ENiGMA½ supports a variety of MCI codes. Some **predefined** codes produce information about the current user, system, or other statistics while others are used to instantiate a **View**.
## General Information
MCI codes are composed of two characters and are prefixed with a percent (%) symbol.
Some MCI codes have additional options that may be set directly from the code itself while others -- and more advanced options -- are controlled via the current theme.
## Relationship with Menus, Art, and Themes
A MCI code that appears in a `menu.hjson` entry corresponds to that found in it's associated art file. This same MCI code can be referenced in the `theme.hjson` in order to apply a theme.
See [Menus](../docs/configuration/menu-hjson.md) and [Themes](themes.md) for more information.
## Predefined Codes
There are many predefined MCI codes that can be used anywhere on the system (placed in any art file).
| `XY` | A special code that may be utilized for placement identification when creating menus or to extend an otherwise empty space in an art file down the screen. |
> :information_source: More are added all the time so also check out [core/predefined_mci.js](https://github.com/NuSkooler/enigma-bbs/blob/master/core/mci_view_factory.js) for a full listing.
| `TL` | Text Label | Displays text | Static content. See [Text View](views/text_view.md) |
| `ET` | Edit Text | Collect user input | Single line entry. See [Edit Text](views/edit_text_view.md) |
| `ME` | Masked Edit Text | Collect user input using a *mask* | See [Masked Edit](views/mask_edit_text_view.md) and **Mask Edits** below. |
| `MT` | Multi Line Text Edit | Multi line edit control | Used for FSE, display of FILE_ID.DIZ, etc. See [Multiline Text Edit](views/multi_line_edit_text_view.md) |
| `BT` | Button | A button | ...it's a button. See [Button](views/button_view.md) |
> :information_source: Peek at [/core/mci_view_factory.js](https://github.com/NuSkooler/enigma-bbs/blob/master/core/mci_view_factory.js) to see additional information.
As mentioned above, MCI codes can (and often should) be explicitly tied to a *View Identifier*. Simply speaking this is a number representing the particular view. These can be useful to reference in code, apply themes, etc.
Predefined MCI codes and other Views can have properties set via `menu.hjson` and further *themed* via `theme.hjson`. See [Themes](themes.md) for more information on this subject.
| `text` | Set's the view's text if applicable, such as a [TextView](./views/text_view.md) or [EditTextView](./views/edit_text_view.md) amongst others. See [MCI Formatting](#mci-formatting) below for advanced formatting options using the |
These are just a few of the properties set on various views. *Use the source Luke*, as well as taking a look at the default `menu.hjson` and `theme.hjson` files!
Often a module will provide custom properties that receive format objects (See [Entry Formatting](#entry-formatting) below). Custom property formatting can be declared in the `config` block. For example, `browseInfoFormat10`..._N_ (where _N_ is up to 99) in the `file_area_list` module received a fairly extensive format object that contains `{fileName}`, `{estReleaseYear}`, etc.
Various strings can be formatted using a syntax that allows width & precision specifiers, text styling, etc. Depending on the context, various elements can be referenced by `{name}`. Additional text styles can be supplied as well. The syntax is largely modeled after Python's [string format mini language](https://docs.python.org/3/library/string.html#format-specification-mini-language).
For more advanced layouts, you may want to apply formatting to MCI codes. In this case, an alternative syntax is supported similar to standard [Entry Formatting](#entry-formatting).
MCI codes can be surrounded by `{` and `}` in the `text` field in your `theme.hjson` for a Text Label (`%TL` aka [Text View](./views/text_view.md)). Some examples:
> :bulb: MCI formatting also applies when programmatically calling [setText()](https://github.com/NuSkooler/enigma-bbs/blob/6710bf8c084487be2ee1d46d72a05d17a7b166f4/core/text_view.js#L148) of [TextView's](./views/text_view.md) and derived views.
Suppose a format object contains the following elements: `userName` and `affils`. We could create a `itemFormat` entry that builds a item to our specifications: `|04{userName!styleFirstLower} |08- |13{affils}`. This may produce a string such as this:
> :bulb: Remember that a Python [string format mini language](https://docs.python.org/3/library/string.html#format-specification-mini-language) style syntax is available for widths, alignment, number prevision, etc. as well. A number can be made to be more human readable for example: `{byteSize:,}` may yield "1,123,456".
