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* Review and extend the documentation, and check it in CI A review of all documentation pages found factual errors, dead links, missing cross-references, and gaps in examples. This fixes them and adds checks so the same problems are caught automatically. Fixes: - wrong signatures and version histories (operator!= C++20 member, binary() subtype type, get<PointerType>(), JSON_NO_THREAD_LOCAL, ...) - stale descriptions (number parsing since #5283, UBJSON table, SAX example that no longer compiled, tsl::ordered_map advice) - dead internal and external links; repology.org badges (the domain is suspended) replaced by badges that query the registries directly - deprecation notes link the migration guide; the guide itself fixed Additions: - "See also" sections, cross-references, 25 runnable examples, 12 Mermaid diagrams, new API pages for json_pointer::operator<=> and byte_container_with_subtype::operator==/!= - landing page, guides for untrusted input and performance - "unreleased" badge after versions newer than the latest release Checks: - strict documentation build (broken links/anchors fail it); CI and the publish workflow fetch the full history the build needs - weekly external link check, Mermaid syntax check in CI - check_structure.py: example titles, heading levels, alt texts, header links, docset index coverage; its unused-example check works again - all examples produce the same output on every platform Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Keep the customer links that could not be fixed A dead link on the customers page is still the evidence of where the use of the library was documented. Keep the original URLs of the entries without a working replacement (Marne, Cisco Webex Desk Camera, Philips Hue, CyberArk) and exclude exactly these URLs from the link check. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Correct the duplicate-key recipe's claim about SAX positions The SAX interface's key() receives no position either; only parse_error() does. Also note that the recipe does not report the path to the repeated key (see discussion #5085). Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Say the library is available as a single header and mention json_fwd.hpp Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Correct documentation errors found while hunting for bugs - patch/patch_inplace: list the JSON pointer errors parse_error.106-109 and out_of_range.402/404, and quote the actual parse_error.105 message. - unflatten: list parse_error.106/107/108 and out_of_range.404. - to_bson: list out_of_range.415 (binary subtype above 255) and note that 412 and 415 are new in 3.13.0. - to_string: state that string_t must be convertible to std::string, also in the StringType requirements table. - JSON Lines: a `while (input >> j)` loop also throws after the last value for concatenated JSON values; show a loop that works for both. - BON8: a string gets 0xFF only if nothing follows it in the message; a string at the end of an array or object is ended by 0xFE. - custom_string_type.hpp: add operator+=(char), which the "Always required" list asks for (json_pointer::to_string, flatten, unflatten, and diff did not compile), and an ADL int_to_string for diff and items. Signed-off-by: Niels Lohmann <mail@nlohmann.me> * Cache the release headers with functools.lru_cache Codacy (Pylint) flagged the mutable default argument that header() used as its cache. functools.lru_cache keeps the same memoization without it. The script's output is unchanged. Signed-off-by: Niels Lohmann <mail@nlohmann.me> --------- Signed-off-by: Niels Lohmann <mail@nlohmann.me>
66 lines
2.8 KiB
Markdown
66 lines
2.8 KiB
Markdown
# <small>nlohmann::</small>json_sax
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```cpp
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template<typename BasicJsonType>
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struct json_sax;
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```
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This class describes the SAX interface used by [sax_parse](../basic_json/sax_parse.md). Each function is called in
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different situations while the input is parsed. The boolean return value informs the parser whether to continue
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processing the input.
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For instance, parsing the JSON text `{"a": [1, true]}` triggers the following callbacks, in order:
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```mermaid
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sequenceDiagram
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participant P as Parser
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participant H as SAX handler
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P->>H: start_object(elements)
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P->>H: key("a")
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P->>H: start_array(elements)
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P->>H: number_unsigned(1)
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P->>H: boolean(true)
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P->>H: end_array()
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P->>H: end_object()
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```
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Note `elements` is passed as `#!cpp std::numeric_limits<std::size_t>::max()` (i.e., "unknown") for JSON text input;
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only binary formats such as CBOR or MessagePack may report the actual number of elements in `start_object`/
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`start_array`. Also note that `1` is reported via `number_unsigned` rather than `number_integer` because it has no
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leading `-` sign.
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## Template parameters
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`BasicJsonType`
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: a specialization of [`basic_json`](../basic_json/index.md)
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## Member types
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- [**number_integer_t**](../basic_json/number_integer_t.md) - `BasicJsonType`'s type for numbers (integer)
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- [**number_unsigned_t**](../basic_json/number_unsigned_t.md) - `BasicJsonType`'s type for numbers (unsigned)
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- [**number_float_t**](../basic_json/number_float_t.md) - `BasicJsonType`'s type for numbers (floating-point)
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- [**string_t**](../basic_json/string_t.md) - `BasicJsonType`'s type for strings
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- [**binary_t**](../basic_json/binary_t.md) - `BasicJsonType`'s type for binary arrays
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## Member functions
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- [**binary**](binary.md) (_virtual_) - a binary value was read
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- [**boolean**](boolean.md) (_virtual_) - a boolean value was read
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- [**end_array**](end_array.md) (_virtual_) - the end of an array was read
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- [**end_object**](end_object.md) (_virtual_) - the end of an object was read
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- [**key**](key.md) (_virtual_) - an object key was read
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- [**null**](null.md) (_virtual_) - a null value was read
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- [**number_float**](number_float.md) (_virtual_) - a floating-point number was read
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- [**number_integer**](number_integer.md) (_virtual_) - an integer number was read
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- [**number_unsigned**](number_unsigned.md) (_virtual_) - an unsigned integer number was read
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- [**parse_error**](parse_error.md) (_virtual_) - a parse error occurred
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- [**start_array**](start_array.md) (_virtual_) - the beginning of an array was read
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- [**start_object**](start_object.md) (_virtual_) - the beginning of an object was read
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- [**string**](string.md) (_virtual_) - a string value was read
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## Version history
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- Added in version 3.2.0.
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- Support for binary values (`binary_t`, `binary`) added in version 3.8.0.
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