derived_properties no longer exists

[Bud-Macaulay]

This endpoint that was attached is no longer in existance.

I think in principle this is fine; however we should be sure to test what this drops. In particular as of current, i was using derived properties to build some visualisers:

structureData:

  const hasDerived =
    nodeData.derived_properties &&
    Object.keys(nodeData.derived_properties).length > 0;

  const lattice = nodeData.attributes?.cell || null;
  const latticeLengths = lattice ? formatLattice(nodeData) : null;
  const volume = hasDerived
    ? nodeData.derived_properties.dimensionality?.value
    : latticeLengths
      ? getVol(nodeData)
      : null;
  const sites = nodeData.attributes?.sites || [];
  const kinds = nodeData.attributes?.kinds || [];
  const numSites = sites.length;
  const dimensionality =
    nodeData.derived_properties?.dimensionality?.dim || null;

KpointsData

    const attrs = nodeData.attributes || {};
    const derived = nodeData.derived_properties || {};

    let b1 = null,
      b2 = null,
      b3 = null;
    if (attrs.cell) {
      [b1, b2, b3] = reciprocalLattice(attrs.cell);
    }

    const bz = attrs.cell
      ? {
          ...derived,
          b1,
          b2,
          b3,
          kpoints: derived.labelled_kpoints_abs,
          path: derived.labelled_path,
        }
      : null;

In particular the KpointsData was being used quite extensively to visualise the brillioun zone and other things. I wouldnt be shocked if the compute for these was expensive and maybe we should not default to this.

[edan-bainglass]

@Bud-Macaulay "no longer exists" where? Was this a REST API or aiida-core feature?

[Bud-Macaulay]

I think this was in the old rest-api /restapi/translator/nodes/data,

it was being used to calculate quite a lot of things (for instance BZ in kpoints data). I think it's probably good if we don't support this as is, instead opting to offer a as_X() method inside AiiDA that the rest-api can hook into if needs be.

Here is the example:

"""Translator for structure data"""

from aiida.restapi.translator.nodes.data import DataTranslator

class StructureDataTranslator(DataTranslator):
    """Translator relative to resource 'structures' and aiida class StructureData"""

    # A label associated to the present class (coincides with the resource name)
    __label__ = 'structures'
    # The AiiDA class one-to-one associated to the present class
    from aiida.orm import StructureData

    _aiida_class = StructureData
    # The string name of the AiiDA class
    _aiida_type = 'data.core.structure.StructureData'

    _result_type = __label__

    @staticmethod
    def get_derived_properties(node):
        """Returns: derived properties of the structure."""
        response = {}

        # Add extra information
        response['dimensionality'] = node.get_dimensionality()
        response['formula'] = node.get_formula()

        return response