TanStack Form supports arrays as values in a form, including sub-object values inside of an array.
To use an array, you can use field.state.value on an array value in conjunction with Index from solid-js:
<script setup lang="ts">
import { useForm } from '@tanstack/vue-form'
const form = useForm({
defaultValues: {
people: [] as Array<{ age: number; name: string }>,
},
onSubmit: ({ value }) => alert(JSON.stringify(value)),
})
</script>
<template>
<form.Field name="people">
<template v-slot="{ field, state }">
<div>
<form.Field
v-for="(_, i) of field.state.value"
:key="i"
:name="`people[${i}].name`"
>
<template v-slot="{ field: subField, state }">
<!-- ... -->
</template>
</form.Field>
</div>
</template>
</form.Field>
</template>
<script setup lang="ts">
import { useForm } from '@tanstack/vue-form'
const form = useForm({
defaultValues: {
people: [] as Array<{ age: number; name: string }>,
},
onSubmit: ({ value }) => alert(JSON.stringify(value)),
})
</script>
<template>
<form.Field name="people">
<template v-slot="{ field, state }">
<div>
<form.Field
v-for="(_, i) of field.state.value"
:key="i"
:name="`people[${i}].name`"
>
<template v-slot="{ field: subField, state }">
<!-- ... -->
</template>
</form.Field>
</div>
</template>
</form.Field>
</template>
This will generate the mapped slot every time you run pushValue on field:
<button @click="field.pushValue({ name: '', age: 0 })" type="button">
Add person
</button>
<button @click="field.pushValue({ name: '', age: 0 })" type="button">
Add person
</button>
Finally, you can use a subfield like so:
<form.Field
v-for="(_, i) of field.state.value"
:key="i"
:name="`people[${i}].name`"
>
<template v-slot="{ field: subField, state }">
<div>
<label>
<div>Name for person {{ i }}</div>
<input
:value="subField.state.value"
@input="
(e) =>
subField.handleChange(
(e.target as HTMLInputElement).value,
)
"
/>
</label>
</div>
</template>
</form.Field>
<form.Field
v-for="(_, i) of field.state.value"
:key="i"
:name="`people[${i}].name`"
>
<template v-slot="{ field: subField, state }">
<div>
<label>
<div>Name for person {{ i }}</div>
<input
:value="subField.state.value"
@input="
(e) =>
subField.handleChange(
(e.target as HTMLInputElement).value,
)
"
/>
</label>
</div>
</template>
</form.Field>
<script setup lang="ts">
import { useForm } from '@tanstack/vue-form'
const form = useForm({
defaultValues: {
people: [] as Array<{ age: number; name: string }>,
},
onSubmit: ({ value }) => alert(JSON.stringify(value)),
})
</script>
<template>
<form
@submit="
(e) => {
e.preventDefault()
e.stopPropagation()
form.handleSubmit()
}
"
>
<div>
<form.Field name="people">
<template v-slot="{ field, state }">
<div>
<form.Field
v-for="(_, i) of field.state.value"
:key="i"
:name="`people[${i}].name`"
>
<template v-slot="{ field: subField, state }">
<div>
<label>
<div>Name for person {{ i }}</div>
<input
:value="subField.state.value"
@input="
(e) =>
subField.handleChange(
(e.target as HTMLInputElement).value,
)
"
/>
</label>
</div>
</template>
</form.Field>
<button
@click="field.pushValue({ name: '', age: 0 })"
type="button"
>
Add person
</button>
</div>
</template>
</form.Field>
</div>
<form.Subscribe>
<template v-slot="{ canSubmit, isSubmitting }">
<button type="submit" :disabled="!canSubmit">
{{ isSubmitting ? '...' : 'Submit' }}
</button>
</template>
</form.Subscribe>
</form>
</template>
<script setup lang="ts">
import { useForm } from '@tanstack/vue-form'
const form = useForm({
defaultValues: {
people: [] as Array<{ age: number; name: string }>,
},
onSubmit: ({ value }) => alert(JSON.stringify(value)),
})
</script>
<template>
<form
@submit="
(e) => {
e.preventDefault()
e.stopPropagation()
form.handleSubmit()
}
"
>
<div>
<form.Field name="people">
<template v-slot="{ field, state }">
<div>
<form.Field
v-for="(_, i) of field.state.value"
:key="i"
:name="`people[${i}].name`"
>
<template v-slot="{ field: subField, state }">
<div>
<label>
<div>Name for person {{ i }}</div>
<input
:value="subField.state.value"
@input="
(e) =>
subField.handleChange(
(e.target as HTMLInputElement).value,
)
"
/>
</label>
</div>
</template>
</form.Field>
<button
@click="field.pushValue({ name: '', age: 0 })"
type="button"
>
Add person
</button>
</div>
</template>
</form.Field>
</div>
<form.Subscribe>
<template v-slot="{ canSubmit, isSubmitting }">
<button type="submit" :disabled="!canSubmit">
{{ isSubmitting ? '...' : 'Submit' }}
</button>
</template>
</form.Subscribe>
</form>
</template>
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