added readme

README.md

@@ -1 +1,101 @@
 # mongoose-i18n-error
+
+mongoose-i18n-error is a lightweight module for node.js/express.js to create beautiful mongoose i18n validation error messages.
+It is built on top of the awesome [i18n-node](https://github.com/mashpie/i18n-node) translation module.
+
+I never liked the mongoose/mongo error messages caused by mongoose validation or duplicate keys. So I decided to write a simple express middleware module to create consistent error messages with i18n support.
+
+```js
+{
+	username: {
+		type: 'required',
+		message: 'is required'',
+		value: undefined
+	},
+	email: {
+		type: 'regexp',
+		message: 'is no valid email',
+		value: 'johndoe.de'
+	}
+}
+```
+
+## Usage
+
+```
+npm install mongoose-i18n-error
+```
+
+Configure your app to support i18n:
+
+```js
+var i18n = require('i18n');
+
+i18n.configure({
+	locales: ['en', 'de'],
+	directory: './locales'
+});
+
+app.use(i18n.init);
+```
+
+Then, simply add the module as an [express error handler middleware](http://expressjs.com/en/guide/error-handling.html):
+
+```js
+var i18nMongooseError = new (require('mongoose-i18n-error'))();
+
+app.use(i18nMongooseError.handler(function(err, req, res, next) {
+	res.status(422).json(err);
+}));
+```
+
+## Options
+
+By default, the plugin will prefix the error messages in your locales files with 'error.':
+
+```
+"error.required": "is required",
+"error.minlength": "needs a minimum length of %s",
+"error.user.password.regexp": "is no valid email",
+"error.cast": "is not valid"
+```
+
+You can change the prefix by passing the prefix attribute as options:
+
+```js
+var i18nMongooseError = new (require('mongoose-i18n-error'))({
+	prefix: 'err.'
+});
+```
+
+## Custom validators
+
+In your custom mongoose validators your error message should now apply to the key in your locales files.
+
+```
+var Schema = new mongoose.Schema({
+	name: {
+		type: String,
+		validate: {
+			validator: function(v) {
+				return /^[A-Z]*$/i.test(v);
+			},
+			message: 'user.name.alpha'	// or simply 'alpha'
+		}
+	}
+});
+```
+
+# Tests
+
+To run the tests you need a local MongoDB instance available. Run with:
+
+```
+npm test
+```
+
+# Issues
+
+Please use the GitHub issue tracker to raise any problems or feature requests.
+
+If you would like to submit a pull request with any changes you make, please feel free!