json-schema-for-humans 0.35.3

Generate static HTML documentation from JSON schemas

JSON Schema for Humans

Quickly generate a beautiful static HTML or Markdown page documenting a JSON schema

Documentation (with visual examples)

Features

• Support for JSON Schema Draft-07
• Since the result is static, it is easier to host and faster to load
• HTML and Markdown output support
• Different templates to choose from. More details: HTML version - Markdown version
• Anchor links, allow to send a user to a specific section of the documentation
• Support for references (even circular!)

Installation

pip install json-schema-for-humans

Usage

Options for generation of the doc are documented using the library itself: HTML version - Markdown version

They can be supplied in various ways:

• Using a JSON or YAML configuration file with the CLI option --config-file
• Using the CLI option --config
• Using the ConfigurationOption object from code

More details are available in the appropriate sections below.

From CLI

generate-schema-doc [OPTIONS] SCHEMA_FILES_OR_DIR [RESULT_FILE_OR_DIR]

SCHEMA_FILES_OR_DIR can be:

• a path to a single schema file;
• a path to a directory, in this case all files with extensions json, yaml, or yml will be used; or
• a comma-separated list of the above

All schemas provided must be a valid JSON Schema (in JSON or YAML format)

Examples:

• my_schema.json
• my_folder
• my_folder/my_schema.yaml,another_schema.json

The default value for RESULT_FILE_OR_DIR depends on the context:

• the current working directory if more than one schema as been provided as input
• schema_doc.html if rendering a single schema as HTML
• schema_doc.md if rendering a single schema as Markdown

In a case where more than one schema is provided as input, RESULT_FILE_OR_DIR must be a directory. The output documentation will have the same name as the input schema, but with a different extension (html or md).

CLI options

--config

Supply generation config parameters. The parameters are documented in the JSON schema config_schema.json at the root of the repo or see the generated doc: HTML version - Markdown version.

Each parameter is in the format --config parameter_name=parameter_value. Example: --config expand_buttons=true. The parameter value must be valid JSON.

For flags, you can also omit the value for true or prefix the parameter name with no_ for false. Example: --config expand_buttons or --config no_expand_buttons.

--config-file

Path to a JSON or YAML configuration file respecting the schema config_schema.json.

Example: --config-file jsfh-conf.yaml where jsfh-conf.yaml is in the current directory and contains the following:

description_is_markdown: false
expand_buttons: true
copy_js: false

From code

To render schema documentation from code, the method to call is generate with the following signature:

def generate(
    schema_file_or_dir: List[Union[str, Path, TextIO]],
    result_file_or_dir: Optional[Union[str, Path, TextIO]],
    config: GenerationConfiguration = None,
    loaded_schemas: Optional[Dict[str, Any]] = None,
) -> Tuple[List[Path], Dict[str, str]]:
    ...

Where:

• schema_file_or_dir is a list of schema file paths or open file pointer
• result_file_or_dir is the output path. If there is more than one schema to render, this should be a directory. The same rules as the CLI call documented above applies.
• config is an instance of the GenerationConfiguration object, see The GenerationConfiguration object below
• loaded_schemas is a dictionary of already loaded schema files. See Pre-load schemas below. This is an advanced option.

The output is a tuple where:

• the first element is a list of the paths to documentation files written. This part is only populated when there is an output path and the files are written to disk
• the second is a dictionary of the rendered schemas in the format input_schema_file_name -> rendered_documentation. This is only populated when there is no output path

Notes:

• When providing a file pointer, it must be open in read mode for the input schema and in write mode for the output documentation files
• If there is an output path and it is not disabled in the config, CSS and JS files are copied to the current working directory with names "schema_doc.css" and "schema_doc.min.js" respectively. These are needed to render the documentation HTML page in a browser

Example:

In this example, my_schema.json will be rendered to my_schema.html in the output directory

from json_schema_for_humans.generate import generate

from pathlib import Path

output_dir = Path.cwd() / "output_dir"
output_dir.mkdir(parents=True, exist_ok=True)

generated = generate(["my_schema.json"], output_dir)

# Returns ([Path('[cwd]/output_dir/my_schema.html')], {})

Shortcut methods

These methods are kept for retrocompatibility and because they are easier to call for simple use cases.

