XContentBuilder Elasticsearch mapping for inner objects - mapping

I am trying to create a mapping for documents of the following structure:
"name":"Peter"
"id":"ABC123",
"values":{
"a":3.0123,
"b":1234
}
So the mapping should look like this:
{
"properties":{"_all":{"enabled":"false"},
"dynamic":"false",
"_timestamp":{"enabled":true,"store":true},
"properties": {
"name":{"type":"string"},
"id":{"type":"string"},
"values": {
"properties": {
"a": {"type":"double"},
"b":{"type":"double"}
}
}
}
}
}
In reality the amount of possible properties in "values" is quite big, let's say 50 possible properties I have to include there..
I am currently generating the mapping json with the XContentBuilder, which works really fine for me.
What I want to do is, encapsulating the inner part's mapping in "values" in a seperate builder, as it makes the process of mapping easier to maintain for me. Also I already have the inner properties' names in a list, which I'd like to iterate.
Thats my normal mapping code here.
XContentBuilder xbMapping = jsonBuilder()
.startObject() // start root
.startObject(PROPERTIES)
.startObject("_all").field("enabled", "false").endObject()
.field("dynamic", "false")
.startObject("_timestamp").field("enabled", true).field("store", true).endObject()
.startObject(PROPERTIES)
.startObject("name").field("type", "string").endObject()
.startObject("id").field("type", "string").endObject()
.startObject("values")
.startObject(PROPERTIES)
// INNER MAPPING HERE!!
.endObject()
.endObject()
.endObject()
.endObject();
I'd like to avoid iterating in between those startObject and endObject and more like to do the complete mapping for the inner type somewhere else and just include that extra part there.
I can't find a sophisticated way at the moment with XContentBuilder.
Thanks for any hints

The XContentBuilder is mutated with every method call, the builder pattern is just for convenience. So you can interrupt the chained calls anytime
private void buildValues(XContentBuilder builder) throws IOException {
String[] values = {"a", "b"};
for (String value : values) {
builder.startObject(value).field("type", "double").endObject();
}
}
XContentBuilder xbMapping = jsonBuilder()
.startObject() // start root
.startObject(PROPERTIES)
.startObject("_all").field("enabled", "false").endObject()
.field("dynamic", "false")
.startObject("_timestamp").field("enabled", true).field("store", true).endObject()
.startObject(PROPERTIES)
.startObject("name").field("type", "string").endObject()
.startObject("id").field("type", "string").endObject()
.startObject("values")
.startObject(PROPERTIES);
buildValues(xbMapping);
xbMapping
.endObject()
.endObject()
.endObject()
.endObject();

Related

Grails 2.5, beforeDelete cannot access one-to-many relationship

Using Grails 2.5.6 here. I'm trying to access a Set of Strings off of my domain class in the beforeDelete GORM event. I'm seeing the deletes for this set getting issued in the database log before even getting to my breakpoint in the beforeDelete.
I'm getting a NullPointerException on my println(strings) below in my domain class.
My test domain class looks like
class DeleteTest {
Integer id
Set<String> stringSet
String prop1
String prop2
static hasMany = [stringSet: String]
static constraints = {
prop1(maxSize: 20)
prop2(maxSize: 20)
}
static mapping = {
stringSet(joinTable: [column: 'delete_test_string_set', length: 15])
}
def beforeDelete() {
withNewSession {
Set<String> strings = this."stringSet"
println(strings)
}
}
}
And I've made a test controller like this.
class DeleteTestController {
def create() {
DeleteTest test = null
DeleteTest.withTransaction {
test = new DeleteTest(
prop1: 'Test',
prop2: 'another test',
stringSet: ['str1', 'str2', 'str3']
).save()
}
render (test as JSON)
}
def delete() {
DeleteTest test = DeleteTest.findByProp1('Test')
DeleteTest.withTransaction {
test.delete()
}
render(test as JSON)
}
}
How can I get my stringSet in the beforeDelete event?
One easy way is to make sure to load stringSet before calling the delete. However, there are clearly some odd behaviors going on here and I'll describe what I have found so far.
Simple Answer
def delete() {
DeleteTest test = DeleteTest.findByProp1('Test')
test.stringSet?.size() // <-- force load here
DeleteTest.withTransaction {
test.delete()
}
render(test as JSON)
}
Other Considerations
I tried making stringSet eager loaded. This did not work as expected and in the beforeDelete code it would often be a single value or blank.
I also tried making StringSet a Set where I defined a single GORM object MyString containing the value. This did work (though I had to make it eagerly fetched), but I did not consider this to be a valid solution for your case since I assume you have data already and can't just replace it.
Based on some debug digging, I'm guessing (but it really is just a guess) that the collection is deleted before the beforeDelete event fires, and so it can't be lazily loaded at that point even in a new transaction. I would expect that someone else could weigh in on whether that's right or not, but grails 2 expertise is getting harder to find these days.

