> For the complete documentation index, see [llms.txt](https://playground.e107sk.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://playground.e107sk.com/alt-auth-plugin/reference/field-mapping.md).

# Field mapping

Authentication answers *yes* or *no*. Field mapping answers *"and what else do you know about this person?"* — it decides which values from the external source are copied onto the local e107 user record on every successful login.

Header text on each method page (`LAN_ALT_27`): *"To transfer a field value into the local database, specify the field name in the corresponding box below. (Username and password are always transferred)"*.

## Which fields each method offers

| e107 field              | LAN key                 | e107db | otherdb |    LDAP    | importdb |
| ----------------------- | ----------------------- | :----: | :-----: | :--------: | :------: |
| User Id                 | *hardcoded* ("User Id") |    ✅   |    —    |      —     |     —    |
| User email field        | `LAN_ALT_12`            |    ✅   |    ✅    | ✅ (`mail`) |     —    |
| Hide email? field       | `LAN_ALT_13`            |    ✅   |    ✅    |      ✅     |     —    |
| User display name field | `LAN_ALT_14`            |    ✅   |    ✅    |      ✅     |     —    |
| User real name field    | `LAN_ALT_15`            |    ✅   |    ✅    |  ✅ (`sn`)  |     —    |
| User Custom Title field | `LAN_ALT_16`            |    ✅   |    —    |      —     |     —    |
| Signature field         | `LAN_ALT_17`            |    ✅   |    ✅    |      —     |     —    |
| Avatar field            | `LAN_ALT_18`            |    ✅   |    ✅    |      —     |     —    |
| Photo field             | `LAN_ALT_19`            |    ✅   |    ✅    |      —     |     —    |
| Join date field         | `LAN_ALT_20`            |    ✅   |    —    |      ✅     |     —    |
| Ban status field        | `LAN_ALT_21`            |    ✅   |    —    |      —     |     —    |
| Class membership field  | `LAN_ALT_22`            |    ✅   |    —    |      —     |     —    |

`importdb` transfers nothing — the user is already in the local table.

**e107db** shows these as **checkboxes** (same column names on both sides). **otherdb** and **LDAP** show them as **text boxes**: you type the name of the foreign column, or the LDAP attribute, that supplies the value.

The *User Id* row carries the help text *"Use with caution"* — see the warning on the [e107 database](/alt-auth-plugin/admin-area/e107db.md) page.

## Conversion methods

Where the two systems agree on the value but not on its shape, a small conversion can be applied as the value is copied. The selector sits next to the field.

| Option      | LAN key      |
| ----------- | ------------ |
| None        | `LAN_ALT_70` |
| TRUE/FALSE  | `LAN_ALT_71` |
| Upper case  | `LAN_ALT_72` |
| Lower case  | `LAN_ALT_73` |
| Upper first | `LAN_ALT_74` |
| Upper words | `LAN_ALT_75` |

In the shipped configuration only *Hide email?* offers a conversion (TRUE/FALSE), because a "hide my address" flag is stored differently almost everywhere. Extended user fields offer all of them.

## Extended user fields

Site-defined **extended user fields** (Admin → Users → Extended fields) can be filled from the external source too. This takes **two steps**, in this order:

1. On [Main configuration](/alt-auth-plugin/admin-area/main-configuration.md), tick the field in the *Extended User Fields* table. This only makes it *available*.
2. On the method's own page, the field now appears in the transfer table. Enter the foreign column / LDAP attribute it comes from.

Extended fields are offered by **all** methods (unlike the standard fields above), and all conversion methods are available for them.

{% hint style="info" %}
Values are copied on **every** successful login, and the local value is overwritten when it differs. If the external source is authoritative for a field, do not let users edit it in their e107 profile — their change is silently reverted on their next login.
{% endhint %}