FHIR DataRequirement metadata type - hl7-fhir

I am implementing a CDS system, and I would like to use the DataRequirement type to ask for additional information. However, I am having some difficulties to understand the filter elements ("codeFilter" and "dateFilter").
For example, the property "path" of the filter elements is of string type, but what is the format to specify this path?
I have been searching some examples from the FHIR specification, and I've tried to follow the "path" in the resource object. I attach below an image with an example and the specification of the resource "MedicationRequest" that is being addressed in this example. Can anyone explain me over this example how to traverse throw the elements? What is the element "code" from the path refering to?
example DataRequirement.codeFilter
Can anyone help me with this issue? Examples of use would be appreciated!
Thanks in advance.

It's referring to the FHIRpath query - see spec.

The path element is a FHIRPath, but for simplicity, it assumes the ability to traverse references. Without that, the dereference would have to be explicit, as in:
medicationReference.resolve().code
The spec isn't clear on this, so I will submit a tracker to add that clarification.

Related

Search resources with reference is null

Maybe, I misunderstood something in search mechanism in FHIR. But I have found a way if I have to find some objects which any value in some parameter.
For example, I wanted to build organization tree, in this case I have to know objects on a "first level" of this tree. And I think it should be an objects with empty partOf property. But documentation says nothing about it.
Or maybe there is another way how to achieve it?
Use the :missing modifier. (http://hl7.org/fhir/2016sep/search.html#modifiers)
E.g.
Organization?partof:missing=true

Can't figure out how to search LOINC using FHIR for a specific test by name?

Can anyone provide some insight on the required syntax to use to search LOINC using FHIR for a specific string in the labs descriptive text portion of an Observation resource?
Is this even possible?
The documentation is all over the place and I can't find an example for this generic kind of search.
I found similar examples here: https://www.hl7.org/fhir/2015Sep/valueset-operations.html
Such as: GET "[base]/ValueSet/23/$validate-code?system=http://loinc.org&code=1963-8&display=test"
But none of them are providing a general enough case to do a global search of the LOINC system for a specific string in an Observation resource.
None of my attempts to use the FHIR UI here, http://polaris.i3l.gatech.edu:8080/gt-fhir-webapp/search?serverId=gatechreadonly&resource=Observation , have been successful. I keep getting a 500 Internal Server Error because I don't know the correct syntax to use for the value part of the search, and I can't find any documentation out of all the copious documents online that explains this very simple concept.
Can anyone provide some insight?
Totally frustrated at this point.
Observation?code=12345-6
or
Observation?code=http://loinc.org|12345-6
where 12345-6 is whatever LOINC code you want to look for (e.g. 39802-4)
The second ensures you'll only match on LOINC codes as opposed to codes from other systems, though given the relatively unique format of LOINC codes, you're mostly safe without including that.
If you want to search for a set of codes, then you can separate the codes or the tuples with commas: E.g.
Observation?code=12345-6,12345-7
or
Observation?code=http://loinc.org|12345-6,http://loinc.org|123456
If you expect to search by a really long list of codes frequently, you can define a value set that includes all the desired codes and then filter by value set:
Observation?code:in=http://somwhere.org/whatever/ValueSet/123
Note: for readability, I haven't escaped the URL contents, but you'll need to escape the URL values appropriately.

Element Paths for Search Parameters

I'm trying to find the most reliable way to determine which element in a resource a given search parameter refers to. So far I process the xpath expression and hope to find a match, but this seems hacky.
Is there a standard or more consistent way to determine what element(s) within a resource a search parameter should use?
Not right now - parsing the XPath is it. This is an active point of discussion in the standards group and will probably result in some modification to the SearchParameter resource (I hope!).

How to uniquly identify an two objects in same page having same url

I Have two objects in same page but with different locations(tabs), I want to verify those objects each a part ...
i cant uniquely any of objects because the have same properties.
These objects clearly are unique to a point because they have completely different text, this means that you will be able to create an object to match only one of them. My suggestion would be to look for the object by using its text property, one of them will always have "Top Ranking" the other you wil need to turn into a regular expression for the text and will be something "Participants (\d+)".
I am assuming that this next answer is unlikely to be possible so saved it for after the answer you are likely to use but the best solution would of course be to get someone with access to give these elements ids for you to search for. This will in the long term be much easier for you to maintain and not using text will allow this test to run in any language.
Manaysah, do these objects have different indexes? Use the object spy and determine which index they have, the ordinal identifier index may be a solution to your problem. You could also try adding an innertext object property if possible, using a wildcard for the number inside the () as it appears dynamic.
try using xpath for the objects...xpath will definitely be different

howto get Builder to create <tag></tag> instead of <tag/>

I,m using Builder::XmlMarkup to create xml. I want to create a tag without content because the api force me to create this.
If I use a blog
xml.tag do
end
I get what i need
<tag></tag>
but I want it shorter
xml.mytag
this gives me
<mytag/>
but i want
<mytag></mytag>
what do I have to pass as option.
regards Kai
Just pass empty string as a parameter. xml.mytag('')
Why do you want <mytag></mytag> instead of <mytag/>? Since the output is XML, downstream applications should not know or care about the difference.
According to the Infoset spec (Appendix D point 7), "The difference between the two forms of an empty element: <foo/> and <foo></foo>" is not represented in the XML Information Set.
This doesn't answer your "how" question, but if you discover that you actually don't need to do what you're trying to do, it may save you from a difficult and unnecessary wild goose chase.
ok empty string is nice, another one-line-way is empty block I found out.
xml.mytag{}

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