Configuring an inferred values drop-down list

Creating or configuring forms > Configuring the <components> element > Configuring an inferred values drop-down list

6.1.6 Configuring an inferred values drop-down list

The inferred values component enables you to have a drop-down menu that is generated at the time the page is loaded, instead of when the configuration file is read. This enables you to configure a component that has dynamic values that change depending on the current state of your environment. There are two ways to source the values that populate the dynamic drop-down menu:

You can use a URL to read in an external script or XML file.

You can retrieve values from Moab.

To add/delete/modify an inferred values drop-down list

Open the appropriate XML file located in the Viewpoint home directory. Locate the <components> element.
Create the <component> with a unique id.
Determine whether to populate the dynamic drop-down menu using a suggest box or from a URL.
- Configure a suggest box to use inferred values.
  1. Set the <inferred-value> child element inside the component.
  2. Set the component attribute to "suggest".
```
<inferred-value source="Moab" type="node-name" component="suggest" />
```
    The user is presented with a text box with suggestions populated as the user types.
- Configure a URL to read in an external script or XML file.
  1. Insert the <inferred-value> element inside the component.
  2. Set the cardinality attribute if the inferred value that is read is in a <select-value>.
  3. Set the value to "one" or "many" to indicate whether a single or multiple items can be selected at once.
  4. Set the source attribute to indicate that the inferred values come from a file, not Moab. Set the value to "exec" if the file is an executable or to "file" if the file is an XML file.
  5. Insert the <url> child element, and set the value attribute to the file’s location.
```
<component id="node_selection" required="false">
  <description>List of nodes available</description>
  <inferred-value cardinality="one" source="file">
    <url value="file:///availableNodes.xml" />
  </inferred-value>
</component>
```
  Both file system-based URL types (i.e., flat text file or executable script) use the file protocol.
  Because the <inferred-value> element is already wrapped in the <component> element, all that needs to be read-in from the script or file is the component details. Two valid returns to the <inferred-value> element are:
```
<select-values>
  <select-value api-value="a" display-value="Value A" />
  <select-value api-value="b" display-value="Value B" />
</select-values>
```
```
<number-value type="int">
  <default>1</default>
  <minimum>2</minimum>
  <maximum>8</maximum>
  <step>1</step>
</number-value>
```