# 2.3	The settingsFields\[] array

The settingsFields\[] array in the object you return from UDI.onInit() describes the configurable fields which people should be able to modify for your indicator.

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There is one special field which fundamentally affects the type and behaviour of your UDI. If your indicator has a Source field then it receives, in UDI.onCalculate(), a single data series such as the close prices or the high prices – or the values from another indicator. If your indicator does not have a Source field then it receives the full data for each bar – open, high, low, close, and volume – and your UDI cannot be applied to another indicator.

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The Source field is defined in the settingsFields\[] array as follows. (It is normal, but not compulsory, for it to be the first field.)

```
settingsFields: [
	{id: "Source"}
	…
]
```

All other fields in the settingsFields\[] array should have an id, a caption, and a type. They can also optionally have other properties depending on the type of field. For example:

```
settingsFields: [
	{id: "Source"},
	{id: "threshold", caption: "Threshold", type: "float", defaultValue: 1, min: 1, step: 0.1},
	{id: "highlightcolor", caption: "Color", type: "color", defaultValue: "rgba(0,0,255,0.5)"},
	{id: "options", caption: "Display type", type: "select", options: [
		{k: "line", v: "Display as line"},
		{k: "marker", v: "Display as histogram"}
	]}
]
```

The types of field which you can use are as follows:

| Field type | Description                                                |
| ---------- | ---------------------------------------------------------- |
| int        | Integer field                                              |
| float      | Numeric, non-integer field                                 |
| yesno      | Yes/no (Boolean) field                                     |
| select     | List of options                                            |
| textline   | Free-text field                                            |
| color      | Colour field                                               |
| maType     | Type of moving average, for use with the Liquid.ta library |

The full set of properties which can be defined for each field is as follows:

| Property           | Description                                                                                                                                                                                                                                                                                 |
| ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| id                 | ID for your field                                                                                                                                                                                                                                                                           |
| caption            | Display text for your field                                                                                                                                                                                                                                                                 |
| type               | The type of field: "int", "color", "textline" etc                                                                                                                                                                                                                                           |
| defaultValue       | Default value for the field (depending on its type)                                                                                                                                                                                                                                         |
| omitFromParameters | Tells the chart that the field should not be displayed in the summary of the indicator's values                                                                                                                                                                                             |
| min                | For numeric fields, the minimum value which can be entered                                                                                                                                                                                                                                  |
| max                | For numeric fields, the maximum value which can be entered                                                                                                                                                                                                                                  |
| step               | For numeric fields, the increment between values                                                                                                                                                                                                                                            |
| options\[]         | For the select field-type only, an array of options for the user to select from. Each entry in the array should have a key, k, and a displayable caption, v. For example: {k: "close", v: "Close price"}. The value which your indicator receives, in UDI.onCalculate(), is the k property. |
