Allow custom base class as node customization point #3110

barcode · 2021-10-30T18:02:47Z

This PR adds an additional template parameter which allows to set a custom base class for nlohmann::json. This class serves as an extension point and allows to add functionality to json node. Examples for such functionality might be metadata or additional member functions (e.g. visitors) or other application specific code.
By default the parameter is set to void and an empty base class is used. In this case the library behaves as it already did.

Pull request checklist

Read the Contribution Guidelines for detailed information.

Changes are described in the pull request, or an existing issue is referenced.
The test suite compiles and runs without error.
Code coverage is 100%. Test cases can be added by editing the test suite. (should be. will update state aver coverall is done)
The source code is amalgamated; that is, after making changes to the sources in the include/nlohmann directory, run make amalgamate to create the single-header file single_include/nlohmann/json.hpp. The whole process is described here.

barcode · 2021-10-30T18:16:34Z

Just saw i used the wrong base branch and fixed it.

coveralls · 2021-10-30T19:22:44Z

Coverage remained the same at 100.0% when pulling 46597f0 on barcode:allow_custom_base_class_as_node_customization_point into 8fcdbf2 on nlohmann:develop.

nlohmann · 2021-10-30T20:55:29Z

Not sure about the cppcheck error, but there are also issues with MSVC.

nlohmann · 2021-10-31T07:49:14Z

Great! Windows seem to work now. The amalgamation check failed though. Please try again after calling make amalgamate.

barcode · 2021-10-31T13:25:21Z

For some strange reason make amalgamate did not do anything (make: Nothing to be done for 'amalgamate'.). After deleting the single include and running make amalgamate again, it also did some formatting. Not sure if that was supposed to happen.

The cppcheck test was skipped this time, so it did not fail. I guess it will fail again.
Not sure why it is complaining about, but it had the same issue on my old PR

Check code with Cppcheck
Checking /__w/json/json/single_include/nlohmann/json.hpp ...
/__w/json/json/single_include/nlohmann/json.hpp:3448:54: error: syntax error [syntaxError]
         class BinaryType = std::vector<std::uint8_t>,
                                                     ^

The ci uses cppcheck 2.7. This seems to be some version of the current main branch. If i build cppcheck main and use it, i get the same error. It looks like a false positive. I could suppress it using // cppcheck-suppress syntaxError.

nlohmann · 2021-10-31T13:29:24Z

For some strange reason make amalgamate did not do anything (make: Nothing to be done for 'amalgamate'.). After deleting the single include and running make amalgamate again, it also did some formatting. Not sure if that was supposed to happen.

Unfortunately, this can happen. You fixed it the right way. Sorry for the inconvenience.

The ci uses cppcheck 2.7. This seems to be some version of the current main branch. If i build cppcheck main and use it, i get the same error. It looks like a false positive. I could suppress it using // cppcheck-suppress syntaxError.

Yes, the CI uses the bleeding-edge version of cppcheck. If you can suppress the issue, then I guess this is the way.

barcode · 2021-11-01T08:23:15Z

~~Finally all checks went green.~~ All but the first commit were fixes for the CI and do not carry important information. I think merge+squash would be a good way to keep the commit history in a readable form.

Not sure why it displayed a green tick earlier...

nlohmann · 2021-11-01T09:33:39Z

std::make_unique is not available in C++11 - I guess that's why the CI fails.

include/nlohmann/detail/json_custom_base_class.hpp

test/src/unit-custom-base-class.cpp

include/nlohmann/detail/json_custom_base_class.hpp

test/src/unit-custom-base-class.cpp

stale · 2022-01-09T02:24:34Z

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

gregmarr · 2022-06-18T17:48:25Z

@barcode @nlohmann I think this just needs some documentation.

barcode · 2022-06-28T08:38:25Z

@nlohmann @gregmarr
I have rebased the branch on develop and added some API documentation.
Let me know, if there is anything else stopping this PR from getting merged.

docs/examples/json_base_class_t.cpp

include/nlohmann/json.hpp

include/nlohmann/json_fwd.hpp

tests/src/unit-custom-base-class.cpp

docs/mkdocs/docs/api/basic_json/json_base_class_t.md

falbrechtskirchinger · 2022-07-11T15:55:59Z

@nlohmann Please approve the workflow run.

barcode · 2022-07-12T08:54:29Z

Strange... not sure why the previous run of cppcheck accepted the code without the suppress comment. I guess it is a sporadic error. Hence i added the comment again.

