DefineUpgradeButton (Harvest)
From OxeyeWiki
| 
 defineUpgradeButton(oldBuilding, newBuilding)  | ||
| 
 Defines an upgrade button for 'upgradeBuildingId'.  | ||
| Parameter | Expected Type | Description | 
| oldBuilding | String | The building identifier name of the building that is upgradable. | 
| newBuilding | String | The building identifier name of the building that it will be upgraded to. | 
| Returns | ||
| 
 Returns nothing.  | ||
Example
harvest.defineUpgrade("SUPERSOLARPLANT", "Super-duper Solar Plant", "This is a really good solar plant.", 300, 100, 30.0, "SparkProducer")
harvest.defineUpgradeButton("SPARKPRODUCER", "SUPERSOLARPLANT")
local function runSuperSolarPlant(entity, params, deltaTime)
   params.timer = params.timer or 0
   params.timer = params.timer + deltaTime
   if params.timer > 0.5 then
      params.timer = params.timer - 0.5
      local id = entity:getId()
      harvest.spawnEnergySpark(id)
   end
end
hook.add("SUPERSOLARPLANT_Update", runSuperSolarPlant)