feature symfony#2926 [LiveComponent] Add validation modifiers (min_length, max_length, min_value, max_value) to data-model inputs (xDeSwa)

This PR was squashed before being merged into the 2.x branch.

Discussion
----------

[LiveComponent] Add validation modifiers (min_length, max_length, min_value, max_value) to data-model inputs

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| Docs?         | yes
| Issues        |
| License       | MIT

**[LiveComponent]**
This PR introduces support for input validation modifiers used in data-model, including:

- min_length(x)
- max_length(x)
- min_value(x)
- max_value(x)

These modifiers prevent model updates and AJAX calls if the user input doesn't meet the validation constraints.
It helps avoid unnecessary re-renders and network traffic.

They can be combined with other modifiers like debounce.

```twig
  <input data-model="name|min_length(3)" />
  <input data-model="price|min_value(1)|max_value(100)" type="number" />
```

Commits
-------

7c015e3 [LiveComponent] Add validation modifiers (min_length, max_length, min_value, max_value) to data-model inputs

Author: Kocal

src/LiveComponent/CHANGELOG.md

@@ -1,5 +1,19 @@
 # CHANGELOG
 
+## 2.28.0
+
+-   Add new modifiers for input validations, useful to prevent uneccessary HTTP requests:
+    - `min_length` and `max_length`: validate length from textual input elements
+    - `min_value` and `max_value`: validate value from numeral input elements
+
+```twig
+<!-- Do not trigger model update until 3 characters are typed -->
+<input data-model="min_length(3)|username" type="text" value="" />
+
+<!-- Only trigger updates when value number is between 10 and 100 -->
+<input data-model="min_value(10)|max_value(100)|quantity" type="number" value="20" />
+```
+
 ## 2.27.0
 
 -  Add events assertions in `InteractsWithLiveComponents`:

src/LiveComponent/assets/dist/Directive/get_model_binding.d.ts

@@ -5,5 +5,9 @@ export interface ModelBinding {
     shouldRender: boolean;
     debounce: number | boolean;
     targetEventName: string | null;
+    minLength: number | null;
+    maxLength: number | null;
+    minValue: number | null;
+    maxValue: number | null;
 }
 export default function (modelDirective: Directive): ModelBinding;

src/LiveComponent/assets/dist/dom_utils.d.ts

@@ -8,3 +8,6 @@ export declare function getModelDirectiveFromElement(element: HTMLElement, throw
 export declare function elementBelongsToThisComponent(element: Element, component: Component): boolean;
 export declare function cloneHTMLElement(element: HTMLElement): HTMLElement;
 export declare function htmlToElement(html: string): HTMLElement;
+export declare function isTextualInputElement(el: HTMLElement): el is HTMLInputElement;
+export declare function isTextareaElement(el: HTMLElement): el is HTMLTextAreaElement;
+export declare function isNumericalInputElement(element: Element): element is HTMLInputElement;

src/LiveComponent/assets/dist/live_controller.js

@@ -475,6 +475,15 @@ const getMultipleCheckboxValue = (element, currentValues) => {
     return finalValues;
 };
 const inputValue = (element) => element.dataset.value ? element.dataset.value : element.value;
+function isTextualInputElement(el) {
+    return el instanceof HTMLInputElement && ['text', 'email', 'password', 'search', 'tel', 'url'].includes(el.type);
+}
+function isTextareaElement(el) {
+    return el instanceof HTMLTextAreaElement;
+}
+function isNumericalInputElement(element) {
+    return element instanceof HTMLInputElement && ['number', 'range'].includes(element.type);
+}
 
 class HookManager {
     constructor() {
@@ -2343,6 +2352,10 @@ function getModelBinding (modelDirective) {
     let shouldRender = true;
     let targetEventName = null;
     let debounce = false;
+    let minLength = null;
+    let maxLength = null;
+    let minValue = null;
+    let maxValue = null;
     modelDirective.modifiers.forEach((modifier) => {
         switch (modifier.name) {
             case 'on':
@@ -2360,6 +2373,18 @@ function getModelBinding (modelDirective) {
             case 'debounce':
                 debounce = modifier.value ? Number.parseInt(modifier.value) : true;
                 break;
+            case 'min_length':
+                minLength = modifier.value ? Number.parseInt(modifier.value) : null;
+                break;
+            case 'max_length':
+                maxLength = modifier.value ? Number.parseInt(modifier.value) : null;
+                break;
+            case 'min_value':
+                minValue = modifier.value ? Number.parseFloat(modifier.value) : null;
+                break;
+            case 'max_value':
+                maxValue = modifier.value ? Number.parseFloat(modifier.value) : null;
+                break;
             default:
                 throw new Error(`Unknown modifier "${modifier.name}" in data-model="${modelDirective.getString()}".`);
         }
@@ -2371,6 +2396,10 @@ function getModelBinding (modelDirective) {
         shouldRender,
         debounce,
         targetEventName,
+        minLength,
+        maxLength,
+        minValue,
+        maxValue,
     };
 }
 
