Previously, if the value of a t-component directive changed, but there
was already a scheduled render for the component before that change, the
rendering of the existing component would get delayed (as it should),
but after the parent's rendering was complete, the old component which
will be destroyed during the patch would still get rendered, despite
being stale. This can cause crashes if that component relies on state
that no longer exists.
This was caused by the fact that when rendering, we check the parent
chain for an active render, and also check that the component still
exists in the parent's fiber childrenMap (ie, we know that the upcoming
patch is not about to destroy the component). To do this, we use the
component's parentKey, but in the case of t-component, the parentKey for
both possible components is the same, causing the stale component to
incorrectly believe that it's not about to be destroyed, by finding the
next component in the childrenMap under the same key.
This commit fixes that by prepending the component's name to the
parentKey, meaning that if the value of the t-component changes, so will
the key, and the render will be further delayed until the new state is
patched, at which point the stale component will be destroyed and the
following attempt to render will be cancelled as expected.
The choice to use the component's name is to simplify the
implementation, this means that if using t-component and switching
between components that have the same class name, this protection will
not work. The alternative would be to generate a unique id for the
component class, eg with a WeakMap, but this both complicates the
implementation and adds runtime overhead, for a case that is likely
extremely rare. We are open to refine the implementation should this
problem occur in practice.
Have a radio group defined inside a t-foreach:
```xml
<t t-foreach="values" t-as="val" t-key="val">
<input name="radiogroup" t-att-value="val" t-model="state.radioGroup" />
</t>
```
Before this commit the algorithm that set the "checked" attribute on the current active
radio button according to the state did not support having a dynamic value (`t-att-value`)
After this commit, this use case works as we go look in the dynamic attributes too.
t-call-context is a feature that's supposed to mask the rendering
context completely, but currently the component remains available
through `this`.
This commit stops treating `this` as a reserved word, so that it's
compiled to a lookup in the rendering context, and adds `this` to the
rendering context when binding the component's rendering function. With
these changes, `this` behaves the same as before when outside a
t-call-context, but when the rendering context is overriden, the
template can no longer access `this`. `this` still represents the
instance of the component inside of the rendering function since it's
needed by owl internally.
A side-effect of this change is that now the rendering context is no
longer the instance of the component by default, but is always an object
with the component in its prototype chain. This was already the case
before in some contexts (eg inside t-foreach, or inside components with
a t-set/t-call anywhere in its template). This can cause issues in rare
cases when a component method was called directly on the rendering
context, as before this change, the method's bound this would be the
component instance (except in a t-foreach, component with a
t-set/t-call, etc), while after this change it is now never the
component instance. When the method only reads on `this` there is no
issue as all the components properties are available on the rendering
contexts, but setting a value on `this` will write on the rendering
context and not the component which is likely a mistake.
While this is a breaking change, simply adding a t-set/t-call to any
template would break components that would be broken by this change,
with this in mind we decided to make this change anyway so that
developers get the error as early as possible in the development cycle
rather than having a seemingly inocuous change break code under them.
Previously, when using a component with a slot within a t-call with
t-call-context, the component would become available again inside the
slot despite the t-call-context. This was caused by the fact that the
capture helper function creates an object with the component as its
prototype which is incorrect. It should just use the previous context as
its prototype.
Previously, when a template contained backslashes, they were not escaped
when creating the blockstring, meaning they would be interpreted as an
escape sequence within the JS string. This means that backslashes
preceding most characters were completely ignored and didn't end up in
the final block, double backslashes were collapsed to a single one, and
backslashes that constituted valid escape sequences in JS would be
treated as those (eg, \n would be a newline).
When creating a JS string expression from a string value, all characters
with special meaning in JS should be escaped, we were correctly escaping
backticks as these would unexpectedly close the string if not escaped,
but forgot to escape backslashes. This commit fixes that.
closes#1300
With this commit, we make sure that the code for t-model is run before
t-on-input event handler. This is useful to make sure that the state
reflected by t-model is up-to-date.
closes#1295
With the introduction of t-call-context, there is now no guarantee that
the ComponentNode can be found in the rendering context, any attempt to
do so can crash when combined with t-call-context. This commit fixes
that by using `this` instead, which in compiled templates refers to the
component that is being rendered.
Currently, if a component has a default slot defined with t-set-slot,
and also content that compiles to something (eg, text or even a comment
node), the content takes priority over the t-set-slot. As t-set-slot is
more explicity, it should have priority.
Currently when checking for duplicate keys, we insert the value of the
key as is in a set then check for unicity against those. When the key is
an object, we check for duplicates based on object identity, whereas the
keys are used by owl as strings, and so using objects can cause
duplicate key errors that do not throw correctly but crash in the owl
internals.
