--- title: "Input and Output Mapping Type Overview" slug: "input-output-types-overview" tags: ["Output", "Input"] updated: 2026-01-13T18:23:56Z published: 2026-01-13T18:23:56Z --- > ## Documentation Index > Fetch the complete documentation index at: https://documentation.decisions.com/llms.txt > Use this file to discover all available pages before exploring further. # Input and Output Mapping Type Overview ## Overview In a****[Flow](/v9/docs/flows), data travels by passing in and out of [steps](https://documentation.decisions.com/step-library/docs). Data passing into a step, or data used to configure a step's Properties, is referred to as its **Input**data. Once the data leaves a step, it is known as its **Output**data. The action of applying data to a step is known as **mapping**; in turn, the method by which data is mapped to a step is known as its **Mapping****Type**. Depending on the Mapping Type, data may be defined from the step itself, or broken into individual properties and mapped separately. --- ## General Usage Tips In the **Flow Designer**, selecting a step will populate the **Properties** tab with step configurations. Steps are typically set up to receive data as inputs, process the data based on the step function, then send the data as outputs. Almost all steps have some sort of input data, but not all steps pass output data. Once inputs are defined for a step, it is a best practice to deselect the step by clicking into blank space so that the new configurations apply. If there are still exceptions after the inputs have been defined, check to see if there are conflicting datatype issues. --- ## Input Mapping Types ### Unknown The default input mapping type is always set to **Unknown**, which is not useable for input values at runtime. The box below each input name prompts the user to type in a value/variable or to pick something from the list of provided data that the step can access. Selecting this mapping type will reveal the list of other mapping types. ![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750257398401.png) ### Constant **Constant** mapping allows a user-defined value will be used as an input. When selecting this mapping type, a field corresponding to the input data type will appear, allowing the value to be specified. For example, the **Show Popup** step expects a String input for "Subject" and "Message". Selecting Constant for these fields will present a text box for string entry. One thing to note with this mapping type is that the value will remain consistent whenever the step is reached at runtime. This is useful for testing purposes in large-scale applications. ### Select From Flow The **Select From Flow** mapping type uses data from the Flow as an input. This data can be values that are defined as Flow constants, or from steps provided earlier in the Flow. Selecting this mapping type opens a window where Flow data can be chosen as the specific input. The data type chosen must match the data type for the input field.![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750257523088.png) ### Null and Ignore The **Null**and **Ignore** mapping types are often mistaken for having the same function. The difference between the two is that Null sets the input with a null value in Decisions and in the database. Ignore will disregard the input value entirely. It is important to note that most steps will return an exception for unexpected null or ignored values. ![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750257590913.png) ### [Converters and Run Converter Flow](/v9/docs/using-converter-flows) The **Run Converter Flow** and mapping types found under **Converters** both execute a **Converter Flow** when selected as on the inputs to a step. These mapping types are mainly used to convert data to a specific type before being processed by the step. It is important to keep in mind that any input or output used with a Converter Flow must be expecting to receive data of the converted output type. Mapping types found under Converters represent pre built Converter Flows while the Run Converter Flow type allows a custom [Converter Flows](/v9/docs/using-converter-flows) to be created and used.![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750257669789.png) ### Merge Text The **Merge Text** mapping type is used to define the message of the step. Text is entered into the editor, but the current user email needs to be defined with Flow Data. To do this, the Flow Data section was expanded on the left side. Click on the selection to add it to the editor. In v9.6 anything on the left-hand menu can be grabbed and dragged onto the editor as well.![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750257783768.png) ### Merge HTML Similar to **Merge Text**, using **Merge HTML** opens a text editor. However, Merge HTML provides additional options such as tables and linking. Like the Merge Text editor, users can drag variables onto the edit field starting in v9.6. In addition, when specifying values for a link, either for images or text, users are able to determine if the link will open a new window. This is defined under the Target input when generating a link. ![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-12-16_11h41_25.png) ### Constant Date/Constant Date and Time The **Constant Data** and **Constant Date and Time** mapping types are available and replace **Constant** when dealing with **DateTime** values in Decisions. Use this mapping type to define a date or date and time that will constantly be used as the value. In the screenshot below, the **Show Form** step is configured to always show the constant date for the related values. NoteIf **Time Zone****Translation** is enabled in **Portal Settings**, DateTime values may display according to the configured **Default Time Zone**. If you need the DateTime interpreted in a specific time zone (such as UTC), convert/format the DateTime before using it in logic or extracting properties (for example, Hours). ![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750257975662.png) ### Current Date Time The **Current Date Time** mapping type shows the date and time as of the moment the input is reached on the step in the Flow. NoteWith **Time Zone****Translation** enabled, Current Date Time (and any derived properties) may render using the **Default Time Zone** rather than UTC. If your Flow logic depends on a specific time zone (such as UTC), convert/format the DateTime explicitly before extracting values like **Hours**. ![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750258210576.png) ### Compute Date The **Compute Date** mapping type gives