refactor(parser): preserve HTML <table> structure (inline + structured item) (#18129)

Stop flattening `<table>` into a single text blob. A `<table>` now emits:
1. an inlined `doc_type_kwd:"text"` item keeping the `<table>…</table>`
markup (row/column structure survives for embedding/retrieval/LLM rendering),
2. a structured `doc_type_kwd:"table"` / `ck_type:"table"` item appended
after the walk, consumed by the downstream chunker.
This commit is contained in:
Jack
2026-08-11 22:15:15 +08:00
committed by GitHub
parent b4dd0f7a0c
commit 875ca966e9
6 changed files with 545 additions and 7 deletions

View File

@@ -107,6 +107,10 @@ func (p *HTMLParser) ParseWithResult(ctx context.Context, filename string, data
// <style>, and <noscript> blocks are skipped entirely so they
// don't pollute the downstream chunker input.
func walkHTMLBlocks(root *html.Node, out *[]map[string]any) {
// tableItems collects the structured doc_type_kwd:"table" items so they
// can be appended after the walk (mirrors markdown_parser.go:366-367,
// which appends tables after all sections to match Python's ordering).
var tableItems []map[string]any
for child := root.FirstChild; child != nil; child = child.NextSibling {
if child.Type == html.TextNode {
if emitsLooseHTMLText(root) {
@@ -129,10 +133,53 @@ func walkHTMLBlocks(root *html.Node, out *[]map[string]any) {
// Wrapper elements: descend into their children.
walkHTMLBlocks(child, out)
continue
case "table":
// Keep the table as its full HTML markup (NOT flattened) so
// row/column structure survives into embedding, retrieval, and
// LLM rendering. This mirrors the markdown table handling
// (markdown_parser.go:305-328) and Python's HtmlParser, which
// keeps the <table>…</table> string as the section text.
markup := renderTableHTML(child)
if strings.TrimSpace(markup) != "" {
// Inlined copy in document order (matches Python's <table>
// section text and markdown's text-flow copy).
*out = append(*out, map[string]any{
"text": markup,
"doc_type_kwd": "text",
})
// Structured table item, appended after the walk.
tableItems = append(tableItems, map[string]any{
"text": markup,
"doc_type_kwd": "table",
"ck_type": "table",
})
}
continue
}
text := htmlLeafText(child)
text := htmlLeafText(child, &tableItems)
appendHTMLTextItem(out, text, htmlTagToCkType(tag), tag != "pre" && tag != "textarea")
}
if len(tableItems) > 0 {
*out = append(*out, tableItems...)
}
}
// renderTableHTML serializes a <table> node back to its outer HTML markup
// (tags preserved), mirroring Python's HtmlParser which keeps the full
// <table>…</table> string as the section text. This preserves row/column
// structure for embedding, retrieval, and LLM rendering, instead of
// flattening cells into a single text blob. It is used both for top-level
// tables (walkHTMLBlocks) and for tables reached via the leaf-text extractor
// (walkHTMLLeaf, i.e. a <table> nested in a div/section/…). On any rendering
// error it returns "" so callers skip the table rather than risk a render
// loop through the leaf extractor — html.Render only fails on unsupported
// node kinds, and a parsed <table> never triggers it.
func renderTableHTML(n *html.Node) string {
var b bytes.Buffer
if err := html.Render(&b, n); err != nil {
return ""
}
return b.String()
}
func emitsLooseHTMLText(root *html.Node) bool {
@@ -241,15 +288,18 @@ func (w *leafWriter) hardBreak() {
// descendants. <script>/<style>/<noscript> subtrees are skipped. Whitespace
// is folded per CSS rules (so "<h1>Hello world</h1>" becomes "Hello world"
// and "<br>" survives as a real line break), while <pre>/<textarea> keep
// their source formatting verbatim.
func htmlLeafText(n *html.Node) string {
// their source formatting verbatim. Any <table> encountered in the subtree is
// rendered as its <table>…</table> markup (so row/column structure survives)
// and registered as a structured doc_type_kwd:"table" item via tableItems —
// see walkHTMLLeaf's "table" case.
func htmlLeafText(n *html.Node, tableItems *[]map[string]any) string {
var b bytes.Buffer
w := &leafWriter{b: &b}
walkHTMLLeaf(n, w)
walkHTMLLeaf(n, w, tableItems)
return b.String()
}
func walkHTMLLeaf(n *html.Node, w *leafWriter) {
func walkHTMLLeaf(n *html.Node, w *leafWriter, tableItems *[]map[string]any) {
switch n.Type {
case html.TextNode:
w.writeText(n.Data)
@@ -265,11 +315,31 @@ func walkHTMLLeaf(n *html.Node, w *leafWriter) {
// Verbatim: no folding, no injected block breaks.
w.pre = true
for child := n.FirstChild; child != nil; child = child.NextSibling {
walkHTMLLeaf(child, w)
walkHTMLLeaf(child, w, tableItems)
}
w.pre = false
return
}
if n.Data == "table" {
// Keep the table as its full HTML markup (NOT flattened) so
// row/column structure survives into the wrapper's text item,
// embedding, retrieval, and LLM rendering. This mirrors the
// top-level walkHTMLBlocks "table" case, and covers tables nested
// in div/section/article/… (which the walkHTMLBlocks case never
// reaches). The structured table item is collected for the
// downstream chunker (appended after the walk by the caller, same
// as the top-level path).
markup := renderTableHTML(n)
if strings.TrimSpace(markup) != "" {
w.writeText(markup)
*tableItems = append(*tableItems, map[string]any{
"text": markup,
"doc_type_kwd": "table",
"ck_type": "table",
})
}
return
}
// Add a line break between block children so headings, paragraphs,
// and list items don't run together.
if !w.pre {
@@ -282,7 +352,7 @@ func walkHTMLLeaf(n *html.Node, w *leafWriter) {
}
}
for child := n.FirstChild; child != nil; child = child.NextSibling {
walkHTMLLeaf(child, w)
walkHTMLLeaf(child, w, tableItems)
}
if !w.pre && isBlockTag(n.Data) && w.b.Len() > 0 && !w.endsNL {
w.hardBreak()

