AttributeValidator

Categories

Data Quality

Strings

Related Transformers

AttributeEncoder

DuplicateFilter

GeometryValidator

JSONValidator

StringCaseChanger

StringLengthCalculator

Tester

TestFilter

XMLValidator

Validates any number of attributes against user-defined test conditions, routing the feature according to the outcome of the test(s) and identifying any tests it has failed.

Jump to Configuration

Typical Uses

  • Performing data quality testing
  • Enforcing data integrity by testing attributes against a set of acceptable conditions
  • Ensuring attributes meet the requirements of constraints and domains in output databases

How does it work?

The AttributeValidator receives features with attributes to be tested against user-defined Validation Rules.

A wide variety of Validation Rule types are available. The rules are created in a table, and each row consists of the attribute(s) to be validated, the type of test to be done, and any configuration required. An attribute may be tested against any number of rules, and a rule may be applied to any number of attributes.

There are two output ports - Passed and Failed.

Passed features are those whose attributes have passed all Validation Rule tests that have been defined.

If any tests are failed, the features will be output via the Failed port, with descriptions of the failures:

  • The first test failed will be documented in the new attribute _fme_validation_message.
  • The first test and any further tests failed will all be documented in the new list attribute _fme_validation_message_list{}.

Tests are evaluated in the order they are listed in the Validation Rules table in the parameters dialog.

Creating Validation Rules

Each rule consists of the attributes to be tested and the test to be performed. The following tests are available.

Validation Rule

Description

Configuration
Type

Tests if the value is compatible with the chosen Type.

You may test for multiple types by adding additional Validation Rules.

Select the Type to test for.

Boolean

Valid Boolean values are the strings:

  • TRUE, True, true, 1, YES, Yes, yes
  • FALSE, False, false, 0, NO, No, no
Double Floating-point number
Integer Integer
Numeric A number (same behavior as Double)
Alphanumeric All characters are either a digit (0-9) or a letter (a-z, A-Z). White space, nulls, control codes, punctuation, and accented or extended characters are not included.
String A sequence of characters. The value is not null or missing, and does not contain any null characters.
XML Checks for valid XML syntax.
JSON Checks for valid JSON syntax.
Date

Date in the form yyyymmdd , as in:

  • 20170206
Datetime

Date and time in the form [Date][Time] as in:

  • 20170206111730.135
Datetime With Offset

Date and time with UTC offset in the form [Datetime][UTC offset] as in:

  • 20170206111730.135-08:00
Time

Time in the form hhmmss or hhmmss.123456789, as in:

  • 111730
  • 111730.135
Time With Offset

Time with UTC offset in the form [Time][UTC offset], as in:

  • 111730.135-08:00
In Range

Tests if the value falls within the numeric range specified in set notation.

Open-ended ranges may be defined by leaving either the lower or upper limit blank.

Range values are separated by a comma and enclosed by brackets.

Square brackets - [ ] - indicate inclusive limits (greater than or equal to, less than or equal to).

Round brackets - ( ) - indicate exclusive limits (greater than, less than).

Valid range examples:

(1,9) Greater than 1 and less than 9

[1,9] Greater than or equal to 1 and less than or equal to 9

(1,9] Greater than 1 and less than or equal to 9

(1,) Greater than 1

[,9] Less than or equal to 9

Case Tests if the value complies with the selected case pattern.

Select a case pattern.

 

Valid (Passed) Example
UPPER CASE ARBUTUS VILLAGE PARK
lower case arbutus village park
Title case Arbutus village park
Full Title Case Arbutus Village Park

Minimum Length

Tests if the number of characters in the value is greater than or equal to the Minimum Length.

All values are evaluated as strings.

Enter an integer.

Example:

If Minimum Length = 4

Bvd: Failed

Blvd: Passed

Boulevard: Passed

Maximum Length

Tests if the number of characters in the value is less than or equal to the Maximum Length.

All values are evaluated as strings.

Enter an integer.

Example:

If Maximum Length = 4

123: Passed

1234: Passed

999999: Failed

In Tests if the value may be found in provided list of possible values and ranges.

Enter any combination of comma-separated strings, numeric values, and/or ranges (in the form of x-y).

Valid configuration examples:

1,10,100

1-99

cat

cat,dog,cats and dogs

dogs,1-9,7

Encodable In Tests if the value is encodable in the specified encoding without data loss.

Select from a list of standard encodings.

Sample encodings:

  • Unicode 32-bit(utf-32)
  • Windows Cyrillic (windows-12510
  • EBCDIC US (ibm037)
Not Null Tests that the attribute exists on the feature, and is not null. <Unused>
Unique

Tests if a value is unique (only used once) within the set of features.

The first occurrence of a value will Pass, and any subsequent occurrences of that value will fail.

<Unused>
Has a Value Tests that the attribute has a value, and is not null, missing, or empty. <Unused>
Contains Regex Tests that the value contains a string that matches a pattern described by a Regular Expression.

Enter a Regular Expression.

The Regular Expression Editor is available via the ellipsis (...) button, and may be used to construct and test expressions.

The regex to test may represent a string to be found anywhere within the value, or may represent the entire value (by creating a regex long enough to represent the extent of the desired value).

Example:

If regex is \d

cats: Failed

9: Passed

cats82: Passed

Examples

In this example, we have a spreadsheet of food cart vendors to test for data quality.

