<tool name="Map parameter value" id="map_param_value" version="0.1.0" tool_type="expression" profile="22.01">
    <macros>
        <xml name="when_element" tokens="type_selection">
            <param name="input_param" type="@TYPE_SELECTION@" optional="true" label="Map this parameter value to a different value"/>
            <repeat name="mappings" label="Add value mapping">
                <param name="from" type="@TYPE_SELECTION@" optional="true" label="Map from this value"></param>
                <param name="to" type="text" label="to this value" help="This value must be coercable to the selected output parameter type"></param>
            </repeat>
        </xml>
    </macros>
    <expression type="ecma5.1">
        <![CDATA[{
const source = $job.input_param_type.input_param;
const mappings = $job.input_param_type.mappings;

const coerceToOutput = function(value) {
    switch($job.output_param_type) {
        case "integer":
            return parseInt(value)
        case "float":
            return parseFloat(value)
        case "boolean":
            if (value == "false" || value == "False") {
                return false
            }
            return !!value
        case "text":
            return value
    }
}

for ( var i = 0; i < mappings.length; i++ ) {
    if ( String(mappings[i].from) == source ) {
        return { output: coerceToOutput(mappings[i].to) };
    }
}
if ( $job.unmapped.on_unmapped == "fail" ) {
    return { __error_message: `text_param ${source} not found in mapping values.` };
} else if ( $job.unmapped.on_unmapped == "default" ) {
    return { output: coerceToOutput($job.unmapped.default_value) };
}
return { output: coerceToOutput(source) };
}]]>
    </expression>
    <inputs>
        <conditional name="input_param_type">
            <param name="type" type="select" label="Select type of input parameter to match">
                <option value="text" selected="true">Text</option>
                <option value="integer">Integer</option>
                <option value="float">Float</option>
                <option value="boolean">Boolean</option>
            </param>
            <when value="text">
                <expand macro="when_element" type_selection="text"/>
            </when>
            <when value="integer">
                <expand macro="when_element" type_selection="integer"/>
            </when>
            <when value="float">
                <expand macro="when_element" type_selection="float"/>
            </when>
            <when value="boolean">
                <expand macro="when_element" type_selection="boolean"/>
            </when>
        </conditional>
        <param name="output_param_type" type="select" label="Select type of parameter to output">
            <option value="text">Text</option>
            <option value="integer">Integer</option>
            <option value="float">Float</option>
            <option value="boolean">Boolean</option>
        </param>
        <conditional name="unmapped">
            <param name="on_unmapped" type="select" label="Select how">
                <option value="input">Use unmodified input parameter value if input parameter value not found in mappings</option>
                <option value="fail">Fail if input parameter value not found in mappings</option>
                <option value="default">Provide a default value to use if input parameter value not found in mappings</option>
            </param>
            <when value="input" />
            <when value="fail" />
            <when value="default">
                <param name="default_value" type="text" label="Use this value if the input parameter value was not found in mappings"/>
            </when>
        </conditional>
    </inputs>
    <outputs>
        <output type="text" name="output_param_text" from="output">
            <filter>output_param_type == 'text'</filter>
        </output>
        <output type="integer" name="output_param_integer" from="output">
            <filter>output_param_type == 'integer'</filter>
        </output>
        <output type="float" name="output_param_float" from="output">
            <filter>output_param_type == 'float'</filter>
        </output>
        <output type="boolean" name="output_param_boolean" from="output">
            <filter>output_param_type == 'boolean'</filter>
        </output>
    </outputs>
    <tests>
        <test expect_num_outputs="1">
            <conditional name="input_param_type">
                <param name="type" value="text"/>
                <param name="input_param" value="A" />
                <repeat name="mappings">
                    <param name="from" value="A" />
                    <param name="to" value="B" />
                </repeat>
            </conditional>
            <output name="output_param_text" value_json="&quot;B&quot;" />
        </test>
        <test expect_num_outputs="1">
            <conditional name="input_param_type">
                <param name="input_param" value="C" />
                <repeat name="mappings">
                    <param name="from" value="A" />
                    <param name="to" value="B" />
                </repeat>
            </conditional>
            <output name="output_param_text" value_json="&quot;C&quot;" />
        </test>
        <test expect_num_outputs="1" expect_failure="true">
            <conditional name="input_param_type">
                <param name="input_param" value="C" />
                <repeat name="mappings">
                    <param name="from" value="A" />
                    <param name="to" value="B" />
                </repeat>
            </conditional>
            <conditional name="unmapped">
