1//===-- Mustache.cpp ------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8#include "llvm/Support/Mustache.h"
9#include "llvm/ADT/SmallVector.h"
10#include "llvm/Support/raw_ostream.h"
11#include <sstream>
12
13using namespace llvm;
14using namespace llvm::mustache;
15
16namespace {
17
18using Accessor = SmallVector<std::string>;
19
20static bool isFalsey(const json::Value &V) {
21 return V.getAsNull() || (V.getAsBoolean() && !V.getAsBoolean().value()) ||
22 (V.getAsArray() && V.getAsArray()->empty());
23}
24
25static bool isContextFalsey(const json::Value *V) {
26 // A missing context (represented by a nullptr) is defined as falsey.
27 if (!V)
28 return true;
29 return isFalsey(V: *V);
30}
31
32static Accessor splitMustacheString(StringRef Str) {
33 // We split the mustache string into an accessor.
34 // For example:
35 // "a.b.c" would be split into {"a", "b", "c"}
36 // We make an exception for a single dot which
37 // refers to the current context.
38 Accessor Tokens;
39 if (Str == ".") {
40 Tokens.emplace_back(Args&: Str);
41 return Tokens;
42 }
43 while (!Str.empty()) {
44 StringRef Part;
45 std::tie(args&: Part, args&: Str) = Str.split(Separator: ".");
46 Tokens.emplace_back(Args: Part.trim());
47 }
48 return Tokens;
49}
50} // namespace
51
52namespace llvm::mustache {
53
54class Token {
55public:
56 enum class Type {
57 Text,
58 Variable,
59 Partial,
60 SectionOpen,
61 SectionClose,
62 InvertSectionOpen,
63 UnescapeVariable,
64 Comment,
65 };
66
67 Token(std::string Str)
68 : TokenType(Type::Text), RawBody(std::move(Str)), TokenBody(RawBody),
69 AccessorValue({}), Indentation(0) {};
70
71 Token(std::string RawBody, std::string TokenBody, char Identifier)
72 : RawBody(std::move(RawBody)), TokenBody(std::move(TokenBody)),
73 Indentation(0) {
74 TokenType = getTokenType(Identifier);
75 if (TokenType == Type::Comment)
76 return;
77 StringRef AccessorStr(this->TokenBody);
78 if (TokenType != Type::Variable)
79 AccessorStr = AccessorStr.substr(Start: 1);
80 AccessorValue = splitMustacheString(Str: StringRef(AccessorStr).trim());
81 }
82
83 Accessor getAccessor() const { return AccessorValue; }
84
85 Type getType() const { return TokenType; }
86
87 void setIndentation(size_t NewIndentation) { Indentation = NewIndentation; }
88
89 size_t getIndentation() const { return Indentation; }
90
91 static Type getTokenType(char Identifier) {
92 switch (Identifier) {
93 case '#':
94 return Type::SectionOpen;
95 case '/':
96 return Type::SectionClose;
97 case '^':
98 return Type::InvertSectionOpen;
99 case '!':
100 return Type::Comment;
101 case '>':
102 return Type::Partial;
103 case '&':
104 return Type::UnescapeVariable;
105 default:
106 return Type::Variable;
107 }
108 }
109
110 Type TokenType;
111 // RawBody is the original string that was tokenized.
112 std::string RawBody;
113 // TokenBody is the original string with the identifier removed.
