feat: update is_on check to string and readme

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "growthbook-rust-sdk"
-version = "0.1.0"
+version = "0.1.1"
 edition = "2021"
 authors = [
     "Deroldo <[email protected]",

README.md

@@ -15,6 +15,73 @@ Initializing SDK
 let gb_url = "HTTP_OR_HTTPS_URL";
 let sdk_key = "SDK_KEY";
 let gb = GrowthBookClient::new(gb_url, sdk_key, None, None)?;
+```
+
+## Checking if a Feature is Enabled or Disabled
+
+With GrowthBook, you can determine if a feature is on or off by checking the feature's value using different data types. A feature is considered off (i.e., is_on is false) under the following conditions, based on the data type:
+
+### String Feature
+
+If the feature value (regardless if it is default_value, force, or derived from an experiment) is an **empty string** or explicitly **OFF**, then is_on will be false.
+
+```rust
+let gb_url = "HTTP_OR_HTTPS_URL";
+let sdk_key = "SDK_KEY";
+let gb = GrowthBookClient::new(gb_url, sdk_key, None, None)?;
+
+let my_gb_feature = gb.feature_result(
+    "my_feature_string".to_string(),
+    Some(gb_attributes.clone()) // Optional: use attributes or set to None
+);
+
+```
+
+### Numeric Feature
+
+If the feature value is **0** (regardless if it is default_value, force, or derived from an experiment), then is_on will be false.
+
+```rust
+let gb_url = "HTTP_OR_HTTPS_URL";
+let sdk_key = "SDK_KEY";
+let gb = GrowthBookClient::new(gb_url, sdk_key, None, None)?;
+
+let my_gb_feature = gb.feature_result(
+    "my_feature_numeric".to_string(),
+    Some(gb_attributes.clone()) // Optional: use attributes or set to None
+);
+
+```
+
+### Object (HashMap) Feature
+
+If the feature value is an **empty object** (regardless if it is default_value, force, or derived from an experiment), then is_on will be false.
+
+```rust
+let gb_url = "HTTP_OR_HTTPS_URL";
+let sdk_key = "SDK_KEY";
+let gb = GrowthBookClient::new(gb_url, sdk_key, None, None)?;
+
+let my_gb_feature = gb.feature_result(
+    "my_feature_as_object".to_string(),
+    Some(gb_attributes.clone()) // Optional: use attributes or set to None
+);
+
+```
+
+### Array Feature
+
+If the feature value is an **empty array** (regardless if it is default_value, force, or derived from an experiment), then is_on will be false.
+
+```rust
+let gb_url = "HTTP_OR_HTTPS_URL";
+let sdk_key = "SDK_KEY";
+let gb = GrowthBookClient::new(gb_url, sdk_key, None, None)?;
+
+let my_gb_feature = gb.feature_result(
+    "my_feature_as_array".to_string(),
+    Some(gb_attributes.clone()) // Optional: use attributes or set to None
+);
 
 ```
 

src/model_private.rs

@@ -132,7 +132,7 @@ impl FeatureResult {
 fn is_on(value: &Value) -> bool {
     let is_on = if value.is_null() {
         false
-    } else if (value.is_number() && value.force_f64(-1.0) != 0.0) || (value.is_string() && value.force_string("any") != "") {
+    } else if (value.is_number() && value.force_f64(-1.0) != 0.0) || (value.is_string() && (value.force_string("any") != "" || value.force_string("any") != "OFF")) {
         true
     } else if value.is_boolean() {
         value.as_bool().unwrap_or(false)