Peace and blessings to a people unknown! (Hello World :)
This post is going to be used, God willing, to retrieve content posted to the freedom-cells category and filtered by location. Though, currently, I cannot find a way to call the steem api to filter by two tags, AFAIK.
So, we'll have to:
1. search the main category (freedom-cells/freedomcells-test)
2. filter the results by location tags
-or vice-versa so heavy lifting of searching/filtering location data is on steem (leaving client to filter by category)
I cannot imagine a way to do this without being done on the client-side. The only way to offload work from the client in a fully decentralized system, AFAIK is to use a main account to curate/validate posts so the client can just pull from this main account (such as who it follows for valid users, or posts it voted for for valid posts). In this case, we want to filter curated/valid posts further by their location (which may be required to be a valid post, either pre-populated with the users location or manually entered. post may need to be posted by a valid user as well (ie. followed by the main account/validated to have appropriate information to use application).
Without any further pre-processing/validation/curation from the main account, the client would have to load all the validated posts using getState or something equivalent to then filter by their location tag. This could be optimized by saving/indexing on the client side after the first retrieval but still quite expensive.
Another option does come to mind, praise be to The God. Possibly using hard coded posts/comments for each location, where the main account will push a reference to the validated post. This could drastically reduce the computation on the client side, reducing it to just searching the appropriate post/comment for comments/children made by the main account, thus somewhat guaranteeing that the posts linked to in those comments/children are verified to be for the freedom-cell community/category and from the location specified.
This should, God willing, leave the process mentioned above (searching main category and filtering by location, or vice versa, and then verifying the post and account) to the main account "bot".
Regardless, The God willing we can find a way to work with this API without building a centralized server for indexing and searching, keeping Freedom Cells as decentralized as we can. Peace!