useChangeMatchSubject

A hook that lets you get a list of Linked Data Objects for subjects matching the provided parameters, and provides tools for modifying and committing changes to those objects within a transaction.

Use this hook for forms that need to modify multiple matching subjects.

import { useChangeMatchSubject, useResource } from "@ldo/solid-react";
import React, { FunctionComponent } from "react";
import { ProfileShapeType } from "./.ldo/Profile.shapeType";

const Component: FunctionComponent = () => {
  const resource = useResource("https://example.com/profiles");

  // Gets all subjects in the database that have a type "Person"
  const [profiles, setProfiles, commitProfiles] = useChangeMatchSubject(
    ProfileShapeType,
    "http://www.w3.org/1999/02/22-rdf-syntax-ns#type",
    "http://xmlns.com/foaf/0.1/Person",
    null,
  );

  const handleUpdateAllNames = () => {
    setProfiles(resource, (profileSet) => {
      profileSet.forEach((profile) => {
        if (profile) {
          profile.fn = "Updated Name";
        }
      });
    });
  };

  const handleAddEmailToAll = () => {
    setProfiles(resource, (profileSet) => {
      profileSet.forEach((profile) => {
        if (profile) {
          profile.mbox = "updated@example.com";
        }
      });
    });
  };

  const handleCommitChanges = async () => {
    try {
      await commitProfiles();
      console.log("All profile changes committed successfully!");
    } catch (error) {
      console.error("Failed to commit changes:", error);
    }
  };

  return (
    <div>
      <div>
        {profiles.map((profile, index) => (
          <div key={index}>
            <p>Name: {profile?.fn}</p>
            <p>Email: {profile?.mbox}</p>
          </div>
        ))}
      </div>
      <button onClick={handleUpdateAllNames}>
        Update All Names
      </button>
      <button onClick={handleAddEmailToAll}>
        Add Email to All
      </button>
      <button onClick={handleCommitChanges}>
        Commit All Changes
      </button>
    </div>
  );
};

Parameters

• ShapeType: ShapeType - The ShapeType dictating the shape of the Linked Data Object
• predicate: string | PredicateNode | null - The predicate to match
• object: string | ObjectNode | null - The object to match
• graph: string | GraphNode | null - The graph to match
• options?: UseMatchSubjectOptions - Optional configuration for the matching behavior

Returns

Returns a tuple containing three elements:

1. subjects - A list of linked data objects corresponding to the given matched items, derived from a transaction dataset.

2. setSubjects - A function for modifying the matched subjects. It takes two parameters:

3. resource: A resource object (typically from useResource) that contains the subjects to modify
4. changer: A callback function that receives the set of subjects and allows you to modify them

setSubjects(resource, (subjectSet) => {
  // Modify the subjects here
  subjectSet.forEach((subject) => {
    if (subject) {
      subject.property = "new value";
    }
  });
});

1. commitSubjects - An async function that commits all changes from the transaction dataset to the global dataset and remote dataset (if connected). Returns a Promise that resolves when the commit is successful or rejects if there's an error.