I am learning how to use nHapi. As many have pointed out, there's not much documentation. Following this doc I've been able to parse a message using the library. But I can't figure out how to access that message using an object model (which is what I really want nHapi to do). Essentially, I want to take an HL7 message as a string and access it using the object model, in the same way that LINQ to SQL takes a database record and lets you access it as an object. I found Parsing an HL7 without a priori messageType knowledge, but it seems to be about something else because the code in the post returns a string instead of an HL7 object (like I need). In the documentation I linked to above they seem to access the parts of a message using a "query"--but I can't find the materials to query IMessages in the library.
Here is the code I'm using, with a line showing what I want to do...
Imports NHapi.Base
Imports NHapi.Base.Parser
Imports NHapi.Base.Model
Module Module1
Sub Main()
Dim msg As String = "MSH|^~\&|SENDING|SENDER|RECV|INST|20060228155525||QRY^R02^QRY_R02|1|P|2.3|QRD|20060228155525|R|I||||10^RD&Records&0126|38923^^^^^^^^&INST|||"
Dim myPipeParser As PipeParser = New PipeParser()
Dim myImsg As IMessage = myPipeParser.Parse(msg)
Dim msgType As String = myImsg.GetStructureName
Dim mySendingFacilityName As String = myImsg.getSendingFacility() //this is what I want
End Sub
Remember with HL7 messages that each segment has to end with a line return.
Also, you'll want to parse the message back to its actual type in order for the object model to be fully populated correctly (notice that when I used myPipeParser.Parse it was cast back to a QRY_R02 message type from the NHapi.Model.V23 Library). So the code should look something like this:
Imports NHapi.Model.V23.Message
Imports NHapi.Base.Parser
Imports NHapi.Base
Module Module1
Sub Main()
Dim msg As String = "MSH|^~\&|SENDING|SENDER|RECV|INST|20060228155525||QRY^R02^QRY_R02|1|P|2.3" & vbNewLine & _
"QRD|20060228155525|R|I||||10^RD&Records&0126|38923^^^^^^^^&INST|||"
Dim myPipeParser As PipeParser = New PipeParser()
Dim myImsg As QRY_R02 = myPipeParser.Parse(msg)
Dim msgType As String = myImsg.GetStructureName
Dim mySendingFacilityName As String = myImsg.MSH.SendingFacility.NamespaceID.Value
Console.WriteLine(mySendingFacilityName)
Console.ReadLine()
End Sub
End Module
I know it was a very long time ago, however I was looking for this resource very recently and found that there is nearly no documentation on how to use this API. And excellent source of examples can be found in the test part of source code in the project NHapi.NUnit.
Sources can be found here
Related
we are trying to add parameters to a transformation at the runtime. The only possible way to do so, is to set every single parameter and not a node. We don't know yet how to create a node for the setParameter.
Current setParameter:
QName TEST XdmAtomicValue 24
Expected setParameter:
<TempNode> <local>Value1</local> </TempNode>
We searched and tried to create a XdmNode and XdmItem.
If you want to create an XdmNode by parsing XML, the best way to do it is:
DocumentBuilder db = processor.newDocumentBuilder();
XdmNode node = db.build(new StreamSource(
new StringReader("<doc><elem/></doc>")));
You could also pass a string containing lexical XML as the parameter value, and then convert it to a tree by calling the XPath parse-xml() function.
If you want to construct the XdmNode programmatically, there are a number of options:
DocumentBuilder.newBuildingStreamWriter() gives you an instance of BuildingStreamWriter which extends XmlStreamWriter, and you can create the document by writing events to it using methods such as writeStartElement, writeCharacters, writeEndElement; at the end call getDocumentNode() on the BuildingStreamWriter, which gives you an XdmNode. This has the advantage that XmlStreamWriter is a standard API, though it's not actually a very nice one, because the documentation isn't very good and as a result implementations vary in their behaviour.
Another event-based API is Saxon's Push class; this differs from most push-based event APIs in that rather than having a flat sequence of methods like:
builder.startElement('x');
builder.characters('abc');
builder.endElement();
you have a nested sequence:
Element x = Document.elem('x');
x.text('abc');
x.close();
As mentioned by Martin, there is the "sapling" API: Saplings.doc().withChild(elem(...).withChild(elem(...)) etc. This API is rather radically different from anything you might be familiar with (though it's influenced by the LINQ API for tree construction on .NET) but once you've got used to it, it reads very well. The Sapling API constructs a very light-weight tree in memory (hance the name), and converts it to a fully-fledged XDM tree with a final call of SaplingDocument.toXdmNode().
