3.4 updates #2625
3.4 updates #2625
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| @@ -52,15 +52,15 @@ Takes a getter function and returns a readonly reactive [ref](#ref) object for t | |||
| ```ts | |||
| // read-only | |||
| function computed<T>( | |||
| getter: () => T, | |||
| getter: (oldValue: T | undefined) => T, | |||
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Is it correct that this is : T | undefined instead of ?: T, if I remember correctly there might be a TS compiler options so that | undefined means that it needs to explicitly pass a variable that can be undefined, instead of not passing a variable at all.
However, because this is a callback, it is not affected by this compile option.
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This function is not passed by the user but provided by the framework, so the argument will always be present.
| model.value = 'hello' | ||
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| // declares "count" prop, consumed by parent via v-model:count | ||
| const count = defineModel('count') |
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some random thoughts
Is it possible to declare multiple models like that?
// v-model:count
const count = defineModel('count')
// v-model:x
const x = defineModel('x')Or will this result in an error?
What happens if someone accidentally redeclared two times the same?
const count = defineModel('count')
const count2 = defineModel('count')Should this be handled by a linter? Will there be a Vue runtime error?
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First case is supported. Second case will throw a compile-time error.
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Could we add docs that different defineModels are supported and can be used that way? I think it is really common to have multiple v-model:* but it works differently as to defineProps or defineEmits where you pass multiple values at once, but for defineModel you suddenly need multiple calls.
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It is already shown in the component v-model guide.
| Like `defineProps` and `defineEmits`, `defineModel` can also receive type arguments to specify the types of the model value and the modifiers: | ||
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| ```ts | ||
| const modelValue = defineModel<string>() |
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Why is it that way? It feels like it behaves the opposite of ref 🤔
Here is an example:
first line: when I leave out the types at ref, it results in Ref<undefined> (legit to me 👍)
second line: when I explicitly use <boolean>, undefined is not a valid value (also legit to me 👍)
so I would assume that defineModel<string>() results in string and defineModel<string | undefined>() results in string | undefined and I don't need a required at all (or suddenly mix generics-TS and options object, where as e.g. defineProps explicitly forbids this mixing)
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Because it accepts parent value via a prop, so it behaves like a prop (can be undefined unless explicitly required)
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ah I see 🤔
should this be also documented, maybe with a :::tip? or might I have just oversee that?
Includes: