From c38e2af14d50a628cd9d2237a5ec3af8b0862278 Mon Sep 17 00:00:00 2001
From: Abdelrahman Awad <me@awad.dev>
Date: Sun, 2 Mar 2025 12:57:42 +0200
Subject: [PATCH] feat: basic implementation of constraints simulator

---
 packages/core/src/useSelect/useSelect.ts      | 19 +++-
 .../src/validation/useContraintsValidator.ts  | 95 +++++++++++++++++++
 packages/playground/src/App.vue               |  4 +-
 .../playground/src/components/InputSelect.vue |  4 +-
 4 files changed, 114 insertions(+), 8 deletions(-)
 create mode 100644 packages/core/src/validation/useContraintsValidator.ts

diff --git a/packages/core/src/useSelect/useSelect.ts b/packages/core/src/useSelect/useSelect.ts
index b4621f22..ba9982be 100644
--- a/packages/core/src/useSelect/useSelect.ts
+++ b/packages/core/src/useSelect/useSelect.ts
@@ -15,6 +15,7 @@ import { useListBox } from '../useListBox';
 import { useLabel, useErrorMessage } from '../a11y';
 import { FieldTypePrefixes } from '../constants';
 import { registerField } from '@formwerk/devtools';
+import { useConstraintsValidator } from '../validation/useContraintsValidator';
 
 export interface SelectProps<TOption, TValue = TOption> {
   /**
@@ -32,6 +33,11 @@ export interface SelectProps<TOption, TValue = TOption> {
    */
   description?: string;
 
+  /**
+   * Whether the select field is required.
+   */
+  required?: boolean;
+
   /**
    * Placeholder text when no option is selected.
    */
@@ -93,7 +99,7 @@ export function useSelect<TOption, TValue = TOption>(_props: Reactivify<SelectPr
     disabled: props.disabled,
     schema: props.schema,
   });
-
+  const triggerEl = ref<HTMLElement>();
   const { fieldValue, setValue, errorMessage, isDisabled } = field;
   const isMutable = () => !isDisabled.value && !toValue(props.readonly);
   const { labelProps, labelledByProps } = useLabel({
@@ -126,7 +132,14 @@ export function useSelect<TOption, TValue = TOption>(_props: Reactivify<SelectPr
     onToggleAfter: toggleAfter,
   });
 
-  const { updateValidity } = useInputValidity({ field });
+  const { element: inputEl } = useConstraintsValidator({
+    type: 'select',
+    required: () => toValue(props.required),
+    value: fieldValue,
+    source: triggerEl,
+  });
+
+  const { updateValidity } = useInputValidity({ field, inputEl });
   const { descriptionProps, describedByProps } = createDescribedByProps({
     inputId,
     description: props.description,
@@ -251,8 +264,6 @@ export function useSelect<TOption, TValue = TOption>(_props: Reactivify<SelectPr
     },
   };
 