114 std::string TokenBody;
115 Accessor AccessorValue;
116 size_t Indentation;
117};
118
119using EscapeMap = DenseMap<char, std::string>;
120
121class ASTNode {
122public:
123 enum Type {
124 Root,
125 Text,
126 Partial,
127 Variable,
128 UnescapeVariable,
129 Section,
130 InvertSection,
131 };
132
133 ASTNode(llvm::StringMap<AstPtr> &Partials, llvm::StringMap<Lambda> &Lambdas,
134 llvm::StringMap<SectionLambda> &SectionLambdas, EscapeMap &Escapes)
135 : Partials(Partials), Lambdas(Lambdas), SectionLambdas(SectionLambdas),
136 Escapes(Escapes), Ty(Type::Root), Parent(nullptr),
137 ParentContext(nullptr) {}
138
139 ASTNode(std::string Body, ASTNode *Parent, llvm::StringMap<AstPtr> &Partials,
140 llvm::StringMap<Lambda> &Lambdas,
141 llvm::StringMap<SectionLambda> &SectionLambdas, EscapeMap &Escapes)
142 : Partials(Partials), Lambdas(Lambdas), SectionLambdas(SectionLambdas),
143 Escapes(Escapes), Ty(Type::Text), Body(std::move(Body)), Parent(Parent),
144 ParentContext(nullptr) {}
145
146 // Constructor for Section/InvertSection/Variable/UnescapeVariable Nodes
147 ASTNode(Type Ty, Accessor Accessor, ASTNode *Parent,
148 llvm::StringMap<AstPtr> &Partials, llvm::StringMap<Lambda> &Lambdas,
149 llvm::StringMap<SectionLambda> &SectionLambdas, EscapeMap &Escapes)
150 : Partials(Partials), Lambdas(Lambdas), SectionLambdas(SectionLambdas),
151 Escapes(Escapes), Ty(Ty), Parent(Parent),
152 AccessorValue(std::move(Accessor)), ParentContext(nullptr) {}
153
154 void addChild(AstPtr Child) { Children.emplace_back(args: std::move(Child)); };
155
156 void setRawBody(std::string NewBody) { RawBody = std::move(NewBody); };
157
158 void setIndentation(size_t NewIndentation) { Indentation = NewIndentation; };
159
160 void render(const llvm::json::Value &Data, llvm::raw_ostream &OS);
161
162private:
163 void renderLambdas(const llvm::json::Value &Contexts, llvm::raw_ostream &OS,
164 Lambda &L);
165
166 void renderSectionLambdas(const llvm::json::Value &Contexts,
167 llvm::raw_ostream &OS, SectionLambda &L);
168
169 void renderPartial(const llvm::json::Value &Contexts, llvm::raw_ostream &OS,
170 ASTNode *Partial);
171
172 void renderChild(const llvm::json::Value &Context, llvm::raw_ostream &OS);
173
174 const llvm::json::Value *findContext();
175
176 StringMap<AstPtr> &Partials;
177 StringMap<Lambda> &Lambdas;
178 StringMap<SectionLambda> &SectionLambdas;
179 EscapeMap &Escapes;
180 Type Ty;
181 size_t Indentation = 0;
182 std::string RawBody;
183 std::string Body;
184 ASTNode *Parent;
185 // TODO: switch implementation to SmallVector<T>
186 std::vector<AstPtr> Children;
187 const Accessor AccessorValue;
188 const llvm::json::Value *ParentContext;
189};
190
191// A wrapper for arena allocator for ASTNodes
192AstPtr createRootNode(llvm::StringMap<AstPtr> &Partials,
193 llvm::StringMap<Lambda> &Lambdas,
194 llvm::StringMap<SectionLambda> &SectionLambdas,
195 EscapeMap &Escapes) {
196 return std::make_unique<ASTNode>(args&: Partials, args&: Lambdas, args&: SectionLambdas, args&: Escapes);
197}
198
199AstPtr createNode(ASTNode::Type T, Accessor A, ASTNode *Parent,
200 llvm::StringMap<AstPtr> &Partials,
201 llvm::StringMap<Lambda> &Lambdas,
202 llvm::StringMap<SectionLambda> &SectionLambdas,
203 EscapeMap &Escapes) {
204 return std::make_unique<ASTNode>(args&: T, args: std::move(A), args&: Parent, args&: Partials, args&: Lambdas,
205 args&: SectionLambdas, args&: Escapes);
206}
207
208AstPtr createTextNode(std::string Body, ASTNode *Parent,
209 llvm::StringMap<AstPtr> &Partials,
210 llvm::StringMap<Lambda> &Lambdas,
211 llvm::StringMap<SectionLambda> &SectionLambdas,
212 EscapeMap &Escapes) {
213 return std::make_unique<ASTNode>(args: std::move(Body), args&: Parent, args&: Partials, args&: Lambdas,
214 args&: SectionLambdas, args&: Escapes);
215}
216
217// Function to check if there is meaningful text behind.
