> For AI agents: the complete documentation index is available at https://nhanbe.id.vn/llms.txt, the full documentation bundle is available at https://nhanbe.id.vn/llms-full.txt.
# Context-Aware Configuration
**Sling Context-Aware Configuration** (CA Config) lets you store configuration values in the content tree so they resolve differently depending on the content context. Unlike OSGi configurations (which are global or per-run-mode), CA Config values are **site-specific, tenant-specific, or even page-specific** - without any code branching.
Use cases:
- Different analytics tracking IDs per site
- API keys that vary between tenants
- Feature flags scoped to a specific brand
- Social media URLs per regional site
***
## How It Works
### The lookup chain
When code requests a CA Config value for a given resource, Sling walks up the content tree looking for a `sling:configRef` property. This property points to a `/conf/...` path where the configuration is stored.
1. Start at the resource (e.g., `/content/brand-a/en/products/shoe`)
2. Walk up: `/content/brand-a/en/products` → `/content/brand-a/en` → `/content/brand-a`
3. Find `sling:configRef = /conf/brand-a` on `/content/brand-a`
4. Look for the configuration under `/conf/brand-a/sling:configs/`
5. If not found, check `/conf/global/sling:configs/` (if configured)
6. If still not found, use the default values from the annotation
### JCR structure
```markdown
/conf/
├── brand-a/
│ └── sling:configs/
│ └── com.myproject.core.config.SiteConfig/
│ ├── analyticsId = "UA-12345-A"
│ ├── socialFacebookUrl = "https://facebook.com/brand-a"
│ └── enableNewHeader = true
├── brand-b/
│ └── sling:configs/
│ └── com.myproject.core.config.SiteConfig/
│ ├── analyticsId = "UA-12345-B"
│ └── enableNewHeader = false
└── global/
└── sling:configs/
└── com.myproject.core.config.SiteConfig/
├── analyticsId = "UA-00000"
├── socialFacebookUrl = ""
└── enableNewHeader = false
/content/
├── brand-a/
│ ├── sling:configRef = "/conf/brand-a" ← links to /conf/brand-a
│ └── en/
│ └── home/
├── brand-b/
│ ├── sling:configRef = "/conf/brand-b"
│ └── en/
```
***
## Defining a Configuration Class
Use Sling CA Config annotations to define a typed configuration:
```java
package com.myproject.core.config;
import org.apache.sling.caconfig.annotation.Configuration;
import org.apache.sling.caconfig.annotation.Property;
@Configuration(
label = "Site Configuration",
description = "Site-specific settings like analytics, social, and feature flags"
)
public @interface SiteConfig {
@Property(label = "Analytics Tracking ID",
description = "Google Analytics or Adobe Analytics tracking ID")
String analyticsId() default "";
@Property(label = "Facebook URL")
String socialFacebookUrl() default "";
@Property(label = "Twitter URL")
String socialTwitterUrl() default "";
@Property(label = "Enable new header",
description = "Feature flag for the redesigned header")
boolean enableNewHeader() default false;
@Property(label = "Max items per page")
int maxItemsPerPage() default 10;
}
```
### Supported property types
| Type | Example | Notes |
| ---------- | ---------------- | ---------------------------- |
| `String` | `"UA-12345"` | Default: `""` |
| `boolean` | `true` / `false` | Default: `false` |
| `int` | `10` | Default: `0` |
| `long` | `1000L` | Default: `0L` |
| `double` | `3.14` | Default: `0.0` |
| `String[]` | `{"a", "b"}` | Arrays of any primitive type |
***
## Reading CA Config in Sling Models
### Using ConfigurationResolver
```java
import org.apache.sling.caconfig.ConfigurationResolver;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.models.annotations.Model;
import org.apache.sling.models.annotations.injectorspecific.OSGiService;
import org.apache.sling.models.annotations.injectorspecific.Self;
import com.myproject.core.config.SiteConfig;
@Model(adaptables = Resource.class)
public class HeaderModel {
@Self
private Resource resource;
@OSGiService
private ConfigurationResolver configResolver;
public boolean isNewHeaderEnabled() {
SiteConfig config = configResolver.get(resource).as(SiteConfig.class);
// as() may return null when no configuration resource is bound to this context.
return config != null && config.enableNewHeader();
}
public String getAnalyticsId() {
SiteConfig config = configResolver.get(resource).as(SiteConfig.class);
return config != null ? config.analyticsId() : null;
}
}
```
### Adapting from a Resource
`ConfigurationBuilder` can also be obtained by adapting from the current `Resource`, avoiding an explicit `@OSGiService` injection:
```java
import javax.annotation.PostConstruct;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.caconfig.ConfigurationBuilder;
import org.apache.sling.models.annotations.Model;
import org.apache.sling.models.annotations.injectorspecific.Self;
import com.myproject.core.config.SiteConfig;
@Model(adaptables = Resource.class)
public class HeaderModel {
@Self
private Resource resource;
private SiteConfig siteConfig;
@PostConstruct
protected void init() {
ConfigurationBuilder builder = resource.adaptTo(ConfigurationBuilder.class);
siteConfig = builder != null ? builder.as(SiteConfig.class) : null;
}
public String getAnalyticsId() {
return siteConfig != null ? siteConfig.analyticsId() : "";
}
public boolean isNewHeaderEnabled() {
return siteConfig != null && siteConfig.enableNewHeader();
}
}
```
### Accessing from HTL
Expose the config values through your Sling Model and use them in HTL:
```html