Schema CLI

The mondrian-schema script wraps the mondrian.schema.yaml.SchemaCli Java tool so you do not have to remember a long mvn exec:java incantation. Use it to convert existing XML schemas to YAML, convert YAML back to XML for deployment, or validate a schema file before saving it to Saiku.

Tip

The first run builds a classpath cache at target/dependency/classpath.txt. Subsequent runs are fast — typically around 130 ms. The cache is rebuilt automatically whenever pom.xml is newer than the cache file.

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Commands

to-yaml — convert XML to YAML

./scripts/mondrian-schema to-yaml <input.xml> [-o output.yaml]

Reads a Mondrian-4 XML schema and writes the equivalent YAML representation. If -o is omitted, the YAML is written to stdout.

Example — convert FoodMart:

./scripts/mondrian-schema to-yaml demo/FoodMart.mondrian.xml -o demo/FoodMart.yaml

Example — preview without saving:

./scripts/mondrian-schema to-yaml demo/FoodMart.mondrian.xml | head -40

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to-xml — convert YAML to XML

./scripts/mondrian-schema to-xml <input.yaml> [-o output.xml]

Reads a Mondrian-4 YAML schema and writes the equivalent XML. If -o is omitted, the XML is written to stdout. This is the same conversion the Saiku engine runs automatically at runtime — running it manually is useful for inspecting the output before deploying or for migrating back to an XML-native toolchain.

Example — convert back to XML:

./scripts/mondrian-schema to-xml demo/FoodMart.yaml -o FoodMart-generated.xml

Example — pipe to a diff to verify round-trip fidelity:

./scripts/mondrian-schema to-xml demo/FoodMart.yaml | diff demo/FoodMart.mondrian.xml -

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lint — validate a schema file

./scripts/mondrian-schema lint <input.{yaml,xml}>

Parses and validates a schema file — either YAML or XML. Errors and warnings are written to stderr. On success, the command exits silently with code 0.

Example — lint a YAML schema:

./scripts/mondrian-schema lint demo/FoodMart.yaml

Example — lint an XML schema:

./scripts/mondrian-schema lint demo/FoodMart.mondrian.xml

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Exit codes

Code	Meaning
0	Success — no errors
1	Bad arguments or missing input file
2	Parse or validation failure — diagnostic written to stderr

These codes are suitable for use in CI pipelines and pre-save hooks.

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Typical workflows

Migrate XML to YAML

1. Convert your existing XML schema to YAML:

   ./scripts/mondrian-schema to-yaml my-schema.xml -o my-schema.yaml

2. Lint the YAML to confirm it is valid:

   ./scripts/mondrian-schema lint my-schema.yaml

3. Review and annotate my-schema.yaml with comments, then upload it to Saiku via the Schemas page.

Validate before saving

1. Author or edit your YAML schema locally.

2. Run lint to catch errors before uploading:

   ./scripts/mondrian-schema lint my-schema.yaml

   A 0 exit code means the schema parsed cleanly. Any errors appear on stderr with a line reference.

3. If you need to supply XML to an external tool (e.g. a legacy reporting client), convert on demand:

   ./scripts/mondrian-schema to-xml my-schema.yaml -o my-schema.xml

CI pipeline

Add a lint step to your CI pipeline to catch schema errors before they reach production:

# In .github/workflows/ci.yml or equivalent
- name: Lint Mondrian schemas
  run: |
    for f in schemas/*.yaml; do
      ./scripts/mondrian-schema lint "$f"
    done

The script exits with code 2 on any parse or validation failure, which will fail the CI job automatically.

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Prerequisites

The script requires:

• Java — available on $PATH (same JVM version used to build the project)
• Maven — for the one-time classpath build; not needed after the cache exists
• The mondrian-saiku repository checked out locally (the script is part of that repo, not a standalone binary)

Note

If you see error: expected pom.xml in ..., the script cannot find the repository root. Run it from within the mondrian-saiku repository directory, or use an absolute path: ./scripts/mondrian-schema from the repo root always works.

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Related

• YAML schemas — the full YAML element reference.
• Schemas — upload and manage schemas in the Saiku dashboard.
• Schema designer — generate a schema from a natural-language description.