Method _consumeAttr

packages/compiler/src/ml_parser/parser.ts:641–704

(attrName: AttributeNameToken)

  }

  private _consumeAttr(attrName: AttributeNameToken): html.Attribute {
    const fullName = mergeNsAndName(attrName.parts[0], attrName.parts[1]);
    let attrEnd = attrName.sourceSpan.end;

    // Consume any quote
    if (this._peek.type === TokenType.ATTR_QUOTE) {
      this._advance();
    }

    // Consume the attribute value
    let value = '';
    const valueTokens: InterpolatedAttributeToken[] = [];
    let valueStartSpan: ParseSourceSpan | undefined = undefined;
    let valueEnd: ParseLocation | undefined = undefined;
    // NOTE: We need to use a new variable `nextTokenType` here to hide the actual type of
    // `_peek.type` from TS. Otherwise TS will narrow the type of `_peek.type` preventing it from
    // being able to consider `ATTR_VALUE_INTERPOLATION` as an option. This is because TS is not
    // able to see that `_advance()` will actually mutate `_peek`.
    const nextTokenType = this._peek.type as TokenType;
    if (nextTokenType === TokenType.ATTR_VALUE_TEXT) {
      valueStartSpan = this._peek.sourceSpan;
      valueEnd = this._peek.sourceSpan.end;
      while (
        this._peek.type === TokenType.ATTR_VALUE_TEXT ||
        this._peek.type === TokenType.ATTR_VALUE_INTERPOLATION ||
        this._peek.type === TokenType.ENCODED_ENTITY
      ) {
        const valueToken = this._advance<InterpolatedAttributeToken>();
        valueTokens.push(valueToken);
        if (valueToken.type === TokenType.ATTR_VALUE_INTERPOLATION) {
          // For backward compatibility we decode HTML entities that appear in interpolation
          // expressions. This is arguably a bug, but it could be a considerable breaking change to
          // fix it. It should be addressed in a larger project to refactor the entire parser/lexer
          // chain after View Engine has been removed.
          value += valueToken.parts.join('').replace(/&([^;]+);/g, decodeEntity);
        } else if (valueToken.type === TokenType.ENCODED_ENTITY) {
          value += valueToken.parts[0];
        } else {
          value += valueToken.parts.join('');
        }
        valueEnd = attrEnd = valueToken.sourceSpan.end;
      }
    }

    // Consume any quote
    if (this._peek.type === TokenType.ATTR_QUOTE) {
      const quoteToken = this._advance<AttributeQuoteToken>();
      attrEnd = quoteToken.sourceSpan.end;
    }

    const valueSpan =
      valueStartSpan &&
      valueEnd &&
      new ParseSourceSpan(valueStartSpan.start, valueEnd, valueStartSpan.fullStart);
    return new html.Attribute(
      fullName,
      value,
      new ParseSourceSpan(attrName.sourceSpan.start, attrEnd, attrName.sourceSpan.fullStart),