218// We determine if a token has meaningful text behind
219// if the right of previous token contains anything that is
220// not a newline.
221// For example:
222// "Stuff {{#Section}}" (returns true)
223// vs
224// "{{#Section}} \n" (returns false)
225// We make an exception for when previous token is empty
226// and the current token is the second token.
227// For example:
228// "{{#Section}}"
229bool hasTextBehind(size_t Idx, const ArrayRef<Token> &Tokens) {
230 if (Idx == 0)
231 return true;
232
233 size_t PrevIdx = Idx - 1;
234 if (Tokens[PrevIdx].getType() != Token::Type::Text)
235 return true;
236
237 const Token &PrevToken = Tokens[PrevIdx];
238 StringRef TokenBody = StringRef(PrevToken.RawBody).rtrim(Chars: " \r\t\v");
239 return !TokenBody.ends_with(Suffix: "\n") && !(TokenBody.empty() && Idx == 1);
240}
241
242// Function to check if there's no meaningful text ahead.
243// We determine if a token has text ahead if the left of previous
244// token does not start with a newline.
245bool hasTextAhead(size_t Idx, const ArrayRef<Token> &Tokens) {
246 if (Idx >= Tokens.size() - 1)
247 return true;
248
249 size_t NextIdx = Idx + 1;
250 if (Tokens[NextIdx].getType() != Token::Type::Text)
251 return true;
252
253 const Token &NextToken = Tokens[NextIdx];
254 StringRef TokenBody = StringRef(NextToken.RawBody).ltrim(Chars: " ");
255 return !TokenBody.starts_with(Prefix: "\r\n") && !TokenBody.starts_with(Prefix: "\n");
256}
257
258bool requiresCleanUp(Token::Type T) {
259 // We must clean up all the tokens that could contain child nodes.
260 return T == Token::Type::SectionOpen || T == Token::Type::InvertSectionOpen ||
261 T == Token::Type::SectionClose || T == Token::Type::Comment ||
262 T == Token::Type::Partial;
263}
264
265// Adjust next token body if there is no text ahead.
266// For example:
267// The template string
268// "{{! Comment }} \nLine 2"
269// would be considered as no text ahead and should be rendered as
270// " Line 2"
271void stripTokenAhead(SmallVectorImpl<Token> &Tokens, size_t Idx) {
272 Token &NextToken = Tokens[Idx + 1];
273 StringRef NextTokenBody = NextToken.TokenBody;
274 // Cut off the leading newline which could be \n or \r\n.
275 if (NextTokenBody.starts_with(Prefix: "\r\n"))
276 NextToken.TokenBody = NextTokenBody.substr(Start: 2).str();
277 else if (NextTokenBody.starts_with(Prefix: "\n"))
278 NextToken.TokenBody = NextTokenBody.substr(Start: 1).str();
279}
280
281// Adjust previous token body if there no text behind.
282// For example:
283// The template string
284// " \t{{#section}}A{{/section}}"
285// would be considered as having no text ahead and would be render as
286// "A"
287// The exception for this is partial tag which requires us to
288// keep track of the indentation once it's rendered.
