some improvements for migrations and for ZINNIA_MARKDOWN_EXTENSIONS

[mavriq]

1. you can use ZINNIA_ENTRY_BASE_MODEL for determine your own model of Entry. But migration is trying to create a model of AbstractEntry. I tried to fix this problem.
2. I think such a definition of ImageEntry.image field would be better
3. I think use the list of modules (or names) while setting options is an better idea than the join this list to one big string, and then split them (for ZINNIA_MARKDOWN_EXTENSIONS)

[mavriq]

sorry. my mistake.
I rushed to publish and correct and not tested parts of the code.
Now try to fix it, and will give results.

[mavriq]

corrected errors
added in demo/ an example of usage ZINNIA_IMAGE_FIELD
this time should work correctly

[Fantomas42]

Hello @mavriq

I will give you a little review of your PR, because you worth it with your impressive PR.

Point 1.

Your solution is really smart, but why not using this setting https://docs.djangoproject.com/en/dev/ref/settings/#migration-modules ? I think your implementation save the case where you have removed some fields in the Entry model, but what do you if I want to add more fields ? I certainly miss something...

Point 3.

This seems perfect. 👀 🐅

Point 2.

I have a real dilemma.
I see that you have put a lot of work and probably time in this feature, but the implementation is exactly that I don't want to do in Zinnia. This treat the image field like an exception. This exception is everywhere in the codebase (=> pain to maintain) and this IF is so ugly that my eyes are melting. :)

Note this review is not final.

Thanks for your work !

[mavriq]

Hello, @Fantomas42
Thank you for your feedbak, and sorry for the long silence.

Point 3.
This seems perfect. 👀 🐅

glad to be helpful. maybe, at this stage, possible to take this changes: 87af853 3d66f63

Your solution is really smart, but why not using this setting https://docs.djangoproject.com/en/dev/ref/settings/#migration-modules

hmm.. just django - is my hobby. yet I have no lot of experience. I saw this parameter, but I did not think that it can be used so :)

I see that you have put a lot of work and probably time in this feature, but the implementation is exactly that I don't want to do in Zinnia

now I see, that the way I chose was wrong. work and time that I put is for my experience, and if it way was unsuccessful... now I know how I should not have to do.
now, I think, I know what is was necessary to do, and what is not.
if you would be interested - I will try in the next couple of days to show it.

[zopieux]

Oh damn, did not see this PR before I opened mine: #406. I did more or less exactly the changes @mavriq did for the MARKDOWN_EXTENSIONS stuff.

I am glad to find out I am not the only one annoyed with that parameter :-)

[Fantomas42]

@mavriq 87af853 has been merged, and your idea of simplification for the Markdown extensions has also been applied.

Thanks for your work !