After a whole lot of facet-wrangling, I've come up with a practical
solution that suits my situation, which is to index each triple as a
series of paths. For example, if the "shelve" process of the
"accessionWF" workflow is "completed," it gets indexed as:
<field name="wf_wps">accessionWF</field>
<field name="wf_wps">accessionWF:shelve</field>
<field name="wf_wps">accessionWF:shelve:completed</field>
<field name="wf_wsp">accessionWF</field>
<field name="wf_wsp">accessionWF:completed</field>
<field name="wf_wsp">accessionWF:completed:shelve</field>
<field name="wf_swp">completed</field>
<field name="wf_swp">completed:accessionWF</field>
<field name="wf_swp">completed:accessionWF:shelve</field>
(I could use PathHierarchyTokenizerFactory to eliminate 2/3 of those
field declarations, but doing it this way keeps me from having to
upgrade my Solr to 3.1 yet.)
That lets solr return a facet structure that looks like this:
<lst name="facet_fields">
<lst name="wf_wps">
<int name="accessionWF">554</int>
<int name="accessionWF:shelve">554</int>
<int name="accessionWF:shelve:completed">550</int>
<int name="accessionWF:shelve:error">4</int>
</lst>
<lst name="wf_wsp">
<int name="accessionWF">554</int>
<int name="accessionWF:completed">554</int>
<int name="accessionWF:completed:shelve">550</int>
<int name="accessionWF:error">4</int>
<int name="accessionWF:error:shelve">4</int>
</lst>
<lst name="wf_swp">
<int name="completed">554</int>
<int name="completed:accessionWF">554</int>
<int name="completed:accessionWF:shelve">550</int>
<int name="error">4</int>
<int name="error:accessionWF">4</int>
<int name="error:accessionWF:shelve">4</int>
</lst>
</lst>
I then use some Ruby post-processing to turn it into:
{
"wf_wps": {
"accessionWF": [554, {
"shelve": [554, {
"completed": 550,
"error": 4
}],
"publish": [554, {
"completed": 554
}]
}]
},
"wf_swp": {
"completed": [554, {
"accessionWF": [554, {
"shelve": 550,
"publish": 554
}]
}],
"error": [4, {
"accessionWF": [4, {
"shelve": 4
}]
}]
},
"wf_wsp": {
"accessionWF": [554, {
"completed": [554, {
"shelve": 550,
"publish": 554
}],
"error": [4, {
"shelve": 4
}]
}]
}
}
Eventually I may try to code up something that does the restructuring
on the solr side, but for now, this suits my purposes.
Michael