289void stripTokenBefore(SmallVectorImpl<Token> &Tokens, size_t Idx,
290 Token &CurrentToken, Token::Type CurrentType) {
291 Token &PrevToken = Tokens[Idx - 1];
292 StringRef PrevTokenBody = PrevToken.TokenBody;
293 StringRef Unindented = PrevTokenBody.rtrim(Chars: " \r\t\v");
294 size_t Indentation = PrevTokenBody.size() - Unindented.size();
295 if (CurrentType != Token::Type::Partial)
296 PrevToken.TokenBody = Unindented.str();
297 CurrentToken.setIndentation(Indentation);
298}
299
300// Simple tokenizer that splits the template into tokens.
301// The mustache spec allows {{{ }}} to unescape variables,
302// but we don't support that here. An unescape variable
303// is represented only by {{& variable}}.
304SmallVector<Token> tokenize(StringRef Template) {
305 SmallVector<Token> Tokens;
306 StringLiteral Open("{{");
307 StringLiteral Close("}}");
308 size_t Start = 0;
309 size_t DelimiterStart = Template.find(Str: Open);
310 if (DelimiterStart == StringRef::npos) {
311 Tokens.emplace_back(Args: Template.str());
312 return Tokens;
313 }
314 while (DelimiterStart != StringRef::npos) {
315 if (DelimiterStart != Start)
316 Tokens.emplace_back(Args: Template.substr(Start, N: DelimiterStart - Start).str());
317 size_t DelimiterEnd = Template.find(Str: Close, From: DelimiterStart);
318 if (DelimiterEnd == StringRef::npos)
319 break;
320
321 // Extract the Interpolated variable without delimiters.
322 size_t InterpolatedStart = DelimiterStart + Open.size();
323 size_t InterpolatedEnd = DelimiterEnd - DelimiterStart - Close.size();
324 std::string Interpolated =
325 Template.substr(Start: InterpolatedStart, N: InterpolatedEnd).str();
326 std::string RawBody = Open.str() + Interpolated + Close.str();
327 Tokens.emplace_back(Args&: RawBody, Args&: Interpolated, Args&: Interpolated[0]);
328 Start = DelimiterEnd + Close.size();
329 DelimiterStart = Template.find(Str: Open, From: Start);
330 }
331
332 if (Start < Template.size())
333 Tokens.emplace_back(Args: Template.substr(Start).str());
334
335 // Fix up white spaces for:
336 // - open sections
337 // - inverted sections
338 // - close sections
339 // - comments
340 //
341 // This loop attempts to find standalone tokens and tries to trim out
342 // the surrounding whitespace.
343 // For example:
344 // if you have the template string
345 // {{#section}} \n Example \n{{/section}}
346 // The output should would be
347 // For example:
348 // \n Example \n
349 size_t LastIdx = Tokens.size() - 1;
350 for (size_t Idx = 0, End = Tokens.size(); Idx < End; ++Idx) {
351 Token &CurrentToken = Tokens[Idx];
352 Token::Type CurrentType = CurrentToken.getType();
353 // Check if token type requires cleanup.
354 bool RequiresCleanUp = requiresCleanUp(T: CurrentType);
355
356 if (!RequiresCleanUp)
357 continue;
358
359 // We adjust the token body if there's no text behind or ahead.
360 // A token is considered to have no text ahead if the right of the previous
361 // token is a newline followed by spaces.
362 // A token is considered to have no text behind if the left of the next
363 // token is spaces followed by a newline.
364 // eg.
365 // "Line 1\n {{#section}} \n Line 2 \n {{/section}} \n Line 3"
366 bool HasTextBehind = hasTextBehind(Idx, Tokens);
367 bool HasTextAhead = hasTextAhead(Idx, Tokens);
368
369 if ((!HasTextAhead && !HasTextBehind) || (!HasTextAhead && Idx == 0))
370 stripTokenAhead(Tokens, Idx);
371
372 if ((!HasTextBehind && !HasTextAhead) || (!HasTextBehind && Idx == LastIdx))
373 stripTokenBefore(Tokens, Idx, CurrentToken, CurrentType);
374 }
375 return Tokens;
376}
377
378// Custom stream to escape strings.
