refactor(web): edit and wrap diagrams with the MCP server's code

- edit_diagram runs the MCP server's editDiagram: every new_xml is checked
  first, one cell per operation, and after the edit only the target page
  is checked, rejecting only errors this edit introduced. An unrelated
  problem elsewhere in the document no longer blocks every edit. The
  error lists each failed operation
- The streaming edit preview uses the MCP applyDiagramOperations
- Delete applyDiagramOperations (292 lines) and wrapWithMxFile from
  lib/utils.ts, and the unused hand-copied scripts/test-diagram-operations.mjs
- One blank document (BLANK_MXFILE) for the web app and the MCP preview,
  replacing four copies
- Saving a .drawio wraps a bare model with normalizeToMxfile
- The empty-diagram check uses hasCells, which also counts cells wrapped
  in a UserObject/object
- DiagramOperation is the MCP type
- The wrapped-cell and empty-diagram tests now run against the MCP code
- New e2e test: edit_diagram changes the canvas, and a failing edit
  leaves it as it was
This commit is contained in:
dayuan.jiang
2026-10-04 12:51:20 +09:00
parent e49e9f0c47
commit bf4e95dcfb
16 changed files with 210 additions and 948 deletions
-7
View File
@@ -53,13 +53,6 @@ export function validateFileParts(messages: any[]): {
return { valid: true }
}
// Helper function to check if diagram is minimal/empty
// Empty means no mxCell besides the root cells "0" and "1". Cells drawn in
// draw.io get random ids, so checking for id="2" is not enough.
export function isMinimalDiagram(xml: string): boolean {
return !/<mxCell\b[^>]*\bid="(?![01]")/.test(xml)
}
// A tool-call input providers accept: a non-empty JSON object
function isValidToolInput(input: unknown): boolean {
return !!input && typeof input === "object" && Object.keys(input).length > 0
-351
View File
@@ -1,9 +1,6 @@
import { type ClassValue, clsx } from "clsx"
import * as pako from "pako"
import { twMerge } from "tailwind-merge"
import type { DiagramOperation } from "@/components/chat/types"
export type { DiagramOperation }
export function cn(...inputs: ClassValue[]) {
return twMerge(clsx(inputs))
@@ -213,61 +210,6 @@ export function convertToLegalXml(xmlString: string): string {
return result
}
/**
* Wrap XML content with the full mxfile structure required by draw.io.
* Always adds root cells (id="0" and id="1") automatically.
* If input already contains root cells, they are removed to avoid duplication.
* LLM should only generate mxCell elements starting from id="2".
* @param xml - The XML string (bare mxCells, <root>, <mxGraphModel>, or full <mxfile>)
* @returns Full mxfile-wrapped XML string with root cells included
*/
export function wrapWithMxFile(xml: string): string {
const ROOT_CELLS = '<mxCell id="0"/><mxCell id="1" parent="0"/>'
if (!xml || !xml.trim()) {
return `<mxfile><diagram name="Page-1" id="page-1"><mxGraphModel><root>${ROOT_CELLS}</root></mxGraphModel></diagram></mxfile>`
}
// Already has full structure
if (xml.includes("<mxfile")) {
return xml
}
// Has mxGraphModel but not mxfile
if (xml.includes("<mxGraphModel")) {
return `<mxfile><diagram name="Page-1" id="page-1">${xml}</diagram></mxfile>`
}
// Has <root> wrapper - extract inner content
let content = xml
if (xml.includes("<root>")) {
content = xml.replace(/<\/?root>/g, "").trim()
}
// Strip trailing LLM wrapper tags (from any provider: Anthropic, DeepSeek, etc.)
