Summary: How to process OData filters in C#.
I spent a few days trying to figure out how to validate OData filte, so I'd like to share a piece of code that performs basic OData parsing. But before I get to code, let me explain what I'm doing here and why.
A typical use case could be a REST APIs built on top of ASP.NET Core (.NET 8) which talks to extrnal REST APIs that requires a consistent way for defining the search queries (or search filters) used by the HTTP GET operations. There are different ways to define search queries. For example, SCIM filtering spec looks simple and robust, but after spending the last decade dealing with SCIM implementations, I do not want to have anything to do with SCIM anymore.
The most reasonable option (other than building one from scratch) would be using OData. OData comes with a lot of goodies, but for our use case, we only needed to figure out how to parse and validate OData filters. I thought in .NET Core, handling OData queries would be simple, but unfortunately, the good people at Microsoft must have assumed that everyone using OData in their custom controllers would rely on entity frameworks, so they made it easy for the apps that integrate OData with their entity data models. Which is not what we do. In our case, we take a search query, validate it, and pass to an external API. What this API does with it, we do not care, but we want to be good citizens and not hand it garbage (and in case we get garbage from the clients, we want to send them meaningful errors explaining why their queries are garbage). To do this, we need to take an OData filter expression from a query string and make sure that it is valid. Should be simple, right?
There are many articles explaining how to integrate OData into the REST API controllers, but the only two posts I found useful for our use case were:
By trial and error, I built a simple program that validates and parses a string holding an OData filter. This program is not perfect (it does not handle all possible functions, operators, and complex scenarios), but for us, it is more than enough. I will make it more robust and implement the logic as a library at some point, but if you need a more or less simple example, showing how to validate and parse a not very complex OData filter, see code below (read the comments that explain the requirements and dependencies).
UPDATE: You can ignore the next section because I made a few improvements to the code and published both the library handling OData filters and the demo programs at GitHub (there is also a Nuget package available).
/*
This .NET Core console app was built and tested with the following Nuget packages {versions}:
- Microsoft.AspNetCore.OData {9.0.0}
- Microsoft.Extensions.DependencyInjection.Abstractions {8.0.1}
- Microsoft.OData.Core {8.0.1}
To install the latest versions of the packages, run from Package Manager Console:
Install-Package Microsoft.Extensions.DependencyInjection.Abstractions
Install-Package Microsoft.OData.Core
Install-Package Microsoft.AspNetCore.OData
SUMMARY:
This program illustrates how to validate and parse basic OData filters in the given text strings.
The code may not be comprehensive and it does not cover advanced OData use cases,
but it shows how to handle typical filter conditions that utilize common operations
and functions ('not', 'eq', 'ne', 'gt', 'ge', 'lt', 'le', 'startsWith', 'endsWith',
'contains', 'in') and grouped using logical operators ('and', 'or').
The filter properties will be mapped to properties of the filter object properties. The filter
objects (there is more than one) identify how OData filter attributes can be mapped to a real
entity that may come from an external resource, such as a web service, database, report, etc.
*/
// The following namespace holds the classes used in the OData filter.
#pragma warning disable IDE0130 // Namespace does not match folder structure
namespace TestOData1;
#pragma warning restore IDE0130 // Namespace does not match folder structure
using Microsoft.OData.Edm;
using Microsoft.OData.ModelBuilder;
using Microsoft.OData.UriParser;
using System.Linq;
/// <summary>
/// Main program.
/// </summary>
internal class Program
{
#region Properties
// Use the same separator for complex (nested) types as the OData filters.
private static readonly string _separator = "/";
// Number of indent characters for the binary tree output.
private static readonly int _indentLength = 2;
// Set this value to true to print object names of the tree nodes.
private static readonly bool _printNode = false;
#endregion
#region Filter examples
// Here are some basic filter we may want to test.
// By default, property names are case-insensitive, but we'll make them case-insensitive.
