Add Alpha rule

Author: Armnajafi

src/Validator.ts

@@ -22,6 +22,7 @@ import { RequiredWithoutAllRule } from './rules/RequiredWithoutAllRule';
 import { UppercaseRule } from './rules/UppercaseRule';
 import { LowercaseRule } from './rules/LowercaseRule';
 import { JsonRule } from './rules/JsonRule';
+import { AlphaRule } from './rules/AlphaRule';
 
 
 export class Validator {
@@ -46,7 +47,8 @@ export class Validator {
     required_without_all: new RequiredWithoutAllRule(),
     uppercase: new UppercaseRule(),
     lowercase: new LowercaseRule(),
-    json: new JsonRule()
+    json: new JsonRule(),
+    alpha: new AlphaRule()
   };
 
   constructor(private locale: string = 'en') {}

src/locales/en.json

@@ -16,5 +16,6 @@
     "required_without_all": "The {field} field is required when none of {other} are present.",
     "uppercase": "The {field} field must be uppercase.",
     "lowercase": "The {field} field must be lowercase.",
-    "json": "The {field} field must be a valid JSON string."
+    "json": "The {field} field must be a valid JSON string.",
+      "alpha": "The {field} field must contain only alphabetic characters."
 }

src/locales/fa.json

@@ -10,6 +10,7 @@
     "required_without_all": "فیلد {field} هنگامی که هیچ یک از فیلدهای {other} موجود نباشند، الزامی است.",
     "uppercase": "فیلد {field} باید با حروف بزرگ باشد.",
     "lowercase": "فیلد {field} باید با حروف کوچک باشد.",
-    "json": "فیلد {field} باید یک رشته JSON معتبر باشد."
+    "json": "فیلد {field} باید یک رشته JSON معتبر باشد.",
+    "alpha": "فیلد {field} باید فقط شامل حروف الفبا باشد."
 }
 

src/rules/AlphaRule.ts

@@ -0,0 +1,35 @@
+import { ValidationRule } from './ValidationRule';
+
+export class AlphaRule implements ValidationRule {
+  private defaultMessage = '';
+  private customMessage?: string;
+  
+  setDefaultMessage(message: string) {
+    this.defaultMessage = message;
+  }
+  
+  setCustomMessage(message: string) {
+    this.customMessage = message;
+  }
+  
+  validate(value: any, ruleValue: any, field: string, inputs: Record<string, any>): string | null {
+    // Skip validation if value is empty
+    if (value === undefined || value === null || value === '') {
+      return null;
+    }
+    
+    // Convert value to string if it's not already
+    const stringValue = String(value);
+    
+    // Check if the string contains only alphabetic characters
+    // Using a regular expression to match only letters (a-z, A-Z)
+    const alphaRegex = /^[a-zA-Z]+$/;
+    
+    if (!alphaRegex.test(stringValue)) {
+      const msg = this.customMessage || this.defaultMessage;
+      return msg.replace('{field}', field);
+    }
+    
+    return null;
+  }
+}