Validate schema program (#41)

* Adds a schema validaion program

* Updates setup.cfg for schema validation install

* Fixes typo

Improves documentation for validate_schema.py

* Adds better error handling for invalid yamls to be validated

Updates setup to include schema folder

fms_yaml_tools/schema/validate_schema.py

@@ -0,0 +1,65 @@
+#!/usr/bin/python3
+import click
+import yaml
+import json
+#import jsonschema
+from jsonschema import validate, ValidationError, SchemaError, Draft7Validator
+""" This program is used for validating a file against a schema.  The
+schema is written in JSON format, so the file it is validating must be
+in a JSON-like format.  That means that this can be used to validate JSON
+or YAML files, but the YAML files must adhere to some of the JSON rules.
+The arguments of this program are the path to the file to be validated
+which is ypath and the path to the schema file which is spath.  
+This program uses click for accepting command like arguments and options
+and jsonschema to run the validation.
+"""
+@click.command()
+# Debug is used to print more information to the screen.
+@click.option('--debug/--no-debug', type=click.BOOL, show_default=True, default=False,
+   help="Print steps in the validation")
+# This option controls whether or not the program prints a success message
+@click.option('--success/--no-show-success', type=click.BOOL, show_default=True, default=False,
+   help="Print success message")
+@click.argument("ypath") # This is the path to the file to be validated
+@click.argument("spath") # This is the path to the schema to use for validation
+
+def valyaml (ypath,spath,debug,success): #main program
+  """ Validates a file (YAML or JSON) based on a schema. \n
+      YPATH - Path to the YAML file to be validated against the schema \n
+      SPATH - Path to the schema file to use for validation \n
+
+  """
+# The debug messages are basically comments showing what the code is doing
+  if debug:
+    print ("Open "+ypath)
+  with open(ypath, 'r') as file:
+    if debug:
+      print ("Load "+ypath)
+    y = yaml.safe_load(file)
+  if debug:
+    print ("Open "+spath)
+  with open(spath, 'r') as f:
+    if debug:
+      print ("Read "+spath)
+    s = f.read()
+  if debug:
+    print ("Load "+spath)
+  schema = json.loads(s)
+  if debug:
+    print ("Validate "+ypath+" against "+spath)
+  try:
+    v = validate(instance=y, schema=schema)
+  except ValidationError as e:
+    print("The following errors have occurred:\n")
+    vr = Draft7Validator(schema)
+    errors = vr.iter_errors(y)
+    i = 1
+    for err in errors:
+      print("("+str(i)+") "+err.message+"---"+str(err.path))
+      i=i+1
+    return -1
+  if success or debug:
+    print (ypath+" was successfully validated against the schema "+spath)
+
+if __name__ == '__main__':
+  valyaml(prog_name="valyaml")

setup.cfg

@@ -23,14 +23,17 @@ project_urls =
 install_requires =
     pyyaml
     click
+    jsonschema
 packages =
+    fms_yaml_tools/schema
     fms_yaml_tools/data_table
     fms_yaml_tools/diag_table
     fms_yaml_tools/field_table
     fms_yaml_tools
 
 [options.entry_points]
 console_scripts =
+    validate-schema = fms_yaml_tools.schema.validate_schema:valyaml
     data-table-to-yaml = fms_yaml_tools.data_table.data_table_to_yaml:main
     is-valid-data-table-yaml = fms_yaml_tools.data_table.is_valid_data_table_yaml:main
     combine-data-table-yamls = fms_yaml_tools.data_table.combine_data_table_yamls:main