the generated code for the component directive was
using the current context as the place to look for static informations
(such as the sub components). However, it is not entirely correct, since
the current context may be different than the current component (which
is easily accessed by using the this variable).
Also, while doing this, we fix some issues in the t-set directive, which
as calling lazy values with the wrong this.
This means that unrelated ids (eg the id of a template, variable or key)
not longer share the same incrementing counter, meaning that you no
longer see a variable named "v2" unless another variable "v1" was
generated previously, this is also true for block data.
t-out automatically escaped content when it is a string not marked
with the `markup` function
t-out renders the raw content if it is a Block, or if it has been marked
with the `markup` funtion.
t-esc has been kept since it is safe and is optimized to render text nodes.
all t-raw calls are in fact the same as t-out.
Samuel Degueldre