Import upstream version 1.7.0

1 files changed, 978 insertions, 0 deletions

diff --git a/pykwalify/core.py b/pykwalify/core.py
new file mode 100644
index 0000000..e94ac80
--- /dev/null
+++ b/pykwalify/core.py
@@ -0,0 +1,978 @@
+# -*- coding: utf-8 -*-
+
+""" pyKwalify - core.py """
+
+# python std lib
+import datetime
+import imp
+import json
+import logging
+import os
+import re
+import sys
+import traceback
+import time
+
+# pyKwalify imports
+import pykwalify
+from pykwalify.compat import unicode, nativestr, basestring
+from pykwalify.errors import CoreError, SchemaError, NotMappingError, NotSequenceError
+from pykwalify.rule import Rule
+from pykwalify.types import is_scalar, is_string, tt
+
+# 3rd party imports
+from pykwalify.compat import yaml
+from dateutil.parser import parse
+
+log = logging.getLogger(__name__)
+
+
+class Core(object):
+    """ Core class of pyKwalify """
+
+    def __init__(self, source_file=None, schema_files=None, source_data=None, schema_data=None, extensions=None, strict_rule_validation=False,
+                 fix_ruby_style_regex=False, allow_assertions=False,):
+        """
+        :param extensions:
+            List of paths to python files that should be imported and available via 'func' keywork.
+            This list of extensions can be set manually or they should be provided by the `--extension`
+            flag from the cli. This list should not contain files specified by the `extensions` list keyword
+            that can be defined at the top level of the schema.
+        """
+        if schema_files is None:
+            schema_files = []
+        if extensions is None:
+            extensions = []
+
+        log.debug(u"source_file: %s", source_file)
+        log.debug(u"schema_file: %s", schema_files)
+        log.debug(u"source_data: %s", source_data)
+        log.debug(u"schema_data: %s", schema_data)
+        log.debug(u"extension files: %s", extensions)
+
+        self.source = None
+        self.schema = None
+        self.validation_errors = None
+        self.validation_errors_exceptions = None
+        self.root_rule = None
+        self.extensions = extensions
+        self.errors = []
+        self.strict_rule_validation = strict_rule_validation
+        self.fix_ruby_style_regex = fix_ruby_style_regex
+        self.allow_assertions = allow_assertions
+
+        if source_file is not None:
+            if not os.path.exists(source_file):
+                raise CoreError(u"Provided source_file do not exists on disk: {0}".format(source_file))
+
+            with open(source_file, "r") as stream:
+                if source_file.endswith(".json"):
+                    self.source = json.load(stream)
+                elif source_file.endswith(".yaml") or source_file.endswith('.yml'):
+                    self.source = yaml.safe_load(stream)
+                else:
+                    raise CoreError(u"Unable to load source_file. Unknown file format of specified file path: {0}".format(source_file))
+
+        if not isinstance(schema_files, list):
+            raise CoreError(u"schema_files must be of list type")
+
+        # Merge all schema files into one single file for easy parsing
+        if len(schema_files) > 0:
+            schema_data = {}
+            for f in schema_files:
+                if not os.path.exists(f):
+                    raise CoreError(u"Provided source_file do not exists on disk : {0}".format(f))
+
+                with open(f, "r") as stream:
+                    if f.endswith(".json"):
+                        data = json.load(stream)
+                    elif f.endswith(".yaml") or f.endswith(".yml"):
+                        data = yaml.safe_load(stream)
+                        if not data:
+                            raise CoreError(u"No data loaded from file : {0}".format(f))
+                    else:
+                        raise CoreError(u"Unable to load file : {0} : Unknown file format. Supported file endings is [.json, .yaml, .yml]")
+
+                    for key in data.keys():
+                        if key in schema_data.keys():
+                            raise CoreError(u"Parsed key : {0} : two times in schema files...".format(key))
+
+                    schema_data = dict(schema_data, **data)
+
+            self.schema = schema_data
+
+        # Nothing was loaded so try the source_data variable
+        if self.source is None:
+            log.debug(u"No source file loaded, trying source data variable")
+            self.source = source_data
+        if self.schema is None:
+            log.debug(u"No schema file loaded, trying schema data variable")
+            self.schema = schema_data
+
+        # Test if anything was loaded
+        if self.source is None:
+            raise CoreError(u"No source file/data was loaded")
+        if self.schema is None:
+            raise CoreError(u"No schema file/data was loaded")
+
+        # Merge any extensions defined in the schema with the provided list of extensions from the cli
+        for f in self.schema.get('extensions', []):
+            self.extensions.append(f)
+
+        if not isinstance(self.extensions, list) and all(isinstance(e, str) for e in self.extensions):
+            raise CoreError(u"Specified extensions must be a list of file paths")
+
+        self._load_extensions()
+
+        if self.strict_rule_validation:
+            log.info("Using strict rule keywords validation...")