If you're familiar with DOM, JDOM2, or XOM, you can construct a tree using any of those libraries and then convert it for use by Saxon. That's a bit convoluted and only really intended for applications that are already using a third-party tree model heavily (or for users who love these APIs and prefer them to anything else).
In the Saxon Java s9api, you can construct temporary trees as SaplingNode/SaplingElement/SaplingDocument, see https://www.saxonica.com/html/documentation12/javadoc/net/sf/saxon/sapling/SaplingDocument.html and https://www.saxonica.com/html/documentation12/javadoc/net/sf/saxon/sapling/SaplingElement.html.
To give you a simple example constructing from a Map, as you seem to want to do:
Processor processor = new Processor();
Map<String, String> xsltParameters = new HashMap<>();
xsltParameters.put("foo", "value 1");
xsltParameters.put("bar", "value 2");
SaplingElement saplingElement = new SaplingElement("Test");
for (Map.Entry<String, String> param : xsltParameters.entrySet())
{
saplingElement = saplingElement.withChild(new SaplingElement(param.getKey()).withText(param.getValue()));
}
XdmNode paramNode = saplingElement.toXdmNode(processor);
System.out.println(paramNode);
outputs e.g. <Test><bar>value 2</bar><foo>value 1</foo></Test>.
So the key is to understand that withChild() returns a new SaplingElement.
The code can be compacted using streams e.g.
XdmNode paramNode2 = Saplings.elem("root").withChild(
xsltParameters
.entrySet()
.stream()
.map(p -> Saplings.elem(p.getKey()).withText(p.getValue()))
.collect(Collectors.toList())
.toArray(SaplingElement[]::new))
.toXdmNode(processor);
System.out.println(paramNode2);
My problem will probably be explained better with code.
Consider the snippet below:
// First read
OntModel m1 = ModelFactory.createOntologyModel();
RDFDataMgr.read(m1,uri0);
m1.loadImports();
// Second read (from the same URI)
OntModel m2 = ModelFactory.createOntologyModel();
RDFDataMgr.read(m2,uri0);
m2.loadImports();
where uri0 points to a valid RDF file describing an ontology model with n imports.
and the following custom ReadHook (which has been set in advance):
#Override
public String beforeRead(Model model, String source, OntDocumentManager odm) {
System.out.println("BEFORE READ CALLED: " + source);
}
Global FileManager and OntDocumentManager are used with the following settings:
processImports = true;
caching = true;
If I run the snippet above, the model will be read from uri0 and beforeRead will be invoked exactly n times (once for each import).
However, in the second read, beforeRead won't be invoked even once.
How, and what should I reset in order for Jena to invoke beforeRead in the second read as well?
What I have tried so far:
At first I thought it was due to caching being on, but turning it off or clearing it between the first and second read didn't do anything.
I have also tried removing all ignoredImport records from m1. Nothing changed.
Finally got to solve this. The problem was in ModelFactory.createOntologyModel(). Ultimately, this gets translated to ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM_RDFS_INF,null).
All ontology models created with the static OntModelSpec.OWL_MEM_RDFS_INF will have their ImportsModelMaker and some of its other objects shared, which results in a shared state. Apparently, this state has blocked the reading hook to be invoked twice for the same imports.
This can be prevented by creating a custom, independent and non-static OntModelSpec instance and using it when creating an OntModel, for example:
new OntModelSpec( ModelFactory.createMemModelMaker(), new OntDocumentManager(), RDFSRuleReasonerFactory.theInstance(), ProfileRegistry.OWL_LANG );
I'm playing around with gambas.
This code gives me the error "unexpected dim in FMain.class:6"
Public Sub Form_Open()
Print "this won't work"
Dim nickname As String = "gambas"
Print "Your new name is " & nickname
End
This code doesn't, and runs fine:
Public Sub Form_Open()
Dim nickname As String = "gambas"
Print "Your new name is " & nickname
End
Does gambas have requirements where variables are declared like pascal? I can't find any mention of it in the documentation. Thanks.
Gambas requires all DIM statements to be placed before any executable code inside a function or Subroutine (emphasis mine):
http://gambaswiki.org/wiki/lang/dim
All DIM declarations must be in the FUNCTION or SUB before the first executable command.
