feat: support i18n and rules config

README.md

@@ -65,16 +65,20 @@ exports.index = function* () {
 
 ### Extend Rules
 
-- app.js
+- config.default.js
 
 ```js
-app.validator.addRule('jsonString', (rule, value) => {
-  try {
-    JSON.parse(value);
-  } catch (err) {
-    return 'must be json string';
+exports.validate = {
+  rules:{
+    jsonString(rule, value){
+      try {
+        JSON.parse(value);
+      } catch (err) {
+        return this.gettext('must be json string');  //here will call ctx.gettext
+      }
+    }
   }
-});
+}
 ```
 
 ## Questions & Suggestions

app/extend/context.js

@@ -1,6 +1,21 @@
 'use strict';
 
+const Parameter = require('parameter');
+const VALIDATOR = Symbol('Context#validator');
 module.exports = {
+  get validator() {
+    if (!this[VALIDATOR]) {
+      const config = this.app.config.validate || {};
+      Object.assign(config, {
+        translate: this.gettext.bind(this),
+      });
+      this[VALIDATOR] = new Parameter(config);
+      config.rules && Object.keys(config.rules).forEach(key => {
+        this[VALIDATOR].addRule(key, config.rules[key].bind(this));
+      });
+    }
+    return this[VALIDATOR];
+  },
   /**
    * validate data with rules
    *
@@ -9,7 +24,7 @@ module.exports = {
    */
   validate(rules, data) {
     data = data || this.request.body;
-    const errors = this.app.validator.validate(rules, data);
+    const errors = this.validator.validate(rules, data);
     if (errors) {
       this.throw(422, 'Validation Failed', {
         code: 'invalid_param',