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User manual 2.20.0 (pre-release)

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Simple evaluation

Description

The Simple evaluation action evaluates the contents of a variable, a field in the result stream, the number of result files, or the log text of the previous workflow action.

Connect two actions with the output of the Simple Evaluation.

The green (success) hop will be called if the condition was evaluated successfully, the red (failure) one will be called if the condition wasn’t evaluated successfully.

Usage

  • A Null value is the same as an empty string. For example, to detect a null for any data type, set the Type to String, and the Success condition to "If value is equal to", and have the Value textbox empty.

  • The Simple evaluation Action is limited. For more complex conditions see: https://hop.apache.org/manual/latest/workflow/actions/eval.html

Options

Option Description

Action name

The name of the workflow action.

Source

Evaluate

Evaluation type:

  • Field from previous result

  • Variable

  • Number of result files

  • Log text from previous result

Field name

The field to evaluate (only shown when evaluating a field)

Type

Data type (hidden when evaluating result files or log text)

Success On

Success when source variable set

The action will always success if the source variable was set otherwise it will fail.

Success condition

  • If value equal to

  • If value different from

  • If value contains

  • If value not contains

  • If value starts with

  • If value not starts with

  • If value ends with

  • If value not ends with

  • If value valid regex

  • If value in list

  • If value not in list

Value

The value to compare.

Result

What this action passes on to the next action. See Action results for how results travel through a workflow.

Result Value

True

The condition under Success On is met. With Success when source variable set, the variable is set.

False

The condition is not met, and the number of errors is 0. When the value can’t be evaluated, the number of errors is 1: there are no result rows, the field doesn’t exist, the Variable name field is empty, or the value or the value to compare is not a valid number or date.

Result files

Passed on unchanged. With Number of result files, the action evaluates how many files it received.

Result rows

Passed on unchanged. With Field from previous result, the action evaluates the field in the first result row.
An invalid regular expression with If value valid regex doesn’t return false: the workflow stops with an error, and no hop is followed.

Tips

Evaluating a variable

Field Value Explanation

Source: Evaluate

Variable

Select this to evaluate a variable set before

Source: Variable name

e. g. ${VAR1}

Enter the variable name using the usual syntax

Source: Type

String, Number etc.

The type of your variable

Success on: Success when source variable set

When this option is selected, the true path is followed when the source variable is set. Note: The workflow action checks if the source variable is defined, so an empty or null value is also true. When testing this within Hop you need to delete the line with the variable in the variables section of the Execute a workflow window. And remember: Once this variable is set, the variable keeps existing, even when deleting it from the list.

Success On: Success condition

Equal/Non equal/etc.

Select the condition to be met for a successful result

Success On: Value

Value to compare the variable to

Evaluating a field

Field Value Explanation

Source: Evaluate

Field from previous result

Select this to evaluate a field value (generated by a pipeline using Copy rows to result)

Source: Field name

Enter the field name from the result row

Source: Type

String, Number etc.

The type of your field

Success On: Success condition

Equal/Non equal/etc.

Select the condition to be met for a successful result

Success On: Value

Value to compare the field to

Evaluating the number of result files

Use this to check how many files the previous action added to the workflow result (for example after Add filenames to result or a pipeline that adds files).

The source is treated as a number. Typical conditions are equal to, greater than, smaller than, or between.

Field Value Explanation

Source: Evaluate

Number of result files

Select this to evaluate how many files the previous action added to the result

Success On: Success condition

Equal/Greater than/Between/etc.

Compare the file count

Success On: Value

Expected number of result files

Evaluating log text from the previous result

Use this to verify that a previous pipeline or workflow action logged an expected snippet, or that an unwanted snippet is absent.

The source is the log text captured for the previous action. It is treated as a string. Typical conditions are If value contains and If value not contains. Regular expressions are also supported.

This is a no-code alternative to checking the previous result log text in a JavaScript action.

Field Value Explanation

Source: Evaluate

Log text from previous result

Select this to evaluate the previous action’s log text

Success On: Success condition

Contains/Not contains/Regex/etc.

Check for presence or absence of a snippet

Success On: Value

The text snippet or regular expression to look for