Custom map script: Blocking units

    -- List of available units, stored as variables for easy access
    _grenadier_squad = {squad = "grenadier_squad_mp"}
    _assault_grenadier_squad = {ability = "assault_grenadiers"}
    _hmg42_team = {squad = "mg42_heavy_machine_gun_squad_mp"}
    _mortar_team = {squad = "mortar_team_81mm_mp"}
    _officer_squad = {ability = "assault_field_officer"}
    _osttruppen_squad = {ability = "ostruppen"}
    _panzer_grenadier_squad = {squad = "panzer_grenadier_squad_mp"}
    _urban_assault_panzer_grenadier_squad = {ability = "urban_assault_grenadiers"}
    _pioneer_squad = {squad = "pioneer_squad_mp"}
    _sniper_squad = {squad = "sniper_squad_mp"}
    _stormtrooper_squad = {ability = "stormtroopers"}

    _pak40_at_gun_squad = {squad = "pak40_75mm_at_gun_squad_mp", isvehicle = true}
    _pak43_at_gun_squad = {ability = "pak_43_emplacement_unlock", entity = "pak43_88mm_at_gun_mp", isvehicle = true}
    _brummbar_squad = {squad = "brummbar_squad_mp", isvehicle = true}
    _elefant_squad = {ability = "elefant_unlock", isvehicle = true}
    _mechanized_250_halftrack_grenadiers_squad = {ability = "mechanized_grenadier_group", isvehicle = true}
    _mortar_250_halftrack_squad = {ability = "mortar_halftrack", isvehicle = true}
    _sdkfz_251_halftrack_squad = {squad = "sdkfz_251_halftrack_squad_mp", isvehicle = true}
    _le_fh18_howitzer_squad = {ability = "howitzer_105mm_emplacement_unlock", entity = "howitzer_105mm_le_fh18_mp", isvehicle = true}
    _opel_blitz_supply_truck_squad = {ability = "supply_truck", isvehicle = true}
    _ostwind_squad = {squad = "ostwind_squad_mp", isvehicle = true}
    _panther_squad = {squad = "panther_squad_mp", isvehicle = true}
    _panzer_iv_squad = {squad = "panzer_iv_squad_mp", isvehicle = true}
    _panzer_iv_command_squad = {ability = "armor_commander", isvehicle = true}
    _panzerwerfer_squad = {squad = "panzerwerfer_squad_mp", isvehicle = true}
    _scoutcar_222_squad = {squad = "scoutcar_sdkfz222_mp", isvehicle = true}
    _stug_3_e_squad = {ability = "stug_iii_e", isvehicle = true}
    _stug_3_squad = {squad = "stug_iii_squad_mp", isvehicle = true}
    _tiger_ace_squad = {ability = "tiger_tank_ace", isvehicle = true}
    _tiger_squad = {ability = "tiger_tank", isvehicle = true}
    _puma_squad = {ability = "puma_dispatch", isvehicle = true}

    _combat_engineer_squad = {squad = "combat_engineer_squad_mp"}
    _conscript_squad = {squad = "conscript_squad_mp"}
    _dshk_38_hmg_squad = {ability = "dshk_mp"}
    _maxim_hmg_squad = {squad = "m1910_maxim_heavy_machine_gun_squad_mp"}
    _mortar_squad = {squad = "pm-82_41_mortar_squad_mp"}
    _mortar_120mm_squad = {ability = "cmd_120mm_mortar_crew"}
    _partisan_squad = {ability = "partisans_commander_anti_infantry"}
    _partisan_at_squad = {ability = "partisans_commander_anti_vehicle"}
    _sniper_squad = {squad = "sniper_team_mp"}
    _guards_troops_squad = {ability = "cmd_guard_troops"}
    _penal_battalion_squad = {squad = "penal_battalion_mp"}
    _shock_troop_squad = {ability = "cmd_shock_troops"}

