ESOUI - How to set action to hotbar

Check the code of addons which already do change the skills on the actionbars, like AlphaGear2.
Should be something like the function AG.LoadSet which e.g initiates the laoding of a defined set of equipped items and skills, or similar.

It will add something to the internal table AG.Jobs with the type AG.JOB_TYPE_LOAD_SKILL_BAR.
And then somewhere this table AG.Jobs will be parsed, using this type to initiated the skill change on the action bars.
If you search for JOB_TYPE_LOAD_SKILL_BAR you'll see it will be in function AG.HandleOnUpdate()
-> elseif (jobType == AG.JOB_TYPE_LOAD_SKILL_BAR) then
AG.LoadBar(param1)

So AG.LoadBar should handle the skill change

Hope this helps.

Lua Code:

--- returns the abilityIndex for a given abilityId
function AG.GetAbility(abilityId)
    trace ('Searching Ability with ID %d', abilityId)
 
 
    -- local exists = DoesAbilityExist(abilityId)
    -- trace ('Ability exists: %s', tostring(exists))
 
    -- local  texName = GetAbilityIcon(abilityId)
    -- trace ('Ability texture: %s', texName)
 
    -- local st, si, ai, mc, ri = GetSpecificSkillAbilityKeysByAbilityId(abilityId)
    -- trace ('Specific keys: %d, %d, %d, %d', si, ai, mc, ri)
 
    -- Returns: boolean hasProgression, number progressionIndex, number lastRankXp, number nextRankXP, number currentXP, boolean atMorph
    local hasProgression, progressionIndex = GetAbilityProgressionXPInfoFromAbilityId(abilityId)
 
    trace ('Progression Index: %s,  %d', tostring(hasProgression), progressionIndex)
 
    if not hasProgression then
        trace('Ability with ID %d has no progression.', abilityId)
        return 0 
    end
 
 
    -- Returns: string name, number morph, number rank
    local _, morph, rank = GetAbilityProgressionInfo(progressionIndex)
 
    -- Returns: string name, string texture, number abilityIndex
    local name, _, abilityIndex = GetAbilityProgressionAbilityInfo(progressionIndex, morph, rank)
    if abilityIndex then
        trace('Found ability %s with Index %d for ID %d.', name, abilityIndex, abilityId)
        return abilityIndex
    else 
        trace('Did not find ability with ID %d.', abilityId)
        return 0
    end
end
 
function AG.LoadSkill(nr, slot)
    if not nr or not slot then return end
 
    local skillID = AG.setdata[nr].Skill[slot]
    
    -- TODO remove skill from bar, if set is locked and skillID == 0
    if skillID == 0 then return end
 
    local currentSkillID = GetSlotBoundId(slot+2)
 
    if skillID ~= currentSkillID then
        trace('SkillId in slot %d changed. Current: %d new: %d', slot, currentSkillID, skillID)
        local newAbilityIndex = AG.GetAbility(skillID)
        local currentAbilityIndex = AG.GetAbility(currentSkillID)
 
        if newAbilityIndex ~= 0 and currentAbilityIndex ~= newAbilityIndex then 
            trace('AbilityIndex has changed, replacing. Current AI: %d, New AI: %d', currentAbilityIndex, newAbilityIndex)
            local res, msg = CallSecureProtected('SelectSlotAbility', newAbilityIndex, slot+2)
 
            if not res then
                -- d("|cFF0000Failed to set new skill. Message:|r "..(msg or "<none>"))
                d("|cFF0000Failed to set new skill due to a bug in ESO.|r Kill a mob and try again!")
            end
        end
    end
end
 
function AG.LoadBar(nr)
    if not nr then return end
    for slot = 1, 6 do AG.LoadSkill(nr,slot) end
end