falbrechtskirchinger

Looks good to me.

falbrechtskirchinger · 2022-08-27T07:23:41Z

Some notes for a follow-up PR:

Make specifying a base class easier/less verbose.
Warn users about potential conflicts with newer versions, i.e., base members should avoid generic names to avoid clashes with future member additions to basic_json.
Doxygen comments should conform to the "new" convention.
(Run reuse.)

nlohmann

Some minor comments, but otherwise looks good to me.

docs/mkdocs/docs/api/basic_json/json_base_class_t.md

include/nlohmann/detail/json_custom_base_class.hpp

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

github-actions · 2022-08-27T15:13:02Z

🔴 Amalgamation check failed! 🔴

The source code has not been amalgamated.

include/nlohmann/detail/json_custom_base_class.hpp

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

nlohmann

Looks good to me.

nlohmann · 2022-08-27T15:35:22Z

Will merge once the CI is green.

github-actions · 2022-08-27T15:55:18Z

🔴 Amalgamation check failed! 🔴

The source code has not been amalgamated.

include/nlohmann/detail/json_custom_base_class.hpp

nlohmann

Looks good to me.

nlohmann · 2022-08-28T11:59:14Z

Thanks a lot!!!

barcode · 2022-08-28T12:03:17Z

Thanks to you guys, too. I really like this library and know it is a lot of work to maintain libraries.

nlohmann · 2023-04-22T13:05:22Z

include/nlohmann/json.hpp

@@ -1200,11 +1204,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @brief move constructor
    /// @sa https://json.nlohmann.me/api/basic_json/basic_json/
    basic_json(basic_json&& other) noexcept
-        : m_type(std::move(other.m_type)),
+        : json_base_class_t(std::move(other)),


@barcode Sorry for being so late, but now I got a warning from Clang-Tidy about accessing other.m_value after moving other in the line before. Any idea how to fix this?

barcode requested a review from nlohmann as a code owner October 30, 2021 18:02

barcode mentioned this pull request Oct 30, 2021

Allow to add metadata to json nodes #3028

Closed

4 tasks

barcode force-pushed the allow_custom_base_class_as_node_customization_point branch from f3671da to 8ed9dd7 Compare October 30, 2021 18:16

barcode force-pushed the allow_custom_base_class_as_node_customization_point branch from 8ed9dd7 to 471b245 Compare October 30, 2021 19:24

nlohmann requested changes Nov 1, 2021

View reviewed changes

barcode requested a review from nlohmann November 1, 2021 17:05

nlohmann requested changes Nov 1, 2021

View reviewed changes

include/nlohmann/detail/json_custom_base_class.hpp Outdated Show resolved Hide resolved

test/src/unit-custom-base-class.cpp Outdated Show resolved Hide resolved

barcode requested a review from nlohmann November 1, 2021 20:04

nlohmann added the review needed It would be great if someone could review the proposed changes. label Nov 4, 2021

barcode mentioned this pull request Nov 28, 2021

Additional information for sax parser via next token start stop #3165

Open

7 tasks

stale bot added the state: stale the issue has not been updated in a while and will be closed automatically soon unless it is updated label Jan 9, 2022

stale bot removed the state: stale the issue has not been updated in a while and will be closed automatically soon unless it is updated label Jun 18, 2022

barcode force-pushed the allow_custom_base_class_as_node_customization_point branch from 3311d11 to e0a30ee Compare June 28, 2022 08:33

falbrechtskirchinger suggested changes Jun 28, 2022

View reviewed changes

shaischaudhry approved these changes Aug 6, 2022

View reviewed changes

nlohmann added the please rebase Please rebase your branch to origin/develop label Aug 7, 2022

barcode force-pushed the allow_custom_base_class_as_node_customization_point branch from 5e700cc to 1b983c8 Compare August 8, 2022 21:47

falbrechtskirchinger approved these changes Aug 27, 2022

View reviewed changes

nlohmann requested changes Aug 27, 2022

View reviewed changes

barcode and others added 6 commits August 27, 2022 17:11

Update docs/mkdocs/docs/api/basic_json/json_base_class_t.md

763c59d

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

Update docs/mkdocs/docs/api/basic_json/json_base_class_t.md

0ce9ded

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

Update docs/mkdocs/docs/api/basic_json/json_base_class_t.md

49ab721

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

Update docs/mkdocs/docs/api/basic_json/json_base_class_t.md

b0f5baf

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

Update docs/mkdocs/docs/api/basic_json/json_base_class_t.md

e9f5e0c

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

Update include/nlohmann/detail/json_custom_base_class.hpp

b3816f1

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

make amalgamate

7d476a0

nlohmann reviewed Aug 27, 2022

View reviewed changes

include/nlohmann/detail/json_custom_base_class.hpp Outdated Show resolved Hide resolved