private static readonly string[] _filters =
[
"not(enabled)",
"not(true)",
"email eq null",
"email ne null",
"email eq 'john@mail.com'",
"email ne 'john@mail.com'",
"email eq displayName",
"email ne displayName",
"contains(email, '@')",
"not contains(email, '@')",
"contains(email, displayName)",
"not contains(email, displayName)",
"startsWith(email, 'john')",
"not startsWith(email, 'john')",
"endsWith(email, '@mail.com')",
"not endsWith(email, '@mail.com')",
"email in ('john@mail.com', 'mary@mail.com')",
"not (email in ('john@mail.com', 'mary@mail.com'))",
"id eq 0",
"id gt 0",
"id lt 2000",
"id ge 1",
"id le 2000",
"name eq null",
"name ne null",
"name/givenName eq null",
"sponsor/name/givenName eq null",
"name/surname ne sponsor/name/surname",
"name/givenName in ('John', 'Mary')",
"name/givenName ne name/nickName",
"startsWith(displayName, 'J')",
"type eq 'Employee'",
"type eq 'Guest' and name/Surname eq 'Johnson'",
"type eq 'Contractor' and not(endsWith(email, '@mail.com'))",
"enabled eq false and type in ('Employee', 'Contractor') ",
"(enabled eq true and type eq 'Employee') or (enabled eq false and (type eq 'Guest' or endsWith(email, '@mail.com')))",
"phoneNumbers/any(p: p eq '123-456-6789')",
"socialLogins/any(s: s/name eq 'Facebook')",
"socialLogins/any(s: s/name eq 'Facebook' or endsWith(s/url, 'google.com'))",
"sponsor/phoneNumbers/any(p: p eq '123-456-6789')",
"sponsor/socialLogins/any(s: s/name eq 'Facebook')"
];
#endregion
#region Main method
private static void Main()
{
// The builder is responsible for mapping OData filter conditions to the object properties.
ODataConventionModelBuilder builder = new();
// UserFilter defines the properties which can be used in our filter (this class is defined below).
// The UserFilter class properties also can be based on other complex types, but they will be
// included implicitly, so no need to reference them.
builder.AddEntityType(typeof(User));
// EDM (Entity Data Model) encapsulates classes that will be used in the OData filters.
IEdmModel model = builder.GetEdmModel();
// Let's print all classes that our EDM schema recognizes.
Console.WriteLine("ODATA SCHEMA ELEMENTS:");
foreach (IEdmSchemaElement element in model.SchemaElements)
{
Console.WriteLine($"- {element.FullName()}: {element.SchemaElementKind}");
}
// If you define the EDM classes not under an explicitly defined namespace,
// make sure you add 'Default.' to the full name because 'Default' would be the implicit
// namespace created by the compiler; if you do not, these types will not be found.
// string qualifiedName = "Default." + typeof(GroupFilter).FullName;
string qualifiedName = typeof(User).FullName ?? "";
// Now, lets use our filter class as the EDM type, so it can be used for OData filter handling.
IEdmType type = model.FindDeclaredType(qualifiedName);
if (type == null)
{
Console.WriteLine($"Type '{qualifiedName}' is not found in the OData schema model.");
return;
}
foreach (string filter in _filters)
{
Console.WriteLine();
Console.WriteLine(new string('-', 72));
Console.WriteLine("EXPRESSION: " + filter);
Console.WriteLine(new string('-', 72));
// This dictionary can include other OData parameters,
// such as "$top", "$skip", "$count", "$select", "$orderby", "$search", etc.
// but we are only interested in the filter.
Dictionary<string, string> options = new()
{
{"$filter", filter}
};
try
{
ODataQueryOptionParser parser = new(model, type, null, options)
{
// By default, property names are case-sensitive,
// so we need to explicitly specify them to be case-insensitive.
Resolver = new ODataUriResolver() { EnableCaseInsensitive = true }
};
FilterClause clause = parser.ParseFilter();
if (clause == null)
{
Console.WriteLine("FilterClause is null.");
}
else
{
ProcessNode(clause.Expression, 0, null);
}
}
catch (Exception ex)
{
while (ex != null)
{
Console.WriteLine(ex.Message + " ");
if (ex.InnerException != null)
{
ex = ex.InnerException;
}
else
{
break;
}
}
Console.WriteLine();
}
}
}
#endregion
#region Node processing methods
/// <summary>
/// Process a node of the OData filter.
/// </summary>
/// <param name="node">
/// Node to process.
/// </param>
/// <param name="level">
/// Indent level of this node.
/// </param>
/// <param name="parentName">
/// Name of the parent property of the nodes under the 'Any' operator.
/// </param>
/// <remarks>
/// OData filter is basically a binary tree, so we'll process it as such.