379class EscapeStringStream : public raw_ostream {
380public:
381 explicit EscapeStringStream(llvm::raw_ostream &WrappedStream,
382 EscapeMap &Escape)
383 : Escape(Escape), WrappedStream(WrappedStream) {
384 SetUnbuffered();
385 }
386
387protected:
388 void write_impl(const char *Ptr, size_t Size) override {
389 llvm::StringRef Data(Ptr, Size);
390 for (char C : Data) {
391 auto It = Escape.find(Val: C);
392 if (It != Escape.end())
393 WrappedStream << It->getSecond();
394 else
395 WrappedStream << C;
396 }
397 }
398
399 uint64_t current_pos() const override { return WrappedStream.tell(); }
400
401private:
402 EscapeMap &Escape;
403 llvm::raw_ostream &WrappedStream;
404};
405
406// Custom stream to add indentation used to for rendering partials.
407class AddIndentationStringStream : public raw_ostream {
408public:
409 explicit AddIndentationStringStream(llvm::raw_ostream &WrappedStream,
410 size_t Indentation)
411 : Indentation(Indentation), WrappedStream(WrappedStream) {
412 SetUnbuffered();
413 }
414
415protected:
416 void write_impl(const char *Ptr, size_t Size) override {
417 llvm::StringRef Data(Ptr, Size);
418 SmallString<0> Indent;
419 Indent.resize(N: Indentation, NV: ' ');
420 for (char C : Data) {
421 WrappedStream << C;
422 if (C == '\n')
423 WrappedStream << Indent;
424 }
425 }
426
427 uint64_t current_pos() const override { return WrappedStream.tell(); }
428
429private:
430 size_t Indentation;
431 llvm::raw_ostream &WrappedStream;
432};
433
434class Parser {
435public:
436 Parser(StringRef TemplateStr) : TemplateStr(TemplateStr) {}
437
438 AstPtr parse(llvm::StringMap<AstPtr> &Partials,
439 llvm::StringMap<Lambda> &Lambdas,
440 llvm::StringMap<SectionLambda> &SectionLambdas,
441 EscapeMap &Escapes);
442
443private:
444 void parseMustache(ASTNode *Parent, llvm::StringMap<AstPtr> &Partials,
445 llvm::StringMap<Lambda> &Lambdas,
446 llvm::StringMap<SectionLambda> &SectionLambdas,
447 EscapeMap &Escapes);
448
449 SmallVector<Token> Tokens;
450 size_t CurrentPtr;
451 StringRef TemplateStr;
452};
453
454AstPtr Parser::parse(llvm::StringMap<AstPtr> &Partials,
455 llvm::StringMap<Lambda> &Lambdas,
456 llvm::StringMap<SectionLambda> &SectionLambdas,
457 EscapeMap &Escapes) {
458 Tokens = tokenize(Template: TemplateStr);
459 CurrentPtr = 0;
460 AstPtr RootNode = createRootNode(Partials, Lambdas, SectionLambdas, Escapes);
461 parseMustache(Parent: RootNode.get(), Partials, Lambdas, SectionLambdas, Escapes);
462 return RootNode;
463}
464
465void Parser::parseMustache(ASTNode *Parent, llvm::StringMap<AstPtr> &Partials,
466 llvm::StringMap<Lambda> &Lambdas,
467 llvm::StringMap<SectionLambda> &SectionLambdas,
468 EscapeMap &Escapes) {
469
470 while (CurrentPtr < Tokens.size()) {
471 Token CurrentToken = Tokens[CurrentPtr];
472 CurrentPtr++;
473 Accessor A = CurrentToken.getAccessor();
474 AstPtr CurrentNode;
475
476 switch (CurrentToken.getType()) {
477 case Token::Type::Text: {
478 CurrentNode = createTextNode(Body: std::move(CurrentToken.TokenBody), Parent,
