---
title: "Resolve your own model"
description: "Implement the shape and the resolver that let templates read your own objects, and the rules the base resolver carries."
audience: "Developers"
kind: "How-to guide"
status: "Current"
version: "main · 3.3 (unreleased)"
slug: "resolve-your-own-model"
url: "https://docs.allors.com/documents/resolve-your-own-model/"
---

# Resolve your own model

> **Status: Current.** How-to guide for developers.

This guide is for a host whose objects are neither plain classes nor dictionaries, such as an object model with metadata of its own. You give the library two views of your model: a shape for `Validate` and a resolver for `Render`.

Two interfaces describe a model. `IShape` is the static view `Validate` walks: the members a value has, whether it is a collection, the shape of its items, and the variants of an abstract shape. `IResolver` is the runtime view the renderer reads through: `TryGetMember`, `Items`, `IsTrue`, `Format`, `Compare` and `Picture`. The `Resolver` base class carries the rules this document describes for iteration, truthiness, formatting and ordering, and takes a byte array as a picture; derive from it, implement `TryGetMember`, and override the rest for your own value types. A resolver may hand out its own value types and recognize them again when it formats, compares or iterates them, which is how a host prints an amount in its currency.

| Provider | Shape | Resolver | Members |
| --- | --- | --- | --- |
| Dictionary, in `Allors.Documents` | `DictionaryShape.Open`, `new DictionaryShape(members)` | `DictionaryResolver` | The keys of a dictionary, exactly as written, and nothing else. |
| Reflection, in `Allors.Documents.Reflection` | `ReflectionShape.Of<T>()`, `ReflectionShape.Arguments<T>()` | `ReflectionResolver` | Dictionary keys as written; on any other object the name with its first letter upper-cased or as written, as a property, a `Get` method, a `get_` method, a string indexer or a field. |

`TryGetMember` returns false for a member the scope does not have, which the renderer reports, and true with a null value for a member that is empty, which prints blank. The renderer never passes a null scope.

To put a resolver of your own in place:

1.  Derive from `Resolver`, implement `TryGetMember`, and override `Items`, `IsTrue`, `Format`, `Compare` and `Picture` where your value types need it.
2.  Implement `IShape` over your metadata, with `Variants` for an abstract shape, and build the root shape a template renders against from the same source.
3.  Pass the resolver in `RenderSettings.Resolver` for every render, and the root shape to `Validate`.
4.  Write a contract test that the shape and the resolver agree: every member the shape declares, the resolver reads, and a collection in the one is a collection in the other.