                <param name="on_unmapped" value="fail"/>
            </conditional>
        </test>
        <test expect_num_outputs="1">
            <conditional name="input_param_type">
                <param name="input_param" value="C" />
                <repeat name="mappings">
                    <param name="from" value="A" />
                    <param name="to" value="B" />
                </repeat>
            </conditional>
            <conditional name="unmapped">
                <param name="on_unmapped" value="default"/>
                <param name="default_value" value="D"/>
            </conditional>
            <param name="output_param_text" value_json="&quot;D&quot;" />
        </test>
        <test expect_num_outputs="1">
            <conditional name="input_param_type">
                <param name="input_param" value="C" />
                <repeat name="mappings">
                    <param name="from" value="A" />
                    <param name="to" value="B" />
                </repeat>
            </conditional>
            <conditional name="unmapped">
                <param name="on_unmapped" value="default"/>
                <param name="default_value" value="X"/>
            </conditional>
            <param name="output_param_text" value_json="&quot;X&quot;" />
        </test>
        <test expect_num_outputs="1">
            <conditional name="input_param_type">
                <param name="input_param" value="C" />
                <repeat name="mappings">
                    <param name="from" value="A" />
                    <param name="to" value="B" />
                </repeat>
                <repeat name="mappings">
                    <param name="from" value="C" />
                    <param name="to" value="D" />
                </repeat>
            </conditional>
            <param name="output_param_text" value_json="&quot;D&quot;" />
        </test>
        <test expect_num_outputs="1">
            <conditional name="input_param_type">
                <param name="type" value="integer" />
                <param name="input_param" value="42" />
                <repeat name="mappings">
                    <param name="from" value="42" />
                    <param name="to" value="true" />
                </repeat>
            </conditional>
            <param name="output_param_type" value="boolean"/>
            <param name="output_param_boolean" value_json="true" />
        </test>
        <test expect_num_outputs="1">
            <conditional name="input_param_type">
                <param name="type" value="float" />
                <param name="input_param" value="1.2" />
                <repeat name="mappings">
                    <param name="from" value="42" />
                    <param name="to" value="true" />
                </repeat>
            </conditional>
            <conditional name="unmapped">
                <param name="on_unmapped" value="default"/>
                <param name="default_value" value="False"/>
            </conditional>
            <param name="output_param_type" value="boolean"/>
            <param name="output_param_boolean" value_json="false" />
        </test>
        <test expect_num_outputs="1">
            <conditional name="input_param_type">
                <param name="type" value="integer" />
                <param name="input_param" value="1" />
                <repeat name="mappings">
                    <param name="from" value="1" />
                    <param name="to" value="1.1" />
                </repeat>
            </conditional>
            <param name="output_param_type" value="float"/>
            <param name="output_param_float" value_json="1.1" />
        </test>
        <test expect_num_outputs="1">
            <conditional name="input_param_type">
                <param name="type" value="string" />
                <param name="input_param" value="A" />
                <repeat name="mappings">
                    <param name="from" value="A" />
                    <param name="to" value="2" />
                </repeat>
            </conditional>
            <param name="output_param_type" value="integer"/>
            <param name="output_param_float" value_json="2" />
        </test>
    </tests>
    <help><![CDATA[
**What it does**

Maps a parameter value to another value.
This can be used to transform any non-data value (text, integer, float and boolean) to a different value of a different type.

**Settings**

 If the value is not found in the mapping the unmodified value is returned by default.
 Select ``Fail if input parameter value not found in mappings`` if you wish the job to fail if an input could not be mapped.

 Select ``Provide a default value to use if input parameter value not found in mappings`` to provide a default value to use in case the input parameter value could not be mapped.
 Select the proper input and output parameter types based on your workflow input and output connections.

**Examples**

You want a user to select from 3 simple options in a workflow, e.g. ``low``, ``medium``, ``high``, which correspond to distinct integer values.

Turn ``Map this parameter value to a different value`` into a a connectable workflow input by clicking on "Add connection to module".

Set the input parameter type to ``Text``, and add 3 mappings:

..

  #.

    * Map from this value: ``low``
    * to this value: ``1``

  #.

    * Map from this value: ``medium``
    * to this value: ``2``

  #.

    * Map from this value: ``high``
    * to this value: ``3``

Set ``Select type of parameter to output`` to ``Integer``.
You can now connect the output to any connectable Integer input in your workflow.

    ]]></help>
</tool>