+
+    def _load_extensions(self):
+        """
+        Load all extension files into the namespace pykwalify.ext
+        """
+        log.debug(u"loading all extensions : %s", self.extensions)
+
+        self.loaded_extensions = []
+
+        for f in self.extensions:
+            if not os.path.isabs(f):
+                f = os.path.abspath(f)
+
+            if not os.path.exists(f):
+                raise CoreError(u"Extension file: {0} not found on disk".format(f))
+
+            self.loaded_extensions.append(imp.load_source("", f))
+
+        log.debug(self.loaded_extensions)
+        log.debug([dir(m) for m in self.loaded_extensions])
+
+    def validate(self, raise_exception=True):
+        """
+        """
+        log.debug(u"starting core")
+
+        self._start_validate(self.source)
+        self.validation_errors = [unicode(error) for error in self.errors]
+        self.validation_errors_exceptions = self.errors
+
+        if self.errors is None or len(self.errors) == 0:
+            log.info(u"validation.valid")
+        else:
+            log.error(u"validation.invalid")
+            log.error(u" --- All found errors ---")
+            log.error(self.validation_errors)
+            if raise_exception:
+                raise SchemaError(u"Schema validation failed:\n - {error_msg}.".format(
+                    error_msg=u'.\n - '.join(self.validation_errors)))
+            else:
+                log.error(u"Errors found but will not raise exception...")
+
+        # Return validated data
+        return self.source
+
+    def _start_validate(self, value=None):
+        """
+        """
+        path = ""
+        self.errors = []
+        done = []
+
+        s = {}
+
+        # Look for schema; tags so they can be parsed before the root rule is parsed
+        for k, v in self.schema.items():
+            if k.startswith("schema;"):
+                log.debug(u"Found partial schema; : %s", v)
+                r = Rule(schema=v)
+                log.debug(u" Partial schema : %s", r)
+                pykwalify.partial_schemas[k.split(";", 1)[1]] = r
+            else:
+                # readd all items that is not schema; so they can be parsed
+                s[k] = v
+
+        self.schema = s
+
+        log.debug(u"Building root rule object")
+        root_rule = Rule(schema=self.schema)
+        self.root_rule = root_rule
+        log.debug(u"Done building root rule")
+        log.debug(u"Root rule: %s", self.root_rule)
+
+        self._validate(value, root_rule, path, done)
+
+    def _validate(self, value, rule, path, done):
+        """
+        """
+        log.debug(u"Core validate")
+        log.debug(u" Root validate : Rule: %s", rule)
+        log.debug(u" Root validate : Rule_type: %s", rule.type)
+        log.debug(u" Root validate : Seq: %s", rule.sequence)
+        log.debug(u" Root validate : Map: %s", rule.mapping)
+        log.debug(u" Root validate : Done: %s", done)
+
+        if rule.required and value is None and not rule.type == 'none':
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                msg=u"required.novalue : '{path}'",
+                path=path,
+                value=value.encode('unicode_escape') if value else value,
+            ))
+            return
+
+        if not rule.nullable and value is None and not rule.type == 'none':
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                msg=u"nullable.novalue : '{path}'",
+                path=path,
+                value=value.encode('unicode_escape') if value else value,
+            ))
+            return
+
+        log.debug(u" ? ValidateRule: %s", rule)
+        if rule.include_name is not None:
+            self._validate_include(value, rule, path, done=None)
+        elif rule.sequence is not None:
+            self._validate_sequence(value, rule, path, done=None)
+        elif rule.mapping is not None or rule.allowempty_map:
+            self._validate_mapping(value, rule, path, done=None)
+        else:
+            self._validate_scalar(value, rule, path, done=None)
+
+    def _handle_func(self, value, rule, path, done=None):
+        """
+        Helper function that should check if func is specified for this rule and
+        then handle it for all cases in a generic way.