View File

@@ -0,0 +1,380 @@
package parser
import (
"context"
"os"
"strings"
"testing"
)
// TestHTMLParser_TableProducesStructuredItems asserts the HTML table
// alignment fix (approach a, mirroring markdown_parser.go:305-328 and
// :366-367): a <table> must NOT be flattened into a single text blob. The
// parser must emit two items:
//
// 1. an inlined copy in the text flow (doc_type_kwd:"text") whose text keeps
// the <table> markup, so embedding/retrieval/LLM rendering preserve the
// row/column structure (no "collapse");
// 2. a structured table item (doc_type_kwd:"table", ck_type:"table") appended
// after the walk, consumed by the downstream chunker (attachMediaContext).
//
// Before the fix, walkHTMLBlocks ran htmlLeafText over the <table>, producing
// ONE flat item (e.g. "Name Age Alice 30") tagged ck_type:"table" but with no
// markup — this test fails on that behavior.
func TestHTMLParser_TableProducesStructuredItems(t *testing.T) {
const html = `<html><body>
<h1>Employee Table</h1>
<table>
<tr><th>Name</th><th>Age</th></tr>
<tr><td>Alice</td><td>30</td></tr>
</table>
<p>Trailing paragraph</p>
</body></html>`
p := NewHTMLParser()
res := p.ParseWithResult(context.Background(), "doc.html", []byte(html))
if res.Err != nil {
t.Fatalf("ParseWithResult: %v", res.Err)
}
var inlinedText, structuredText string
inlinedIdx, structuredIdx, trailingIdx := -1, -1, -1
for i, it := range res.JSON {
text, _ := it["text"].(string)
switch it["doc_type_kwd"] {
case "text":
if strings.Contains(text, "<table") {
inlinedText = text
inlinedIdx = i
}
if text == "Trailing paragraph" {
trailingIdx = i
}
case "table":
structuredText = text
structuredIdx = i
}
}
if inlinedIdx < 0 {
t.Fatalf("no inlined doc_type_kwd:\"text\" item contains <table> markup; got items: %#v", res.JSON)
}
if !strings.Contains(inlinedText, "<table") ||
!strings.Contains(inlinedText, "Name") ||
!strings.Contains(inlinedText, "Alice") {
t.Errorf("inlined table copy missing markup/cells: %q", inlinedText)
}
if structuredIdx < 0 {
t.Fatalf("no structured doc_type_kwd:\"table\" item emitted; got items: %#v", res.JSON)
}
if got, want := res.JSON[structuredIdx]["ck_type"], "table"; got != want {
t.Errorf("structured table item ck_type = %v, want %v", got, want)
}
if structuredText != inlinedText {
t.Errorf("structured table text differs from inlined copy:\n inlined=%q\n struct =%q", inlinedText, structuredText)
}
// The structured table item must be appended after the walk, i.e. after
// the in-walk text items (mirrors markdown_parser.go:366-367). The trailing
// <p> is an in-walk text item, so the structured item must come after it.
if trailingIdx < 0 {
t.Fatalf("trailing paragraph text item missing; got items: %#v", res.JSON)
}
if structuredIdx <= trailingIdx {
t.Errorf("structured table item at index %d must come after the trailing paragraph at index %d", structuredIdx, trailingIdx)
}
}
// TestHTMLParser_NestedTableProducesStructuredItems asserts the table fix also
// covers tables that are NOT direct children of <body> — i.e. a <table> wrapped
// in a layout container such as <div>/<section>/<article> (the common real-world
// case). walkHTMLBlocks only special-cases a <table> that is a direct child of
// the walk root; a nested <table> is reached via the default-branch leaf-text
// extractor (htmlLeafText → walkHTMLLeaf). Before the fix, that path ran
// htmlLeafText over the wrapper, flattening the table into a single text blob
// ("Name Age Alice 30") with no markup — the same collapse as the top-level case,
// just hidden one level deeper. After the fix, walkHTMLLeaf must render the
// <table> markup inline (so it survives inside the wrapper's single text item)
// AND register a structured doc_type_kwd:"table"/ck_type:"table" item (appended
// after the walk like the top-level path).
func TestHTMLParser_NestedTableProducesStructuredItems(t *testing.T) {
const html = `<html><body>
<h1>Heading</h1>
<div class="content">
<table>
<tr><th>Name</th><th>Age</th></tr>
<tr><td>Alice</td><td>30</td></tr>
</table>
</div>
<p>Trailing paragraph</p>
</body></html>`
p := NewHTMLParser()
res := p.ParseWithResult(context.Background(), "nested.html", []byte(html))
if res.Err != nil {
t.Fatalf("ParseWithResult: %v", res.Err)
}
var inlinedText, structuredText string
inlinedIdx, structuredIdx, trailingIdx := -1, -1, -1
for i, it := range res.JSON {
text, _ := it["text"].(string)
switch it["doc_type_kwd"] {
case "text":
if strings.Contains(text, "<table") {
inlinedText = text
inlinedIdx = i
}
if text == "Trailing paragraph" {
trailingIdx = i
}
case "table":
structuredText = text
structuredIdx = i
}
}
if inlinedIdx < 0 {
