Possible formats conflict

[ikokostya]

Problem

Currently z-schema uses one shared storage for all custom formats. There are two possible errors:

• Different instances of validator can't use different formats with the same name.
• User can unexpectedly get format which was registered in another npm module, because npm v3 try to install dependencies without nesting.

Suggestion

• Add solution when custom format can be registered per validator instance.

• Deprecate global registration of custom formats. If user wants to use same format in different validator instances, it can safely create factory:

  function createSchemaValidator() {
      var validator = new ZSchema();
      // Register common formats
      validator.registerFormat(...);
      return validator;
  }
  
  var validator1 = createSchemaValidator();
  var validator2 = createSchemaValidator();

[ikokostya]

@zaggino What do you think?

[zaggino]

👍 agree with you, if you'll open a PR with tests passing i'll merge it