Demystifying the Document Not Defined Error with Flowbite and Angular 18 SSR

Are you tired of encountering the dreaded “Document not defined” error while working with Flowbite and Angular 18 Server-Side Rendering (SSR)? You’re not alone! This pesky error has been the bane of many developers’ existence, but fear not, dear reader, for we’re about to dive into the depths of this issue and emerge victorious on the other side.

What is the Document Not Defined Error?

The “Document not defined” error typically occurs when your Angular application, which uses Flowbite for its component library, is trying to access the `document` object in a Server-Side Rendering (SSR) context. Yes, you read that right – SSR is the culprit behind this error. But before we dive into the solution, let’s take a step back and understand the root cause of this issue.

Why Does This Error Occur?

In a traditional client-side rendering (CSR) setup, the `document` object is readily available and can be accessed without any issues. However, when you switch to Server-Side Rendering (SSR), the game changes. SSR involves rendering your Angular application on the server, which means that the `document` object is not available in the Node.js environment.

This is where Flowbite comes into play. As a component library, it relies heavily on the `document` object to function correctly. When Flowbite tries to access the `document` object in an SSR context, it throws the “Document not defined” error, bringing your application to a screeching halt.

Fixing the Document Not Defined Error

Now that we’ve established the cause of the error, it’s time to explore the solutions. Don’t worry, we’ll break it down into easy-to-follow steps, so you can get back to building your amazing Angular application.

Step 1: Check Your Angular Version

Before we proceed, ensure you’re running Angular 18 or later. If you’re still stuck on an earlier version, upgrade to the latest version to take advantage of the built-in SSR support.

Step 2: Configure Your SSR Setup

In your `angular.json` file, make sure you have the following configuration:

"projects": {
  "your-app": {
    ...
    "architect": {
      "server": {
        "builder": "@angular-devkit/build-angular:server",
        "options": {
          "outputPath": "dist/server",
          "main": "src/main.server.ts",
          "tsConfig": "src/tsconfig.server.json"
        }
      }
    }
  }
}

This configuration sets up your Angular application for Server-Side Rendering.

Step 3: Create a Custom Renderer

Create a new file called `custom-renderer.ts` in the root of your project:

import { RendererFactory2 } from '@angular/core';
import { DomRendererFactory2 } from '@angular/platform-server';

export class CustomRendererFactory extends RendererFactory2 {
  createRenderer(hostElement: any, type: any): any {
    const renderer = new DomRendererFactory2().createRenderer(hostElement, type);
    return renderer;
  }
}

This custom renderer will help us bypass the `document` object issue.

Step 4: Update Your main.server.ts File

In your `main.server.ts` file, add the following code:

import { enableProdMode } from '@angular/core';
import { platformServer } from '@angular/platform-server';
import { ɵgetEventManager } from '@angular/core';
import { CustomRendererFactory } from './custom-renderer';

enableProdMode();

export function renderModule(module: any, doc: any) {
  const url =('/')
  const renderPlatform = platformServer();
  renderPlatform.bootstrapModule(module, {
    providers: [
      { provide: RendererFactory2, useClass: CustomRendererFactory },
    ],
  }).then((moduleRef) => {
    const eventManager = ɵgetEventManager();
    const transferState = moduleRef.injector.get(TransferState);
    return moduleRef.renderToString(doc, {
      url,
      extraProviders: [
        { provide: EVENT_MANAGER_PLUGINS, multi: true, useValue: eventManager },
        { provide: TRANSFER_STATE, useValue: transferState },
      ],
    });
  });
}

In this code, we’re importing our custom renderer and using it to bootstrap our Angular module.

Step 5: Update Your Server-side Rendering Module

In your server-side rendering module (e.g., `app.server.module.ts`), add the following code:

import { NgModule } from '@angular/core';
import { ServerModule } from '@angular/platform-server';
import { AppModule } from './app.module';
import { CustomRendererFactory } from './custom-renderer';

@NgModule({
  imports: [ServerModule, AppModule],
  providers: [
    { provide: RendererFactory2, useClass: CustomRendererFactory },
  ],
})
export class AppServerModule {}

Here, we’re importing our custom renderer and providing it as a singleton instance.

Conclusion

Voilà! With these steps, you should now be able to overcome the “Document not defined” error when using Flowbite with Angular 18 SSR. Remember to update your `angular.json` file, create a custom renderer, and configure your SSR setup correctly.

Additional Tips and Tricks

• Make sure to update your Flowbite version to the latest release, as older versions might not be compatible with Angular 18 SSR.
• If you’re still experiencing issues, try deleting the `node_modules` folder and running `npm install` again to ensure all dependencies are up-to-date.
• For more advanced scenarios, you can explore using Angular’s built-in `Renderer2` API to create custom renderers that accommodate your specific use case.

angular.json Configuration	Custom Renderer	main.server.ts Update	Server-side Rendering Module Update
enabled	created	updated	updated

By following these steps and tips, you should now be able to smoothly integrate Flowbite with Angular 18 SSR, minus the “Document not defined” error. Happy coding, and remember to stay awesome!

1. Angular Official Documentation: Server-Side Rendering (SSR) with Angular
2. Flowbite Official Documentation: Getting Started with Flowbite
3. Angular Issues: Document not defined error with SSR

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Frequently Asked Question

Get answers to the most common questions about the pesky “Document not defined error” when using Flowbite with Angular 18 SSR.