// Find the last valid mxCell ending and remove everything after it
const lastSelfClose = content.lastIndexOf("/>")
const lastMxCellClose = content.lastIndexOf("</mxCell>")
const lastValidEnd = Math.max(lastSelfClose, lastMxCellClose)
if (lastValidEnd !== -1) {
const endOffset = lastMxCellClose > lastSelfClose ? 9 : 2
const suffix = content.slice(lastValidEnd + endOffset)
// If suffix is only closing tags (wrapper tags), strip it
if (/^(\s*<\/[^>]+>)*\s*$/.test(suffix)) {
content = content.slice(0, lastValidEnd + endOffset)
}
}
// Remove any existing root cells from content (LLM shouldn't include them, but handle it gracefully)
// Use flexible patterns that match both self-closing (/>) and non-self-closing (></mxCell>) formats
content = content
.replace(/<mxCell[^>]*\bid=["']0["'][^>]*(?:\/>|><\/mxCell>)/g, "")
.replace(/<mxCell[^>]*\bid=["']1["'][^>]*(?:\/>|><\/mxCell>)/g, "")
.trim()
return `<mxfile><diagram name="Page-1" id="page-1"><mxGraphModel><root>${ROOT_CELLS}${content}</root></mxGraphModel></diagram></mxfile>`
}
/**
* Replace nodes in a Draw.io XML diagram
* @param currentXML - The original Draw.io XML string
@@ -370,299 +312,6 @@ export function replaceNodes(currentXML: string, nodes: string): string {
}
}
// ============================================================================
// ID-based Diagram Operations
// ============================================================================
export interface OperationError {
type: "update" | "add" | "delete"
cellId: string
message: string
}
export interface ApplyOperationsResult {
result: string
errors: OperationError[]
}
/**
* draw.io wraps cells that have links, tooltips or custom data in
* <object>/<UserObject>, and the wrapper carries the id instead of the mxCell.
*/
function getCellWrapper(cell: Element): Element | null {
const parent = cell.parentElement
return parent?.tagName === "object" || parent?.tagName === "UserObject"
? parent
: null
}
/** Id of a cell, read from its wrapper when the mxCell has none */
function getCellId(cell: Element): string | null {
return (
cell.getAttribute("id") ||
getCellWrapper(cell)?.getAttribute("id") ||
null
)
}
/** Element to replace or remove for a cell (the wrapper if there is one) */
function getCellNode(cell: Element): Element {
return getCellWrapper(cell) || cell
}
/**
* Apply diagram operations (update/add/delete) using ID-based lookup.
* This replaces the text-matching approach with direct DOM manipulation.
*
* @param xmlContent - The full mxfile XML content
* @param operations - Array of operations to apply
* @returns Object with result XML and any errors
*/
export function applyDiagramOperations(
xmlContent: string,
operations: DiagramOperation[],
): ApplyOperationsResult {
const errors: OperationError[] = []
// Parse the XML
const parser = new DOMParser()
const doc = parser.parseFromString(xmlContent, "text/xml")
// Check for parse errors
const parseError = doc.querySelector("parsererror")
if (parseError) {
return {
result: xmlContent,
errors: [
{
type: "update",
cellId: "",
message: `XML parse error: ${parseError.textContent}`,
},
],
}
}
// Find the root element (inside mxGraphModel)
const root = doc.querySelector("root")
if (!root) {
return {
result: xmlContent,
errors: [
{
type: "update",
cellId: "",
message: "Could not find <root> element in XML",
},
],
}
}
// Build a map of cell IDs to elements (wrapper elements for wrapped cells)
const cellMap = new Map<string, Element>()
root.querySelectorAll("mxCell").forEach((cell) => {
const id = getCellId(cell)
if (id) cellMap.set(id, getCellNode(cell))
})
// Cells removed by delete operations in this batch
const deletedIds = new Set<string>()
// Process each operation
for (const op of operations) {
if (op.operation === "update") {
const existingCell = cellMap.get(op.cell_id)
if (!existingCell) {
errors.push({
type: "update",
cellId: op.cell_id,
message: `Cell with id="${op.cell_id}" not found`,
})
continue
}
if (!op.new_xml) {
errors.push({
type: "update",
cellId: op.cell_id,
message: "new_xml is required for update operation",
})
continue
}
// Parse the new XML
const newDoc = parser.parseFromString(
`<wrapper>${op.new_xml}</wrapper>`,
"text/xml",
)
