Why use uvm_config_db to pass vif or configuration object is recommended?

UVM
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7

In reply to cgales:

Hi cgales:
It’s correct that before component is created, the assignment can’t be done.
By the way, build_phase() will be called automatically when children use new() to create instance.
I thinks build_phase() is top-down phase, after making assignmet of agent config in env’s build_phase(), even finish involking env’s build_phase(), the children(agent)'s build_phase() is involked. So it has no effect that agents can use these values provided in the configuration object to configurate it’s structure etc.

class x_agent extends uvm_agent;
  x_agent_config cfg;

  x_coverage_collector collector;
  ...

  function void build_phase (uvm_phase phase);
    if (cfg.coverage_enable)
      collector = x_coverage_collector::type_id::create("collector");
    ...
  endfunction : build_phase
endclass : x_agent

The code above can work fine, is there any other reason please?

Thanks a lot!