The features are routed into an AttributeValidator.

In the parameters dialog, we construct three tests to perform:

  • Has a Value: All attributes are tested for the existence of any value, which will identify any missing data.
  • In: The DESCRIPTION attribute is tested to see if its values are in a list of valid options. The list is typed in, with items separated by commas. Items that fail this test may have the wrong information, or data entry errors such as the wrong case or spelling.
  • Type: The LAT and LON attributes are tested to see if they contain floating-point numbers. As these contain the location of the vendors, items that fail this test may have invalid coordinates.

Features that fail any of the tests are output via the Failed port. A new attribute - _fme_validation_message - has been added, and contains details of the first test failed for each feature. Note that the tests are applied in the order they appear in the Validation Rule table.

A new list attribute has also been added (which is not visible in the Table view) - _fme_validation_message_list{}. All tests failed are added to the list attribute.

Note that this feature has failed two tests - the BUSINESS_NAME does not have a value, and the DESCRIPTION has failed because the value HOT DOGS does not match the list item Hot Dogs (the case is wrong).

Usage Notes

  • Output feature order may be controlled with the Advanced > Preserve Feature Order parameter.

Configuration

Input Ports

Features with attributes to be validated.

Output Ports

If the test(s) pass, the feature is output via the Passed port.

If any test fails, the feature is output via the Failed port, with additional attributes describing the failure.

Parameters

See Creating Validation Rules above for further detail.

Attributes to Validate Select the attribute(s) to be tested.
Validation Rule

Select the type of test to be performed. Options include:

  • Type
    • Boolean
    • Double
    • Integer
    • Numeric
    • Alphanumeric
    • String
    • XML
    • JSON
    • Date
    • Datetime
    • Datetime with Offset
    • Time
    • Time with Offset
  • In Range
  • Case
    • UPPER CASE
    • lower case
    • Title case
    • Full Title Case
  • Minimum Length
  • Maximum Length
  • In
  • Encodable In
  • Not Null
  • Unique
  • Has a Value
  • Contains Regex
Rule Configuration Enter any supplementary configuration information for the test selected.
Preserve Feature Order

This parameter controls the order in which features exit a transformer.

When a transformer has more than one output port, features usually exit one port at a time. At times, it may be useful to keep the order that features arrived in, switching from port to port as necessary. This allows feature order to be preserved, though at a potential cost in processing efficiency.

Select a method for feature ordering.

Per Output Port (Default)

Only preserve the input order of features as they occur within the group of features exiting a given output port.

All features exiting an output port retain their ordering relative to each other (within the group), but not relative to features exiting other output ports.

This option is generally the most efficient, where large chunks of features will exit an output port together (taking advantage of bulk mode).

As features exiting different output ports may not be strictly output in the order they arrived, output ordering may be unpredictable.

Across Output Ports Strictly preserve the input order of features, regardless of which output port they exit. Features will be output singly in the same order they arrived, switching from port to port as necessary. This option is generally less efficient as the processing gains of bulk mode are less likely to apply - however, feature order is predictable.

Editing Transformer Parameters

Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click beside the applicable parameter. For more information, see Transformer Parameter Menu Options.

Defining Values

There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters. There are a number of tools and shortcuts that can assist in constructing values, generally available from the drop-down context menu adjacent to the value field.

Using the Text Editor

The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.

Text Editor

Using the Arithmetic Editor

The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.

Arithmetic Editor

Conditional Values

Set values depending on one or more test conditions that either pass or fail.

Parameter Condition Definition Dialog

Content

Expressions and strings can include a number of functions, characters, parameters, and more.

When setting values - whether entered directly in a parameter or constructed using one of the editors - strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.

String Functions

These functions manipulate and format strings.

Special Characters

 A set of control characters is available in the Text Editor.

Math Functions

Math functions are available in both editors.
Date/Time Functions Date and time functions are available in the Text Editor.

Math Operators

These operators are available in the Arithmetic Editor.

FME Feature Functions

These return primarily feature-specific values.

FME Parameters

FME and workspace-specific parameters may be used.
Creating and Modifying User Parameters Create your own editable parameters.

Dialog Options - Tables

Transformers with table-style parameters have additional tools for populating and manipulating values.

Row Reordering

Enabled once you have clicked on a row item. Choices include:

  • Add a row
  • Remove a row
  • Move current row up one
  • Move current row down one
  • Move current row to top
  • Move current row to bottom

Cut, Copy, and Paste

Enabled once you have clicked on a row item. Choices include:

  • Cut a row - delete and copy to clipboard
  • Copy a row to the clipboard
  • Paste a row from the clipboard

Cut, copy, and paste may be used within a transformer, or between transformers.

Filter

Start typing a string, and the matrix will only display rows matching those characters. Searches all columns. This only affects the display of attributes within the transformer - it does not alter which attributes are output.

Import

Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers.

Reset/Refresh

Generally resets the table to its initial state, and may provide additional options to remove invalid entries. Behavior varies between transformers.

Note: Not all tools are available in all transformers.

Reference

Processing Behavior

Feature-Based

Feature Holding

No
Dependencies None
Aliases AttributeClassifier, StringClassifier
History This transformer replaced the AttributeClassifier transformer.

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Examples may contain information licensed under the Open Government Licence – Vancouver and/or the Open Government Licence – Canada.