Is it difficult to rewrite a site from Yii to Yii2?

Question

Yii

Our online store was made on Yii 10 years ago. How much work will it take to upgrade to Yii2 and the latest PHP version to meet modern standards? Is it like making a website from scratch or easier?
What is it for?
1) There is no understanding whether it is possible to upgrade to the latest version of PHP on Yii 1.x. I assume that you first need to upgrade to Yii 2.x, and then run 7.x.
2) We constantly want to improve something according to our needs, but we can’t find specialists, everyone strongly recommends remaking it on 2.x or another modern framework.
3) As far as I understand, search engines now react negatively to old codes and lower them in the search results.

Answer 1

To a large extent it depends on how your site is made. The fact that this is not 2 lines of code is for sure. But is it worth doing from scratch, you need to look at your code. By the way, yii3 will be released relatively soon. Maybe it makes sense to wait, although the 2nd and 3rd versions will not differ as much as the 2nd and 1st.
But the main question - why do you need it? It is being finalized and you ran into an unsolvable problem? Load reduction issue? Is there a valid reason?
this is somehow strange, except perhaps if you sell it as cms. It's just that otherwise the user sees front, he has no idea whether you have yii there or not and what version.

Answer 2

>3) search engines now react negatively to old codes and lower them in search results.
Absolute nonsense. If someone argues for you to switch to yii2 on this basis, do not deal with these people.
>2) can't find specialists,
just keep looking. There are 100% such people. Yes, not everyone is comfortable on yii1, especially after yii2. First of all, find a specialist you will trust and build a plan with him.
>1) I assume that you first need to upgrade to Yii 2.x.
If you have a large site, then a normal conscious migration of yii1->yii2 may take a year or more. Those. no need to do migration for the sake of migration - these are not very meaningful costs.
PS:
But you really need to update projects. How exactly and what to do is a completely different question.
I migrated yii1->yii2 projects "a couple of times". This can be done, but the decision must be conscious and the process carefully planned.
For example, here is a technique: https://habr.com/post/417677/

Answer 3

Depends on the complexity of the application itself. Sometimes it's easier from scratch.
In any case, most likely it will be a transfer and will cost more than a new project.

Answer 4

yii2 has excellent documentation on this topic, there are 2 ways but this is only for strong nerves...