This commit fixes that by making the duplicate checking code serialize
the key to string before insertion and when comparing against existing
keys.
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 template compiler would guess the next block id
that will be generated when compiling the body of a tcall. This is
correct IF there are not nested t-call, but otherwise wrong, because the
next block id could be mixed up: the first t-call would save the next
block id (let's say n), then the inner t-call would also save the same
block id (so, n), will then generate its own block (n+1), then the outer
t-call would use the block n index instead of n+1
The best fix, in my opinion, is to make sure we get the next block var
name, so we do not have to guess. To do that, each compile block type
function needs to properly return the information.
closes#1267
A recent commit fixes the props validation code to make it work
regardless of the rendering context (important with the recent
t-call-context directive). Unfortunately, it then breaks props
validation through slots, because it assumed that the parent node in the
virtual node was the parent of the component, but it is not necessarily
true.
To fix this, we can use a simple property of the template functions:
they are bound to the current instance of the component, so we can
simply use "this"
The code for props validation assumed that the rendering context was a
component. This was actually true when it was written, but is no longer
true since t-call-context was introduced.
Because of that, it would crash when trying to access the internals of
the component, such as the static components object.
The fix is simple: instead of passing the context to the props
validation code, which can now be anything, we pass the component node,
which is guaranteed to give a reference to the component (and also to
the app). This also make the code slightly simpler.
closes#1261
Before this commit, a crash could occur when a component with no props
is defined in a slot, and that slot is conditionally displayed in
multiple locations.
The reason for that is that the key provided to the callSlot function
was identical, so from the perspective of the component function, it was
not possible to make the difference between a component located in
either places. With this commit, we make sure that a unique key is used
when a slot is reused in a template (or if it is dynamic, because in
that case, we have no idea at compile time if it will be unique or not)
closes#1246
Recently, we made it so that when a component is rendered, it always
updates the property values for computed properties. This was done by
wrapping the value in a String or Boolean object. One issue with this is
that wrapping a falsy value in a String doesn't yield an empty string,
but a string containing the value as text (eg new String(undefined) ->
"undefined"), which causes the value to not remain empty as per the
spec. This commit fixes that by adding a fallback to the empty string
for falsy values before converting to a String object.
closes: #1236
This commit makes all errors thrown in owl use a custom error class. The
main point of this is to always wrap user-code errors that happen during
the owl lifecycle so that they can be treated uniformly in onError by
checking the cause property, and also allows user code to differenciate
owl errors from non-owl errors reliably at runtime.
Before this commit, owl would incorrectly skip patching html properties
when the new value is the same as the value used in the previous render.
However, this is incorrect, since the user may have changed the value by
clicking on a checkbox, or changing some text in an input.
So, to be more correct, owl has to force the update whenever it
encounters a prop. This is however hard to do without impacting the
main update loop, so we kind of work around the problem by using String
and Boolean instance, instead of primitive values.
Before this commit, whenever Owl encounter a t-if, it generates an
anchor (a "hole") in the current block being compiled. However, in some
cases, the content of the t-if may not have any content at all, and the
anchor is then useless. Worse, the code generating the anchor generates
an index based on the number of sub blocks, but if there is no content,
the next anchor being created will have the same index, which then may
cause weird bugs.
A possible way to fix this could be to make sure we increment properly
the anchor index, but we could even do better: not having an anchor at
all.
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.
Before this commit, the generated code crashed if an attribute in
the template contained backticks. The compiler output something
like
```js
let block1 = createBlock(`<div foo="`bar`"/>`);
```
The backticks are now properly escaped.
Previously, the support for the "in" operator was iffy, and "new" was
not supported at all, "in" would fail when checking if a nested property
was in something else, as the leading space would be stripped, and "new"
would fail because the following space would be stripped.
This commit fixes that by preserving the significant whitespace where
necessary.
Before this commit, there were 2 different ways of generating variable
identifiers. And it was possible to have a situation with two different
variable in a template with the same identifier, which caused a crash.
This commit ensures that we go through a unique helper method, so this
cannot occur anymore. Also, the code is slightly simpler.
A little typo was preventing a dynamic t-slot with a scope
(`<t t-slot="{{ state.name }}" myScope="someValue" />`)
to work properly.
This commit corrects this.
Before this commit, a t-set-slot that has no content was not even compiled, and thus not passed
to the component for which it has was defined
After this commit, we allow a t-set-slot to have no content (because it can have slot props)
With this commit, component only render child
components if they have different props (shallow
equality). Otherwise, we trust the reactivity
system to make sure that all impacted components
are updated
Samuel Degueldre