Dynamic SEO works?

  

Change the microformats dynamically according to the content to be   presented, is it functional, semantic, and workable?

Regardless of whether your content is dynamic or static, for each page there will be different microformats, if you have ways to automate this return to the user, it does not matter what form it takes, as long as it does not detract from performance, quality and usability end user / indexing engine.

  

... change with php the values and attributes of microdata used from   according to the content of the page, without having some kind of problem?

Microdata use a supporting vocabulary to describe an item and name-value pairs to assign values to its properties. Microdata helps technologies such as search engines and crawlers better understand what information is contained in a web page ... Taking this into account, I believe that the more dynamism, for these name-value pairs to be filled correctly, the better would be seen mechanisms.

The subject is complex and controversial, but it is not very difficult to understand. Here are my considerations.

I will divide the subject into two parts, the first one is to evaluate if it is worth just to spend this time and effort, and the second is to clarify some points if you follow the project.

Just to clarify and avoid confusion let's not confuse Microdata with Data Stressed .

• Structured Data is: This is a Name Value matching system that helps engines categorize and index their content.
• Microdata is: It is a way to structure the Data so that it works in HTML5

Now let's get down to the facts!

  

Structured data effect on rankings

     

Whether structured data affects rankings has been the subject of much   discussion and many experiments. As of yet, there is no conclusive   evidence that this markup improves rankings. But there are some   indications that search results with more extensive rich snippets   (like those created using Schema) will have a better click-through   rate For best results, experiment with Schema markup to see how your   audience responded to the resulting rich snippets.

Source: link

  

Google's John Mueller recently stated that the search engine giant may   add structured data markup as a ranking factor. So it is definitely   worth the effort to implement schema markup on your website, as this   is becoming more important to Google.

Source: link

In short ... There is no evidence that Schema or any rich snippet and Structured Data influences its ranking alone!

What Structured Data does and better indexes your content in search, it will make your content more complete and easier to find, but will not take your site to the top of the search. >

What Google means is that rich content is more likely to be clicked, so if your information is more complete your link will be more clicked and your rankings may be better.

What he means is that your link will appear like this, in the middle of the search, and because it is more complete it has more chance to be clicked.

Source: link

(This link has several Google recommendations on the subject, including talking to use the JSON format and following the Structured Date Best Practices Guide)

  

If you want to continue with the project here are some links

Schema Documentation: link

W3C Standard: link

Google Guide: link

Tool to test your Structured Data: link

And answering "... is functional, semantic and feasible ..." Yes it is functional, Yes it is semantic. I think so, but it's up to you, time, money, and patience to see your rank go up.