How to Fix AEM Tracking Events Not Firing

General Guide: See Global Events Not Firing Guide for universal concepts and fixes.

AEM-Specific Causes

1. WCMMode Not Checked

Tracking fires in Author mode:

<!-- Problem: No WCMMode check -->
<script>
    gtag('event', 'page_view');
</script>

2. Client Library Load Order

Scripts loaded before dependencies:

<!-- Problem: tracking before dataLayer -->
<sly data-sly-call="${clientlib.js @ categories='mysite.tracking'}"/>
<script>window.dataLayer = [];</script>

3. Dispatcher Caching Headers

Cached responses blocking cookies:

Cache-Control: public, max-age=86400
// Session cookies not set

4. CSP Blocking Analytics

Content Security Policy too restrictive:

Content-Security-Policy: script-src 'self'
// Blocks googletagmanager.com

5. HTL Context Escaping

XSS protection breaking JavaScript:

<!-- Problem: Script content escaped -->
<script>
    var data = ${dataJson}; // Escaped as text
</script>

AEM-Specific Fixes

Fix 1: Check WCMMode in HTL

Only fire tracking on Publish:

<sly data-sly-use.tracking="${'com.mysite.core.models.TrackingModel'}"
     data-sly-test="${tracking.shouldTrack}">

    <script>
        gtag('event', 'page_view', {
            'page_title': '${tracking.pageTitle}'
        });
    </script>
</sly>

@Model(adaptables = SlingHttpServletRequest.class)
public class TrackingModel {

    @Self
    private SlingHttpServletRequest request;

    public boolean shouldTrack() {
        WCMMode mode = WCMMode.fromRequest(request);
        return mode == WCMMode.DISABLED;
    }
}

Fix 2: Correct Client Library Order

Ensure proper dependency chain:

Base clientlib (loads first):

<?xml version="1.0" encoding="UTF-8"?>
<jcr:root xmlns:jcr="http://www.jcp.org/jcr/1.0"
    jcr:primaryType="cq:ClientLibraryFolder"
    categories="[mysite.datalayer]"/>

Tracking clientlib (loads after):

<?xml version="1.0" encoding="UTF-8"?>
<jcr:root xmlns:jcr="http://www.jcp.org/jcr/1.0"
    jcr:primaryType="cq:ClientLibraryFolder"
    categories="[mysite.tracking]"
    dependencies="[mysite.datalayer]"/>

In page template:

<sly data-sly-call="${clientlib.js @ categories='mysite.datalayer'}"/>
<sly data-sly-call="${clientlib.js @ categories='mysite.tracking'}"/>

Fix 3: Configure Dispatcher for Tracking

Allow cookies in cached responses:

dispatcher.any

/cache {
    /rules {
        /0001 { /type "allow" /glob "*.html" }
    }

    # Don't cache if tracking cookies present
    /invalidate {
        /0001 { /glob "*" /type "deny" }
    }
}

# Pass through tracking parameters
/filter {
    /0100 { /type "allow" /url "/content/*" /query "*_ga=*" }
}

Fix 4: Configure CSP for Analytics

Add analytics domains to CSP:

Dispatcher configuration:

/headers {
    "Content-Security-Policy" {
        "script-src 'self' 'unsafe-inline' https://www.googletagmanager.com https://www.google-analytics.com;"
        "connect-src 'self' https://www.google-analytics.com https://analytics.google.com https://region1.google-analytics.com;"
        "img-src 'self' https://www.googletagmanager.com https://www.google-analytics.com;"
    }
}

Or via Sling Rewriter:

@Component(service = TransformerFactory.class,
           property = {
               "pipeline.type=csp-transformer"
           })
public class CSPTransformerFactory implements TransformerFactory {
    // Add CSP headers
}

Fix 5: Use Proper HTL Context

Use unsafe context for JSON:

<sly data-sly-use.data="${'com.mysite.core.models.DataLayerModel'}">
    <script>
        window.dataLayer = window.dataLayer || [];
        dataLayer.push(${data.json @ context='unsafe'});
    </script>
</sly>

@Model(adaptables = SlingHttpServletRequest.class)
public class DataLayerModel {

    private String json;

    @PostConstruct
    protected void init() {
        ObjectMapper mapper = new ObjectMapper();
        Map<String, Object> data = new HashMap<>();
        data.put("pageType", getPageType());
        data.put("pageName", getPageName());

        try {
            this.json = mapper.writeValueAsString(data);
        } catch (JsonProcessingException e) {
            this.json = "{}";
        }
    }

    public String getJson() {
        return json;
    }
}

Fix 6: Debug with AEM Tools

Add debug logging:

@Model(adaptables = SlingHttpServletRequest.class)
public class TrackingDebugModel {

    private static final Logger LOG = LoggerFactory.getLogger(TrackingDebugModel.class);

    @Self
    private SlingHttpServletRequest request;

    @PostConstruct
    protected void init() {
        LOG.debug("WCMMode: {}", WCMMode.fromRequest(request));
        LOG.debug("Request URI: {}", request.getRequestURI());
        LOG.debug("User: {}", request.getUserPrincipal());
    }
}

Enable in OSGi Console:

com.mysite.core.models=DEBUG

Debugging Checklist

Step 1: Check WCMMode

// In browser console on Author
console.log('WCMMode from cookie:', document.cookie.includes('wcmmode'));

Step 2: Verify Client Libraries

// Check if tracking loaded
console.log('dataLayer:', window.dataLayer);
console.log('gtag:', typeof gtag);
console.log('GTM:', typeof google_tag_manager);

Step 3: Check Network Requests

In DevTools Network tab:

• Filter by "google"
• Look for blocked requests (red)
• Check CSP errors in Console

Step 4: Test on Publish

Always test tracking on Publish instance:

1. Deploy to Publish
2. Clear Dispatcher cache
3. Access page in incognito
4. Check GTM Preview

Common Error Patterns

Next Steps

• GA4 Setup
• GTM Setup
• Global Tracking Issues