TextDecoder

Categories

Strings

Decodes a string from a number of different text encodings into plain text. The following encoding types are supported:

URL (Percent Encoding)

This encoding is used to ensure that a string is valid for inclusion in a URL. All characters that are not a letter, digit, dash, period, underscore or tilde will be encoded. The TextDecoder converts an encoded string such as black%20%26%20white into its decoded form black & white.

Unicode

This encoding is used to encode non-ascii characters in an ascii string. The TextDecoder will decode from any of these code point representations, where the XX...X string represents the hexadecimal value of a Unicode code point:

\uXXXX

\UXXXX

\u{XX...X}

\UXXXXXXXX

U+XXXX

For example, the Cyrillic character Ӥ is represented as \U04E4 or U+04E4. The TextDecoder converts a string containing code point references to a UTF-8 string, with the code points dereferenced. Any characters which are not part of a Unicode code point will be unchanged. For example, the string ‘U+0F06 εA \U03A8’ will be decoded to ‘༆ εA Ψ’

XML

This encoding is used to ensure strings are acceptable for use in an XML document. Characters that have syntactic meaning in XML are escaped, using the following mapping:

Character Encoded Value
< &lt;
> &gt;
" &quot;
& &amp;
' &apos;

In addition, the XML encoding allows for any character to be represented using the decimal or hexadecimal representation of its Unicode code point. The TextDecoder converts an XML encoded string, such as black &amp; white into its plain text representation, black & white.

HTML

This encoding is an extension of the XML encoding. The HTML encoding includes many characters which cannot be represented using a simple Latin character set, such as ♪, ± or ∞. The TextDecoder will convert an HTML encoded string, such as this &plusm; that into its plain text representation, this ± that.

Base64

Base64 encoding is a method of storing arbitrary data as an ASCII string. The TextDecoder will convert Base64 encoded data into a text string. The Base64 data will be decoded into a sequence of bytes, which will then be interpreted using the character encoding given in the Character Encoding for Binary Data parameter.

HEX

HEX encoding is another method used to store arbitrary data as an ASCII string. HEX encoded data is not as compact as Base64 encoded data. The TextDecoder will convert HEX encoded data to a text string. The HEX data will be decoded into a sequence of bytes, which will then be interpreted using the character encoding given in the Character Encoding for Binary Data parameter.

Octal

Octal encoding is another method used to store arbitrary data as an ASCII string. Octal encoded data is not as compact as HEX or Base64 encoded data. The TextDecoder will convert Octal encoded data to a text string. The Octal data will be decoded into a sequence of bytes, which will then be interpreted using the character encoding given in the Character Encoding for Binary Data parameter.

Parameters

Identifies the method the transformer will use to decode the attribute.

The value of this parameter will be decoded using the selected method.

This attribute will store the decoded string.

This optional parameter only applies to the HEX, Octal, and Base64 encoding methods. If no value is given, the output attribute will be left as binary data.

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.

 

Transformer History

Selecting URL as the Encoding Type replaces the URLDecoder transformer, which is now deprecated.

FME Community

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Search for samples and information about this transformer on the FME Community.

Keywords: URLDecoder decode encode