479 Partials, Lambdas, SectionLambdas, Escapes);
480 Parent->addChild(Child: std::move(CurrentNode));
481 break;
482 }
483 case Token::Type::Variable: {
484 CurrentNode = createNode(T: ASTNode::Variable, A: std::move(A), Parent,
485 Partials, Lambdas, SectionLambdas, Escapes);
486 Parent->addChild(Child: std::move(CurrentNode));
487 break;
488 }
489 case Token::Type::UnescapeVariable: {
490 CurrentNode = createNode(T: ASTNode::UnescapeVariable, A: std::move(A), Parent,
491 Partials, Lambdas, SectionLambdas, Escapes);
492 Parent->addChild(Child: std::move(CurrentNode));
493 break;
494 }
495 case Token::Type::Partial: {
496 CurrentNode = createNode(T: ASTNode::Partial, A: std::move(A), Parent, Partials,
497 Lambdas, SectionLambdas, Escapes);
498 CurrentNode->setIndentation(CurrentToken.getIndentation());
499 Parent->addChild(Child: std::move(CurrentNode));
500 break;
501 }
502 case Token::Type::SectionOpen: {
503 CurrentNode = createNode(T: ASTNode::Section, A, Parent, Partials, Lambdas,
504 SectionLambdas, Escapes);
505 size_t Start = CurrentPtr;
506 parseMustache(Parent: CurrentNode.get(), Partials, Lambdas, SectionLambdas,
507 Escapes);
508 const size_t End = CurrentPtr - 1;
509 std::string RawBody;
510 for (std::size_t I = Start; I < End; I++)
511 RawBody += Tokens[I].RawBody;
512 CurrentNode->setRawBody(std::move(RawBody));
513 Parent->addChild(Child: std::move(CurrentNode));
514 break;
515 }
516 case Token::Type::InvertSectionOpen: {
517 CurrentNode = createNode(T: ASTNode::InvertSection, A, Parent, Partials,
518 Lambdas, SectionLambdas, Escapes);
519 size_t Start = CurrentPtr;
520 parseMustache(Parent: CurrentNode.get(), Partials, Lambdas, SectionLambdas,
521 Escapes);
522 const size_t End = CurrentPtr - 1;
523 std::string RawBody;
524 for (size_t Idx = Start; Idx < End; Idx++)
525 RawBody += Tokens[Idx].RawBody;
526 CurrentNode->setRawBody(std::move(RawBody));
527 Parent->addChild(Child: std::move(CurrentNode));
528 break;
529 }
530 case Token::Type::Comment:
531 break;
532 case Token::Type::SectionClose:
533 return;
534 }
535 }
536}
537void toMustacheString(const json::Value &Data, raw_ostream &OS) {
538 switch (Data.kind()) {
539 case json::Value::Null:
540 return;
541 case json::Value::Number: {
542 auto Num = *Data.getAsNumber();
543 std::ostringstream SS;
544 SS << Num;
545 OS << SS.str();
546 return;
547 }
548 case json::Value::String: {
549 auto Str = *Data.getAsString();
550 OS << Str.str();
551 return;
552 }
553
554 case json::Value::Array: {
555 auto Arr = *Data.getAsArray();
556 if (Arr.empty())
557 return;
558 [[fallthrough]];
559 }
560 case json::Value::Object:
561 case json::Value::Boolean: {
562 llvm::json::OStream JOS(OS, 2);
563 JOS.value(V: Data);
564 break;
565 }
566 }
567}
568
569void ASTNode::render(const json::Value &CurrentCtx, raw_ostream &OS) {
570 // Set the parent context to the incoming context so that we
571 // can walk up the context tree correctly in findContext().
