StringReplacer

Categories

Strings

Related Transformers

StringPairReplacer

StringSearcher

Replaces substrings matching a string or regular expression in the string contained in the source attribute.  

Parameters

This parameter specifies which attributes will have substrings replaced.

This parameter specifies whether the Text To Replace parameter specifies a regular expression or text pattern to search for.

  • Yes: The transformer will perform case-sensitive substring matching.
  • No: The transformer will perform case-insensitive substring matching.

This parameter specifies the string or regular expression that will be replaced if it is found in an attribute value.

The Replacement Text parameter specifies the substring that will replace instances of the Text To Replace parameter.

If replacement text contains \#, where # is a digit between 1 and 9, then it is replaced in the substitution with the portion of string that matched the n-th parenthesized subexpression of the regular expression.

Special character sequences can be used in both the Text to Replace and Replacement Text parameters.

If the Mode parameter is set to Replace Regular Expression, Advanced Regular Expressions (AREs) are supported. An ARE is one or more branches, separated by "|", matching anything that matches any of the branches.

This table lists the special characters:

Special Character Description
| separates "branches" (or choices)
*  a sequence of 0 or more matches of what precedes it
+ a sequence of 1 or more matches of what precedes it
? a sequence of 0 or 1 matches of what precedes it
. matches any single character
^ matches the start of the value
$ matches the end of the value
[ ] enclose a set of character choices
( ) enclose a "subexpression"
a any character can be listed to be matched

Characters can be expressed as regular characters but they can also include any number of control characters.

Special character sequences are interpreted as shown below:

Sequence Description

Ctrl+Shift+h (^H)

Backspace (0x08)

Ctrl+Shift+l (^L)

Form feed (0x0c)

Ctrl+Shift+j (^J)

Newline (0x0a)

Ctrl+Shift+r (^M)

Carriage return (0x0d)

Ctrl+Shift+i (^I)

Tab (0x09)

Ctrl+Shift+k (^K)

Vertical tab (0x0b)

Defining Special Characters

You can define special characters through the Text Editors. Click Open Text Editor from the parameter menu:

Text Editor

Enter characters using the shortcuts from the table above.

Note: To see tab characters, click the Options menu on the bottom left and select Show Spaces/Tabs.

If Attribute Value Does Not Contain Text

If the Text To Replace parameter is not found, the attribute value will be set to the value specified by this parameter.

Examples

In this example, a pure substitution of text is made without any use of regular expression functionality. This is the simplest kind of substring replacement.

   Source String: Bobby

   Text to Find: obb

   Replacement Text: ill

   Use Regular Expression: no

   Case Sensitive: yes

   Result: Billy

In this example, a pattern matching zero or more ’b’ characters is replaced with nothing.

   Source String: Bobby

   Text to Find: b*

   Replacement Text:

   Use Regular Expression: yes

   Case Sensitive: yes

   Result: Boy

In this example, a pattern matching zero or more ’b’ characters followed by a y is duplicated in the result (prepended by hyphens)

   Source String: Bobby

   Text to Find: (b*y)

   Replacement Text: --\1-\1

   Use Regular Expression: yes

   Case Sensitive: yes

   Result: Bo--bby-bby

Usage Notes

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.

FME Community

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