Method Name	Schema input	Output	CSS and JS copied?
generate_from_schema	schema_file as str, Path (from pathlib) or a file object	Rendered HTML as a str	No
generate_from_filename	schema_file_name as a str or Path	Rendered HTML written to the file at path result_file_name	Yes
generate_from_file_object	schema_file as an open file object (read mode)	Rendered HTML written to the file at result_file, which must be an open file object (in write mode)	Yes

Notes:

• When using file objects, it is assumed that files are opened with encoding "utf-8"
• CSS and JS files are copied to the current working directory with names "schema_doc.css" and "schema_doc.min.js" respectively
• Other parameters of these methods are analogous to the CLI parameters documented above.

The GenerationConfiguration object

To reduce the number of parameters to pass from function to function in the code, there is a GenerationConfiguration object that should be used for providing options.

Example:

from json_schema_for_humans.generate import generate_from_filename
from json_schema_for_humans.generation_configuration import GenerationConfiguration

config = GenerationConfiguration(copy_css=False, expand_buttons=True)

generate_from_filename("my_schema.json", "schema_doc.html", config=config)

# Your doc is now in a file named "schema_doc.html". Next to it, "schema_doc.min.js" was copied, but not "schema_doc.css"
# Your doc will contain a "Expand all" and a "Collapse all" button at the top

Pre-load schemas

generate_from_schema has a loaded_schemas parameter that can be used to pre-load schemas. This must be a dict with the key being the real path of the schema file and the value being the result of loading the schema (with json.load or yaml.safe_load, for example).

This should not be necessary in normal scenarios.

What's supported

See the excellent Understanding JSON Schema to understand what are those checks

The following are supported:

• Types
• Regular expressions
• String length
• Numeric types multiples and range
• Constant and enumerated values
• Required properties
• Pattern properties
• Default values
• Array minItems, maxItems, uniqueItems, items (schema that must apply to all of the array items), and contains
• Combining schema with oneOf, allOf, anyOf, and not
• Examples
• Conditional subschemas

These are not supported at the moment (PRs welcome!):

• String format
• Property names and size
• Array items at specific index (for example, first item must be a string and second must be an integer)
• Property dependencies
• Media

References

References are supported:

• To another part of the schema, e.g. { $ref: "#/definitions/something" }
• To a local file, {"$ref": "references.json"}, {"$ref": "references.json#/definitions/something"}
• To a URL, {"$ref": "http://example.com/schema.json"}, {"$ref": "http://example.com/schema.json#/definitions/something"}

You can have a description next to a $ref, it will be displayed in priority to the description from the referenced element.

If you have several attributes using the same definition, the definition will only be rendered once. All other usages of the same definition will be replaced with an anchor link to the first render of the definition. This can be turned off using --config no_link_to_reused_ref. See With references in the examples.

Templates

Templates control the style of the generated documentation.

js

This is the default template. It uses Bootstrap along with minimal Javascript to allow for the following:

• Properties are in expandable dynamic sections. You can include a button to expand or collapse all. (See doc: HTML version - Markdown version)
• Conditional subschemas (anyOf, oneOf, allOf) are in tabbed sections
• Anchor links will scroll to, expand, and animate the target section
• Long descriptions are collapsed by default

When using this template, you need to include the Javascript file (schema_doc.min.js) that is automatically copied next to the output HTML file (schema_doc.html by default).

flat

Note: This template is a work in progress

It is sometimes not possible or desirable to include custom Javascript in documentation. This template addresses this issue by removing interactive elements in favor of simpler HTML.

At the moment, this means the whole documentation is generated without any collapsible sections, which may make it hard to understand the schema structure. Contributions are welcomed to improve it!

MD (Markdown)

Note: This template is a work in progress

This template allows users to publish the generated documentation without hosting an HTTP server.

On GitHub, this format is rendered directly when browsing code.

A table of content is provided at the beginning of the file for easy navigation.

You can display some important information as badge using an option. See doc: HTML version - Markdown version

Contributions are welcomed to improve it!

Contributing

See CONTRIBUTING.md