feat(core): create content strategy

npm/ng-packs/packages/core/src/lib/strategies/content.strategy.ts

@@ -0,0 +1,52 @@
+import { ContentSecurityStrategy, CONTENT_SECURITY_STRATEGY } from './content-security.strategy';
+import { DomStrategy, DOM_STRATEGY } from './dom.strategy';
+
+export abstract class ContentStrategy<T extends HTMLScriptElement | HTMLStyleElement = any> {
+  constructor(
+    public content: string,
+    protected domStrategy: DomStrategy = DOM_STRATEGY.AppendToHead(),
+    protected contentSecurityStrategy: ContentSecurityStrategy = CONTENT_SECURITY_STRATEGY.None(),
+  ) {}
+
+  abstract createElement(): T;
+
+  insertElement() {
+    const element = this.createElement();
+
+    this.contentSecurityStrategy.applyCSP(element);
+    this.domStrategy.insertElement(element);
+  }
+}
+
+export class StyleContentStrategy extends ContentStrategy<HTMLStyleElement> {
+  createElement(): HTMLStyleElement {
+    const element = document.createElement('style');
+    element.textContent = this.content;
+
+    return element;
+  }
+}
+
+export class ScriptContentStrategy extends ContentStrategy<HTMLScriptElement> {
+  createElement(): HTMLScriptElement {
+    const element = document.createElement('script');
+    element.textContent = this.content;
+
+    return element;
+  }
+}
+
+export const CONTENT_STRATEGY = {
+  AppendScriptToBody(content: string) {
+    return new ScriptContentStrategy(content, DOM_STRATEGY.AppendToBody());
+  },
+  AppendScriptToHead(content: string) {
+    return new ScriptContentStrategy(content, DOM_STRATEGY.AppendToHead());
+  },
+  AppendStyleToHead(content: string) {
+    return new StyleContentStrategy(content, DOM_STRATEGY.AppendToHead());
+  },
+  PrependStyleToHead(content: string) {
+    return new StyleContentStrategy(content, DOM_STRATEGY.PrependToHead());
+  },
+};