t.Fatalf("no inlined doc_type_kwd:\"text\" item contains <table> markup (nested table flattened?); got items: %#v", res.JSON)
}
if !strings.Contains(inlinedText, "<table") ||
!strings.Contains(inlinedText, "Name") ||
!strings.Contains(inlinedText, "Alice") {
t.Errorf("inlined nested table copy missing markup/cells: %q", inlinedText)
}
if structuredIdx < 0 {
t.Fatalf("no structured doc_type_kwd:\"table\" item emitted for nested table; got items: %#v", res.JSON)
}
if got, want := res.JSON[structuredIdx]["ck_type"], "table"; got != want {
t.Errorf("structured nested table item ck_type = %v, want %v", got, want)
}
if !strings.Contains(structuredText, "<table") ||
!strings.Contains(structuredText, "Name") ||
!strings.Contains(structuredText, "Alice") {
t.Errorf("structured nested table item missing markup/cells: %q", structuredText)
}
// The structured table item must be appended after the walk, i.e. after
// every in-walk text item (mirrors the top-level path and markdown).
if trailingIdx < 0 {
t.Fatalf("trailing paragraph text item missing; got items: %#v", res.JSON)
}
if structuredIdx <= inlinedIdx || structuredIdx <= trailingIdx {
t.Errorf("structured nested table item at index %d must come after the inlined text item at %d and trailing paragraph at %d", structuredIdx, inlinedIdx, trailingIdx)
}
}
// TestHTMLParser_NestedListItemsPreserved verifies a nested <ul> (a list
// containing a sublist) does NOT lose any item text — i.e. it is NOT subject to
// the same kind of collapse the table path once had. Unlike tables (whose markup is
// dropped and cells can fuse), list items are separated by hard breaks inside
// walkHTMLLeaf, so every <li> text survives in document order. This mirrors
// Python's RAGFlowHtmlParser: read_text_recursively (html_parser.py:108-160)
// assigns each block its own block_id and emits flat, depth-less records for
// nested <li>s — so BOTH sides preserve item content and NEITHER represents
// nesting depth. The accepted divergence is granularity: Python emits one
// record per <li> while Go emits the whole <ul> as a single text item (its
// "one item per block-level element" model); the primary alignment gate is
// content equivalence (PARSER_ALIGNMENT_HANDOFF.md §2.3), which this test
// guards. A regression here would be Go dropping or fusing list items.
func TestHTMLParser_NestedListItemsPreserved(t *testing.T) {
const html = `<html><body>
<ul>
<li>Item 1</li>
<li>Item 2
<ul>
<li>Sub A</li>
<li>Sub B</li>
</ul>
</li>
</ul>
</body></html>`
p := NewHTMLParser()
res := p.ParseWithResult(context.Background(), "nested-list.html", []byte(html))
if res.Err != nil {
t.Fatalf("ParseWithResult: %v", res.Err)
}
// Join every item's text in order to check content + order + fusion.
var all string
for _, it := range res.JSON {
if txt, _ := it["text"].(string); txt != "" {
all += txt + "\n"
}
}
for _, want := range []string{"Item 1", "Item 2", "Sub A", "Sub B"} {
if !strings.Contains(all, want) {
t.Errorf("nested list lost item %q; joined output: %q", want, all)
}
}
// Document order must survive: the sublist items must follow their parent.
i2 := strings.Index(all, "Item 2")
ia := strings.Index(all, "Sub A")
ib := strings.Index(all, "Sub B")
if i2 < 0 || ia < 0 || ib < 0 || !(ia > i2 && ib > i2) {
t.Errorf("nested list order not preserved (parent must precede sub-items): %q", all)
}
// No collapse: items must not be fused without a separator
// (e.g. "Item 2" directly adjacent to "Sub A" with no break).
if strings.Contains(all, "Item 2Sub") || strings.Contains(all, "Sub ASub") {
t.Errorf("nested list items fused together (collapse): %q", all)
}
// The whole top-level <ul> is emitted as ONE text item tagged
// ck_type:"list" (Go's "one item per block-level element" model). Guard
// against a regression that would drop the list tag or split it
// unexpectedly. Note: a list nested inside a non-list container
// (div/section/…) is folded into that container's single text item and
// therefore loses ck_type:"list" (becomes "text") — a fidelity nuance,
// not a collapse, since downstream chunking reads doc_type_kwd not ck_type.
var listText string
for _, it := range res.JSON {
if it["ck_type"] == "list" {
listText, _ = it["text"].(string)
break
}
}
if listText == "" {
t.Fatalf("top-level <ul> not tagged ck_type:\"list\"; got items: %#v", res.JSON)
}
for _, want := range []string{"Item 1", "Item 2", "Sub A", "Sub B"} {
if !strings.Contains(listText, want) {
t.Errorf("ck_type:\"list\" item missing %q: %q", want, listText)
}
}
}
// TestHTMLParser_PrePreservesVerbatim guards that <pre> (and <textarea>) blocks
// are emitted verbatim — indentation and internal newlines must survive, NOT be
