Overriding the Core Models and Controllers

Question

What could be the best method to override the core classes for the following scenario?.

I just want to change the error message thrown from a controller or from a model. For example, I want to change the login error message as 'Please sign in correctly' instead 'Invalid username or password'.

For this simple case should I use preference or plugin? Plugins may be used so that we can simply override the method itself. But is there any way which even simplifies the process for those kind of simple ovverriding?

Answer 1

If your purpose for override the core classes is to only Change the Error Message. You can use the Locale Translation to change the error message. As all error messages can be update from i18n locale CSV file.

Updated: As you mentioned, If it is required to change the message in only one particular file. Use Plugins instead of rewriting core files again. There are so many good resource available for the same:

http://devdocs.magento.com/guides/v2.0/extension-dev-guide/plugins.html

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How to Override Core Block, Model and controller in Magento2

Answer 2

If you want to change the success or error message everywhere, just change it in the i18n translation file. If you only want to change the message in one place, use Plugin instead of Preference.