+        """
+        func = rule.func
+
+        # func keyword is not defined so nothing to do
+        if not func:
+            return
+
+        found_method = False
+
+        for extension in self.loaded_extensions:
+            method = getattr(extension, func, None)
+            if method:
+                found_method = True
+
+                # No exception will should be caught. If one is raised it should bubble up all the way.
+                ret = method(value, rule, path)
+
+                # If False or None or some other object that is interpreted as False
+                if not ret:
+                    raise CoreError(u"Error when running extension function : {0}".format(func))
+
+                # Only run the first matched function. Sinc loading order is determined
+                # it should be easy to determine which file is used before others
+                break
+
+        if not found_method:
+            raise CoreError(u"Did not find method '{0}' in any loaded extension file".format(func))
+
+    def _validate_include(self, value, rule, path, done=None):
+        """
+        """
+        # TODO: It is difficult to get a good test case to trigger this if case
+        if rule.include_name is None:
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                msg=u'Include name not valid',
+                path=path,
+                value=value.encode('unicode_escape')))
+            return
+        include_name = rule.include_name
+        partial_schema_rule = pykwalify.partial_schemas.get(include_name)
+        if not partial_schema_rule:
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                msg=u"Cannot find partial schema with name '{include_name}'. Existing partial schemas: '{existing_schemas}'. Path: '{path}'",
+                path=path,
+                value=value,
+                include_name=include_name,
+                existing_schemas=", ".join(sorted(pykwalify.partial_schemas.keys()))))
+            return
+
+        self._validate(value, partial_schema_rule, path, done)
+
+    def _validate_sequence(self, value, rule, path, done=None):
+        """
+        """
+        log.debug(u"Core Validate sequence")
+        log.debug(u" Sequence : Data: %s", value)
+        log.debug(u" Sequence : Rule: %s", rule)
+        log.debug(u" Sequence : RuleType: %s", rule.type)
+        log.debug(u" Sequence : Path: %s", path)
+        log.debug(u" Sequence : Seq: %s", rule.sequence)
+        log.debug(u" Sequence : Map: %s", rule.mapping)
+
+        if len(rule.sequence) <= 0:
+            raise CoreError(u"Sequence must contains atleast one item : {0}".format(path))
+
+        if value is None:
+            log.debug(u" * Core seq: sequence data is None")
+            return
+
+        if not isinstance(value, list):
+            if isinstance(value, str):
+                value = value.encode('unicode_escape')
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                u"Value '{value}' is not a list. Value path: '{path}'",
+                path,
+                value,
+            ))
+            return
+
+        # Handle 'func' argument on this sequence
+        self._handle_func(value, rule, path, done)
+
+        ok_values = []
+        error_tracker = []
+
+        unique_errors = {}
+        map_unique_errors = {}
+
+        for i, item in enumerate(value):
+            processed = []
+
+            for r in rule.sequence:
+                tmp_errors = []
+
+                try:
+                    # Create a sub core object to enable error tracking that do not
+                    #  collide with this Core objects errors
+                    tmp_core = Core(source_data={}, schema_data={})
+                    tmp_core.fix_ruby_style_regex = self.fix_ruby_style_regex
+                    tmp_core.allow_assertions = self.allow_assertions
+                    tmp_core.strict_rule_validation = self.strict_rule_validation
+                    tmp_core.loaded_extensions = self.loaded_extensions
+                    tmp_core._validate(item, r, "{0}/{1}".format(path, i), done)
+                    tmp_errors = tmp_core.errors
+                except NotMappingError:
+                    # For example: If one type was specified as 'map' but data
+                    # was 'str' a exception will be thrown but we should ignore it
+                    pass
+                except NotSequenceError:
+                    # For example: If one type was specified as 'seq' but data
+                    # was 'str' a exception will be thrown but we shold ignore it
+                    pass
+
+                processed.append(tmp_errors)
+
+                if r.type == "map":
+                    log.debug(u" * Found map inside sequence")
+                    unique_keys = []
+
+                    if r.mapping is None:
+                        log.debug(u" + No rule to apply, prolly because of allowempty: True")
+                        return
+
+                    for k, _rule in r.mapping.items():
+                        log.debug(u" * Key: %s", k)
+                        log.debug(u" * Rule: %s", _rule)
+
+                        if _rule.unique or _rule.ident:
+                            unique_keys.append(k)
+
+                    if len(unique_keys) > 0:
+                        for v in unique_keys:
+                            table = {}
+                            for j, V in enumerate(value):
+                                # If key do not exists it should be ignored by unique because that is not a broken constraint
+                                val = V.get(v, None)
+
+                                if val is None:
+                                    continue
+
+                                if val in table:
+                                    curr_path = "{0}/{1}/{2}".format(path, j, v)
+                                    prev_path = "{0}/{1}/{2}".format(path, table[val], v)
+                                    s = SchemaError.SchemaErrorEntry(
+                                        msg=u"Value '{duplicate}' is not unique. Previous path: '{prev_path}'. Path: '{path}'",
+                                        path=curr_path,
+                                        value=value,
+                                        duplicate=val,
+                                        prev_path=prev_path,
+                                    )
+                                    map_unique_errors[s.__repr__()] = s
+                                else:
+                                    table[val] = j
+                elif r.unique:
+                    log.debug(u" * Found unique value in sequence")
+                    table = {}
+
+                    for j, val in enumerate(value):
+                        if val is None:
+                            continue
+
+                        if val in table:
+                            curr_path = "{0}/{1}".format(path, j)
+                            prev_path = "{0}/{1}".format(path, table[val])
+                            s = SchemaError.SchemaErrorEntry(
+                                msg=u"Value '{duplicate}' is not unique. Previous path: '{prev_path}'. Path: '{path}'",
+                                path=curr_path,
+                                value=value,
+                                duplicate=val,
+                                prev_path=prev_path,
+                            )
+                            unique_errors[s.__repr__()] = s
+                        else:
+                            table[val] = j
+
+            error_tracker.append(processed)
+            no_errors = []
+            for _errors in processed:
+                no_errors.append(len(_errors) == 0)
+
+            if rule.matching == "any":
+                log.debug(u" * any rule %s", True in no_errors)
+                ok_values.append(True in no_errors)
+            elif rule.matching == "all":
+                log.debug(u" * all rule".format(all(no_errors)))
+                ok_values.append(all(no_errors))
+            elif rule.matching == "*":
+                log.debug(u" * star rule", "...")
+                ok_values.append(True)
+
+        for _error in unique_errors:
+            self.errors.append(_error)
+
+        for _error in map_unique_errors:
+            self.errors.append(_error)
+
+        log.debug(u" * ok : %s", ok_values)
+
+        # All values must pass the validation, otherwise add the parsed errors
+        # to the global error list and throw up some error.
+        if not all(ok_values):
+            # Ignore checking for '*' type because it should allways go through
+            if rule.matching == "any":
+                log.debug(u" * Value: %s did not validate against one or more sequence schemas", value)
+            elif rule.matching == "all":
+                log.debug(u" * Value: %s did not validate against all possible sequence schemas", value)
+
+            for i, is_ok in enumerate(ok_values):
+                if not is_ok:
+                    for error in error_tracker[i]:
+                        for e in error:
+                            self.errors.append(e)
+
+        log.debug(u" * Core seq: validation recursivley done...")
+
+        if rule.range is not None:
+            rr = rule.range
+
+            self._validate_range(
+                rr.get("max"),
+                rr.get("min"),
+                rr.get("max-ex"),
+                rr.get("min-ex"),
+                len(value),
+                path,
+                "seq",
+            )
+
+    def _validate_mapping(self, value, rule, path, done=None):
+        """
+        """
+        log.debug(u"Validate mapping")
+        log.debug(u" Mapping : Data: %s", value)
+        log.debug(u" Mapping : Rule: %s", rule)
+        log.debug(u" Mapping : RuleType: %s", rule.type)
+        log.debug(u" Mapping : Path: %s", path)
+        log.debug(u" Mapping : Seq: %s", rule.sequence)
+        log.debug(u" Mapping : Map: %s", rule.mapping)
+
+        if not isinstance(value, dict):
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                u"Value '{value}' is not a dict. Value path: '{path}'",
+                path,
+                value,
+            ))
+            return
+
+        if rule.mapping is None:
+            log.debug(u" + No rule to apply, prolly because of allowempty: True")
+            return
+
+        # Handle 'func' argument on this mapping
+        self._handle_func(value, rule, path, done)
+
+        m = rule.mapping
+        log.debug(u"   Mapping: Rule-Mapping: %s", m)
+
+        if rule.range is not None:
+            r = rule.range
+
+            self._validate_range(
+                r.get("max"),
+                r.get("min"),
+                r.get("max-ex"),
+                r.get("min-ex"),
+                len(value),
+                path,
+                "map",
+            )
+
+        for k, rr in m.items():
+            # Handle if the value of the key contains a include keyword
+            if rr.include_name is not None:
+                include_name = rr.include_name
+                partial_schema_rule = pykwalify.partial_schemas.get(include_name)
+
+                if not partial_schema_rule:
+                    self.errors.append(SchemaError.SchemaErrorEntry(
+                        msg=u"Cannot find partial schema with name '{include_name}'. Existing partial schemas: '{existing_schemas}'. Path: '{path}'",
+                        path=path,
+                        value=value,