// CSS-collapsed into single spaces. Code is high-value content: if the verbatim
// path regressed to the folded leaf-text path, indented code would lose its
// structure and the LLM / user would see broken code. This mirrors Python's
// RAGFlowHtmlParser, which keeps pre/textarea verbatim (_PRE_TAGS in
// deepdoc/parser/html_parser.py). Both blocks keep doc_type_kwd:"text"; <pre>
// is tagged ck_type:"code" while <textarea> falls back to ck_type:"text"
// (htmlTagToCkType has no textarea case) — a labeling nuance, not a content
// divergence. Note: the single leading newline immediately after <pre>/<textarea>
// is dropped by the HTML parser per spec (pre/textarea eat one leading newline);
// that is correct browser behavior, not folding. What must survive is the
// indentation and the internal newlines.
func TestHTMLParser_PrePreservesVerbatim(t *testing.T) {
const html = `<html><body>
<pre>
def foo():
if x:
return 1
return 0
</pre>
<textarea>
SELECT * FROM t
WHERE a = 1
</textarea>
</body></html>`
p := NewHTMLParser()
res := p.ParseWithResult(context.Background(), "pre.html", []byte(html))
if res.Err != nil {
t.Fatalf("ParseWithResult: %v", res.Err)
}
var preItem, textareaItem map[string]any
for _, it := range res.JSON {
txt, _ := it["text"].(string)
switch {
case strings.Contains(txt, "def foo()"):
preItem = it
case strings.Contains(txt, "SELECT * FROM t"):
textareaItem = it
}
}
if preItem == nil {
t.Fatalf("no <pre> item found; got items: %#v", res.JSON)
}
if preItem["ck_type"] != "code" {
t.Errorf("<pre> item ck_type = %v, want code", preItem["ck_type"])
}
preText, _ := preItem["text"].(string)
// 4-space and 8-space indents must survive verbatim (a folded path would
// collapse them to a single space).
if !strings.Contains(preText, " if x:") {
t.Errorf("<pre> lost 4-space indent (folded?): %q", preText)
}
if !strings.Contains(preText, " return 1") {
t.Errorf("<pre> lost 8-space indent (folded?): %q", preText)
}
// Internal newlines must survive (line structure preserved).
if !strings.Contains(preText, "def foo():\n") {
t.Errorf("<pre> lost internal newline (folded?): %q", preText)
}
if textareaItem == nil {
t.Fatalf("no <textarea> item found; got items: %#v", res.JSON)
}
taText, _ := textareaItem["text"].(string)
// 2-space indent must survive verbatim.
if !strings.Contains(taText, " WHERE a = 1") {
t.Errorf("<textarea> lost 2-space indent (folded?): %q", taText)
}
}
// TestHTMLParser_AlignmentGolden verifies Go's ParseWithResult output is
// content-equivalent to Python's RAGFlowHtmlParser on the shared sample, using
// the shared concatenation-normalization alignment tool (align_test.go).
// Python keeps raw HTML and splits on block elements (deepdoc/parser/html_parser.py:
// read_text_recursively + merge_block_text); Go emits clean per-block text.
// The comparison normalizes both (HTML heading markers "#{1,6}", HTML tags,
// whitespace collapsed) and ignores "table" items, which are accepted
// representation differences (the <table> markup stays inline as a "text"
// item in both, see TestHTMLParser_TableProducesStructuredItems). The
// accepted divergences are declared in the golden's meta block, not hardcoded
// here.
//
// The baseline lives in testdata/html.python.en.golden.json / testdata/html.python.zh.golden.json as {meta, items}
// document (see its "meta" block for how to regenerate it from the Python
// engine — no committed generator script).
func TestHTMLParser_AlignmentGolden(t *testing.T) {
ctx := t.Context()
p := NewHTMLParser()
cases := []struct {
name string
sample string
golden string
}{
{"en", "testdata/html.sample.en.html", "testdata/html.python.en.golden.json"},
{"zh", "testdata/html.sample.zh.html", "testdata/html.python.zh.golden.json"},
}
for _, tc := range cases {
t.Run(tc.name, func(t *testing.T) {
sample, err := os.ReadFile(tc.sample)
if err != nil {
t.Fatalf("read sample: %v", err)
}
res := p.ParseWithResult(ctx, tc.sample, sample)
if res.Err != nil {
t.Fatalf("ParseWithResult: %v", res.Err)
}
doc := LoadGoldenDoc(t, tc.golden)
// Drop the meta-declared accepted divergences on both sides (here "table"):
// Go appends a structured doc_type_kwd:"table" item, while Python keeps the
// <table> markup inline as a "text" item. The inline markup remains in both
// runs and is still compared — that is exactly what guards against collapse.
drop := AcceptedDivergences(doc.Meta)
goText := FilterOutDocTypes(res.JSON, drop)
pyText := FilterOutDocTypes(doc.Items, drop)
if ok, diff := CompareAlignment(goText, pyText, HTMLAlignOptions()); !ok {
t.Fatalf("html parser not aligned with Python golden:%s", diff)
}
})
}
}