some input configuration options for computing a date and time in the future or in the past, based on the defined offset of time. When this mapping type is used, a Compute Type dropdown appears with an option for InFuture or InPast. Either option must have the **Start** and **Offset** inputs configured. If the Start is set for the current date/time and the Offset is one day, the computed date/time should be exactly one day from the date/time of when the input was reached in the Flow. **Note**If **Time Zone Translation** is enabled, computed DateTime values may display using the configured Default Time Zone. For time zone-sensitive calculations, convert/format the Start value or the computed result to the intended time zone before mapping it into later steps. ![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750258273376.png) ### Troubleshooting: Hours and 24-hour formatting with Time zone Translation If **Time Zone Translation** is enabled, **DateTime.Hours** may reflect the configured **Default Time Zone**. If you need a consistent hour value (for example, a UTC hour) or need a **24-hour** representation, format the DateTime explicitly and then convert the result to a number if required. - **24-hour token:** Use **HH** for a 24-hour hour value (for example, 00–23) rather than **hh** (12-hour clock). - **If an Int32 is required:** Format the DateTime to an hour string (HH) and convert/parse it to an Int32 using a **Formula** or a **Converter Flow**. **Note**Some DateTime formatting subproperties may not be directly selectable as step input types. In those cases, formatting + conversion is the recommended approach. ### Build Data The **Build Data** mapping type becomes available to use when the properties of a data structure must be built manually. Using this option on an input expecting an object of a certain data type will allow the user to expand the properties of that object and manually map them to input definitions. For example, a **Show Form** step receives name, email, and position to create an object of the EmployeeProfile data structure. The **Build Data** option is used on the inputs to a later step which opens the [Mapping Editor](/v9/docs/using-the-mapping-editor) and exposes the properties of the EmployeeProfile object. These properties are then mapped as inputs to the later step.![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2024-12-16_12h01_43.png) ### Build Array The **Build Array** mapping type works similar to **Build Data** except that it only applies to inputs that are expecting a list of a data type, such as a String. For example, two text entries are captured from a Form and sent to the **Create Data** step, which is expecting a String list called "Customer Cart". The Build Array mapping type is used to add separate items together which compile the array (or list) of String entries.![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750258468648.png) ### Formula The Formula mapping type allows users to run a [Formula](https://documentation.decisions.com/docs/formulas) for the input. Users can use any previously created Formulas, or they can make on through the designer. ![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750258569835.png) --- ## Output Mapping Types ### Rename If a step contains an output, the step will default to using **Rename** for its mapping type. This mapping type is mainly used to rename the modified data, providing a way to identify the output on the **Data Explorer** panel within a Flow. For example, an **Add** step takes in two values as the input and returns the sum of those values. The output data of the Add step is renamed to Add_Output automatically to indicate the new data value as it will appear in the Flow. This output data could be renamed to something suitable for the project, like "total". This change will be reflected within the **Data Explorer** panel. ![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750258654105.png) ### Change Value The **Change Value** mapping type can be used to update existing data that matches the data type to the field. When this outcome is selected, an option to pick the variable will appear. If the selected data does not have a matching data type, then the Step will display an error. ![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750258746806.png) ### Expose Properties If a Flow step is expected to output a composite datatype, the **Expose Properties** mapping type can reveal all of the individual data members associated with the composite type. Those individual properties will need to have output mapping type options of their own selected. ![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750258945355.png) ### Reference The **Reference** mapping functions similarly to the **Change Value,**creating new data that serves as a reference to the output. This data can then be selected and used later in a Flow.![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750259002873.png) ### Pass Through This mapping type is similar to **Rename** in that it exists only to pass the data through with the same name, instead of creating a new piece of Flow data that can be used. The name for the output will default to Output when viewed in the Flow and on the Data **Explorer** panel.![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750259043534.png) ### Ignore and Run Converter These mapping types operate in the same fashion as they do for inputs, where the value of the output is either ignored or converted using a Flow. ![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1750259326556.png) --- ## Feature Changes | Description | Version | Release Date | Developer Task | | --- | --- | --- | --- | | Data Definition type picker design has been updated. | [9.5](https://documentation.decisions.com/v99/docs/version-95x-release-notes) | November 2024 | [DT-042023] | | Input mapping has been enhanced. | [9.5](https://documentation.decisions.com/v99/docs/version-95x-release-notes) | November 2024 | [DT-040638] | | Text merge editor UI has been updated. | [9.5](https://documentation.decisions.com/v99/docs/version-95x-release-notes) | November 2024 | [DT-042634] | | Entity pickers across the platform have had their UI updated. | [9.5](https://documentation.decisions.com/v99/docs/version-95x-release-notes) | November 2024 | [DT-042825] | | Variables in the Merge Text editors can now be dragged onto the field. | [9.6](https://documentation.decisions.com/v99/docs/version-96x-release-notes) | January 2025 | [DT-043231] | For further information on Flows, visit the [Decisions Forum](https://community.decisions.com/categories/Flows).