    _is_2_squad = {ability = "cmd_is2_heavy_tank", isvehicle = true}
    _isu_152_squad = {ability = "cmd_isu-152", isvehicle = true}
    _katyusha_squad = {squad = "katyusha_bm-13n_squad_mp", isvehicle = true}
    _kv_1_squad = {ability = "cmd_kv-1_unlock", isvehicle = true}
    _kv_2_squad = {ability = "kv-2", isvehicle = true}
    _kv_8_squad = {ability = "cmd_kv-8_unlock_mp", isvehicle = true}
    _m3a1_squad = {squad = "m3a1_scout_car_squad_mp", isvehicle = true}
    _m5_squad = {squad = "m5_halftrack_squad_mp", isvehicle = true}
    _howitzer_203mm_squad = {ability = "b4_203mm_howitzer", entity = "artillery_203mm_b4", isvehicle = true}
    _howitzer_152mm_squad = {ability = "cmd_ml_20", entity = "m1937_152mm_ml_20_artillery_mp", isvehicle = true}
    _zis_3_at_gun_squad = {squad = "m1942_zis-3_76mm_at_gun_squad_mp", isvehicle = true}
    _k_45mm_at_gun_squad = {ability = "m-42_at_gun", isvehicle = true}
    _su_76_squad = {squad = "su-76m_mp", isvehicle = true}
    _su_85_squad = {squad = "su-85_mp", isvehicle = true}
    _t_34_squad = {squad = "t_34_76_squad_mp", isvehicle = true}
    _t_34_85_squad = {ability = "cmd_t34_85_medium_tank", isvehicle = true}
    _t_34_85_one_squad = {ability = "cmd_advanced_t34_85_medium_tank", isvehicle = true}
    _t_70_squad = {squad = "t-70m_mp", isvehicle = true}
    _m4c_sherman_squad = {ability = "sherman_soviet_dispatch", isvehicle = true}

    -- List of units in a table
    _unitList = {
        _panzer_iv_command_squad,_dshk_38_hmg_squad,_conscript_squad,_sdkfz_251_halftrack_squad,_stormtrooper_squad,_tiger_ace_squad,_t_70_squad,
        _partisan_at_squad,_tiger_squad,_t_34_85_squad,_kv_2_squad,_mortar_squad,_penal_battalion_squad,_le_fh18_howitzer_squad,_su_76_squad,_sniper_squad,
        _m5_squad,_zis_3_at_gun_squad,_isu_152_squad,_is_2_squad,_mortar_team,_pak43_at_gun_squad,_howitzer_203mm_squad,_osttruppen_squad,_maxim_hmg_squad,
        _k_45mm_at_gun_squad,_grenadier_squad,_brummbar_squad,_combat_engineer_squad,_panzer_grenadier_squad,_assault_grenadier_squad,_officer_squad,
        _howitzer_152mm_squad,_t_34_squad,_katyusha_squad,_kv_1_squad,_scoutcar_222_squad,_kv_8_squad,_pioneer_squad,_su_85_squad,_pak40_at_gun_squad,
        _t_34_85_one_squad,_elefant_squad,_partisan_squad,_guards_troops_squad,_mortar_120mm_squad,_m3a1_squad,_stug_3_squad,_stug_3_e_squad,_panzerwerfer_squad,
        _panzer_iv_squad,_shock_troop_squad,_ostwind_squad,_opel_blitz_supply_truck_squad,_mortar_250_halftrack_squad,_mechanized_250_halftrack_grenadiers_squad,
        _hmg42_team,_panther_squad,_urban_assault_panzer_grenadier_squad,
    }

    -- List of units to block
    _block_list = {
        _zis_3_at_gun_squad, _t_70_squad,
        _conscript_squad, _katyusha_squad,
    }

    -- Method of blocking units.
    --  ITEM_REMOVED = The production icon/ability icon of the unit is removed.
    --  ITEM_LOCKED = The production icon/ability icon of the unit is visible but locked
    _block_method = ITEM_LOCKED

    -- Block all vehicles by default, true/false
    _disable_vehicles = true

    -- Free text, displayed as a reason if the blocking method is ITEM_LOCKED
    _block_message = "You are not allowed to use this unit."

    -- String converstion to a loc string
    local _loc = LOC(_block_message)
    _loc[1] = _block_message
    _block_message = _loc

    -- Helper function for applying unit restrictions
    local _blockItem = function(item)
        for i = 1, World_GetPlayerCount() do
            local player = World_GetPlayerAt(i)
            if item.squad then
                Player_SetSquadProductionAvailabilityInternal(player, BP_GetSquadBlueprint(item.squad), _block_method, _block_message)
            end
            if item.entity then
                Player_SetEntityProductionAvailabilityInternal(player, BP_GetEntityBlueprint(item.entity), _block_method, _block_message)
            end
            if item.ability then
                Player_SetAbilityAvailabilityInternal(player, BP_GetAbilityBlueprint(item.ability), _block_method, _block_message)
            end
        end
    end
    -- Apply unit restrictions based on the table _block_list
    for key, item in ipairs(_block_list) do
        _blockItem(item)
    end

    -- Block all vehicles if _disable_vehicles set to true
    if _disable_vehicles then
        for key, item in pairs(_unitList) do
            if item.isvehicle then
                _blockItem(item)
            end
        end
    end