A library to validate the syntax of CityJSON objects (CityJSON + CityJSONFeatures).
It validates against the CityJSON schemas and additional functions have been implemented (because these can't be expressed with JSON Schema).
The following is error checks are performed:
- JSON syntax: is the file a valid JSON file?
- CityJSON schemas: validation against the schemas (CityJSON v1.0 or v1.1)
- Extension schemas: validate against the extra schemas if there's an Extension in the input file
- parents_children_consistency: if a City Object references another in its
children
, this ensures that the child exists. And that the child has the parent in itsparents
- wrong_vertex_index: checks if all vertex indices exist in the list of vertices
- semantics_array: checks if the arrays for the semantics in the geometries have the same shape as that of the geometry and if the values are consistent
It also verifies the following, these are not errors since the file is still considered valid and usable, but they can make the file larger and some parsers might not understand all the properties:
- extra_root_properties: if CityJSON has extra root properties, these should be documented in an Extension. If not this warning is returned
- duplicate_vertices: duplicated vertices in
vertices
are allowed, but they take up spaces and decreases the topological relationships explicitly in the file. If there are any, cjio has the operatorclean
to fix this automatically. - unused_vertices: vertices that are not referenced in the file, they take extra space. If there are any, cjio has the operator
clean
to fix this automatically.
cjval
is a library and has 3 different binaries:
cjval
to validate a CityJSON file (it downloads automatically Extensions)cjfval
to validate a stream of CityJSONFeature (from stdin)cjvalext
to validate a CityJSON Extension file
- install the Rust compiler
cargo install cjval --features build-binary
- install the Rust compiler
git clone https://github.com/cityjson/cjval.git
cargo build --release --features build-binary
(this will ensure the binaries are compiled too)./target/release/cjval myfile.json
The code is use at https://validator.cityjson.org, that is it is compiled as WebAssembly (WASM code here).
The CityJSON schemas are built-in the binary, so it suffices to:
$ cjval myfile.city.json
(the latest schemas of a X.Y version will be automatically fetched)
If the file contains one or more Extensions, eg:
{
"type": "CityJSON",
"version": "1.1",
"extensions":
{
"Generic":
{
"url": "https://www.cityjson.org/extensions/generic.ext.json",
"version": "1.0"
}
}
...
then cjval
will fetch/download automatically the schema(s).
If instead you want to use your own local Extension schema(s), you can pass them as argument with the argument -e
and this will overwrite the automatic download:
$ cjval myfile.city.json -e ./myextensions/generic.ext.json
To validate a stream of CityJSONFeature (this uses cjio to generate a stream from a CityJSON file):
$ cjio --suppress_msg myfile.city.json export jsonl stdout | cjfval --verbose
and you'll get a short report per line (which is one CityJSON
or CityJSONFeature
).
- @hugoledoux
- @josfeenstra (started the project for a course at TU Delft, original code)