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fix(scopes): correctly meassure perf impact of one-time expressions #124
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Previously, one-time expressions were supposed to not trigger perf timers. There were a couple of issues with the implementation: 1. One-time expressions were not detected as such if there was whitespace before the `::`. 2. It depended on internal AngularJS implementation details in a way that would fail to identify certain usecases (e.g. multiple interpolations in a single attribute value or node text). 3. Time spent on the initial evaluation of the one-time expressions would not be accounted for, but could still impact the duration of the first `$digest`. 4. While it is not common, there are cases were one-time expressions don't settle immediately. In such cases, their impact on the `$digest` should not be ignored. This commit fixes the above issues by ensuring that only the "final" call to `$watch` is intercepted (in contrast to intermediate calls that might call a `$$watchDelegate`, which will then create the actual `$watch`er). One-time expressions are intercepted normally and stop triggering perf times as soon as their `unwatch` function is called. Although the dependency on internal AngularJS implementation details could not be avoided, the new implementation is a little more robust, as it relies on fewer and less brittle details :D Fixes angular#109 Closes angular#122
test/scopes.spec.js
Outdated
| scope.$apply('c.d = "foo"'); | ||
| expect(calls.count()).toBe(1); | ||
| expect(countWatchEventsFor(0)).toBe(6); // Change: 2 loops | ||
| expect(reactions).toEqual([2, 2, 2]); |
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might be worth a comment here, indicating that this is the first time the one time bindings have a value, which is why the reactions are called for a second time.
test/scopes.spec.js
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| '<span>{{::c.d}}</span>' + | ||
| '<span>{{ ::c.d }}</span>' + | ||
| '<span>{{ :: c.d }}</span>' + | ||
| '<span>{{::c.d}}{{ ::c.d }}{{ :: c.d }}</span>' + |
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Is it useful to check these for non-interpolation bindings such as ng-if as well?
|
@petebacondarwin, PTAL. |
petebacondarwin
approved these changes
Mar 30, 2017
gkalpak
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Mar 30, 2017
Previously, one-time expressions were supposed to not trigger perf timers. There were a couple of issues with the implementation: 1. One-time expressions were not detected as such if there was whitespace before the `::`. 2. It depended on internal AngularJS implementation details in a way that would fail to identify certain usecases (e.g. multiple interpolations in a single attribute value or node text). 3. Time spent on the initial evaluation of the one-time expressions would not be accounted for, but could still impact the duration of the first `$digest`. 4. While it is not common, there are cases were one-time expressions don't settle immediately. In such cases, their impact on the `$digest` should not be ignored. This commit fixes the above issues by ensuring that only the "final" call to `$watch` is intercepted (in contrast to intermediate calls that might call a `$$watchDelegate`, which will then create the actual `$watch`er). One-time expressions are intercepted normally and stop triggering perf times as soon as their `unwatch` function is called. Although the dependency on internal AngularJS implementation details could not be avoided, the new implementation is a little more robust, as it relies on fewer and less brittle details :D Fixes #109 Closes #122 Closes #124
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Previously, one-time expressions were supposed to not trigger perf timers. There
were a couple of issues with the implementation:
the
::.fail to identify certain usecases (e.g. multiple interpolations in a single
attribute value or node text).
accounted for, but could still impact the duration of the first
$digest.settle immediately. In such cases, their impact on the
$digestshould notbe ignored.
This commit fixes the above issues by ensuring that only the "final" call to
$watchis intercepted (in contrast to intermediate calls that might call a$$watchDelegate, which will then create the actual$watcher). One-timeexpressions are intercepted normally and stop triggering perf times as soon as
their
unwatchfunction is called.Although the dependency on internal AngularJS implementation details could not
be avoided, the new implementation is a little more robust, as it relies on
fewer and less brittle details :D
Fixes #109
Closes #122