feat(ui): new composable - useId() quasarframework#16792

docs/src/assets/menu.js

@@ -667,6 +667,11 @@ export default [
         badge: 'new',
         path: 'use-hydration'
       },
+      {
+        name: 'useId',
+        badge: 'new',
+        path: 'use-id'
+      },
       {
         name: 'useRenderCache',
         badge: 'new',

docs/src/pages/vue-composables/use-id.md

@@ -0,0 +1,63 @@
+---
+title: useId composable
+desc: What is useId() composable and how you can use it
+keys: useId
+badge: Quasar v2.15+
+---
+
+The `useId()` composable returns an "id" which is a ref() that can be used as a unique identifier to apply to a DOM node attribute.
+
+Should you supply a function (`getValue` from the typing below) to get the value that the id might have, it will make sure to keep it updated.
+
+On SSR, it takes into account the process of hydration so that your component won't generate any such errors.
+
+## Syntax
+
+```js
+import { useId } from 'quasar'
+
+setup () {
+  const { id } = useId()
+  // ...
+}
+```
+
+```js
+function useId(
+  opts?: {
+    getValue?: () => string | null | undefined,
+    required?: boolean // default: true
+  }
+): {
+  id: Ref<string>;
+};
+```
+
+## Example
+
+```html
+<template>
+  <div :id="id">
+    Some component
+  </div>
+</template>
+
+<script>
+import { useId } from 'quasar'
+
+export default {
+  props: {
+    for: String
+  },
+
+  setup () {
+    const { id } = useId({
+      getValue: () => props.for,
+      required: true
+    })
+
+    return { id }
+  }
+}
+</script>
+```

ui/src/components/btn-dropdown/QBtnDropdown.js

@@ -6,7 +6,7 @@ import QBtnGroup from '../btn-group/QBtnGroup.js'
 import QMenu from '../menu/QMenu.js'
 
 import { getBtnDesignAttr, useBtnProps } from '../btn/use-btn.js'
-import useId from '../../composables/private/use-id.js'
+import useId from '../../composables/use-id.js'
 import { useTransitionProps } from '../../composables/private/use-transition.js'
 
 import { createComponent } from '../../utils/private/create.js'

ui/src/components/expansion-item/QExpansionItem.js

@@ -8,7 +8,7 @@ import QSlideTransition from '../slide-transition/QSlideTransition.js'
 import QSeparator from '../separator/QSeparator.js'
 
 import useDark, { useDarkProps } from '../../composables/private/use-dark.js'
-import useId from '../../composables/private/use-id.js'
+import useId from '../../composables/use-id.js'
 import { useRouterLinkProps } from '../../composables/private/use-router-link.js'
 import useModelToggle, { useModelToggleProps, useModelToggleEmits } from '../../composables/private/use-model-toggle.js'
 

ui/src/components/fab/QFab.js

@@ -4,7 +4,7 @@ import QBtn from '../btn/QBtn.js'
 import QIcon from '../icon/QIcon.js'
 
 import useFab, { useFabProps } from './use-fab.js'
-import useId from '../../composables/private/use-id.js'
+import useId from '../../composables/use-id.js'
 import useModelToggle, { useModelToggleProps, useModelToggleEmits } from '../../composables/private/use-model-toggle.js'
 
 import { createComponent } from '../../utils/private/create.js'

ui/src/composables.js

@@ -4,6 +4,7 @@ import useMeta from './composables/use-meta.js'
 import useQuasar from './composables/use-quasar.js'
 
 import useHydration from './composables/use-hydration.js'
+import useId from './composables/use-id.js'
 import useRenderCache from './composables/use-render-cache.js'
 import useSplitAttrs from './composables/use-split-attrs.js'
 import useTick from './composables/use-tick.js'
@@ -16,6 +17,7 @@ export {
   useQuasar,
 
   useHydration,
+  useId,
   useRenderCache,
   useSplitAttrs,
   useTick,

ui/src/composables/private/use-field.js

@@ -1,10 +1,10 @@
-import { h, ref, computed, watch, Transition, nextTick, onActivated, onDeactivated, onBeforeUnmount, onMounted, getCurrentInstance } from 'vue'
+import { h, ref, computed, Transition, nextTick, onActivated, onDeactivated, onBeforeUnmount, onMounted, getCurrentInstance } from 'vue'
 
 import QIcon from '../../components/icon/QIcon.js'
 import QSpinner from '../../components/spinner/QSpinner.js'
 
 import useDark, { useDarkProps } from '../../composables/private/use-dark.js'
-import useId, { getId } from './use-id.js'
+import useId from '../use-id.js'
 import useValidate, { useValidateProps } from './use-validate.js'
 import useSplitAttrs from '../use-split-attrs.js'
 
@@ -72,7 +72,10 @@ export function useFieldState ({ requiredForAttr = true, tagProp } = {}) {
   const { props, proxy } = getCurrentInstance()
 
   const isDark = useDark(props, proxy.$q)
-  const targetUid = useId(props.for, requiredForAttr)
+  const targetUid = useId({
+    required: requiredForAttr,
+    getValue: () => props.for
+  })
 
   return {
     requiredForAttr,
@@ -256,12 +259,6 @@ export default function (state) {
     return acc
   })
 
-  watch(() => props.for, val => {
-    // don't transform targetUid into a computed
-    // prop as it will break SSR
-    state.targetUid.value = getId(val, state.requiredForAttr)
-  })
-
   function focusHandler () {
     const el = document.activeElement
     let target = state.targetRef !== void 0 && state.targetRef.value

ui/src/composables/use-id.js

@@ -0,0 +1,50 @@
+import { ref, computed, watch, onMounted } from 'vue'
+
+import uid from '../utils/uid.js'
+
+import { isRuntimeSsrPreHydration } from '../plugins/Platform.js'
+
+function parseValue (val) {
+  return val === void 0 || val === null
+    ? null
+    : val
+}
+
+function getId (val, required) {
+  return val === void 0 || val === null
+    ? (required === true ? `f_${ uid() }` : null)
+    : val
+}
+
+/**
+ * Returns an "id" which is a ref() that can be used as
+ * a unique identifier to apply to a DOM node attribute.
+ *
+ * On SSR, it takes care of generating the id on the client side (only) to
+ * avoid hydration errors.
+ */
+export default function ({ getValue, required = true } = {}) {
+  if (isRuntimeSsrPreHydration.value === true) {
+    const id = getValue !== void 0
+      ? ref(parseValue(getValue()))
+      : ref(null)
+
+    if (required === true && id.value === null) {
+      onMounted(() => {
+        id.value = `f_${ uid() }` // getId(null, true)
+      })
+    }
+
+    if (getValue !== void 0) {
+      watch(getValue, newId => {
+        id.value = getId(newId, required)
+      })
+    }
+
+    return id
+  }
+
+  return getValue !== void 0
+    ? computed(() => getId(getValue(), required))
+    : ref(`f_${ uid() }`) // getId(null, true)
+}

ui/types/composables.d.ts

@@ -31,6 +31,13 @@ export function useHydration(): {
   isHydrated: Ref<boolean>;
 };
 
+export function useId(opts?: {
+  getValue?: () => string | null | undefined;
+  required?: boolean;
+}): {
+  id: Ref<string>;
+};
+
 export function useMeta(options: MetaOptions | (() => MetaOptions)): void;
 
 export function useQuasar(): QVueGlobals;