MemberFilterContext Struct

Provides context for member filtering during rendering.

Definition

namespace Dumpify;

public readonly struct MemberFilterContext
{
    public IValueProvider Member { get; }
    public object? Value { get; }
    public object Source { get; }
    public int Depth { get; }
}

Properties

Property	Type	Description
`Member`	`IValueProvider`	The member (property/field) being filtered. Provides access to member metadata.
`Value`	`object?`	The actual value of the member. Lazily evaluated when accessed.
`Source`	`object`	The parent object that contains this member.
`Depth`	`int`	The current rendering depth (0 = root object).

Usage

MemberFilterContext is passed to member filter functions configured via MembersConfig.MemberFilter or the memberFilter parameter on Dump methods.

Basic Filtering

// Exclude null values
DumpConfig.Default.MembersConfig.MemberFilter = ctx => ctx.Value is not null;

// Exclude specific property names
DumpConfig.Default.MembersConfig.MemberFilter = ctx => 
    ctx.Member.Name != "Password" && 
    ctx.Member.Name != "Secret";

Filtering by Depth

// Only show top-level properties
DumpConfig.Default.MembersConfig.MemberFilter = ctx => ctx.Depth == 0;

// Show details only for first 2 levels
DumpConfig.Default.MembersConfig.MemberFilter = ctx => ctx.Depth < 2;

Filtering by Type

// Exclude byte arrays (e.g., large binary data)
DumpConfig.Default.MembersConfig.MemberFilter = ctx => 
    ctx.Member.MemberType != typeof(byte[]);

// Only show string and numeric properties
DumpConfig.Default.MembersConfig.MemberFilter = ctx =>
{
    var type = ctx.Member.MemberType;
    return type == typeof(string) || 
           type.IsPrimitive || 
           type == typeof(decimal);
};

Per-Call Filtering

myObject.Dump(memberFilter: ctx => ctx.Value is not null);

IValueProvider Interface

The Member property exposes an IValueProvider with useful metadata:

public interface IValueProvider
{
    string Name { get; }           // Property or field name
    MemberInfo Info { get; }       // Reflection metadata
    Type MemberType { get; }       // The type of the member
    object? GetValue(object source);
}

Accessing Member Metadata

DumpConfig.Default.MembersConfig.MemberFilter = ctx =>
{
    // Check for custom attributes
    var hasIgnoreAttr = ctx.Member.Info
        .GetCustomAttribute<JsonIgnoreAttribute>() != null;
    
    return !hasIgnoreAttr;
};

Performance Considerations

The Value property is lazily evaluated - it only calls GetValue() when accessed. This means:

// Good: Only evaluates Value when needed
ctx => ctx.Member.Name != "ExpensiveProperty" && ctx.Value != null

// Better for performance if filtering by name is common
ctx => ctx.Member.Name == "ExpensiveProperty" || ctx.Value != null

If your filter doesn’t need the actual value, avoid accessing ctx.Value for better performance.

Examples

Hide Sensitive Data

var sensitiveNames = new HashSet<string> 
{ 
    "Password", "Secret", "ApiKey", "Token", "ConnectionString" 
};

DumpConfig.Default.MembersConfig.MemberFilter = ctx => 
    !sensitiveNames.Contains(ctx.Member.Name);

Show Only Changed Values

// Assuming you have a way to determine default values
DumpConfig.Default.MembersConfig.MemberFilter = ctx =>
{
    var value = ctx.Value;
    if (value is null) return false;
    if (value is string s && string.IsNullOrEmpty(s)) return false;
    if (value is 0 or 0L or 0.0 or 0.0f) return false;
    return true;
};

Depth-Based Detail Levels

DumpConfig.Default.MembersConfig.MemberFilter = ctx =>
{
    // Always show top level
    if (ctx.Depth == 0) return true;
    
    // At deeper levels, hide collections and complex objects
    if (ctx.Depth > 1 && ctx.Value is IEnumerable && ctx.Value is not string)
        return false;
    
    return true;
};