[ExpressionLanguage] Add support for Nullsafe syntax for accessing object's properties and methods #16630
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javiereguiluz
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Actually, the nullsafe operator only guards against null. It does not guard against undefined properties/keys. |
nicolas-grekas
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…r (mytuny) This PR was merged into the 6.1 branch. Discussion ---------- [ExpressionLanguage] Add support for null-safe operator | Q | A | ------------- | --- | Branch? | 6.1 | Bug fix? | no | New feature? | yes | Deprecations? | no | Tickets | Fix #45411, #21691 | License | MIT | Doc PR | symfony/symfony-docs#16630 This is a long-time-lasting feature for the `ExpressionLanguage` component. I've been waiting for the support of `Nullsafe operator` in expressions dealing with mutable objects, until I finally decided to work on it once for all 👍 The lack of [nullsafety feature](https://wiki.php.net/rfc/nullsafe_operator) has been repeatedly reported as a BUG several time (e.g [#45411](#45411) & [#21691](#21691)) when it is actually a missing feature. Currently, expressions like `foo.bar` assumes that the property `bar` "always" exists on the object `foo` and if doesn't the parser throws a `RuntimeException`. Although, sometimes, that's exactly the behavior we need, some other times we may work with mutable objects with uncontrolled structure, thus, such assumption is error-prone and will force adding extra checks making the expression uglier and less readable. The proposed work, introduces the support for the `?.` syntax alongside with the usual `.` syntax to help working with objects with dynamic structure. The two notations works identically in all normal cases. The difference occurs when trying to access non-existant properties and/or methods where the `.` notation will throw a `RuntimeException` as usual and the `?.` notation will return `null` instead and no errors nor exceptions will be thrown. Hence the name "Null-Safe". PS: This work account ONLY for accessing **object's** properties and methods. It does not account for non-existant **array** items which is a seperate problem that can be addressed by introducing the [null coalescing](https://wiki.php.net/rfc/isset_ternary) operator. Another feature that I'm currently working on as well 💯 Commits ------- 946c59f [ExpressionLanguage] Add support for null-safe operator
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Sofien thanks for providing these docs ... and congrats on your first Symfony Docs contribution 🎉 Nicolas, I reworded the explanation as you said while merging. Thanks! |
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Thanks @javiereguiluz! |
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[ExpressionLanguage] [NEW FEATURE]
This PR introduces the support for
nullsafe operatorin expressions that works with accessing object's properties and methods.The proposed change here, includes a paragraph under the sub-page
/expression_language/syntaxto describe the new feature usage. The sub-paragraph has a title ofNullsafe operatorunder the paragraphWorking with Objects.The actual work related to this Doc PR available as Symfony PR #45795.