Hy,
I’m new to milo (and OPC-UA) and try to implement an OPC-UA server with Historical Data Access. I reused the current milo server example and create a history node. On this node I can query (with the Prosys OPC UA Client) the empty history. I know that I have to implement the persistency of the history nodes by myself.
So far so good – but I could not found any information about to handle the history read request and how to return the response. More precisely how to add the HistoryData to an HistoryReadResult
#Override
public void historyRead(HistoryReadContext context, HistoryReadDetails readDetails, TimestampsToReturn timestamps,
List<HistoryReadValueId> readValueIds)
{
List<HistoryReadResult> results = Lists.newArrayListWithCapacity(readValueIds.size());
for (HistoryReadValueId readValueId : readValueIds){
//return 3 historical entries
DataValue v1 = new DataValue(new Variant(new Double(1)), StatusCode.GOOD, new DateTime(Date.from(Instant.now().minus(1, ChronoUnit.MINUTES))));
DataValue v2 = new DataValue(new Variant(new Double(2)), StatusCode.GOOD, new DateTime(Date.from(Instant.now().minus(2, ChronoUnit.MINUTES))));
DataValue v3 = new DataValue(new Variant(new Double(3)), StatusCode.GOOD, new DateTime(Date.from(Instant.now().minus(3, ChronoUnit.MINUTES))));
HistoryData data = new HistoryData(new DataValue[] {v1,v2,v3});
//???
HistoryReadResult result = new HistoryReadResult(StatusCode.GOOD, ByteString.NULL_VALUE, ??? );
results.add(result);
}
context.complete(results);
}
You're going to need access to the spec to successfully implement historical access services. Part 4 and Part 11.
The last parameter in the HistoryReadResult constructor is supposed to be a HistoryData structure. ExtensionObject is basically the container that structures are encoded and transferred in.
To create that ExtensionObject you would first create a HistoryData (or HistoryModifiedData, depends... see the spec) and then do something like ExtensionObject.encode(historyData) to get the object you need to finish building the HistoryReadResult.
Overrides historyRead is the correct way to do.
HistoryReadResult result = new HistoryReadResult(StatusCode.GOOD, ByteString.NULL_VALUE,ExtensionObject.encode(data) );
However method was not called by generic client such as UA-Expert before defining my variableNode with specific AccessLevel and Historizing mode like this :
Set<AccessLevel> acclevels = new LinkedHashSet<>();
acclevels.add(AccessLevel.CurrentRead);
acclevels.add(AccessLevel.CurrentWrite);
acclevels.add(AccessLevel.HistoryRead);
UaVariableNode node = new UaVariableNode.UaVariableNodeBuilder(server.getNodeMap())
.setNodeId(new NodeId(namespaceIndex, "HelloWorld/Test/" + name))
.setAccessLevel(ubyte(AccessLevel.getMask(acclevels)))
.setUserAccessLevel(ubyte(AccessLevel.getMask(acclevels)))
.setBrowseName(new QualifiedName(namespaceIndex, name))
.setDisplayName(LocalizedText.english(name))
.setDataType(typeId)
.setTypeDefinition(Identifiers.BaseDataVariableType)
.setHistorizing(true)
.build();
Related
I am looking for a way to get a delta of Appointments. Basically what I want is to react on newly created Appointments.
To get newly created / unread messages there is a SearchFilter in the java ews api that I use. Unfortunately AppointmentSchema does not provide any fitting Enum for the filter.
new SearchFilter.SearchFilterCollection(LogicalOperator.And, new SearchFilter.IsEqualTo(EmailMessageSchema.IsRead, false));
I get the Appointments like:
CalendarFolder calendarFolder = CalendarFolder.bind(service, WellKnownFolderName.Calendar, new PropertySet());
var result = calendarFolder.findAppointments(cView);
so back to my question. How can I notice if someone invited me to a new Appointment or an email with a new Appointment invitation?
I have already found a solution, luckily. MeetingRequest is the Item I am looking for.
FindItemsResults<Item> result = service.findItems(new FolderId(WellKnownFolderName.Inbox, new Mailbox(getCredentials())), getUnreadEmailFilter(), new ItemView(10));
result.forEach(n -> {
if (n instanceof MeetingRequest) {
System.out.println("New Appointment - MeetingRequest found!");
MeetingRequest req = (MeetingRequest) n;
req.accept(true);
}
}
I'm listening for connection changes through events pluging ("amq.rabbitmq.event", "connection.#").
It works properly so I'm adding at java side two additional parameters as clientproperties, to get the identity of the user that connects or disconnect.
