Counter
Adds a numeric attribute to a feature and assigns a value. Each subsequent feature passing through the transformer receives an incremented value – in other words, the Counter is counting the features.
This transformer can be useful for assigning a unique, numeric ID number to a set of features, for counting the number of features, or for creating a basic histogram for values of a given attribute.
Usage Notes
Using Multiple Counters
When multiple Counters have the same name and Count Scope is Global, they produce a single count. When multiple Counters have different names, each Counter produces a unique count starting at 0 (or the number determined by the Count Start parameter). You can rename any Counter by editing the Transformer Name parameter.
For example, there are two workspaces each with two Counters. Ten features passed through each Counter would result in the following:
Workspace 1
Counter Name: Counter1 - features numbered 1 - 10
Counter Name: Counter2 - features numbered 1 - 10
Workspace 2
Counter Name: Counter - features numbered 1 - 10
Counter Name: Counter - features numbered 11 - 20
You can use this feature as needed to produce different results.
Configuration
Input Ports
This transformer accepts any feature.
Output Ports
Features with an added Count attribute as specified in parameters.
The dynamic <Rejected> port appears when a parameter is set to a non-literal value that might make processing impossible.
For example, if a numeric parameter such as Line Width, Count Start, or Decimal Places is set to an expression, attribute value, or user parameter, it is possible to pass in a non-numeric value that cannot be used. Decimal Places = Cat cannot be processed, so the feature will be output via this port.
Rejected features will have an fme_rejection_code attribute explaining the reason for rejection.
Rejected Feature Handling: can be set to either terminate the translation or continue running when it encounters a rejected feature. This setting is available both as a default FME option and as a workspace parameter.
Parameters
Count Start |
Use this parameter to specify a starting value for the Counter. This is useful for applications where ranges of values have meanings in the problem domain. See Usage Notes below. |
Count Scope |
Specify whether the scope of this counter is Global (throughout the entire workspace) or Local (for this transformer only). Global counters with the same Count Domain will share the same counting and Group ID sequences, while Local counters will each have independent counting and Group ID sequences. Local counters can optionally group features by attributes as well. Defaulted to Global. |
Count Domain |
Create separate sequences of numbers to be assigned, either by placing several Counter transformers with each having a different Count Domain, or by choosing an attribute whose value will be used as the Count Domain as each feature passes through. (In effect, using an attribute to supply the Count Domain is like having a Group By option for the Counter.) |
Group Processing
Group processing is enabled when Count Scope is Local.
Group By |
The default behavior is to use the entire set of features as the group. This option allows you to select attributes that define which groups to form, creating separate sequences of numbers. |
Complete Groups |
When to complete processing groups. By default groups will not be considered complete until all features have been received. Otherwise, groups will complete processing when the group changes. |
Count |
The name of the attribute that will contain the count result, and will appear in the list of Output port attributes. |
Group ID |
The name of the attribute that will contain the Group ID of a feature, and will appear in the list of Output port attributes. The Group ID value will be a unique number associated with the group by value(s) within a scope. The first group ID will start at 1, counting up for each unique group processed after. |
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.
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.
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.
These functions manipulate and format strings. | |
Special Characters |
A set of control characters is available in the Text Editor. |
Math functions are available in both editors. | |
Date/Time Functions | Date and time functions are available in the Text Editor. |
These operators are available in the Arithmetic Editor. | |
These return primarily feature-specific values. | |
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
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Enabled once you have clicked on a row item. Choices include:
|
Cut, Copy, and Paste
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Enabled once you have clicked on a row item. Choices include:
Cut, copy, and paste may be used within a transformer, or between transformers. |
Filter
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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
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Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers. |
Reset/Refresh
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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.
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