roam-research-mcp/build/tools/helpers/fetch-children.js

MCP server and CLI for Roam Research

import { q } from '@roam-research/roam-api-sdk';
const childrenQuery = `[:find ?parentUid ?childUid ?childString ?childOrder ?childHeading
                        :in $ [?parentUid ...]
                        :where [?parent :block/uid ?parentUid]
                               [?parent :block/children ?child]
                               [?child :block/uid ?childUid]
                               [?child :block/string ?childString]
                               [?child :block/order ?childOrder]
                               [(get-else $ ?child :block/heading 0) ?childHeading]]`;
/**
 * Recursively fetch children for a set of parent UIDs up to maxDepth levels deep.
 * Returns a map of parent UID → sorted array of child RoamBlocks (with their children attached).
 */
export async function fetchChildrenByDepth(graph, parentUids, maxDepth, currentDepth = 0) {
    if (currentDepth >= maxDepth || parentUids.length === 0)
        return {};
    const results = await q(graph, childrenQuery, [parentUids]);
    if (!results || results.length === 0)
        return {};
    const childrenByParent = {};
    const allChildUids = [];
    for (const [parentUid, childUid, childString, childOrder, childHeading] of results) {
        if (!childrenByParent[parentUid])
            childrenByParent[parentUid] = [];
        childrenByParent[parentUid].push({
            uid: childUid,
            string: childString,
            order: childOrder,
            heading: childHeading || undefined,
            children: [],
        });
        allChildUids.push(childUid);
    }
    const grandChildren = await fetchChildrenByDepth(graph, allChildUids, maxDepth, currentDepth + 1);
    for (const parentUid in childrenByParent) {
        for (const child of childrenByParent[parentUid]) {
            child.children = grandChildren[child.uid] || [];
        }
        childrenByParent[parentUid].sort((a, b) => a.order - b.order);
    }
    return childrenByParent;
}