+                        include_name=include_name,
+                        existing_schemas=", ".join(sorted(pykwalify.partial_schemas.keys()))))
+                    return
+
+                rr = partial_schema_rule
+
+            # Find out if this is a regex rule
+            is_regex_rule = False
+            required_regex = ""
+            for regex_rule in rule.regex_mappings:
+                if k == "regex;({})".format(regex_rule.map_regex_rule) or k == "re;({})".format(regex_rule.map_regex_rule):
+                    is_regex_rule = True
+                    required_regex = regex_rule.map_regex_rule
+
+            # Check for the presense of the required key
+            is_present = False
+            if not is_regex_rule:
+                is_present = k in value
+            else:
+                is_present = any([re.search(required_regex, v) for v in value])
+
+            # Specifying =: as key is considered the "default" if no other keys match
+            if rr.required and not is_present and k != "=":
+                self.errors.append(SchemaError.SchemaErrorEntry(
+                    msg=u"Cannot find required key '{key}'. Path: '{path}'",
+                    path=path,
+                    value=value,
+                    key=k))
+            if k not in value and rr.default is not None:
+                value[k] = rr.default
+
+        for k, v in value.items():
+            # If no other case was a match, check if a default mapping is valid/present and use
+            # that one instead
+            r = m.get(k, m.get('='))
+            log.debug(u"  Mapping-value : %s", m)
+            log.debug(u"  Mapping-value : %s %s", k, v)
+            log.debug(u"  Mapping-value : %s", r)
+
+            regex_mappings = [(regex_rule, re.search(regex_rule.map_regex_rule, str(k))) for regex_rule in rule.regex_mappings]
+            log.debug(u"  Mapping-value: Mapping Regex matches: %s", regex_mappings)
+
+            if r is not None:
+                # validate recursively
+                log.debug(u"  Mapping-value: Core Map: validate recursively: %s", r)
+                self._validate(v, r, u"{0}/{1}".format(path, k), done)
+            elif any(regex_mappings):
+                sub_regex_result = []
+
+                # Found at least one that matches a mapping regex
+                for mm in regex_mappings:
+                    if mm[1]:
+                        log.debug(u"  Mapping-value: Matching regex patter: %s", mm[0])
+                        self._validate(v, mm[0], "{0}/{1}".format(path, k), done)
+                        sub_regex_result.append(True)
+                    else:
+                        sub_regex_result.append(False)
+
+                if rule.matching_rule == "any":
+                    if any(sub_regex_result):
+                        log.debug(u"  Mapping-value: Matched at least one regex")
+                    else:
+                        log.debug(u"  Mapping-value: No regex matched")
+                        self.errors.append(SchemaError.SchemaErrorEntry(
+                            msg=u"Key '{key}' does not match any regex '{regex}'. Path: '{path}'",
+                            path=path,
+                            value=value,
+                            key=k,
+                            regex="' or '".join(sorted([mm[0].map_regex_rule for mm in regex_mappings]))))
+                elif rule.matching_rule == "all":
+                    if all(sub_regex_result):
+                        log.debug(u"  Mapping-value: Matched all regex rules")
+                    else:
+                        log.debug(u"  Mapping-value: Did not match all regex rules")
+                        self.errors.append(SchemaError.SchemaErrorEntry(
+                            msg=u"Key '{key}' does not match all regex '{regex}'. Path: '{path}'",
+                            path=path,
+                            value=value,
+                            key=k,
+                            regex="' and '".join(sorted([mm[0].map_regex_rule for mm in regex_mappings]))))
+                else:
+                    log.debug(u"  Mapping-value: No mapping rule defined")
+            else:
+                if not rule.allowempty_map:
+                    self.errors.append(SchemaError.SchemaErrorEntry(
+                        msg=u"Key '{key}' was not defined. Path: '{path}'",
+                        path=path,
+                        value=value,
+                        key=k))
+
+    def _validate_scalar(self, value, rule, path, done=None):
+        """
+        """
+        log.debug(u"Validate scalar")
+        log.debug(u" Scalar : Value : %s", value)
+        log.debug(u" Scalar : Rule :  %s", rule)
+        log.debug(u" Scalar : RuleType : %s", rule.type)
+        log.debug(u" Scalar : Path %s", path)
+
+        # Handle 'func' argument on this scalar
+        self._handle_func(value, rule, path, done)
+
+        if rule.assertion is not None:
+            self._validate_assert(rule, value, path)
+
+        if value is None:
+            return True
+
+        if rule.enum is not None and value not in rule.enum:
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                msg=u"Enum '{value}' does not exist. Path: '{path}'",
+                path=path,
+                value=nativestr(value) if tt['str'](value) else value,
+            ))
+
+        # Set default value
+        if rule.default and value is None:
+            value = rule.default
+
+        if not self._validate_scalar_type(value, rule.type, path):
+            return
+
+        if value is None:
+            return
+
+        if rule.pattern is not None:
+            #
+            # Try to trim away the surrounding slashes around ruby style /<regex>/ if they are defined.