/// </remarks>
private static void ProcessNode
(
SingleValueNode node,
int level,
string? parentName
)
{
// The filter tree consists of nodes all of which are directly derived from SingleValueNode.
if (node == null)
{
// Shouldn't happen, but just in case.
return;
}
else if (node is BinaryOperatorNode binaryOperatorNode)
{
ProcessBinaryOperatorNode(binaryOperatorNode, level, parentName);
}
else if (node is SingleComplexNode singleComplexNode)
{
ProcessSingleComplexNode(singleComplexNode, level, parentName);
}
else if (node is SingleValueFunctionCallNode singleValueFunctionCallNode)
{
ProcessSingleValueFunctionCallNode(singleValueFunctionCallNode, level, parentName);
}
else if (node is SingleValueOpenPropertyAccessNode singleValueOpenPropertyAccessNode)
{
ProcessSingleValueOpenPropertyAccessNode(singleValueOpenPropertyAccessNode, level, parentName);
}
else if (node is SingleValuePropertyAccessNode singleValuePropertyAccessNode)
{
ProcessSingleValuePropertyAccessNode(singleValuePropertyAccessNode, level, parentName);
}
else if (node is InNode inNode)
{
ProcessInNode(inNode, level, parentName);
}
else if (node is ConstantNode constantNode)
{
ProcessConstantNode(constantNode, level);
}
else if (node is ConvertNode convertNode)
{
ProcessConvertNode(convertNode, level, parentName);
}
else if (node is UnaryOperatorNode unaryOperatorNode)
{
ProcessUnaryOperatorNode(unaryOperatorNode, level, parentName);
}
else if (node is AnyNode anyNode)
{
ProcessAnyNode(anyNode, level);
}
else if (node is NonResourceRangeVariableReferenceNode nonResourceRangeVariableReferenceNode)
{
ProcessNonResourceRangeVariableReferenceNode(nonResourceRangeVariableReferenceNode, level, parentName);
}
else
{
// There may be more node types that need to be handled explicitly,
// but for now, let's handle all unexpected nodes as a simple node.
ProcessSingleValueNode(node, level);
}
}
/// <inheritdoc cref="ProcessNode(SingleValueNode, int, string?)" path="param"/>
/// <summary>
/// Handles all kinds of nodes,
/// e.g. holding elements that must be converted to a certain data type, such as enum,
/// operator nodes, value nodes, etc.
/// </summary>
private static void ProcessConvertNode
(
ConvertNode node,
int level,
string? parentName
)
{
ProcessNode(node.Source, level, parentName);
}
/// <inheritdoc cref="ProcessNode(SingleValueNode, int, string?)" path="params"/>
/// <summary>
/// Handles the simplest node holding a single element.
/// </summary>
/// <remarks>
/// This method will also handle any nodes that are not handled by the node type-specific methods.
/// </remarks>
private static void ProcessSingleValueNode
(
SingleValueNode node,
int level
)
{
if (_printNode)
{
WriteLine(level, FormatNode(node.Kind));
}
}
/// <inheritdoc cref="ProcessNode(SingleValueNode, int, string?)" path="param"/>
/// <summary>
/// Handles a node holding a simple constant value, such as a string, a number, or a boolean.
/// </summary>
private static void ProcessConstantNode
(
ConstantNode node,
int level
)
{
WriteLine(level, FormatValue(node.Value ?? "(null)"));
}
/// <inheritdoc cref="ProcessNode(SingleValueNode, int, string?)" path="param"/>
/// <summary>
/// Handles values in the collection object (such as a collection inside of the 'in' clause).
/// </summary>
private static void ProcessCollectionConstantNode
(
CollectionConstantNode node,
int level,
string? parentName
)
{
foreach(var value in node.Collection)
{
ProcessNode(value, level, parentName);
}
}
/// <inheritdoc cref="ProcessNode(SingleValueNode, int, string?)" path="param"/>
/// <summary>
/// Handles a node holding a complex (i.e. nested) object property.
/// </summary>
private static void ProcessSingleComplexNode
(
SingleComplexNode node,
int level,
string? parentName
)
{
WriteLine(level, FormatProperty(node.Property.Name));
}
/// <inheritdoc cref="ProcessNode(SingleValueNode, int, string?)" path="param"/>
/// <summary>
/// Handles a node holding a simple object property.
/// </summary>
private static void ProcessSingleValuePropertyAccessNode
(
SingleValuePropertyAccessNode node,
int level,
string? parentName
)
{
WriteLine(level, FormatProperty(GetPropertyName(node, parentName)));
}
/// <inheritdoc cref="ProcessNode(SingleValueNode, int, string?)" path="param"/>
/// <summary>
/// Not sure what node this is, but based on the name it should be similar to SingleValuePropertyAccessNode.
