LiveUpdate API documentation

function init(self)
    self.manifest = liveupdate.get_current_manifest()
end

local function callback_store_resource(self, hexdigest, status)
     if status == true then
          print("Successfully stored resource: " .. hexdigest)
     else
          print("Failed to store resource: " .. hexdigest)
     end
end

local function load_resources(self, target)
     local resources = collectionproxy.missing_resources(target)
     for _, resource_hash in ipairs(resources) do
          local baseurl = "http://example.defold.com:8000/"
          http.request(baseurl .. resource_hash, "GET", function(self, id, response)
               if response.status == 200 then
                    liveupdate.store_resource(self.manifest, response.response, resource_hash, callback_store_resource)
               else
                    print("Failed to download resource: " .. resource_hash)
               end
          end)
     end
end

local function store_manifest_cb(self, status)
  if status == liveupdate.LIVEUPATE_OK then
    pprint("Successfully stored manifest. This manifest will be loaded instead of the bundled manifest the next time the engine starts.")
  else
    pprint("Failed to store manifest")
  end
end

local function download_and_store_manifest(self)
  http.request(MANIFEST_URL, "GET", function(self, id, response)
      if response.status == 200 then
        liveupdate.store_manifest(response.response, store_manifest_cb)
      end
    end)
end

local LIVEUPDATE_URL = <a file server url>

-- This can be anything, but you should keep the platform bundles apart
local ZIP_FILENAME = 'defold.resourcepack.zip'

local APP_SAVE_DIR = "LiveUpdateDemo"

function init(self)
    self.proxy = "levels#level1"

    print("INIT: is_using_liveupdate_data:", liveupdate.is_using_liveupdate_data())
    -- let's download the archive
    msg.post("#", "attempt_download_archive")
end

-- helper function to store headers from the http request (e.g. the ETag)
local function store_http_response_headers(name, data)
    local path = sys.get_save_file(APP_SAVE_DIR, name)
    sys.save(path, data)
end

local function load_http_response_headers(name)
    local path = sys.get_save_file(APP_SAVE_DIR, name)
    return sys.load(path)
end

-- returns headers that can potentially generate a 304
-- without redownloading the file again
local function get_http_request_headers(name)
    local data = load_http_response_headers(name)
    local headers = {}
    for k, v in pairs(data) do
        if string.lower(k) == 'etag' then
            headers['If-None-Match'] = v
        elseif string.lower(k) == 'last-modified' then
            headers['If-Modified-Since'] = v
        end
    end
    return headers
end

local function store_archive_cb(self, path, status)
    if status == true then
        print("Successfully stored live update archive!", path)
        sys.reboot()
    else
        print("Failed to store live update archive, ", path)
        -- remove the path
    end
end

function on_message(self, message_id, message, sender)
    if message_id == hash("attempt_download_archive") then

        -- by supplying the ETag, we don't have to redownload the file again
        -- if we already have downloaded it.
        local headers = get_http_request_headers(ZIP_FILENAME .. '.json')
        if not liveupdate.is_using_liveupdate_data() then
            headers = {} -- live update data has been purged, and we need do a fresh download
        end

        local path = sys.get_save_file(APP_SAVE_DIR, ZIP_FILENAME)
        local options = {
            path = path,        -- a temporary file on disc. will be removed upon successful liveupdate storage
            ignore_cache = true -- we don't want to store a (potentially large) duplicate in our http cache
        }

        local url = LIVEUPDATE_URL .. ZIP_FILENAME
        print("Downloading", url)
        http.request(url, "GET", function(self, id, response)
            if response.status == 304 then
                print(string.format("%d: Archive zip file up-to-date", response.status))
            elseif response.status == 200 and response.error == nil then
                -- register the path to the live update system
                liveupdate.store_archive(response.path, store_archive_cb)
                -- at this point, the "path" has been moved internally to a different location

                -- save the ETag for the next run
                store_http_response_headers(ZIP_FILENAME .. '.json', response.headers)
            else
                print("Error when downloading", url, "to", path, ":", response.status, response.error)
            end

            -- If we got a 200, we would call store_archive_cb() then reboot
            -- Second time, if we get here, it should be after a 304, and then
            -- we can load the missing resources from the liveupdate archive
            if liveupdate.is_using_liveupdate_data() then
                msg.post(self.proxy, "load")
            end
        end,
        headers, nil, options)