Ruby
Installation
Install the tggl
package:
Quick start
Instantiate a client with your API key and call eval_context
to evaluate a context. A single API call evaluating all flags is performed, making all subsequent flag checking methods extremely fast.
This means that you do not need to cache results of isActive and get since they do not trigger an API call, they simply look up the data in the already fetched response.
Differences between is_active?
and get
By design, inactive flags are not in the response, which means that you have no way of telling apart those cases:
- The flag is inactive due to some conditions
- The flag does not exist
- The flag was deleted
- The API key is not valid
- Some network error
This design choice prevents unforeseen event from breaking your app, like someone deleting a flag or messing up the API key rotation. Your app will simply consider any flag to be inactive.
is_active?
will return true if the flag exists and is active regardless of its value (and there is no network error).
get
gives you the actual value of an active flag, and this value may be "falsy" (null, false, 0, or empty string). This may lead to unforeseen behavior if you are not careful:
In both cases, if the flag is explicitly inactive, or if there is a network error, the block won't be executed.
Hard-coded fallback values
When using get
, you can provide a fallback value that will be returned if the flag is inactive, does not exist, or in case of network error:
Having the possibility of providing a fallback value is useful when you want to have a default behavior when a flag is deleted or when the user encounters a network error:
Evaluating contexts in batches
If you have multiple contexts to evaluate at once, you can batch your calls in a single HTTP request which is much more performant:
Evaluate flags locally
It is possible to evaluate flags locally on the server but not recommended unless you have performance issues evaluating flags at a high frequency. Evaluating flags locally forces you to maintain the copy of flags configuration up to date and might be a source of issues.
Make sure to add the right keys to your context to be perfectly consistent with the Tggl API.
You should cache the configuration and instantiate the client with the cached version, so you don't need to call fetchConfig for every request:
It is your responsibility to keep the cache of the configuration up to date by calling fetchConfig
when needed. You can use webhooks to be notified when the configuration changes.