Subscribe on changes!

Use useSlots().default method to determine whether the slot is in doubt after the contents of the slot have been commented out

avatar
Feb 13th 2023

Vue version

^3.2.13

Link to minimal reproduction

https://sfc.vuejs.org/#eNqNUctuwjAQ/JXFl4LaOHdIkar2D8rRlzTZQFD8kHdDK6H8e9d5FC5IlSx5H7PjnfFVvYWgLz2qrSqoim1gIOQ+7I1rbfCRAT47z4fyCE30Fp50/u7tOPJknHFFPk0JXhJGG7qSUTIAKOr2MkaGDRczTQJKOpZWWTaBDqeWQE7p5DjPQlFDaLFC8A1UvsYiTzjIshthfmOUx2BCpI3+tlAvahKR2TLoM3knMq8jwdwgo7YwVlJNRKXcqBNzoG2eU1MlpWfSPh5ziXTsHbcWNZLNvqL/JoxCbFSiGIwb5MnFn8eWXqEnTNsTDLOti5+VdyR46X1gU/YdwyusVgt8vdH1VN7BhPUd6s4f10bNDcCflpiSCni+J9rs/vlbS5xmgZHE6ftWKu+FKF2PnR9+AULVzac=

Steps to reproduce

SlotTag Component:

html:

script: const slotDefault = !!useSlots().default; console.log("default exists: " + slotDefault);

App.vue: html:

browser console output: default exists: (...args) => { // If a user calls a compiled slot inside a template expression (#1745), it // can mess up block tracking, so by default we disable block tracking and // force bail out whe…

What is expected?

the code for the annotation should not be detected, expecting a undefined value to be returned Expect the output to be log below: default exists: false

What is actually happening?

I'm furiously reading the vue design and implementation book, trying to figure out what's going on

System Info

No response

Any additional comments?

No response

avatar
Feb 13th 2023

I think you can find why useSlots().default is a function from this line:https://github.com/vuejs/core/blob/main/packages/runtime-core/src/componentSlots.ts#L130. I hope that can help you.

avatar
Mar 7th 2023

I have the same question.

avatar
Mar 7th 2023

I think you can find why useSlots().default is a function from this line:https://github.com/vuejs/core/blob/main/packages/runtime-core/src/componentSlots.ts#L130. I hope that can help you.

I think the problem is not whether useSlots().default is a function, but whether the comment node can be judged in slot by passing in my example

avatar
Mar 7th 2023

image

@DavidAwing
After looking at the compiled result, the comment node is also a case of vnode, so there is no problem with useSlots().default being true. But I still think this performance makes me confused in development ....

avatar
Mar 7th 2023

fe40053dc9ac651ced88a93145add13

One more question is: since the comment node vnode is created, why is this comment not mounted when viewing dom?