How to customize Yii core messages?
Yii core messages refer to static text strings in the core Yii framework code which are meant to be displayed to end-users (e.g. core exception messages, default validation error messages). Customization of these core messages is needed in two circumstances: * When an application is written for non-English users, these core messages need to be translated and the framework does not have the required translation. * Some core messages need to be modified slightly for various reasons. For example, the messages are too technical; the messages are inappropriate in certain scenarios; the messages contain syntax errors. In the last example, bugs should be reported, but not every application can wait till the bugs are fixed. In this article, we introduce a technique to customize the core messages in a systematic way. If you are only interested in customizing a few validation error messages, you may refer to the article "[How to customize the error message of a validation rule](/doc/cookbook/1/)". When Yii displays a core message, it actually undergoes an implicit translation process with the help of an application component named "[coreMessages|CApplication::coreMessages]". The component translates the core message into the [target language|CApplication::language] which is displayed ultimately. If a translation cannot be found, the original core message will be displayed, instead. The idea here is to customize the `coreMessages` component by changing the place where it looks for translated messages. We can do so by configuring the component with the following application configuration: ~~~ [php] return array( ...... 'language'=>'de', 'components'=>array( 'coreMessages'=>array(
'basePath'=>Yii::getPathOfAlias('application.messages'),), ...... ), ); ~~~ In the above, we specify that the application is targeted to German users and thetranslated messages are located under the directory aliased as `application.messages`. In a default setting, the path alias would refer tothe directory `protected/messages`. Next, we need to provide our translations. Under the directory `protected/messages`, create a subdirectory named `de` which corresponds to the target language we set in the application configuration. And under the `de` directory, create a new file named `yii.php`. To this end, we should have the following directory structure: ~~~ WebRoot/ protected/ messages/ de/ yii.php controllers/ views/ ...... ~~~ Finally, we put message translations in the `yii.php` file. To save time, we may simply copy the content from `framework/messages/de/yii.php` and modify it as needed. > Tip: You may wonder why we would take so much trouble in order to customize the core messages. Why don't we modify the file `framework/messages/de/yii.php` directly? The answer is that you should never modify any core framework file. If you do that, you will face the danger that a future upgrade of the framework may overwrite your change.