Tags: FALV
The latest version of each part of FALV can be found on github repository https://github.com/fidley/falv which you can use in abapGit for easier up to date handling. 
In standard ALV when you don't pass a container for a log then a popup with errors appears when you enter wrong data to cell. FALV allows you to use built-in split container which will show errors only when they appear and directly when the errors are gone, also container of errors is hidden. Check out the video.

"! This is demo for FALV with error log
"! done by Lukasz Pegiel for http://abapblog.com
report zdemo_falv12.

datasflight type standard table of sflight.

parametersp_embeed radiobutton group gr1 default 'X',
            p_notemb radiobutton group gr1.


  select up to 100 rows
  into corresponding fields of table @sflight
  from sflight.

  "FALV creation with only table passed

  if p_embeed eq abap_true.
   data(falvzcl_falv=>createexporting i_applog_embedded abap_true  changing ct_table sflight ).
   falv zcl_falv=>createchanging ct_table sflight ).
  "Add title variable
  falv->title_v1 'ZDEMO_FALV12'.

    "set whole grid editable
   falv->layout->set_editabap_true ).
    "Change grid to edit mode
  falv->set_editableiv_modify abap_true ).

  "Display full screen grid

Video with demo result