# Survey first, then choose detail

Prerequisite: [opening a Rift](nexus.md). Start at `rift.space.frame_viewer`.
The host-level multi-frame view can enumerate frames without selecting one.
The frame, conduit, and spell views require a frame name.

## Control the amount you read

Use `list_*` to discover names and IDs, a brief description to decide what matters,
then detail or a specific facet for the selected object. For spells, the ladder is
`describe_spell_brief`, `describe_spell`, `describe_spell_detail`, and
`describe_spell_payload`. Source, binding, identity, resolution, and research reads
let a caller request a particular concern.

The viewer lessons inspect the method surface and show that a fresh Rift can have
an empty assigned-frame set. An empty survey is different from a frame-local
request that lacks the required target.

## Missing is not always absent

A visibility-filtered description may omit a section because it does not exist
or because this Rift may not see it. Use the missing-section/visible-surface probes
to understand that boundary. They report withheld section names without exposing
their hidden payload bodies.

On the facade, `frame_name` selects the frame. On a view already bound to a frame,
an optional frame name can instead be an assertion that it matches. Read the
specific signature rather than treating those two surfaces as interchangeable.


## The workflow in code

These are the core steps from the saved example. Use its complete linked script for all class definitions and setup.

```{literalinclude} ../downloads/03_advanced/13_the_frame_viewer_facade.py
:language: python
:pyobject: main
:linenos:
```


## Runnable examples

- [The frame viewer facade](../examples/advanced/13-the-frame-viewer-facade.md) — Advanced 13
- [The describe ladder](../examples/advanced/14-the-describe-ladder.md) — Advanced 14
- [What you cannot see](../examples/advanced/15-what-you-cannot-see.md) — Advanced 15

[All advanced examples](../examples/advanced/index.md) · [Level contents](index.md) · [Full contents](../contents.md)

[Canonical page source](https://github.com/Synaptic724/melder/blob/0895ce795453cd87e35d70665957b4e89aad3317/docs/advanced/viewers.md)