This commit tries to improve the interactions involving unmounted
components, or components mounted in an htmelement which is detached
from the main DOM, and rendering actions.
The main example is mounting a component in detached div, to prepare all
children. If we just mount the component, it will work as expected: the
full component tree is rendered in memory, and ready to be really
mounted at the desired target.
However, if before doing that, we update the component and call render
on it (for example, with a change in an observed state), then this
rendering will be ignored, and therefore, the full subcomponent tree is
not uptodate.
This commit will also solve another issue in the compatibility layer in
odoo: in the form renderer, we mount components with the adapter in a
div, which is not yet attached to the DOM. We then manually call the
mounted hook when on_attach_callback is called. This means that before
this commit, any change to the components between the initial rendering
and the call to mounted will be ignored.
As a bonus, this commit has the effect of bringing closer the semantics
of render and mount operations, which is certainly good.
closes#823
Components can implement shouldUpdate to return false. In that case,
renderings coming from above should be ignored.
However, if the component was unmounted and is remounted, we actually
need to force a rerendering in that case, so it is mounted, otherwise
the subcomponent is left in unmounted state, which means that rendering
are ignored.
closes#800
Owl has to manage a lot of interesting situations. One of them is when
a rendering is initiated, which creates a sub component, but then
another rendering starts, which invalidate the previous one, and will
create another sub component. Since the first sub component was not
ever in the DOM, we cannot rely on the vdom patching process to remove
it, so we have to do it manually.
Sadly, this is actually a very tricky situation, since there are other
subtle situations where the code that remove an unmounted widget could
be executed, in particular when the parent component is unmounted, then
remounted, then modified to trigger yet another rendering.
In this commit, we handle this case more carefully by making sure that
the destroyed subcomponent properly configures its pvnode so the patch
process happens as expected.
joint work with the framework team, and in particular LPE for his work on
finding a testcase!
closes#724, #731
Have
```xml
<body t-name="webclient" />
```
and
```js
const comp = new WebClient();
comp.mount(document.body, {position: 'self'});
```
Before this commit, the body that was there before anything had happened
was *replaced* by the new body node created by the WebClient OWL component
After this commit, we ensure that the element body is the same at reference level
In most cases, we just want Component<any, Env>. But since it was so
annoying to have always the type Env, we actually used
Component<any,any> everywhere.
With this commit, the generic types have a default (and their order is
swapped), so we can simply use Component in most cases, and
Component<Props> when we want to type the props.