572 ParentContext = &CurrentCtx;
573 const json::Value *ContextPtr = Ty == Root ? ParentContext : findContext();
574
575 switch (Ty) {
576 case Root:
577 renderChild(Context: CurrentCtx, OS);
578 return;
579 case Text:
580 OS << Body;
581 return;
582 case Partial: {
583 auto Partial = Partials.find(Key: AccessorValue[0]);
584 if (Partial != Partials.end())
585 renderPartial(Contexts: CurrentCtx, OS, Partial: Partial->getValue().get());
586 return;
587 }
588 case Variable: {
589 auto Lambda = Lambdas.find(Key: AccessorValue[0]);
590 if (Lambda != Lambdas.end()) {
591 renderLambdas(Contexts: CurrentCtx, OS, L&: Lambda->getValue());
592 } else if (ContextPtr) {
593 EscapeStringStream ES(OS, Escapes);
594 toMustacheString(Data: *ContextPtr, OS&: ES);
595 }
596 return;
597 }
598 case UnescapeVariable: {
599 auto Lambda = Lambdas.find(Key: AccessorValue[0]);
600 if (Lambda != Lambdas.end()) {
601 renderLambdas(Contexts: CurrentCtx, OS, L&: Lambda->getValue());
602 } else if (ContextPtr) {
603 toMustacheString(Data: *ContextPtr, OS);
604 }
605 return;
606 }
607 case Section: {
608 auto SectionLambda = SectionLambdas.find(Key: AccessorValue[0]);
609 bool IsLambda = SectionLambda != SectionLambdas.end();
610
611 if (IsLambda) {
612 renderSectionLambdas(Contexts: CurrentCtx, OS, L&: SectionLambda->getValue());
613 return;
614 }
615
616 if (isContextFalsey(V: ContextPtr))
617 return;
618
619 if (const json::Array *Arr = ContextPtr->getAsArray()) {
620 for (const json::Value &V : *Arr)
621 renderChild(Context: V, OS);
622 return;
623 }
624 renderChild(Context: *ContextPtr, OS);
625 return;
626 }
627 case InvertSection: {
628 bool IsLambda = SectionLambdas.contains(Key: AccessorValue[0]);
629 if (isContextFalsey(V: ContextPtr) && !IsLambda) {
630 // The context for the children remains unchanged from the parent's, so
631 // we pass this node's original incoming context.
632 renderChild(Context: CurrentCtx, OS);
633 }
634 return;
635 }
636 }
637 llvm_unreachable("Invalid ASTNode type");
638}
639
640const json::Value *ASTNode::findContext() {
641 // The mustache spec allows for dot notation to access nested values
642 // a single dot refers to the current context.
643 // We attempt to find the JSON context in the current node, if it is not
644 // found, then we traverse the parent nodes to find the context until we
645 // reach the root node or the context is found.
646 if (AccessorValue.empty())
647 return nullptr;
648 if (AccessorValue[0] == ".")
649 return ParentContext;
650
651 const json::Object *CurrentContext = ParentContext->getAsObject();
652 StringRef CurrentAccessor = AccessorValue[0];
653 ASTNode *CurrentParent = Parent;
654
655 while (!CurrentContext || !CurrentContext->get(K: CurrentAccessor)) {
656 if (CurrentParent->Ty != Root) {
657 CurrentContext = CurrentParent->ParentContext->getAsObject();
658 CurrentParent = CurrentParent->Parent;
659 continue;
660 }
661 return nullptr;
662 }
663 const json::Value *Context = nullptr;
664 for (auto [Idx, Acc] : enumerate(First: AccessorValue)) {
665 const json::Value *CurrentValue = CurrentContext->get(K: Acc);
666 if (!CurrentValue)
667 return nullptr;
668 if (Idx < AccessorValue.size() - 1) {
669 CurrentContext = CurrentValue->getAsObject();
670 if (!CurrentContext)
671 return nullptr;