Can't count the occurences of the entity with a field of particular value inside a nested property using Spring Data ElasticSearch Repository

I have the Article entity and inside it there is a nested property, let's say Metadata.
I need to count all articles, which have a particular field inside this nested property, let's say indexed, assigned to e.g. 1.
Java Document Snippet:
#Document(indexName = "article", type = "article", useServerConfiguration = true, createIndex = false)
#Setting(settingPath = "/mappings/settings.json")
#Mapping(mappingPath = "/mappings/articles.json")
public class Article {
// getters and setters, empty constructor are omitted for brevity
#Id
private String id;
private Metadata metadata;
// remainder of the body is omitted
}
Metadata.class snippet
public class Metadata {
// getters and setters, empty constructor are omitted for brevity
private Integer indexed;
// remainder of the body is omitted
}
The query I use to retrieve articles, which satisfy the given criteria and which I put as a value of #org.springframework.data.elasticsearch.annotations.Query on top of the custom method:
{
"query": {
"bool": {
"must": [
{
"nested": {
"path": "metadata",
"query": {
"bool": {
"must": [
{
"match": {
"metadata.indexed": 1
}
}
]
}
}
}
}
]
}
}
}
My custom Spring Data ElasticSearch repository snippet with a custom method:
public CustomSpringDataElasticsearchRepository extends ElasticsearchRepository<Article, String> {
#Query("The query from above")
Long countByMetadata_Indexed(int value);
}
When I use the repository method shown above , I get java.lang.IllegalArgumentException: Expected 1 but found n results.
Custom Spring Data Elasticsearch Repository method(without #Query) returns 0(version without underscore returns 0 as well) though it should return everything correctly.
How do I get the correct results using Spring Data ElasticSearch Repository? Why does the custom method without #Query doesn't work as well?
UPD: The version of spring-data-elasticsearch used is 3.1.1.RELEASE.
Repository query methods currently(3.2.4.RELEASE) don't support the count by the fields inside nested fields.
As was mentioned previously, #Query annotation doesn't support custom count queries as of the latest version(3.2.4.RELEASE).
In other words, currently, the only way to do this query through Spring Data ElasticSearch is to use ElasticsearchTemplate bean or ElasticsearchOperations bean.
Credit: P.J.Meisch

Grails XML converters - change root node name

I have following code in my groovy class and I want to change the name for root node. My domain object name is EMP and I want to change it to when I convert my domain in XML.
def init = {
XML.registerObjectMarshaller Emp
{ emp, xml ->
xml.build {
emp_name(emp.name)
emp_dept(emp.dept)
}
}
}
In order to change the root name you will need to use the NameAwareMarshaller which is slightly more complicated than the implementation you are currently using.
While slightly dated, this blog entry explains all the steps in detail. In particular you want to pay attention to the startNode property of the converter.
public void marshalObject(Object object, XML converter) {
Foo foo = object as Foo
converter.startNode 'name'
converter.chars foo.name
converter.end()
Map map = [firstKey: 'firstValue', secondKey: 'secondValue']
converter.startNode 'locallyDefinedMap'
converter.convertAnother map
converter.end()
}

grails unknown number of model objects in the view

Working in Grails 2.2
I have a situation where I need to be able to handle an unknown number of CommitteeMembers in the view. These need to be both created and displayed.
Each one has the usual attributes - name, address, contact information, userid.
I understand that if I name form fields the same name, Grails will return a collection for me to iterate over. In this case, however, I am faced with this situation:
cm_firstname
cm_lastname
cm_address
cm_email
cm_userid
So does this mean I will be given collections of each of these fields? That is not as useful as there is no way to corelate the various firstnames with the correct lastnames, etc.
I am enjoying Grails and am looking forward to your feedback.
You can use Grails Command objects to do this work for you. Here's an example in a SO question. Basically you will have a single collection of CommitteeMembers that will be populated in your controller thorugh data binding.
As #Gregg says, in the view you need the fields to have an index.
class MyDomain {
String name
}
class MyDomainCommand {
List<MyDomain> instances = ListUtils.lazyList([], FactoryUtils.instantiateFactory(MyDomain))
}
class MyController {
def save() {
MyDomainCommand command = new MyDomainCommand()
bindData(command, params, [include: 'instances'])
}
}
I'll tell you what I do, which may or may not be the best option. I do this mainly because I don't like data binding.
For your case as an example, I would name my fields: "cm.firstName, cm.lastName, cm.address, cm.email, cm.userId".
If you are in a service:
GrailsWebRequest webUtils = WebUtils.retrieveGrailsWebRequest()
List committeeMembers = [].withDefault {new GrailsParameterMap([:], webUtils.getCurrentRequest())}
In a controller:
List committeeMembers = [].withDefault {new GrailsParameterMap([:], request)}
Then
params.cm.each { k, v ->
if (v instanceof String[]) {
v.eachWithIndex { val, idx ->
committeeMembers[idx]."$k" = val
}
}
else {
committeeMembers[0]."$k" = v
}
}
Then you can do:
committeeMembers.each {
<Create from it.firstName, it.lastName, etc>
}