+            # This is a quirk from ruby that they define regex patterns with surrounding slashes.
+            # Docs on how ruby regex works can be found here: https://ruby-doc.org/core-2.4.0/Regexp.html
+            # The original ruby implementation uses this code to validate patterns
+            #   unless value.to_s =~ rule.regexp
+            # Becuase python do not work with surrounding slashes we have to trim them away in order to make the regex work
+            #
+            if rule.pattern.startswith('/') and rule.pattern.endswith('/') and self.fix_ruby_style_regex:
+                rule.pattern = rule.pattern[1:-1]
+                log.debug("Trimming slashes around ruby style regex. New pattern value: '{0}'".format(rule.pattern))
+
+            try:
+                log.debug("Matching pattern '{0}' to regex '{1}".format(rule.pattern, value))
+                res = re.match(rule.pattern, value, re.UNICODE)
+            except TypeError:
+                res = None
+
+            if res is None:  # Not matching
+                self.errors.append(SchemaError.SchemaErrorEntry(
+                    msg=u"Value '{value}' does not match pattern '{pattern}'. Path: '{path}'",
+                    path=path,
+                    value=nativestr(str(value)),
+                    pattern=rule._pattern))
+            else:
+                log.debug("Pattern matched...")
+
+        if rule.range is not None:
+            if not is_scalar(value):
+                raise CoreError(u"value is not a valid scalar")
+
+            r = rule.range
+
+            try:
+                v = len(value)
+                value = v
+            except Exception:
+                pass
+
+            self._validate_range(
+                r.get("max"),
+                r.get("min"),
+                r.get("max-ex"),
+                r.get("min-ex"),
+                value,
+                path,
+                "scalar",
+            )
+
+        if rule.length is not None:
+            self._validate_length(
+                rule.length,
+                value,
+                path,
+                'scalar',
+            )
+
+        # Validate timestamp
+        if rule.type == "timestamp":
+            self._validate_scalar_timestamp(value, path)
+
+        if rule.type == "date":
+            if not is_scalar(value):
+                raise CoreError(u'value is not a valid scalar')
+            date_format = rule.format
+            self._validate_scalar_date(value, date_format, path)
+
+    def _validate_scalar_timestamp(self, timestamp_value, path):
+        """
+        """
+        def _check_int_timestamp_boundaries(timestamp):
+            """
+            """
+            if timestamp < 1:
+                # Timestamp integers can't be negative
+                self.errors.append(SchemaError.SchemaErrorEntry(
+                    msg=u"Integer value of timestamp can't be below 0",
+                    path=path,
+                    value=timestamp,
+                    timestamp=str(timestamp),
+                ))
+            if timestamp > 2147483647:
+                # Timestamp integers can't be above the upper limit of
+                # 32 bit integers
+                self.errors.append(SchemaError.SchemaErrorEntry(
+                    msg=u"Integer value of timestamp can't be above 2147483647",
+                    path=path,
+                    value=timestamp,
+                    timestamp=str(timestamp),
+                ))
+
+        if isinstance(timestamp_value, (int, float)):
+            _check_int_timestamp_boundaries(timestamp_value)
+        elif isinstance(timestamp_value, datetime.datetime):
+            # Datetime objects currently have nothing to validate.