@@ -3153,6 +3182,27 @@ class LiveControllerDefault extends Controller {
             }
         }
         const finalValue = getValueFromElement(element, this.component.valueStore);
+        if (isTextualInputElement(element) || isTextareaElement(element)) {
+            if (modelBinding.minLength !== null &&
+                typeof finalValue === 'string' &&
+                finalValue.length < modelBinding.minLength) {
+                return;
+            }
+            if (modelBinding.maxLength !== null &&
+                typeof finalValue === 'string' &&
+                finalValue.length > modelBinding.maxLength) {
+                return;
+            }
+        }
+        if (isNumericalInputElement(element)) {
+            const numericValue = Number(finalValue);
+            if (modelBinding.minValue !== null && numericValue < modelBinding.minValue) {
+                return;
+            }
+            if (modelBinding.maxValue !== null && numericValue > modelBinding.maxValue) {
+                return;
+            }
+        }
         this.component.set(modelBinding.modelName, finalValue, modelBinding.shouldRender, modelBinding.debounce);
     }
     dispatchEvent(name, detail = {}, canBubble = true, cancelable = false) {

src/LiveComponent/assets/src/Directive/get_model_binding.ts

@@ -6,12 +6,20 @@ export interface ModelBinding {
     shouldRender: boolean;
     debounce: number | boolean;
     targetEventName: string | null;
+    minLength: number | null;
+    maxLength: number | null;
+    minValue: number | null;
+    maxValue: number | null;
 }
 
 export default function (modelDirective: Directive): ModelBinding {
     let shouldRender = true;
     let targetEventName = null;
     let debounce: number | boolean = false;
+    let minLength: number | null = null;
+    let maxLength: number | null = null;
+    let minValue: number | null = null;
+    let maxValue: number | null = null;
 
     modelDirective.modifiers.forEach((modifier) => {
         switch (modifier.name) {
@@ -38,6 +46,26 @@ export default function (modelDirective: Directive): ModelBinding {
             case 'debounce':
                 debounce = modifier.value ? Number.parseInt(modifier.value) : true;
 
+                break;
+
+            case 'min_length':
+                minLength = modifier.value ? Number.parseInt(modifier.value) : null;
+
+                break;
+
+            case 'max_length':
+                maxLength = modifier.value ? Number.parseInt(modifier.value) : null;
+
+                break;
+
+            case 'min_value':
+                minValue = modifier.value ? Number.parseFloat(modifier.value) : null;
+
+                break;
+
+            case 'max_value':
+                maxValue = modifier.value ? Number.parseFloat(modifier.value) : null;
+
                 break;
             default:
                 throw new Error(`Unknown modifier "${modifier.name}" in data-model="${modelDirective.getString()}".`);
@@ -52,5 +80,9 @@ export default function (modelDirective: Directive): ModelBinding {
         shouldRender,
         debounce,
         targetEventName,
+        minLength,
+        maxLength,
+        minValue,
+        maxValue,
     };
 }

src/LiveComponent/assets/src/dom_utils.ts

@@ -262,3 +262,24 @@ const getMultipleCheckboxValue = (element: HTMLInputElement, currentValues: Arra
 
 const inputValue = (element: HTMLInputElement): string =>
     element.dataset.value ? element.dataset.value : element.value;
+
+/**
+ * Checks whether the given element is a textual input (input[type=text/email/...]).
+ */
+export function isTextualInputElement(el: HTMLElement): el is HTMLInputElement {
+    return el instanceof HTMLInputElement && ['text', 'email', 'password', 'search', 'tel', 'url'].includes(el.type);
+}
+
+/**
+ * Checks whether the given element is a textarea.
+ */
+export function isTextareaElement(el: HTMLElement): el is HTMLTextAreaElement {
+    return el instanceof HTMLTextAreaElement;
+}
+
+/**
+ * Checks whether the given element is a numerical input (input[type=number] or input[type=range]).
+ */
+export function isNumericalInputElement(element: Element): element is HTMLInputElement {
+    return element instanceof HTMLInputElement && ['number', 'range'].includes(element.type);
+}

src/LiveComponent/assets/src/live_controller.ts

@@ -13,7 +13,14 @@ import SetValueOntoModelFieldsPlugin from './Component/plugins/SetValueOntoModel
 import ValidatedFieldsPlugin from './Component/plugins/ValidatedFieldsPlugin';
 import { type DirectiveModifier, parseDirectives } from './Directive/directives_parser';
 import getModelBinding from './Directive/get_model_binding';
-import { elementBelongsToThisComponent, getModelDirectiveFromElement, getValueFromElement } from './dom_utils';
+import {
+    elementBelongsToThisComponent,
+    getModelDirectiveFromElement,
+    getValueFromElement,
+    isNumericalInputElement,
+    isTextareaElement,
+    isTextualInputElement,
+} from './dom_utils';
 import getElementAsTagText from './Util/getElementAsTagText';
 
