make loadDynamicData() and saveDynamicData() public methods

[hmueller01]

See discussion #17. Also added a flag to not load data twice, if already loaded. Also renamed CREDENTIALS_FILENAME and wm_cred.dat to DYNAMIC_DATA_FILENAME and wm_dynamic.dat to align with method names (the credentials are stored in CONFIG_FILENAME). I tested/compiled the code on ESP8266 with LittleFS and EEPROM. What I did not check is ESP32, as I do not have the dev env.

[khoih-prog]

Hi @hmueller01

Thanks for your precious time to make the PR.

But sorry I think this way is too drastic, and requires much more time to test, verify to be sure OK and not breaking anything.

I suggest you just create 2 new public functions, such as

bool extLoadDynamicData(bool forceLoad = false)
{
  // Condition to be satisfied before calling this
  if (checking_everything_OK)
  {
    return loadDynamicData(forceLoad);
  }
  else
  {
    ESP_WML_LOGERROR("Some error");
    return false;
  }
}

void extSaveDynamicData()
{
  // similar checking, etc before calling  saveDynamicData()
  // Condition to be satisfied before calling this
  if (checking_everything_OK)
  {
    saveDynamicData();
  }
  else
  {
    ESP_WML_LOGERROR("Some error");
  }
}

then you can do whatever you'd like without worrying breaking anything.

[hmueller01]

It took me much time to implement the feature in way of this PR. For the moment it works good for me so I do not like to do more work on this. I'll keep my branch and can merge to your main any time.

[hmueller01]

BTW your suggestion won't work. I added hadDynamicData to avoid loading dynamic data a second time. This needs to be located in your private methods. And this is important to avoid loading data a second time while changed and possibly not yet saved data are in RAM. So the main change needs to be done anyway.

I'll give you an example:

  // host_name is in dynamic data and is empty per default
  m_wifi_manager->loadDynamicData();
  if (os_strlen(host_name) == 0) {
    Serial.println(F("host_name was empty, setting default host name"));
    os_sprintf(host_name, "ESP-%08X", ESP.getChipId());
    m_wifi_manager->saveDynamicData(); // if you forget this before begin() changes are lost without hadDynamicData flag!
  }
  m_wifi_manager->setConfigPortal(host_name, "password");
  // Set customized DHCP HostName
  m_wifi_manager->begin(host_name);