672 } else {
673 Context = CurrentValue;
674 }
675 }
676 return Context;
677}
678
679void ASTNode::renderChild(const json::Value &Contexts, llvm::raw_ostream &OS) {
680 for (AstPtr &Child : Children)
681 Child->render(CurrentCtx: Contexts, OS);
682}
683
684void ASTNode::renderPartial(const json::Value &Contexts, llvm::raw_ostream &OS,
685 ASTNode *Partial) {
686 AddIndentationStringStream IS(OS, Indentation);
687 Partial->render(CurrentCtx: Contexts, OS&: IS);
688}
689
690void ASTNode::renderLambdas(const json::Value &Contexts, llvm::raw_ostream &OS,
691 Lambda &L) {
692 json::Value LambdaResult = L();
693 std::string LambdaStr;
694 raw_string_ostream Output(LambdaStr);
695 toMustacheString(Data: LambdaResult, OS&: Output);
696 Parser P = Parser(LambdaStr);
697 AstPtr LambdaNode = P.parse(Partials, Lambdas, SectionLambdas, Escapes);
698
699 EscapeStringStream ES(OS, Escapes);
700 if (Ty == Variable) {
701 LambdaNode->render(CurrentCtx: Contexts, OS&: ES);
702 return;
703 }
704 LambdaNode->render(CurrentCtx: Contexts, OS);
705}
706
707void ASTNode::renderSectionLambdas(const json::Value &Contexts,
708 llvm::raw_ostream &OS, SectionLambda &L) {
709 json::Value Return = L(RawBody);
710 if (isFalsey(V: Return))
711 return;
712 std::string LambdaStr;
713 raw_string_ostream Output(LambdaStr);
714 toMustacheString(Data: Return, OS&: Output);
715 Parser P = Parser(LambdaStr);
716 AstPtr LambdaNode = P.parse(Partials, Lambdas, SectionLambdas, Escapes);
717 LambdaNode->render(CurrentCtx: Contexts, OS);
718}
719
720void Template::render(const json::Value &Data, llvm::raw_ostream &OS) {
721 Tree->render(CurrentCtx: Data, OS);
722}
723
724void Template::registerPartial(std::string Name, std::string Partial) {
725 Parser P = Parser(Partial);
726 AstPtr PartialTree = P.parse(Partials, Lambdas, SectionLambdas, Escapes);
727 Partials.insert(KV: std::make_pair(x&: Name, y: std::move(PartialTree)));
728}
729
730void Template::registerLambda(std::string Name, Lambda L) { Lambdas[Name] = L; }
731
732void Template::registerLambda(std::string Name, SectionLambda L) {
733 SectionLambdas[Name] = L;
734}
735
736void Template::overrideEscapeCharacters(EscapeMap E) { Escapes = std::move(E); }
737
738Template::Template(StringRef TemplateStr) {
739 Parser P = Parser(TemplateStr);
740 Tree = P.parse(Partials, Lambdas, SectionLambdas, Escapes);
741 // The default behavior is to escape html entities.
742 const EscapeMap HtmlEntities = {{'&', "&amp;"},
743 {'<', "&lt;"},
744 {'>', "&gt;"},
745 {'"', "&quot;"},
746 {'\'', "&#39;"}};
747 overrideEscapeCharacters(E: HtmlEntities);
748}
749
750Template::Template(Template &&Other) noexcept
751 : Partials(std::move(Other.Partials)), Lambdas(std::move(Other.Lambdas)),
752 SectionLambdas(std::move(Other.SectionLambdas)),
753 Escapes(std::move(Other.Escapes)), Tree(std::move(Other.Tree)) {}
754
755Template::~Template() = default;
756
757Template &Template::operator=(Template &&Other) noexcept {
758 if (this != &Other) {
759 Partials = std::move(Other.Partials);
760 Lambdas = std::move(Other.Lambdas);
761 SectionLambdas = std::move(Other.SectionLambdas);
762 Escapes = std::move(Other.Escapes);
763 Tree = std::move(Other.Tree);
764 Other.Tree = nullptr;
765 }
766 return *this;
767}
768} // namespace llvm::mustache
769