Update include/nlohmann/detail/json_custom_base_class.hpp

c5ede1a

Co-authored-by: Niels Lohmann <niels.lohmann@gmail.com>

nlohmann approved these changes Aug 27, 2022

View reviewed changes

nlohmann added this to the Release 3.11.3 milestone Aug 27, 2022

make amalgamate

19423a7

nlohmann requested changes Aug 28, 2022

View reviewed changes

include/nlohmann/detail/json_custom_base_class.hpp Show resolved Hide resolved

Add include for nlohmann/detail/abi_macros.hpp

46597f0

barcode requested a review from nlohmann August 28, 2022 11:57

nlohmann approved these changes Aug 28, 2022

View reviewed changes

nlohmann merged commit bed648c into nlohmann:develop Aug 28, 2022

gregmarr mentioned this pull request Oct 17, 2022

json_fwd.hpp doesn't work #3796

Closed

2 tasks

This was referenced Dec 26, 2022

Add helper types to make it easier to create a basic_json type with modified template parameters #3898

Open

Clean up custom base class #3899

Open

nlohmann reviewed Apr 22, 2023

View reviewed changes

nlohmann mentioned this pull request Nov 28, 2023

JSON for Modern C++ 3.11.3 #4222

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Allow custom base class as node customization point #3110

Allow custom base class as node customization point #3110

barcode commented Oct 30, 2021 •

edited

Loading

barcode commented Oct 30, 2021

coveralls commented Oct 30, 2021 •

edited

Loading

nlohmann commented Oct 30, 2021

nlohmann commented Oct 31, 2021

barcode commented Oct 31, 2021

nlohmann commented Oct 31, 2021

barcode commented Nov 1, 2021 •

edited

Loading

nlohmann commented Nov 1, 2021

stale bot commented Jan 9, 2022

gregmarr commented Jun 18, 2022

barcode commented Jun 28, 2022

falbrechtskirchinger commented Jul 11, 2022

barcode commented Jul 12, 2022

falbrechtskirchinger left a comment

falbrechtskirchinger commented Aug 27, 2022 •

edited

Loading

nlohmann left a comment

github-actions bot commented Aug 27, 2022

nlohmann left a comment

nlohmann commented Aug 27, 2022

github-actions bot commented Aug 27, 2022

nlohmann left a comment

nlohmann commented Aug 28, 2022

barcode commented Aug 28, 2022

nlohmann Apr 22, 2023

Allow custom base class as node customization point #3110

Allow custom base class as node customization point #3110

Conversation

barcode commented Oct 30, 2021 • edited Loading

Pull request checklist

barcode commented Oct 30, 2021

coveralls commented Oct 30, 2021 • edited Loading

nlohmann commented Oct 30, 2021

nlohmann commented Oct 31, 2021

barcode commented Oct 31, 2021

nlohmann commented Oct 31, 2021

barcode commented Nov 1, 2021 • edited Loading

nlohmann commented Nov 1, 2021

stale bot commented Jan 9, 2022

gregmarr commented Jun 18, 2022

barcode commented Jun 28, 2022

falbrechtskirchinger commented Jul 11, 2022

barcode commented Jul 12, 2022

falbrechtskirchinger left a comment

Choose a reason for hiding this comment

falbrechtskirchinger commented Aug 27, 2022 • edited Loading

nlohmann left a comment

Choose a reason for hiding this comment

github-actions bot commented Aug 27, 2022

🔴 Amalgamation check failed! 🔴

nlohmann left a comment

Choose a reason for hiding this comment

nlohmann commented Aug 27, 2022

github-actions bot commented Aug 27, 2022

🔴 Amalgamation check failed! 🔴

nlohmann left a comment

Choose a reason for hiding this comment

nlohmann commented Aug 28, 2022

barcode commented Aug 28, 2022

nlohmann Apr 22, 2023

Choose a reason for hiding this comment

barcode commented Oct 30, 2021 •

edited

Loading

coveralls commented Oct 30, 2021 •

edited

Loading

barcode commented Nov 1, 2021 •

edited

Loading

falbrechtskirchinger commented Aug 27, 2022 •

edited

Loading