How can I exclude a subject in a Mosaic content listing tile?

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1

Any trick how to customize the content-listing tile or add-on?
Thanks for any hint!

2

Perhaps, override the template plone.app.standardtiles/listing_view.pt at main · plone/plone.app.standardtiles · GitHub via z3c.jbot

3

I'm thinking of creating an additional criterium operation
plone.app.querystring.operation.selection.not
This is, I bet, already done by someone.

4

I use a boolean Field via Behavior for "News Item", if this checked then the News is a "Sticky News" and pinned on top of site in a viewlet.
I think it can be adapted for "isEmpty" or "shouldNotContain" or whatever.

You need a catalog index

<!--catalog.xml-->
  <index
    name="is_sticky"
    meta_type="BooleanIndex">
    <indexed_attr value="is_sticky" />
  </index>

You need a indexer

<!--indexer.zcml-->
<configure xmlns="http://namespaces.zope.org/zope">
  <adapter
    factory=".my_indexer.sticky_news"
    name="is_sticky" />
</configure>

# my_indexer.py
# -*- coding: utf-8 -*-
from plone.app.contenttypes.interfaces import INewsItem
from plone.indexer import indexer
from my.addon.behaviors.sticky_news import StickyNews

@indexer(INewsItem)
def sticky_news(obj):
    """Calculate and return the value for the indexer"""
    sticky = StickyNews(obj)
    if not sticky:
        return False
    return sticky.enable

You need a querystring definition

<!--registry.xml-->
<records
  interface="plone.app.querystring.interfaces.IQueryField"
  prefix="plone.app.querystring.field.is_sticky">
  <value
    key="title"
    i18n:translate="">Sticky News</value>
  <value key="description">check is the sticky news behavior available and set</value>
  <value key="enabled">True</value>
  <value key="sortable">False</value>
  <value key="operations">
    <element>plone.app.querystring.operation.boolean.isTrue</element>
    <element>plone.app.querystring.operation.boolean.isFalse</element>
  </value>
  <value key="group">Custom</value>
</records>

with all these steps, a filter in a collection is available.

5

That's nice. To avoid forcing the editor to mark the content, a boolean index with "not these subjects" would do. It's a hack cause it's tailored for one single use case, but hey. Obviously querying does not offer a boolean NOT. Should have known.

6

I have asked a similar question (here), but I did not find it.

The solution is to make a new indexer (that 'return True' when not these subject)

7

afaict portal_catalog nowadays support not queries. Maybe something like plone.api.content.find(not={'my:' 'query'} works?

8

The problem is I think not in what portal_catalog supports, but in the expressiveness of the querystring widget and the underlying key-operation-value triplets that are stored (I forgot the exact terminolgy in there).

This for example also limits/does not support grouping filter statements in logical and/or groups and other more advanced queries.

Maybe you can get away with adding a 'not' operation but the ordering of other filter items and those following the not becomes important, (should another rule after the not be additive again?) there is no reordering, etc etc.

9

The query argument is a logical conjunction. Logical conjunctions are commutative. That means the order of the operands does not change the result.

10

Unfortunatly multiple operands on the same index are allowed in a Mosaic content listing tile. The last wins.

11

Just for the records: An operation
plone.app.querystring.operation.selection.exclude is possible (as ZCatalog actually supports boolean NOT in queries on KeywordIndex since version 3) and makes sense to add it to

<records interface="plone.app.querystring.interfaces.IQueryField"
             prefix="plone.app.querystring.field.Subject">

but the result is the set of documents that are indexed: all documents with a 'Subject'. So all documents without Subjects are ignored. Which is not what is expected. There's more work to do.

The operation method would be

def _exclude(context, row):
    return {row.index: {'not': row.values}}