private async Task SetAgentButton_Clicked(Button setAgentButton, ScriptProbe scriptProbe)
{
List <Input> agentSelectionInputs = new List <Input>();
// show any existing agents
List <IScriptProbeAgent> currentAgents = null;
// android allows us to dynamically load code assemblies, but iOS does not. so, the current approach
// is to only support dynamic loading on android and force compile-time assembly inclusion on ios.
#if __ANDROID__
// try to extract agents from a previously loaded assembly
try
{
currentAgents = ScriptProbe.GetAgents(scriptProbe.AgentAssemblyBytes);
}
catch (Exception)
{ }
#elif __IOS__
currentAgents = ScriptProbe.GetAgents();
// display warning message, as there is no other option to load agents.
if (currentAgents.Count == 0)
{
await SensusServiceHelper.Get().FlashNotificationAsync("No agents available.");
return;
}
#endif
// let the user pick from currently available agents
ItemPickerPageInput currentAgentsPicker = null;
if (currentAgents != null && currentAgents.Count > 0)
{
currentAgentsPicker = new ItemPickerPageInput("Available agent" + (currentAgents.Count > 1 ? "s" : "") + ":", currentAgents.Cast <object>().ToList())
{
Required = false
};
agentSelectionInputs.Add(currentAgentsPicker);
}
#if __ANDROID__
// add option to scan qr code to import a new assembly
QrCodeInput agentAssemblyUrlQrCodeInput = new QrCodeInput(QrCodePrefix.SURVEY_AGENT, "URL:", false, "Agent URL:")
{
Required = false
};
agentSelectionInputs.Add(agentAssemblyUrlQrCodeInput);
#endif
List <Input> completedInputs = await SensusServiceHelper.Get().PromptForInputsAsync("Survey Agent", agentSelectionInputs, null, true, "Set", null, null, null, false);
if (completedInputs == null)
{
return;
}
// check for QR code on android. this doesn't exist on ios.
string agentURL = null;
#if __ANDROID__
agentURL = agentAssemblyUrlQrCodeInput.Value?.ToString();
#endif
// if there is no URL, check if the user has selected an agent.
if (string.IsNullOrWhiteSpace(agentURL))
{
if (currentAgentsPicker != null)
{
IScriptProbeAgent selectedAgent = (currentAgentsPicker.Value as List <object>).FirstOrDefault() as IScriptProbeAgent;
// set the selected agent, watching out for a null (clearing) selection that needs to be confirmed
if (selectedAgent != null || await DisplayAlert("Confirm", "Are you sure you wish to clear the survey agent?", "Yes", "No"))
{
scriptProbe.Agent = selectedAgent;
setAgentButton.Text = "Set Agent" + (scriptProbe.Agent == null ? "" : ": " + scriptProbe.Agent.Id);
if (scriptProbe.Agent == null)
{
await SensusServiceHelper.Get().FlashNotificationAsync("Survey agent cleared.");
}
}
}
}
#if __ANDROID__
else
{
// download agent assembly from scanned QR code
byte[] downloadedBytes = null;
string downloadErrorMessage = null;
try
{
// download the assembly and extract agents
downloadedBytes = scriptProbe.AgentAssemblyBytes = await new WebClient().DownloadDataTaskAsync(new Uri(agentURL));
List <IScriptProbeAgent> qrCodeAgents = ScriptProbe.GetAgents(downloadedBytes);
if (qrCodeAgents.Count == 0)
{
throw new Exception("No agents were present in the specified file.");
}
}
catch (Exception ex)
{
downloadErrorMessage = ex.Message;
}
// if error message is null, then we have 1 or more agents in the downloaded assembly.
if (downloadErrorMessage == null)
{
// redisplay the current input prompt including the agents we just downloaded
scriptProbe.AgentAssemblyBytes = downloadedBytes;
await SetAgentButton_Clicked(setAgentButton, scriptProbe);
}
else
{
SensusServiceHelper.Get().Logger.Log(downloadErrorMessage, LoggingLevel.Normal, typeof(Protocol));
await SensusServiceHelper.Get().FlashNotificationAsync(downloadErrorMessage);
}
}
#endif
}