However at c# side I can only access these properties as a list of byte[], and not sure on how to convert it to a Dictionary or so..
If I print all entries
if (args.BasicProperties.Headers.TryGetValue("client_properties", out object value))
{
var items = value as List<object>;
foreach(var item in items)
{
Console.WriteLine($"{item.GetType().ToString()}");
var bytes = item as byte[];
result.Add(Encoding.UTF8.GetString(bytes));
}
}
I can see this:
{<<"platform">>,longstr,<<"Java">>}
{<<"capabilities">>,table,[{<<"connection.blocked">>,bool,true},{<<"basic.nack">>,bool,true},{<<"exchange_exchange_bindings">>,bool,true},{<<"authentication_failure_close">>,bool,true},{<<"publisher_confirms">>,bool,true},{<<"consumer_cancel_notify">>,bool,true}]}
{<<"groupId">>,longstr,<<"1e6e935f0d4d9ec446d67dadc85cbafd10d1a095">>}
{<<"information">>,longstr,<<"Licensed under the MPL. See http://www.rabbitmq.com/">>}
{<<"version">>,longstr,<<"4.8.1">>}
{<<"copyright">>,longstr,<<"Copyright (c) 2007-2018 Pivotal Software, Inc.">>}
{<<"product">>,longstr,<<"RabbitMQ">>}
What kind of object format is and how can I parse this?:
{<<id>>,type,<<value>>}
Apparently ( as for an answer I got on Rabbit client google group for this questions ), client_properties is something that's not created to being read by the receiving party..
However is a really good way to have something like LWT ( Last Will and Testament ), then I am using it at the minute doing the parse by myself.
if (args.BasicProperties.Headers.TryGetValue("client_properties", out object value))
{
var items = value as List<object>;
foreach (var item in items)
{
var bytes = item as byte[];
//{<<id>>, type, <<value>>}
String itemStr = Encoding.UTF8.GetString(bytes);
var parts = itemStr.Split(",");
var key = CleanErlangString(parts[0]);
var value = CleanErlangString(parts[2]);
// Do things with key/value
}
}
ClearErlangFunction
private static string CleanErlangString(string toClean)
{
return toClean
.Replace("{", "").Replace("}", "")
.Replace("\"", "")
.Replace("<<", "").Replace(">>", "");
}
What I am doing to use it as LWT, is setting a custom property on client side and then obtaining it while reading events at "amq.rabbitmq.event", "connection.#". With that I know who have disconnected and even process something as LWT with my core server.
I hope this helps someone :)
I am learning Amazon Cloud Search but I couldn't find any code in either C# or Java (though I am creating in C# but if I can get code in Java then I can try converting in C#).
This is just 1 code I found in C#: https://github.com/Sitefinity-SDK/amazon-cloud-search-sample/tree/master/SitefinityWebApp.
This is 1 method i found in this code:
public IResultSet Search(ISearchQuery query)
{
AmazonCloudSearchDomainConfig config = new AmazonCloudSearchDomainConfig();
config.ServiceURL = "http://search-index2-cdduimbipgk3rpnfgny6posyzy.eu-west-1.cloudsearch.amazonaws.com/";
AmazonCloudSearchDomainClient domainClient = new AmazonCloudSearchDomainClient("AKIAJ6MPIX37TLIXW7HQ", "DnrFrw9ZEr7g4Svh0rh6z+s3PxMaypl607eEUehQ", config);
SearchRequest searchRequest = new SearchRequest();
List<string> suggestions = new List<string>();
StringBuilder highlights = new StringBuilder();
highlights.Append("{\'");
if (query == null)
throw new ArgumentNullException("query");
foreach (var field in query.HighlightedFields)
{
if (highlights.Length > 2)
{
highlights.Append(", \'");
}
highlights.Append(field.ToUpperInvariant());
highlights.Append("\':{} ");
SuggestRequest suggestRequest = new SuggestRequest();
Suggester suggester = new Suggester();
suggester.SuggesterName = field.ToUpperInvariant() + "_suggester";
suggestRequest.Suggester = suggester.SuggesterName;
suggestRequest.Size = query.Take;
suggestRequest.Query = query.Text;
SuggestResponse suggestion = domainClient.Suggest(suggestRequest);
foreach (var suggest in suggestion.Suggest.Suggestions)
{
suggestions.Add(suggest.Suggestion);
}
}
highlights.Append("}");
if (query.Filter != null)
{
searchRequest.FilterQuery = this.BuildQueryFilter(query.Filter);
}
if (query.OrderBy != null)
{
searchRequest.Sort = string.Join(",", query.OrderBy);
}
if (query.Take > 0)
{
searchRequest.Size = query.Take;
}
if (query.Skip > 0)
{
searchRequest.Start = query.Skip;
}
searchRequest.Highlight = highlights.ToString();
searchRequest.Query = query.Text;
searchRequest.QueryParser = QueryParser.Simple;
var result = domainClient.Search(searchRequest).SearchResult;
//var result = domainClient.Search(searchRequest).SearchResult;
return new AmazonResultSet(result, suggestions);
}
I have already created domain in Amazon Cloud Search using AWS console and uploaded document using Amazon predefine configuration option that is movie Imdb json file provided by Amazon for demo.