+            # In the future, more options will be added to datetime validation
+            pass
+        elif isinstance(timestamp_value, basestring):
+            v = timestamp_value.strip()
+
+            # parse("") will give a valid date but it should not be
+            # considered a valid timestamp
+            if v == "":
+                self.errors.append(SchemaError.SchemaErrorEntry(
+                    msg=u"Timestamp value is empty. Path: '{path}'",
+                    path=path,
+                    value=nativestr(timestamp_value),
+                    timestamp=nativestr(timestamp_value)))
+            else:
+                # A string can contain a valid unit timestamp integer. Check if it is valid and validate it
+                try:
+                    int_v = int(v)
+                    _check_int_timestamp_boundaries(int_v)
+                except ValueError:
+                    # Just continue to parse it as a timestamp
+                    try:
+                        parse(timestamp_value)
+                        # If it can be parsed then it is valid
+                    except Exception:
+                        self.errors.append(SchemaError.SchemaErrorEntry(
+                            msg=u"Timestamp: '{timestamp}'' is invalid. Path: '{path}'",
+                            path=path,
+                            value=nativestr(timestamp_value),
+                            timestamp=nativestr(timestamp_value)))
+        else:
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                msg=u"Not a valid timestamp",
+                path=path,
+                value=timestamp_value,
+                timestamp=timestamp_value,
+            ))
+
+    def _validate_scalar_date(self, date_value, date_formats, path):
+        log.debug(u"Validate date : %(value)s : %(format)s : %(path)s" % {
+            'value': date_value,
+            'format': date_formats,
+            'path': path,
+        })
+
+        if isinstance(date_value, str):
+            # If a date_format is specefied then use strptime on all formats
+            # If no date_format is specefied then use dateutils.parse() to test the value
+            log.debug(date_formats)
+
+            if date_formats:
+                # Run through all date_formats and it is valid if atleast one of them passed time.strptime() parsing
+                valid = False
+                for date_format in date_formats:
+                    try:
+                        time.strptime(date_value, date_format)
+                        valid = True
+                    except ValueError:
+                        pass
+
+                if not valid:
+                    self.errors.append(SchemaError.SchemaErrorEntry(
+                        msg=u"Not a valid date: {value} format: {format}. Path: '{path}'",
+                        path=path,
+                        value=date_value,
+                        format=date_format,
+                    ))
+                    return
+            else:
+                try:
+                    parse(date_value)
+                except ValueError:
+                    self.errors.append(SchemaError.SchemaErrorEntry(
+                        msg=u"Not a valid date: {value} Path: '{path}'",
+                        path=path,
+                        value=date_value,
+                    ))
+        elif isinstance(date_value, (datetime.date, datetime.datetime)):
+            # If the object already is a datetime or date object it passes validation
+            pass
+        else:
+            # If value is any other type then raise error
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                msg=u"Not a valid date: {value} date must be a string or a datetime.date not a '{type}'",
+                path=path,
+                value=date_value,
+                type=type(date_value).__name__,
+            ))
+
+    def _validate_length(self, rule, value, path, prefix):
+        if not is_string(value):
+            raise CoreError("Value: '{0}' must be a 'str' type for length check to work".format(value))
+
+        value_length = len(str(value))
+        max_, min_, max_ex, min_ex = rule.get('max'), rule.get('min'), rule.get('max-ex'), rule.get('min-ex')
+
+        log.debug(
+            u"Validate length : %s : %s : %s : %s : %s : %s",
+            max, min, max_ex, min_ex, value, path,
+        )
+
+        if max_ is not None and max_ < value_length:
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                msg=u"Value: '{value_str}' has length of '{value}', greater than max limit '{max_}'. Path: '{path}'",
+                value_str=value,
+                path=path,
+                value=len(value),
+                prefix=prefix,
+                max_=max_))
+
+        if min_ is not None and min_ > value_length:
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                msg=u"Value: '{value_str}' has length of '{value}', greater than min limit '{min_}'. Path: '{path}'",
+                value_str=value,
+                path=path,
+                value=len(value),
+                prefix=prefix,
+                min_=min_))
+
+        if max_ex is not None and max_ex <= value_length:
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                msg=u"Value: '{value_str}' has length of '{value}', greater than max_ex limit '{max_ex}'. Path: '{path}'",
+                value_str=value,
+                path=path,
+                value=len(value),
+                prefix=prefix,
+                max_ex=max_ex))
+
+        if min_ex is not None and min_ex >= value_length:
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                msg=u"Value: '{value_str}' has length of '{value}', greater than min_ex limit '{min_ex}'. Path: '{path}'",
+                value_str=value,
+                path=path,
+                value=len(value),
+                prefix=prefix,
+                min_ex=min_ex))
+
+    def _validate_assert(self, rule, value, path):
+        if not self.allow_assertions:
+            raise CoreError('To allow usage of keyword "assert" you must use cli flag "--allow-assertions" or set the keyword "allow_assert" in Core class')
+
+        # Small hack to make strings work as a value.