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@@ -0,0 +1,33 @@
{
"meta": {
"python_engine": "deepdoc.parser.html_parser.RAGFlowHtmlParser",
"generator": "rag/flow/parser/parser.py:_html (HtmlParser()(name, blob, 512))",
"sample": "internal/parser/parser/testdata/html.sample.en.html",
"delimiter": "\\n!?;。;!?",
"separate_tables": false,
"accepted_divergences": ["table"],
"note": "No generator script is committed. To regenerate: call RAGFlowHtmlParser.read_text_recursively on the sample at chunk_token_num=512, apply the TITLE_TAGS heading prefix (\"# \"/\"## \" …) inline, emit every block (including the inline <table>…</table> markup) as a {\"text\": …, \"doc_type_kwd\": \"text\"} record, then wrap in {meta, items}. Go also appends a structured doc_type_kwd:\"table\" item; that extra record is excluded via meta.accepted_divergences in the alignment test."
},
"items": [
{
"text": "# Product Guide",
"doc_type_kwd": "text"
},
{
"text": "Step 1: Open the app. Step 2: Click Settings to complete the setup.",
"doc_type_kwd": "text"
},
{
"text": "<table>\n<tr><th>Name</th><th>Age</th></tr>\n<tr><td>Alice</td><td>30</td></tr>\n<tr><td>Bob</td><td>25</td></tr>\n</table>",
"doc_type_kwd": "text"
},
{
"text": "## Terms of Use",
"doc_type_kwd": "text"
},
{
"text": "Welcome to our smart assistant, which helps you complete tasks quickly.",
"doc_type_kwd": "text"
}
]
}