But in this method I am not getting how to use this method, like if I want to search Director name then how do I pass in this method as because this method parameter is of type ISearchQuery?
I'd suggest using the official AWS CloudSearch .NET SDK. The library you were looking at seems fine (although I haven't look at it any detail) but the official version is more likely to expose new CloudSearch features as soon as they're released, will be supported if you need to talk to AWS support, etc, etc.
Specifically, take a look at the SearchRequest class -- all its params are strings so I think that obviates your question about ISearchQuery.
I wasn't able to find an example of a query in .NET but this shows someone uploading docs using the AWS .NET SDK. It's essentially the same procedure as querying: creating and configuring a Request object and passing it to the client.
EDIT:
Since you're still having a hard time, here's an example. Bear in mind that I am unfamiliar with C# and have not attempted to run or even compile this but I think it should at least be close to working. It's based off looking at the docs at http://docs.aws.amazon.com/sdkfornet/v3/apidocs/
// Configure the Client that you'll use to make search requests
string queryUrl = #"http://search-<domainname>-xxxxxxxxxxxxxxxxxxxxxxxxxx.us-east-1.cloudsearch.amazonaws.com";
AmazonCloudSearchDomainClient searchClient = new AmazonCloudSearchDomainClient(queryUrl);
// Configure a search request with your query
SearchRequest searchRequest = new SearchRequest();
searchRequest.Query = "potato";
// TODO Set your other params like parser, suggester, etc
// Submit your request via the client and get back a response containing search results
SearchResponse searchResponse = searchClient.Search(searchRequest);
I am creating a Java web app to manage meetings between a set of students and teachers. All of them already use Outlook to manage their email and personal calendar.
I would like to know if it's even possible to build the schedule feature of my web app using Exchange, Office365 or Sharepoint Team Calendar via REST service in order to check the availability and create a meeting for a student and one of the teachers available:
SharePoint 2013 REST service
So far, the most promising mechanism I have found is Microsoft Sharepoint Server's calendar, which collaborative features makes possible to create a meeting and check availability for a list of users. The downside is that it does not support one to one meetings but for the entire team (as far I have found).
My second option would be to require everyone in the group (students and teachers of the department) to make public their personal calendar so the web app be able to check the availability of both student and teacher and send a meeting request. The obvious problem is the privacy/security concern derived from this approach.
My last option (and by far the less favourite because it feels like re-inventing the wheel) is to build a proprietary calendar within the web app and send iCal requests to each person. The obvious problem with this approach is synchronisation between the two separated calendars.
In addition, this feature must be a pretty common need so there should be tons of blogs explaining how to take advantage of Exchange/Sharepoint/Office365 to implement it (other platforms are not considered since my employer's infrastructure is based on Microsoft). However, whether it is so obvious that nobody talks about it or I have not searched in the right place. Any advice to point me in the right direction?
Exchange natively shows user calendar availability exposed in EWS (Exchange Web Services), your network administrator must configure Exchange server enabling EWS.
But guess what... Office 365 (as I know) have EWS services enabled, due exchange is part of office 365 offer.
As EWS are normal Web services you should create a "service stub" or proxy in whatever you use in java to create services references mapping wsdl files.
Exchanged EWS is my preferred solution.
Hope this helps.
This is the reference page, this link show how to use the service references from C# to make the right API calls.
http://msdn.microsoft.com/en-us/library/exchange/aa494212(v=exchg.140).aspx
static void GetUserAvailability(ExchangeServiceBinding esb)
{
// Identify the time to compare free/busy information.
Duration duration = new Duration();
duration.StartTime = DateTime.Now;
duration.EndTime = DateTime.Now.AddHours(4);
// Identify the options for comparing free/busy information.
FreeBusyViewOptionsType fbViewOptions = new FreeBusyViewOptionsType();
fbViewOptions.TimeWindow = duration;
fbViewOptions.RequestedView = FreeBusyViewType.MergedOnly;
fbViewOptions.RequestedViewSpecified = true;
fbViewOptions.MergedFreeBusyIntervalInMinutes = 35;
fbViewOptions.MergedFreeBusyIntervalInMinutesSpecified = true;
MailboxData[] mailboxes = new MailboxData[1];
mailboxes[0] = new MailboxData();
// Identify the user mailbox to review for free/busy data.
