Explain why componentDidMount is a better place to make an ajax request

In the docs, in componentWillMount section section it says:

Avoid introducing any side-effects or subscriptions in this method

And in the componentDidMount section:

If you need to load data from a remote endpoint, this is a good place to instantiate the network request

Which for me is confusing because I won't like to wait for the component to be mounted to dispatch an ajax call to fulfill the component data dependencies. I would like to do it as soon as possible, like in the constructor, not even in componentWillMount.

Clearly you may have a reason why you say this in the docs, I might be not seeing the bigger picture. So it will be nice if you can explain a bit more in detail or point me in the direction of where I can find the reason.

Lee las secciones enlazadas sobre componentWillMount y componentDidMount en la documentación de React, junto con las indicaciones circundantes sobre el ciclo de vida. Aclara por qué la documentación recomienda iniciar las solicitudes remotas en componentDidMount y aborda la preocupación por esperar hasta el montaje; el issue estará terminado cuando las indicaciones sobre los tiempos y la justificación sean claras.