Reference

Reference

Both overloads live in Vali_Flow.NoSql.Firestore.Extensions.ValiFlowFirestoreExtensions.

ToFirestore<T>(this ValiFlow<T> flow, Func<object?, object?>? customConverter = null)

Translates the conditions accumulated in a ValiFlow<T> builder into a native Filter.

Parameter	Type	Required	Description
flow	ValiFlow<T>	Yes	The builder containing the conditions. Throws ArgumentNullException if null.
customConverter	Func<object?, object?>?	No	Hook for mapping CLR types not handled by the built-in switch. Return null to fall through to the default conversion. Scoped to this call only (thread-safe).

Returns: Filter — pass directly to Query.Where(filter).

ToFirestore<T>(this Expression<Func<T, bool>> expression, Func<object?, object?>? customConverter = null)

Same translation for a pre-built Expression<Func<T, bool>>.

Expression<Func<Order, bool>> expr = o => o.Status == "Pending" && o.Total > 50m;
Filter filter = expr.ToFirestore();

Both overloads are thin wrappers over FirestoreFilterTranslator.Translate(IConditionNode, Func<object?, object?>?) — the ValiFlow<T> overload calls flow.ToNoSqlIR() first, the expression overload calls expression.ToNoSqlIR() first.

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Supported Operations

ValiFlow method	IR node	Firestore Filter call
.EqualTo(x => x.Field, v)	EqualNode(IsNegated: false)	Filter.EqualTo(field, value)
.NotEqualTo(x => x.Field, v)	EqualNode(IsNegated: true)	Filter.NotEqualTo(field, value)
.GreaterThan(x => x.Field, v)	ComparisonNode(GreaterThan)	Filter.GreaterThan(field, value)
.GreaterThanOrEqualTo(x => x.Field, v)	ComparisonNode(GreaterThanOrEqual)	Filter.GreaterThanOrEqualTo(field, value)
.LessThan(x => x.Field, v)	ComparisonNode(LessThan)	Filter.LessThan(field, value)
.LessThanOrEqualTo(x => x.Field, v)	ComparisonNode(LessThanOrEqual)	Filter.LessThanOrEqualTo(field, value)
.In(x => x.Field, list)	InNode	Filter.InArray(field, values)
.IsNull(x => x.Field)	NullNode(IsNull)	Filter.EqualTo(field, null)
.IsNotNull(x => x.Field)	NullNode(IsNotNull)	Filter.NotEqualTo(field, null)
.And(a, b)	AndNode	Filter.And(left, right)
.Or(a, b)	OrNode	Filter.Or(left, right)
.Contains / .StartsWith / .EndsWith	LikeNode	throws NotSupportedException
.Not(inner)	NotNode	throws NotSupportedException

And/Or nest recursively, exactly mirroring the shape of the IR tree — there is no flattening into a single Filter.And(a, b, c, ...) call even if the source expression chains more than two conditions; each binary node becomes one nested Filter.And/Filter.Or call.

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Type Mapping

The built-in switch inside FirestoreFilterTranslator (method ToValue) handles these CLR types before handing the value to Filter.*:

CLR type	Value passed to Filter.*
null	null
Enum	int (via Convert.ToInt32(e))
DateTimeOffset	Timestamp.FromDateTimeOffset(dto)
DateTime	Timestamp.FromDateTime(...) — converted to UTC first if dt.Kind != DateTimeKind.Utc
anything else (string, int, long, double, bool, decimal, ...)	passed through unchanged — the Firestore SDK serializes these natively

Resolution order: customConverter (if provided) runs first via ConditionValueResolver.Resolve; if it returns null, the built-in switch above applies.

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Custom Value Converter

Use customConverter for domain types the built-in switch doesn't know about, or to override a default (for example, storing a decimal as double instead of letting the SDK serialize it as-is).

The converter runs before the built-in switch. Return null to let the default handle the value.

// Domain type
record Money(decimal Amount, string Currency);

// Converter: store Money as a double amount
Filter filter = new ValiFlow<Product>()
    .GreaterThan(x => x.Price, new Money(100m, "USD"))
    .ToFirestore(value =>
    {
        if (value is Money m)
            return (double)m.Amount;
        return null; // fall through for everything else
    });

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Advanced Example

// Custom converter for Money type
Filter filter = new ValiFlow<Order>()
    .GreaterThan(o => o.Total, 100m)
    .ToFirestore(obj => obj is Money m ? (double)m.Amount : null);