EmailAddress emailAddress = new EmailAddress();
emailAddress.Address = "tplate#contoso.com";
emailAddress.Name = String.Empty;
mailboxes[0].Email = emailAddress;
mailboxes[0].ExcludeConflicts = false;
// Make the request.
GetUserAvailabilityRequestType request = new GetUserAvailabilityRequestType();
// Set the time zone of the request.
request.TimeZone = new SerializableTimeZone();
request.TimeZone.Bias = 480;
request.TimeZone.StandardTime = new SerializableTimeZoneTime();
request.TimeZone.StandardTime.Bias = 0;
request.TimeZone.StandardTime.DayOfWeek = DayOfWeekType.Sunday.ToString();
request.TimeZone.StandardTime.DayOrder = 1;
request.TimeZone.StandardTime.Month = 11;
request.TimeZone.StandardTime.Time = "02:00:00";
request.TimeZone.DaylightTime = new SerializableTimeZoneTime();
request.TimeZone.DaylightTime.Bias = -60;
request.TimeZone.DaylightTime.DayOfWeek = DayOfWeekType.Sunday.ToString();
request.TimeZone.DaylightTime.DayOrder = 2;
request.TimeZone.DaylightTime.Month = 3;
request.TimeZone.DaylightTime.Time = "02:00:00";
// Add the mailboxes to the request.
request.MailboxDataArray = mailboxes;
// Add the view options to the request.
request.FreeBusyViewOptions = fbViewOptions;
try
{
// Send the request and get the response.
GetUserAvailabilityResponseType response = esb.GetUserAvailability(request);
// Access free/busy information.
if (response.FreeBusyResponseArray.Length < 1)
{
throw new Exception("No free/busy response data available.");
}
else
{
foreach (FreeBusyResponseType fbrt in response.FreeBusyResponseArray)
{
if (fbrt.ResponseMessage.ResponseClass == ResponseClassType.Error)
{
Console.WriteLine(string.Format("Error: {0}", fbrt.ResponseMessage.MessageText));
}
else
{
// Show the free/busy stream.
FreeBusyView fbv = fbrt.FreeBusyView;
Console.WriteLine(string.Format("Merged free/busy data: {0}", fbv.MergedFreeBusy));
}
}
}
}
catch (Exception e)
{
// Perform error processing.
Console.WriteLine(e.Message);
Console.ReadLine();
}
}
I am new to memcache of GAE and I need a help in this.
Basically, I have a datastore which exceeded the Datastore Read Operations limit because of the fact that I didn't use memcache. My datastore has minimal writes but many reads and every time there's a write, it should be available for the read. Since, the site is up and I need a quick resolution for it so I need a design help in this. So the thing is, whenever there's a write in the datastore the new entry should get memcached. One more thing I would like to know that how the datastore can be replicated to the memcache. In parallel, I am working on it but since the site is up I am asking it here without any code in hand.
Thanks
UPDATE:
Java code looks like this:
MemcacheService memcache = MemcacheServiceFactory.getMemcacheService();
if(memcache.contains("LocationInfo"))
{
JSONArray js = new JSONArray((String)memcache.get("LocationInfo"));
result = new ArrayList<LocationInfo>();
for(int i = 0; i < js.length(); i++)
{
JSONObject jso = (JSONObject)js.get(i);
LocationInfo loc = new LocationInfo(jso);
result.add(loc);
}
}
else
{
q1= pm.newQuery(LocationInfo.class);
q1.setFilter(filter);
result = (List<LocationInfo>)q1.execute();
JSONArray js = new JSONArray();
for(LocationInfo loc : result)
{
js.put(loc.toJSON());
}
memcache.put("LocationInfo", js.toString());
}
from google.appengine.ext import db
from google.appengine.api import memcache
def top_arts(update = False):
key = 'top'
#Getting arts from memcache
arts = memcache.get(key)
#Check if key is defined in memcache
#or an update has been invoked
if update or not arts:
#Querying the Google Data store using GQL
arts = db.GqlQuery('SELECT * from Art ORDER BY created DESC LIMIT 10')
memcache.set(key, arts)
return arts
You can use the same function for reading from memcache and then writing data into
memcache
Eg:
for reading from memcache:-
arts = top_arts()
when writing into database:-
#write your entry in database
<some database code>
#update memcache with this new entry
top_arts(update=True)