Frictionless

Generate a Frictionless Data Package. Every class becomes a CSV table, described by its own Table Schema, and references between classes become foreign keys between the tables. The files are a datapackage.json plus one schemas/<table>.json per table.

Usage

CLI

ohi get w3c/prov-o
ohi linkml to frictionless --pruning-mode schema \
  --to datapackage/ prov-o.linkml.yaml

Python

import ohi_linkml

with ohi_linkml.load_file("prov-o.linkml.yaml") as schema:
    files = schema.frictionless(pruning_mode="schema")

JavaScript

import { readFileSync } from "node:fs";
import { LinkML } from "@neverblink/linkml";

const yaml = readFileSync("prov-o.linkml.yaml", "utf8");
const { view, report } = LinkML.loadFromString(yaml, {});
if (!view) throw new Error(JSON.stringify(report));
const files = view.frictionless({ pruning_mode: "schema" });

Scala

import eu.neverblink.linkml.generator.options.*
import eu.neverblink.linkml.generator.frictionless.FrictionlessGenerator
import eu.neverblink.linkml.schemaview.{SchemaIssues, SchemaView}

val loaded = SchemaView.loadSchemaViewFromUri("prov-o.linkml.yaml")
given SchemaView = SchemaIssues.orThrow(loaded)
val files = FrictionlessGenerator().generateFiles(
  FrictionlessGeneratorOptions(pruningMode = PruningMode.Schema),
)

C

#include <stddef.h>
#include "ohi_linkml.h"

linkml_init_threads();
char *report = NULL, *error = NULL;
long long schema =
    linkml_load_file("prov-o.linkml.yaml", NULL, &report, &error);
char *files = linkml_frictionless(
    schema,
    "{\"pruning_mode\": \"schema\"}",
    &error
);
linkml_free(files);
linkml_free(report);
linkml_free(error);
linkml_close(schema);

Try it in the playground, with PROV-O

Options

metadata_languagestringdefault en

CLI --metadata-languageScala metadataLanguage

The language of the titles and descriptions in the output, for schemas with text in more than one language.

pruning_modePruningModedefault skip

CLI --pruning-modeScala pruningMode

Which classes become tables.

• tree_root The elements reachable from the tree root class. Without a tree root, the same as schema.
• schema Everything defined in the root schema, and every element reachable from it. This leaves out the unused parts of imported schemas, such as most of linkml:types.
• skip Every element of the root schema and of all its imports.

skip_classes_without_identifierbooleandefault false

CLI --skip-classes-without-identifierScala skipClassesWithoutIdentifier

Whether to skip the classes with no identifier slot. The table of such a class has no primary key, and so no references from other tables.

tree_rootstring

CLI --tree-rootScala treeRoot

The class to use as the tree root, instead of the class with tree_root: true in the schema. Only for the tree_root pruning mode.