Finding The Super Class of a class just before Top Class with Jena

I am using jena framework to process my owl ontology.
I want to write a method which can find the super class it belongs which is just under the Thing class.
Four example, if there are 5 level hierarchy, lets say first level is Thing, second level is secondAncestor, third level is ThirdAncestor and so on. If I pass a class FifthAncestor, I want to return SecondAncestor because Thing does not make any sense. If I pass ThirdAncestor, I want to return SecondAncestor. In other words, most general class it belongs to but not the top one (Thing).
Method one
This will depend on your model having a reasoner, because owl:Thing isn't normally asserted into a model, and so won't be present in a model with no reasoner. Given that, then:
OntModel m = ... your OntModel ...;
OntClass thing = m.getOntClass( OWL.Thing.getURI() );
for (Iterator<OntClass> i = thing.listSubClasses(true); i.hasNext(); ) {
OntClass hierarchyRoot = i.next();
....
}
Note the use of the flag direct = true in the listSubClasses() call.
Method two
Does not require a reasoner.
for (Iterator<OntClass> i = m.listHierarchyRootClasses(); i.hasNext(); ) {
OntClass hierarchyRoot = i.next();
....
}
Note that this method will return the root classes, even if they are anonymous resources representing a class expression. For UI purposes, this often isn't what you want (it's hard to display a bNode in a meaningful way to a user). In this case, use OntTools.namedHierarchyRoots instead.
Update
I now understand that Alan wants the root classes that are parents of a particular class, whereas namedHierarchyRoots will list all of the root classes of the class hierarchy. Note that, in general, a class may have zero, one or many named-superclasses between it and Thing.
Anyway, here's how I would solve this. Again, this solution assumes the model is not using a reasoner. With a reasoner, it would be much easier:
private boolean hasSubClassTransitive( OntClass parent, OntClass child ) {
return OntTools.findShortestPath( child.getOntModel(), child, parent,
new OntTools.PredicateFilter( RDFS.subClassOf ) ) != null;
}
public List<OntClass> namedRootsOf( OntClass c ) {
List<OntClass> cRoots = new ArrayList<OntClass>();
for (OntClass root: OntTools.namedHierarchyRoots( c.getOntModel() )) {
if (hasSubClassTransitive( root, c )) {
cRoots.add( root );
}
}
return cRoots;
}
I find solution in following way without using reasoner. It is not perfect solution but it works. This solution also solves problem, if you get unnamed (anonymous) class as super class.
First I created an array which stores top level class names.
A simple method which searches in my created array, if the passed parameter is a top class.
public Boolean IsTopClass(String ontologyClass)
{
//NS is URI of ontology
String onClass=ontologyClass.replace(NS, "");
for(String oClass: topLevelClassList)
{
if(oClass.equalsIgnoreCase(onClass))
return true;
}
return false;
}
Then the main method which finds most general class under thing:
public String FindSuperClassUnderThing(OntClass subClass)
{
OntClass prevSubClass=subClass;
OntClass prevprevSubClass=null;
String topClass="";
String supClass=subClass.toString();
ExtendedIterator<OntClass> superClassList=null;
while(!this.IsTopClass(topClass))
{
prevprevSubClass=prevSubClass;
prevSubClass=prevSubClass.getSuperClass();
//if returned class is a anonymous class (not a named one)
//get list of superclasses and check if there is a topclass
//inside the super class list
if(!prevSubClass.toString().startsWith(NS))
{
prevSubClass=prevprevSubClass;
superClassList= prevSubClass.listSuperClasses();
while(superClassList.hasNext())
{
OntClass OntClassFromList= superClassList.next();
if(this.IsTopClass(OntClassFromList.toString()))
{
topClass= OntClassFromList.toString();
}
}
}
else
{
if (this.IsTopClass(prevSubClass.toString()))
{
topClass= prevSubClass.toString();
}
}
}
return topClass;
}

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