-  const triggerEl = ref<HTMLElement>();
-
   const triggerProps = computed<SelectTriggerDomProps>(() => {
     return withRefCapture(
       {
diff --git a/packages/core/src/validation/useContraintsValidator.ts b/packages/core/src/validation/useContraintsValidator.ts
new file mode 100644
index 00000000..02b022bc
--- /dev/null
+++ b/packages/core/src/validation/useContraintsValidator.ts
@@ -0,0 +1,95 @@
+import { MaybeRefOrGetter, onMounted, Ref, shallowRef, toValue, watchEffect } from 'vue';
+import { Maybe } from '../types';
+import { useEventListener } from '../helpers/useEventListener';
+
+export interface ConstraintOptions<TValue> {
+  value: MaybeRefOrGetter<TValue>;
+  source: Ref<Maybe<HTMLElement>>;
+}
+
+interface BaseConstraints extends ConstraintOptions<unknown> {
+  required?: MaybeRefOrGetter<Maybe<boolean>>;
+}
+
+interface TextualConstraints extends BaseConstraints {
+  type: 'text';
+  minLength?: MaybeRefOrGetter<Maybe<number>>;
+  maxLength?: MaybeRefOrGetter<Maybe<number>>;
+}
+
+interface SelectConstraints extends BaseConstraints {
+  type: 'select';
+}
+
+interface NumericConstraints extends BaseConstraints {
+  type: 'number';
+  min?: MaybeRefOrGetter<Maybe<number>>;
+  max?: MaybeRefOrGetter<Maybe<number>>;
+}
+
+interface DateConstraints extends BaseConstraints {
+  type: 'date';
+  min?: MaybeRefOrGetter<Maybe<Date>>;
+  max?: MaybeRefOrGetter<Maybe<Date>>;
+}
+
+export type Constraints = TextualConstraints | SelectConstraints | NumericConstraints | DateConstraints;
+
+export function useConstraintsValidator(constraints: Constraints) {
+  const element = shallowRef<HTMLInputElement>();
+
+  onMounted(() => {
+    element.value = document.createElement('input');
+    element.value.type = constraints.type === 'select' ? 'text' : constraints.type;
+  });
+
+  watchEffect(() => {
+    if (!element.value) {
+      return;
+    }
+
+    element.value.required = toValue(constraints.required) ?? false;
+
+    if (constraints.type === 'text') {
+      element.value.setAttribute('minlength', toValue(constraints.minLength)?.toString() ?? '');
+      element.value.setAttribute('maxlength', toValue(constraints.maxLength)?.toString() ?? '');
+    }
+
+    if (constraints.type === 'number') {
+      element.value.setAttribute('min', toValue(constraints.min)?.toString() ?? '');
+      element.value.setAttribute('max', toValue(constraints.max)?.toString() ?? '');
+    }
+
+    if (constraints.type === 'date') {
+      element.value.setAttribute('min', toValue(constraints.min)?.toISOString() ?? '');
+      element.value.setAttribute('max', toValue(constraints.max)?.toISOString() ?? '');
+    }
+  });
+
+  watchEffect(() => {
+    if (!element.value) {
+      return;
+    }
+
+    const val = toValue(constraints.value);
+    if (constraints.type === 'text' || element.value.type === 'text') {
+      element.value.value = String(val ?? '');
+    }
+
+    if (constraints.type === 'number') {
+      element.value.value = String(val ?? '');
+    }
+
+    if (constraints.type === 'date') {
+      element.value.value = val ? new Date(String(val)).toISOString() : '';
+    }
+  });
+
+  useEventListener(constraints.source, ['change', 'blur', 'input'], evt => {
+    element.value?.dispatchEvent(new Event(evt.type));
+  });
+
+  return {
+    element,
+  };
+}
diff --git a/packages/playground/src/App.vue b/packages/playground/src/App.vue
index 83d7f8ca..8ded3ae8 100644
--- a/packages/playground/src/App.vue
+++ b/packages/playground/src/App.vue
@@ -11,6 +11,7 @@ import Switch from '@/components/Switch.vue';
 import InputTextArea from '@/components/InputTextArea.vue';
 import { ref } from 'vue';
 import AllForm from './components/AllForm.vue';
+import Slider from './components/Slider.vue';
 
 const min = new Date(2025, 0, 4, 0, 0, 0, 0);
 const value = new Date('2025-01-15');
@@ -27,14 +28,13 @@ const isNotificationsEnabled = ref(false);
 
 <template>
   <div class="">
-    <DateField name="birthdate" label="Birth Date" :value="value" :min="min" :max="max" />
+    <InputSelect name="country" label="Country" required :options="options" />
 
     <!-- <h2 class="text-2xl font-bold mb-6">Fields Outside Form</h2>
     <InputText name="username" label="Username" placeholder="Enter username" />
     <InputNumber name="age" label="Age" :min="0" :max="120" />
     <InputTextArea name="description" label="Description" placeholder="Enter description" />
     <DateField name="birthdate" label="Birth Date" :value="value" :min="min" :max="max" />
-    <InputSelect name="country" label="Country" :options="options" />
 
     <CheckboxGroup name="hobbies" label="Hobbies">
       <CheckboxItem name="hobbies" value="reading" label="Reading" />
diff --git a/packages/playground/src/components/InputSelect.vue b/packages/playground/src/components/InputSelect.vue
index d373fc6b..6cfc20c5 100644
--- a/packages/playground/src/components/InputSelect.vue
+++ b/packages/playground/src/components/InputSelect.vue
@@ -11,7 +11,7 @@ export interface TheProps<TOption, TValue> extends SelectProps<TOption, TValue>
 
 const props = defineProps<TheProps<TOption, TValue>>();
 
-const { triggerProps, labelProps, errorMessageProps, isTouched, displayError, fieldValue, listBoxProps } =
+const { triggerProps, labelProps, errorMessageProps, isTouched, errorMessage, fieldValue, listBoxProps } =
   useSelect(props);
 </script>
 
@@ -64,7 +64,7 @@ const { triggerProps, labelProps, errorMessageProps, isTouched, displayError, fi
     </div>
 
     <span v-bind="errorMessageProps" class="error-message">
-      {{ displayError() }}
+      {{ errorMessage }}
     </span>
   </div>
 </template>