View File

@@ -0,0 +1,33 @@
{
"meta": {
"python_engine": "deepdoc.parser.html_parser.RAGFlowHtmlParser",
"generator": "rag/flow/parser/parser.py:_html (HtmlParser()(name, blob, 512))",
"sample": "internal/parser/parser/testdata/html.sample.zh.html",
"delimiter": "\\n!?;。;!?",
"separate_tables": false,
"accepted_divergences": ["table"],
"note": "No generator script is committed. To regenerate: call RAGFlowHtmlParser.read_text_recursively on the sample at chunk_token_num=512, apply the TITLE_TAGS heading prefix (\"# \"/\"## \" …) inline, emit every block (including the inline <table>…</table> markup) as a {\"text\": …, \"doc_type_kwd\": \"text\"} record, then wrap in {meta, items}. Go also appends a structured doc_type_kwd:\"table\" item; that extra record is excluded via meta.accepted_divergences in the alignment test."
},
"items": [
{
"text": "# 产品指南",
"doc_type_kwd": "text"
},
{
"text": "第一步:打开应用。第二步:点击设置完成配置。",
"doc_type_kwd": "text"
},
{
"text": "<table>\n<tr><th>姓名</th><th>年龄</th></tr>\n<tr><td>张三</td><td>30</td></tr>\n<tr><td>李四</td><td>25</td></tr>\n</table>",
"doc_type_kwd": "text"
},
{
"text": "## 使用条款",
"doc_type_kwd": "text"
},
{
"text": "欢迎使用我们的智能助手,它能帮你快速完成任务。",
"doc_type_kwd": "text"
}
]
}

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@@ -0,0 +1,11 @@
<html><body>
<h1>Product Guide</h1>
<p>Step 1: Open the app. Step 2: Click Settings to complete the setup.</p>
<table>
<tr><th>Name</th><th>Age</th></tr>
<tr><td>Alice</td><td>30</td></tr>
<tr><td>Bob</td><td>25</td></tr>
</table>
<h2>Terms of Use</h2>
<p>Welcome to our smart assistant, which helps you complete tasks quickly.</p>
</body></html>

View File

@@ -0,0 +1,11 @@
<html><body>
<h1>产品指南</h1>
<p>第一步:打开应用。第二步:点击设置完成配置。</p>
<table>
<tr><th>姓名</th><th>年龄</th></tr>
<tr><td>张三</td><td>30</td></tr>
<tr><td>李四</td><td>25</td></tr>
</table>
<h2>使用条款</h2>
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