 export { Component };
@@ -30,6 +37,7 @@ export interface LiveController {
     element: HTMLElement;
     component: Component;
 }
+
 export default class LiveControllerDefault extends Controller<HTMLElement> implements LiveController {
     static values = {
         name: String,
@@ -429,6 +437,36 @@ export default class LiveControllerDefault extends Controller<HTMLElement> imple
 
         const finalValue = getValueFromElement(element, this.component.valueStore);
 
+        if (isTextualInputElement(element) || isTextareaElement(element)) {
+            if (
+                modelBinding.minLength !== null &&
+                typeof finalValue === 'string' &&
+                finalValue.length < modelBinding.minLength
+            ) {
+                return;
+            }
+
+            if (
+                modelBinding.maxLength !== null &&
+                typeof finalValue === 'string' &&
+                finalValue.length > modelBinding.maxLength
+            ) {
+                return;
+            }
+        }
+
+        if (isNumericalInputElement(element)) {
+            const numericValue = Number(finalValue);
+
+            if (modelBinding.minValue !== null && numericValue < modelBinding.minValue) {
+                return;
+            }
+
+            if (modelBinding.maxValue !== null && numericValue > modelBinding.maxValue) {
+                return;
+            }
+        }
+
         this.component.set(modelBinding.modelName, finalValue, modelBinding.shouldRender, modelBinding.debounce);
     }
 

src/LiveComponent/assets/test/Directive/get_model_binding.test.ts

@@ -4,34 +4,105 @@ import getModelBinding from '../../src/Directive/get_model_binding';
 describe('get_model_binding', () => {
     it('returns correctly with simple directive', () => {
         const directive = parseDirectives('firstName')[0];
+
         expect(getModelBinding(directive)).toEqual({
             modelName: 'firstName',
             innerModelName: null,
             shouldRender: true,
             debounce: false,
             targetEventName: null,
+            minLength: null,
+            maxLength: null,
+            minValue: null,
+            maxValue: null,
         });
     });
 
     it('returns all modifiers correctly', () => {
         const directive = parseDirectives('on(change)|norender|debounce(100)|firstName')[0];
+
         expect(getModelBinding(directive)).toEqual({
             modelName: 'firstName',
             innerModelName: null,
             shouldRender: false,
             debounce: 100,
             targetEventName: 'change',
+            minLength: null,
+            maxLength: null,
+            minValue: null,
+            maxValue: null,
         });
     });
 
     it('parses the parent:inner model name correctly', () => {
         const directive = parseDirectives('firstName:first')[0];
+
         expect(getModelBinding(directive)).toEqual({
             modelName: 'firstName',
             innerModelName: 'first',
             shouldRender: true,
             debounce: false,
             targetEventName: null,
+            minLength: null,
+            maxLength: null,
+            minValue: null,
+            maxValue: null,
+        });
+    });
+
+    it('parses min_length and max_length modifiers', () => {
+        const directive = parseDirectives('min_length(3)|max_length(20)|username')[0];
+
+        expect(getModelBinding(directive)).toEqual({
+            modelName: 'username',
+            innerModelName: null,
+            shouldRender: true,
+            debounce: false,
+            targetEventName: null,
+            minLength: 3,
+            maxLength: 20,
+            minValue: null,
+            maxValue: null,
+        });
+    });
+
+    it('parses min_value and max_value modifiers', () => {
+        const directive = parseDirectives('min_value(18)|max_value(65)|age')[0];
+
+        expect(getModelBinding(directive)).toEqual({
+            modelName: 'age',
+            innerModelName: null,
+            shouldRender: true,
+            debounce: false,
+            targetEventName: null,
+            minLength: null,
+            maxLength: null,
+            minValue: 18,
+            maxValue: 65,
+        });
+    });
+
+    it('handles mixed modifiers correctly', () => {
+        const directive = parseDirectives('on(change)|norender|debounce(100)|min_value(18)|max_value(65)|age:years')[0];
+
+        expect(getModelBinding(directive)).toEqual({
+            modelName: 'age',
+            innerModelName: 'years',
+            shouldRender: false,
+            debounce: 100,
+            targetEventName: 'change',
+            minLength: null,
+            maxLength: null,
+            minValue: 18,
+            maxValue: 65,
         });
     });
+
+    it('handles empty modifier values gracefully', () => {
+        const directive = parseDirectives('min_length|max_length|username')[0];
+        const binding = getModelBinding(directive);
+
+        expect(binding.minLength).toBeNull();
+        expect(binding.maxLength).toBeNull();
+    });
 });