Use Observer |

This is a companion discussion topic for the original entry at

Hi! The final project for observer doesn’t work, it shows 100% on the cells after completing any of it? Mine also doesn’t update the cells after putting the code in. Anyway the resources can be updated with correct final code? thanks!

@jrg.developer, it looks like we directly access the value in model by a cell view. Is it ok in MVC? Or please explain what I misunderstood? =)

@jrg.developer Can you please help with this when you get a chance? Thank you - much appreciated! :]

This isn’t a “completed,” but rather, a “score” for the questions that you go right versus the total questions answered. Hence, if you mark 8 questions are right and 2 as wrong, your score is 80% (8 / (8 + 2).

Make sure you typed everything correctly and exactly as shown. If needed, you can also copy/paste from the final project too. If you have any specific problems/questions not addressed, let me know! :]

Design patterns are a starting point –– a template, not a complete solution. As most things, there are tradeoffs with each decision.

When evaluating whether a decision is “okay” or not for a given question, I normally ask two questions,

  1. “Does it violate SOLID?”

  2. And if it does, “Am I okay with the consequences that will result?”

I go into more details about SOLID on this thread.


It’s probably okay, as long as you understand the consequences of doing so. If you anticipate a problem that it will cause, design for it. :wink:

1 Like