NGSW Config File

• appData: any kind of data which describe the version of the app
• index: specifies the file that serves as the index page to satisfy navigation requests. Usually this is /index.html
• assetGroups: cached resources at build time (essential resources to start => App Shell)
• dataGroups: cached resources at runtime

Each named groups can choose two caching strategies

NGSW assetGroups

• name: (mandatory) to identify this particular group of assets through the versions of the configuration
• resources: files, versionedFiles (& urls)
• installMode & updateMode: two strategies => prefetch & lazy

        interface AssetGroup {
            name: string;
            installMode?: 'prefetch' | 'lazy';
            updateMode?: 'prefetch' | 'lazy';
            resources: {
                files?: string[];
                versionedFiles?: string[];
                urls?: string[];
            };
        }
    

NGSW dataGroups

• name: (mandatory) to identify this particular group of assets between versions of the configuration
• urls: a list of URL patterns. URLs that match these patterns will be cached according to this data group's policy
• version: (default: 0) provides a mechanism to indicate that the resources being cached have been updated in a backwards-incompatible way, and that the old cache entries—those from previous versions—should be discarded
• cacheConfig: dress up the cache policy again two strategies => prefetch & lazy

        export interface DataGroup {
            name: string;
            urls: string[];
            version?: number;
            cacheConfig: {
                maxSize: number;
                maxAge: string;
                timeout?: string;
                strategy?: 'freshness' | 'performance';
            };
        }
    

NGSW Resource Patterns

• **: matches 0 or more path segments
• *: matches exactly one path segment or filename segment
• !: prefix marks the pattern as being negative, meaning that only files that don't match the pattern will be included

        # all files
        "https://localhost:3002/**" 

        # specifies all JSON files
        "https://localhost:3002/**/*.json"

        # specifies only HTML files in the root
        "https://localhost:3002/*.html" 

        # exclude all sourcemaps
        "!https://localhost:3002/**/*.map"