So change your code to this:
Public Sub Form_Open()
Dim nickname As String = "gambas"
Print "this will work"
Print "Your new name is " & nickname
End
Gambas' requirement for forward declaration of all local variables is very old-school. Sometimes it does make it easier to make self-documenting code and it incentivizes making functions short, but if a function has many intermediate short-lived local variables that cannot be immediately initialized (e.g. inside nested loops inside a function) then it hinders readability. YMMV.
This is not required anymore since Gambas 3.12.
But I suggest to continue declaring variables at the top function. It makes the code far more readable two years later.
I want to read the error messages from messages file but I am unable to. What mistake am I making?
The code where I want to read the string from messages file is
Future { Ok(Json.toJson(JsonResultError(messagesApi("error.incorrectBodyType")(langs.availables(0))))) }
The messages file error.incorrectBodyType=Incorrect body type. Body type must be JSON
The messagesApi("error.incorrectBodyType") should return Incorrect body type. Body type must be JSON but it returns error.incorrectBodyType.
If I remove double quotes in messagesApi(error.incorrectBodyType) then the code doesn't compile
Update
I added a couple of debug prints and notice that the keys I am using in MessagesApi are not defined. I don't know why though as I have created them in messages file.
println("langs array"+langs.availables)
println("app.title"+messagesApi.isDefinedAt("app.title")(langs.availables(0)))
println("error"+messagesApi.isDefinedAt("error.incorrectBodyType")(langs.availables(0)))
prints
langs arrayList(Lang(en_GB))
app.titlefalse
errorfalse
Update 2
I might have found the issue but I don't know how to resolve it. Basically, I am running my test case without an instance of the Application. I am mocking messagesApi by calling stubMessagesApi() defined in Helpers.stubControllerComponents, If I run the same code using an Application eg class UserControllerFunctionalSpec extends PlaySpec with OneAppPerSuiteWithComponents then app.title and error are defined. It seems without an instance of Application, MessagesApi is not using the messages file.
I was able to solve the issue by creating a new instance of MessagesApi using DefaultMessagesApi
val messagesApi = new DefaultMessagesApi( //takes map of maps. the first is the language file, the 2nd is the map between message title and description
Map("en" -> //the language file
Map("error.incorrectBodyType" -> "Incorrect body type. Body type must be JSON") //map between message title and description
)
)
val controller = new UserController(mockUserRepository,mockControllerComponents,mockSilhouette,messagesApi,stubLangs())
I'm using OpenDDS v3.6, and trying to send a message to a specific DDS peer, one of many. In the IDL, the message structure looks like the following:
module Test
{
#pragma DCPS_DATA_TYPE "Test::MyMessage"
#pragma DCPS_DATA_KEY "Test::MyMessage dest_id"
struct MyMessage {
short dest_id;
string txt;
};
};
My understanding is that because the data key is unique, this is a new instance of the topic being written to, and any further msgs written w/ the same data key send to this specific instance of the topic. My send code is as follows:
DDS::ReturnCode_t ret;
Test::MyMessage msg;
// populate msg
msg.dest_id = n;
DDS::InstanceHandle_t handle;
handle = msg_writer->register_instance(msg);
ret = msg_writer->write(msg, handle);
So now I need to figure out how to get the receiving peer to read only from this topic instance and not receive all the other messages being sent to other peers. I started with the following, but not sure how to properly select a specific topic instance.
DDS::InstanceHandle_t instance;
status = msg_dr->take_next_instance(spec, si, 1, DDS::ANY_SAMPLE_STATE,
DDS::ANY_VIEW_STATE, DDS::ANY_INSTANCE_STATE);
Any help much appreciated.
The easiest way to achieve what you are looking for is by using a ContentFilteredTopic. This class is a specialization of the TopicDescription class and allows you to specify an expression (like a SQL WHERE-clause) of the samples that you are interested in.
Suppose you want your DataReader to only receive samples with dest_id equal to 42, then the corresponding code for creating the ContentFilteredTopic would look something like
DDS::ContentFilteredTopic_var cft =
participant->create_contentfilteredtopic("MyTopic-Filtered",
topic,
"dest_id = 42",
StringSeq());
From there on, you create your DataReader using cft as the parameter for the TopicDescription. The resulting reader will look like a regular DataReader, except that it only receives the desired samples and nothing else. Since the field dest_id happens to be the field that identifies the instance, the end result is that you will only have one instance in your DataReader.
You can check out the DDS specification (section 7.1.2.3.3) or OpenDDS Developer's Guide (section 5.2) for more details.