feat: add initial data node

frontend/src/lib/csvParse.ts

@@ -0,0 +1,54 @@
+/**
+ * Parse a CSV string into an array of row objects (first row = headers).
+ * Handles quoted fields with commas.
+ */
+export function parseCsvToRows(csvText: string): { columns: string[]; rows: Record<string, string>[] } {
+  const lines = csvText.trim().split(/\r?\n/)
+  if (lines.length === 0) return { columns: [], rows: [] }
+
+  const parseRow = (line: string): string[] => {
+    const out: string[] = []
+    let i = 0
+    while (i < line.length) {
+      if (line[i] === '"') {
+        let cell = ''
+        i += 1
+        while (i < line.length) {
+          if (line[i] === '"') {
+            i += 1
+            if (line[i] === '"') {
+              cell += '"'
+              i += 1
+            } else break
+          } else {
+            cell += line[i]
+            i += 1
+          }
+        }
+        out.push(cell)
+        if (line[i] === ',') i += 1
+      } else {
+        const comma = line.indexOf(',', i)
+        const value = comma === -1 ? line.slice(i) : line.slice(i, comma)
+        out.push(value.trim())
+        i = comma === -1 ? line.length : comma + 1
+      }
+    }
+    return out
+  }
+
+  const headers = parseRow(lines[0])
+  const columns = headers.map((h) => h.trim() || `Column${headers.indexOf(h) + 1}`)
+  const rows: Record<string, string>[] = []
+
+  for (let r = 1; r < lines.length; r++) {
+    const cells = parseRow(lines[r])
+    const row: Record<string, string> = {}
+    for (let c = 0; c < columns.length; c++) {
+      row[columns[c]] = cells[c] ?? ''
+    }
+    rows.push(row)
+  }
+
+  return { columns, rows }
+}

frontend/src/lib/flowUtils.ts

@@ -70,6 +70,7 @@ export const DEFAULT_NODE_STYLE: Record<string, { width: number; height: number
   render: { width: 384, height: 320 },
   variable: { width: 224, height: 180 },
   function: { width: 288, height: 260 },
+  data: { width: 360, height: 280 },
 }
 
 /** Default data for a new node. Uses nodeRegistry when type is registered. */

frontend/src/lib/nodeHelp.tsx

@@ -1,6 +1,6 @@
 import type React from 'react'
 
-export type NodeType = 'config' | 'render' | 'variable' | 'function'
+export type NodeType = 'config' | 'render' | 'variable' | 'function' | 'data'
 
 export type NodeHelpEntry = {
     title: string
@@ -77,6 +77,19 @@ export const NODE_HELP: Record<NodeType, NodeHelpEntry> = {
             </>
         ),
     },
+    data: {
+        title: 'Data node',
+        content: (
+            <>
+                <Section title="How to use">
+                    <p>Data nodes hold CSV data. Drop a .csv file onto the node to load it; the table is shown in the node. Connect this node to a Config node to use the data in Nunjucks templates.</p>
+                </Section>
+                <Section title="Using in templates">
+                    <p>In a Config template connected to this data node, the variable <Code>{'{{ '}<em>nodeId</em>{' }}'}</Code> is an array of row objects (one per CSV row). Each row has keys from the CSV header. Example: <Code>{'{% for row in data_001 %}{{ row.name }}, {{ row.value }}{% endfor %}'}</Code></p>
+                </Section>
+            </>
+        ),
+    },
 }
 
 export function getNodeHelp(nodeType: NodeType): NodeHelpEntry {

frontend/src/lib/nodeTypes.ts

@@ -7,7 +7,8 @@ import type { ConfigNodeData } from '@/components/nodes/ConfigNode'
 import type { RenderingNodeData } from '@/components/nodes/RenderingNode'
 import type { VariableNodeData } from '@/components/nodes/VariableNode'
 import type { FunctionNodeData } from '@/components/nodes/FunctionNode'
+import type { DataNodeData } from '@/components/nodes/DataNode'
 
-export type AppNodeData = ConfigNodeData | RenderingNodeData | VariableNodeData | FunctionNodeData
+export type AppNodeData = ConfigNodeData | RenderingNodeData | VariableNodeData | FunctionNodeData | DataNodeData
 export type AppNode = Node<AppNodeData>
 export type AppEdge = Edge

frontend/src/lib/nunjucksAutocomplete.ts

@@ -43,6 +43,7 @@ export function nunjucksCompletionSource(
     variableIds: string[],
     configTitles?: string[],
     functionIds?: string[],
+    dataIds?: string[],
 ): (context: CompletionContext) => CompletionResult | null {
     return (context: CompletionContext) => {
         const { state, pos } = context
@@ -81,6 +82,11 @@ export function nunjucksCompletionSource(
                 }
             }
         }
+        for (const dataId of dataIds ?? []) {
+            if (!word || dataId.toLowerCase().startsWith(word.toLowerCase())) {
+                options.push({ label: dataId, type: 'variable', info: 'Data (array of rows)' })
+            }
+        }
 
         if (options.length === 0) return null
         return {

frontend/src/lib/registerBuiltinNodes.tsx

@@ -4,13 +4,14 @@
  */
 
 import React from 'react'
-import { ScrollText, Sparkles, Variable, Code2 } from 'lucide-react'
+import { ScrollText, Sparkles, Variable, Code2, Database } from 'lucide-react'
 import { registerNodeType } from './nodeRegistry'
 import { NODE_HELP } from './nodeHelp'
 import ConfigNode from '../components/nodes/ConfigNode'
 import RenderingNode from '../components/nodes/RenderingNode'
 import VariableNode from '../components/nodes/VariableNode'
 import FunctionNode from '../components/nodes/FunctionNode'
+import DataNode from '../components/nodes/DataNode'
 
 const ICON_CLASS = 'mr-2 h-4 w-4'
 
@@ -24,7 +25,7 @@ export function registerBuiltinNodes(): void {
     hasInput: true,
     hasOutput: true,
     classification: 'psyche',
-    allowedSourceTypes: ['config', 'variable', 'function'],
+    allowedSourceTypes: ['config', 'variable', 'function', 'data'],
     allowedTargetTypes: ['config', 'render'],
     help: NODE_HELP.config,
     menuLabel: 'Config',
@@ -73,6 +74,22 @@ export function registerBuiltinNodes(): void {
     menuIcon: <Variable className={ICON_CLASS} />,
   })
 
+  registerNodeType({
+    id: 'data',
+    component: DataNode,
+    defaultStyle: { width: 360, height: 280 },
+    defaultData: { rows: [], columns: [], fileName: '' },
+    idPrefix: 'data_',
+    hasInput: false,
+    hasOutput: true,
+    classification: 'physis',
+    allowedTargetTypes: ['config'],
+    help: NODE_HELP.data,
+    menuLabel: 'Data',
+    menuIcon: <Database className={ICON_CLASS} />,
+    connectionLabel: 'data source',
+  })
+
   registerNodeType({
     id: 'function',
     component: FunctionNode,