Extracting meaningful data from the XML response to the /search/facet/cube REST API

Answer

The following sample API call, which applies to content analytic collections that include any type of data source, returns an XML response:

<context-root>/search/facet/cube?collection=sample&facets=[{"namespace":"keyword","id":"$._word.noun","count":10},{"namespace":"keyword","id":"$._word.verb","count":10}]&correlation=facetPairs&query=*:*

To extract relevant data that corresponds to the facet pairs, refer to the following explanation of the XML response to this API call:

<es:countArray> and <es:correlationArray> represents a 2-dimension array.

For example, the response contains the following element:

<es:xxArray>
    <es:value>
        <es:value>a</es:value>
        <es:value>b</es:value>
        <es:value>c</es:value>
    <es:value>
    <es:value>
        <es:value>d</es:value>
        <es:value>e</es:value>
        <es:value>f</es:value>
    <es:value>
    <es:value>
        <es:value>g</es:value>
        <es:value>h</es:value>
        <es:value>i</es:value>
    <es:value>
</es:xxArray>

This element indicates that the second array is:

[i][j] = [ [a , b, c], [d, e, f], [g, h, k] ]

The first dimension, i, represents a rank of facets of the first facet in the facet pair, and the second dimension, j, represents a rank of facets of the second facet.

For example, if the first dimension is "Noun" and the second dimension is "Verb", the facet ranks are as follows:

<ibmsc:facet label="Noun">
    <ibmsc:facetValue label="series" />
    <ibmsc:facetValue label="film" />
    <ibmsc:facetValue label="world" />
</ibmsc:facet>

<ibmsc:facet label="Verb">
    <ibmsc:facetValue label="be" />
    <ibmsc:facetValue label="write" />
    <ibmsc:facetValue label="have" />
</ibmsc:facet>

If the result becomes as follows:

<es:xxArray>
    <es:value>
        <es:value>a</es:value>
        <es:value>b</es:value>
        <es:value>c</es:value>
    <es:value>
    <es:value>
        <es:value>d</es:value>
        <es:value>e</es:value>
        <es:value>f</es:value>
    <es:value>
    <es:value>
        <es:value>g</es:value>
        <es:value>h</es:value>
        <es:value>i</es:value>
    <es:value>
</es:xxArray>

The following results represent the second array:

          be    write   have
series    a     b       c
film      d     e       f
world     g     h       i