When Angular runs a root. initializer roots (environment, platform and
app initializers) finish before bootstrap roots (bootstrap component or
module, bootstrap listeners) start. first-http-request and
first-injection run whenever that happens, which can be inside an
initializer (an initializer that uses HttpClient constructs the
interceptors). custom marks a root given by method.
When Angular runs a root.
initializerroots (environment, platform and app initializers) finish beforebootstraproots (bootstrap component or module, bootstrap listeners) start.first-http-requestandfirst-injectionrun whenever that happens, which can be inside an initializer (an initializer that uses HttpClient constructs the interceptors).custommarks a root given bymethod.