const newCell = newDoc.querySelector("mxCell")
if (!newCell) {
errors.push({
type: "update",
cellId: op.cell_id,
message: "new_xml must contain an mxCell element",
})
continue
}
// Validate ID matches
const newCellId = getCellId(newCell)
if (newCellId !== op.cell_id) {
errors.push({
type: "update",
cellId: op.cell_id,
message: `ID mismatch: cell_id is "${op.cell_id}" but new_xml has id="${newCellId}"`,
})
continue
}
// Import and replace the node (with its wrapper, if any)
const importedNode = doc.importNode(getCellNode(newCell), true)
existingCell.parentNode?.replaceChild(importedNode, existingCell)
// Update the map with the new element
cellMap.set(op.cell_id, importedNode)
} else if (op.operation === "add") {
// Check if ID already exists
if (cellMap.has(op.cell_id)) {
errors.push({
type: "add",
cellId: op.cell_id,
message: `Cell with id="${op.cell_id}" already exists`,
})
continue
}
if (!op.new_xml) {
errors.push({
type: "add",
cellId: op.cell_id,
message: "new_xml is required for add operation",
})
continue
}
// Parse the new XML
const newDoc = parser.parseFromString(
`<wrapper>${op.new_xml}</wrapper>`,
"text/xml",
)
const newCell = newDoc.querySelector("mxCell")
if (!newCell) {
errors.push({
type: "add",
cellId: op.cell_id,
message: "new_xml must contain an mxCell element",
})
continue
}
// Validate ID matches
const newCellId = getCellId(newCell)
if (newCellId !== op.cell_id) {
errors.push({
type: "add",
cellId: op.cell_id,
message: `ID mismatch: cell_id is "${op.cell_id}" but new_xml has id="${newCellId}"`,
})
continue
}
// Import and append the node (with its wrapper, if any)
const importedNode = doc.importNode(getCellNode(newCell), true)
root.appendChild(importedNode)
// Add to map
cellMap.set(op.cell_id, importedNode)
} else if (op.operation === "delete") {
// Protect root cells from deletion
if (op.cell_id === "0" || op.cell_id === "1") {
errors.push({
type: "delete",
cellId: op.cell_id,
message: `Cannot delete root cell "${op.cell_id}"`,
})
continue
}
const existingCell = cellMap.get(op.cell_id)
if (!existingCell) {
// Cells cascade-deleted earlier in this batch are skipped silently
// (AI may redundantly list children/edges)
if (!deletedIds.has(op.cell_id)) {
errors.push({
type: "delete",
cellId: op.cell_id,
message: `Cell with id="${op.cell_id}" not found`,
})
}
continue
}
// Cascade delete: collect all cells to delete (children + edges + self)
const cellsToDelete = new Set<string>()
// Recursive function to find all descendants
const collectDescendants = (cellId: string) => {
if (cellsToDelete.has(cellId)) return
cellsToDelete.add(cellId)
// Find children (cells where parent === cellId)
const children = root.querySelectorAll(
`mxCell[parent="${cellId}"]`,
)
children.forEach((child) => {
const childId = getCellId(child)
if (childId && childId !== "0" && childId !== "1") {
collectDescendants(childId)
}
})
}
// Collect the target cell and all its descendants
collectDescendants(op.cell_id)
// Find edges referencing any of the cells to be deleted
// Also recursively collect children of those edges (e.g., edge labels)
for (const cellId of cellsToDelete) {
const referencingEdges = root.querySelectorAll(
`mxCell[source="${cellId}"], mxCell[target="${cellId}"]`,
)
referencingEdges.forEach((edge) => {
const edgeId = getCellId(edge)
// Protect root cells from being added via edge references
if (edgeId && edgeId !== "0" && edgeId !== "1") {
// Recurse to collect edge's children (like labels)
collectDescendants(edgeId)
}
})
}
// Log what will be deleted
if (cellsToDelete.size > 1) {
console.log(
`[applyDiagramOperations] Cascade delete "${op.cell_id}" → deleting ${cellsToDelete.size} cells: ${Array.from(cellsToDelete).join(", ")}`,
)
}
// Delete all collected cells
for (const cellId of cellsToDelete) {
const cell = cellMap.get(cellId)
if (cell) {
cell.parentNode?.removeChild(cell)
cellMap.delete(cellId)
deletedIds.add(cellId)
}
}
}
}
// Serialize back to string
const serializer = new XMLSerializer()
const result = serializer.serializeToString(doc)
return { result, errors }
}
/**
* Decode an xmlsvg export (SVG data URL) into uncompressed diagram XML.
* Only the first page is returned; for the full multi-page document use the