+        if isinstance(value, str):
+            assert_value_str = '"{0}"'.format(value)
+        else:
+            assert_value_str = '{0}'.format(value)
+
+        assertion_string = "val = {0}; assert {1}".format(assert_value_str, rule.assertion)
+        try:
+            exec(assertion_string, {}, {})
+        except AssertionError:
+            self.errors.append(SchemaError.SchemaErrorEntry(
+                msg=u"Value: '{0}' assertion expression failed ({1})".format(value, rule.assertion),
+                path=path,
+                value=value,
+            ))
+            return
+        except Exception as err:
+            error_class = err.__class__.__name__
+            detail = err.args[0]
+            cl, exc, tb = sys.exc_info()
+            line_number = traceback.extract_tb(tb)[-1][1]
+            raise Exception("Unknown error during assertion\n{0}\n{1}\n{2}\n{3}\n{4}\n{5}".format(
+                error_class, detail, cl, exc, tb, line_number,
+            ))
+
+    def _validate_range(self, max_, min_, max_ex, min_ex, value, path, prefix):
+        """
+        Validate that value is within range values.
+        """
+        if not isinstance(value, int) and not isinstance(value, float):
+            raise CoreError("Value must be a integer type")
+
+        log.debug(
+            u"Validate range : %s : %s : %s : %s : %s : %s",
+            max_,
+            min_,
+            max_ex,
+            min_ex,
+            value,
+            path,
+        )
+
+        if max_ is not None and max_ < value:
+                self.errors.append(SchemaError.SchemaErrorEntry(
+                    msg=u"Type '{prefix}' has size of '{value}', greater than max limit '{max_}'. Path: '{path}'",
+                    path=path,
+                    value=nativestr(value) if tt['str'](value) else value,
+                    prefix=prefix,
+                    max_=max_))
+
+        if min_ is not None and min_ > value:
+                self.errors.append(SchemaError.SchemaErrorEntry(
+                    msg=u"Type '{prefix}' has size of '{value}', less than min limit '{min_}'. Path: '{path}'",
+                    path=path,
+                    value=nativestr(value) if tt['str'](value) else value,
+                    prefix=prefix,
+                    min_=min_))
+
+        if max_ex is not None and max_ex <= value:
+                self.errors.append(SchemaError.SchemaErrorEntry(
+                    msg=u"Type '{prefix}' has size of '{value}', greater than or equals to max limit(exclusive) '{max_ex}'. Path: '{path}'",
+                    path=path,
+                    value=nativestr(value) if tt['str'](value) else value,
+                    prefix=prefix,
+                    max_ex=max_ex))
+
+        if min_ex is not None and min_ex >= value:
+                self.errors.append(SchemaError.SchemaErrorEntry(
+                    msg=u"Type '{prefix}' has size of '{value}', less than or equals to min limit(exclusive) '{min_ex}'. Path: '{path}'",
+                    path=path,
+                    value=nativestr(value) if tt['str'](value) else value,
+                    prefix=prefix,
+                    min_ex=min_ex))
+
+    def _validate_scalar_type(self, value, t, path):
+        """
+        """
+        log.debug(u" # Core scalar: validating scalar type : %s", t)
+        log.debug(u" # Core scalar: scalar type: %s", type(value))
+
+        try:
+            if not tt[t](value):
+                self.errors.append(SchemaError.SchemaErrorEntry(
+                    msg=u"Value '{value}' is not of type '{scalar_type}'. Path: '{path}'",
+                    path=path,
+                    value=unicode(value) if tt['str'](value) else value,
+                    scalar_type=t))
+                return False
+            return True
+        except KeyError as e:
+            # Type not found in valid types mapping
+            log.debug(e)
+            raise CoreError(u"Unknown type check: {0!s} : {1!s} : {2!s}".format(path, value, t))