Class attributes are managed in a specific way in owl: they are merged
with existing class attributes, and also, they can be defined in
multiple ways (t-att-class, t-attf-class, t-att=['class', ...] and each
of these can be combined together.
Before this commit, the `t-att` syntax was handled as a normal
attribute, and therefore, would not combine as required with existing
classes.
closes#1453
Before this commit, properties were just handled as a special case of
attributes. But it does not make that much sense, since they are
different. For example, the `readOnly` property does not have the same
name as the `readonly` attribute. The confusion probably comes from the
fact that QWeb does not distinguish between property and attributes, so
Owl has to infer which one is which.
With this commit, we introduce a `block-property` directive in blockdom,
and change the compiler to use it in emitted code. It has the additional
benefits of slightly shrinking the runtime code, since the `isProp`
function can now be located in the compiler.
In 3536f41f00 we added a fallback when setting a
property to a falsy value so that the property was set to the empty string. The
objective being to not get the string "undefined"/"null"/"false" as property
value. However, using t-att- to set a property to 0 is perfectly reasonable and
in fact quite common.
This commit fixes some issues with falsy attributes not being properly
set/removed in various situations. Also, the behaviour was not
consistent between normal attribute (key/value) and generic attributes
(pair or object)
Géry Debongnie