Sometimes it is useful for frontend engineers to be able to save unstructured data into the database without bothering backend engineers to add yet another tables/fields/endpoints.
The KeyValue service serves this need.
Unfortunately it is hard to write a generic service for this purpose without knowing the authorization rules of the specific application, but the KeyValue service sidesteps this issue by assigning ownership of a Key to the User or Department that first created it.
For an imperfect* example consider the following:
You are a Reddit developer and want to save unstructured theming options for subreddits. Now assuming the moderators all belong to the same Department, all you have to do is to set the value like this:
await keyValueService.set({
token: myToken,
value: {
key: "$subreddit-id",
namespace: "themingOptions",
// key will be owned by the department and not the
// user that saves this key
ownedByUser: false,
// public means the options will be publicly readable
// ie. without a token
public: true,
// department of the subreddit
departmentId: "$subbredit-department-id"
value: { 'background-color': '#ff0000' },
},
});After saving the above values will only be settable by the subreddit moderators.
An important limitation here to understand is that the key must be "acquired" ideally before the subreddit ID is published, otherwise some other department might "take it".
- imperfect because at the moment Actio doesn't work well with when a user belongs to a huge number of subreddits, but this is easy to fix and will be fixed later.
Below are the fields for the Value type that this service accepts (see models.ts).
The key : ). (Everyone knows what a horse is).
This is most likely an object id that exists somewhere else in your application. A subreddit ID, a webshop ID, a user ID etc.
The namespace simply exists so you can save multiple things for a key. For a user ID key you could save namespaces like "preferences", "settings", "history" etc.
If true, it is the user that owns the key and not their department.
If true then the key will be publicly (ie. without a token) readable.
If true, the key will have no concept of ownership, anyone can write or read it.