Plugin Recipes

These focused recipes build on Plugin Authoring and Plugin Hooks. For generated modules, entry composition, wrappers, middleware, HTML tags, and resolution changes, use Generated Contributions IR.

Add Deployment Metadata

Use transformOutput() when a deployment adapter needs plugin-owned metadata:

import { definePlugin } from "@evjs/ev/plugin";

export const deployMetadata = definePlugin({
  id: "deploy-metadata",
  setup() {
    return {
      transformOutput(output) {
        output.deployment = {
          platform: "custom",
          builtAt: new Date().toISOString(),
        };
      },
    };
  },
});

transformOutput() can change only linked AssetGroup contents and deployment metadata. See Build Output Ownership for the framework-owned fields. Deployment metadata must contain only plain, losslessly JSON-serializable values; evjs validates it after every output hook.

Add Per-Page Metadata

Use ctx.owner.kind to target Page-owned documents:

import { definePlugin } from "@evjs/ev/plugin";

export const pageMetadata = definePlugin({
  id: "page-metadata",
  setup() {
    return {
      transformHtml(doc, ctx) {
        if (ctx.owner.kind !== "page") return;
        const meta = doc.createElement("meta");
        meta.setAttribute("name", "evjs-page");
        meta.setAttribute("content", ctx.owner.pageId);
        doc.head?.appendChild(meta);
      },
    };
  },
});

Static HTML files and Page-specific request-time document shells both pass through transformHtml(). Do not infer ownership from the filename.

Add a CSP Nonce

transformHtml() exposes a parsed, bundler-independent document:

import crypto from "node:crypto";
import { definePlugin } from "@evjs/ev/plugin";

export const cspNonce = definePlugin({
  id: "csp-nonce",
  setup() {
    return {
      transformHtml(doc) {
        const nonce = crypto.randomBytes(16).toString("base64");
        for (const script of doc.querySelectorAll("script")) {
          script.setAttribute("nonce", nonce);
        }
      },
    };
  },
});

For production CSP, ensure the response header uses the same nonce as the document transformation. The mechanism for carrying that value depends on the deployment runtime.