Many developers building with Salesforce’s Lightning Web Components (LWC) have likely encountered security-related errors like: “This page has an error. [NoErrorObjectAvailable] Script error.” While such issues initially cause frustration, they’re critical reminders about the importance of Lightning Web Security (LWS).
Lightning Web Components (LWC) offer a modern, standards-based framework that simplifies building performant apps on the Salesforce Platform. However, as you’re adding scripts—particularly external analytics or third-party libraries—you may find yourself bumping into security roadblocks.
Salesforce’s Lightning Web Security (LWS) is designed precisely for this reason: protecting applications from vulnerabilities. But what happens when LWS distorts essential features, such as setting script.src, triggering these frustrating errors?
Error Encountered: Understanding “NoErrorObjectAvailable”
When you’re trying to integrate external scripts, your browser may show cryptic error messages like “This page has an error. [NoErrorObjectAvailable] Script error”. Initially, this error feels ambiguous and doesn’t provide much detail, leaving developers puzzled about what’s actually causing the breakage.
Behind the scenes, this vague error often appears due to Salesforce’s strict security model—Lightning Web Security—actively distorting or preventing manipulation of certain script attributes. Specifically, the issue lies in the way LWC and LWS handle the script.src setter.
In simpler terms, Salesforce intentionally restricts how scripts load to protect against common vulnerabilities such as Cross-site scripting (XSS). However, these protections can accidentally block some genuine use-cases like loading analytics or marketing scripts.
Root Cause Analysis: script.src Setter Distortion by Lightning Web Security
In typical JavaScript, injecting scripts dynamically involves something as straightforward as the following:
// Typical JavaScript snippet to load external script
const script = document.createElement('script');
script.src = 'https://thirdpartydomain.com/script.js';
document.head.appendChild(script);
However, with LWS enabled, the above seemingly innocent code falls prey to distortion. Salesforce applies restrictions or “distortions” to certain JavaScript APIs for your application’s security. The script.src setter is a victim here.
In practice, Salesforce’s Lightning Web Security “proxifies” or “wraps” components and DOM interactions, altering them so that scripts cannot dynamically fetch external code without explicit permission. Since externally loaded scripts pose high security risks if not regulated, LWS immediately flags and halts these attempts.
Think of distortion like airport security. Although frustrating at times, the checks prevent harmful elements from threatening the overall safety—strict but necessary.
Effects of Lightning Web Security on Script Loading
Distortion impacts scripts in two notable ways:
- Disruption in script execution: It blocks execution entirely or renders it ineffective, resulting in obscure errors like “this page has an error” thrown by Salesforce.
- Prevention of code injection: Positively, it mitigates the risks associated with dynamically injected external scripts which might contain malicious exploits.
Developers working with external scripts often face a challenging trade-off between convenience and security. But in Salesforce, security almost always wins—and understandably so.
Analyzing the Provided Analytics Script
Suppose the original problematic code snippet is something like this:
const scriptTag = document.createElement('script');
scriptTag.type = 'text/javascript';
scriptTag.async = true;
scriptTag.src = 'https://analytics.example.com/script.js'; // this line triggers distortion
document.head.appendChild(scriptTag);
Here’s what’s happening above:
- A new script element is created to track analytics data.
- The
async=trueattribute ensures asynchronous loading for performance. - Finally, we set
script.srcto the URL of our third-party analytics script.
When you execute code like this in Salesforce LWC with LWS activated, setting script.src directly leads to an error due to distortive proxying by Salesforce security wrappers.
Proposed Fixes: Effective Approaches to Load Scripts Safely
Now, knowing the cause, what can you do? Luckily, there are effective alternatives:
1. Static Resource Loading
Upload your scripts into Salesforce as static resources and load them using the Lightning platform’s own security-compliant mechanism:
import { loadScript } from 'lightning/platformResourceLoader';
import analytics from '@salesforce/resourceUrl/analyticsScript';
connectedCallback() {
loadScript(this, analytics)
.then(() => {
// Do stuff after script loads
})
.catch(error => {
console.error('Loading error:', error);
});
}
This method is fully compliant and recommended by Salesforce themselves.
2. Using Lightning Locker Compatible Scripts
Consider vendor analytics scripts or common libraries explicitly compatible with Salesforce LWS or Locker Service (Salesforce’s security predecessor). Popular platforms often offer Salesforce-specific versions or packages designed to align well with LWS restrictions.
3. Salesforce Named Credentials and APIs
If analytics integration involves API calls, instead use Salesforce provided features like Named Credentials or Apex controllers to fetch data securely. This not only sidesteps client-script issues but integrates seamlessly with Salesforce permissions.
Implementation Guidelines: Best Practices for Script Execution
When dealing with external scripts and security models like LWS, keep these essential principles in mind:
- Favor static resources and Salesforce-approved patterns where possible.
- Minimize dynamic injections—they introduce vulnerabilities or incompatibilities.
- Thoroughly test before deployment on environments with Salesforce’s security activated.
- Review official Salesforce documentation for Lightning Web Components guidelines.
Real-world Salesforce LWC Implementations That Overcome LWS Distortion
One practical example: many developers previously experienced similar distortion issues when integrating tracking tools like Google Analytics. They solved it by either switching to Salesforce static resources or using Salesforce’s own connectors and APIs.
Another success story comes from integrating Stripe for payments within Salesforce. Developers switched to pulling Stripe assets from Salesforce static resources instead of dynamically fetching via script.src, neatly sidestepping the distortion issue entirely.
The Salesforce Trailhead module on Lightning Web Security even highlights successful adjustments made by developers:
- Replacing custom dynamic analytics scripts with static Salesforce equivalents.
- API integrations preferred vs. client-script scenarios.
Their adjustments preserve security without sacrificing functionality.
Maintaining security without compromising essential script integration can initially seem intimidating. But by thoroughly understanding Salesforce LWS restrictions and following guideline-compliant patterns, script.src errors can easily become a thing of the past.
Lightning Web Security, despite its complexity, remains critical for robust application security. Learning how to navigate these protections effectively ensures a secure, functional application.
Next time, before reaching towards hacks or insecure methods, keep Lightning Web Security’s best practices and proven solutions in mind. Good coding involves more than functionality—it involves safe, secure, and efficient code too.
Have you faced similar script errors due to Lightning Web Security? How have you adapted your LWC implementations to handle them effectively? Share your thoughts below!
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