/// </summary>
private static void ProcessSingleValueOpenPropertyAccessNode
(
SingleValueOpenPropertyAccessNode node,
int level,
string? parentName
)
{
WriteLine(level, FormatProperty(GetPropertyName(node, parentName)));
}
/// <inheritdoc cref="ProcessNode(SingleValueNode, int, string?)" path="params"/>
/// <summary>
/// Handles the nodes holding dynamic value such as aliases use in the 'Any' operator.
/// </summary>
private static void ProcessNonResourceRangeVariableReferenceNode
(
NonResourceRangeVariableReferenceNode node,
int level,
string? parentName
)
{
// In filter 'phoneNumbers/any(p: p eq '123-456-6789')', since 'p' is just an alias,
// we want to print 'phoneNumbers' because it is the name of the collection to
// to which the filter is applied.
// This node should be under a parent's 'Any' operation.
if (!string.IsNullOrEmpty(parentName))
{
WriteLine(level, FormatProperty(parentName));
}
// But just in case, we can just print the alias (e.g. 'p' in our example).
else
{
WriteLine(level, FormatProperty(node.RangeVariable.Name));
}
}
/// <inheritdoc cref="ProcessNode(SingleValueNode, int, string?)" path="param"/>
/// <summary>
/// Handles a unary operation node, such as 'not'.
/// </summary>
private static void ProcessUnaryOperatorNode
(
UnaryOperatorNode node,
int level,
string? parentName
)
{
ProcessSingleValueNode(node, level);
WriteLine(level, FormatOperator(node.OperatorKind));
ProcessNode(node.Operand, level + 1, parentName);
}
/// <inheritdoc cref="ProcessNode(SingleValueNode, int, string?)" path="param"/>
/// <summary>
/// Handles an any operation applicable to arrays, lists and collections.
/// </summary>
private static void ProcessAnyNode
(
AnyNode node,
int level
)
{
ProcessSingleValueNode(node, level);
WriteLine(level, FormatOperator(node.Kind));
string? parentName = null;
if (node.Source is CollectionPropertyAccessNode collectionPropertyAccessNode)
{
parentName = GetPropertyName(collectionPropertyAccessNode, null);
}
else if (node.Source is CollectionComplexNode collectionComplexNode)
{
parentName = GetPropertyName(collectionComplexNode, null);
}
if (!string.IsNullOrEmpty(parentName))
{
WriteLine(level + 1, FormatProperty(parentName));
ProcessNode(node.Body, level + 2, parentName);
}
else
{
ProcessNode(node.Body, level + 1, null);
}
}
/// <inheritdoc cref="ProcessNode(SingleValueNode, int, string?)" path="param"/>
/// <summary>
/// Handles a node holing an 'in' operation.
/// </summary>
private static void ProcessInNode
(
InNode node,
int level,
string? parentName
)
{
ProcessSingleValueNode(node, level);
WriteLine(level, FormatOperator(node.Kind));
// The left element of the in node holds the property name.
if (node.Left is SingleValuePropertyAccessNode singleValuePropertyAccessNode &&
!string.IsNullOrEmpty(singleValuePropertyAccessNode.Property?.Name))
{
WriteLine(level + 1, FormatProperty(GetPropertyName(singleValuePropertyAccessNode.Property?.Name ?? "", parentName)));
}
else if (node.Left is SingleValueOpenPropertyAccessNode singleValueOpenPropertyAccessNode &&
!string.IsNullOrEmpty(singleValueOpenPropertyAccessNode.Name))
{
WriteLine(level + 1, FormatProperty(GetPropertyName(singleValueOpenPropertyAccessNode.Name ?? "", parentName)));
}
// The right element of the in node holds the collection of the values.
if (node.Right is CollectionConstantNode collectionConstantNode)
{
ProcessCollectionConstantNode(collectionConstantNode, level + 1, parentName);
}
}
/// <inheritdoc cref="ProcessNode(SingleValueNode, int, string?)" path="param"/>
/// <summary>
/// Handles a node holding a function call, such as 'startsWith', 'contains', etc.
/// </summary>
private static void ProcessSingleValueFunctionCallNode
(
SingleValueFunctionCallNode node,
int level,
string? parentName
)
{
ProcessSingleValueNode(node, level);
WriteLine(level, FormatOperator(node.Name));
// The first item in the array of parameters holds the property being used in the function.
if (node.Parameters.FirstOrDefault() is SingleValuePropertyAccessNode param)
{
WriteLine(level + 1, FormatProperty(GetPropertyName(param.Property.Name, parentName)));
}
// The rest of the items must be constants.
IEnumerable<QueryNode> values = node.Parameters.Skip(1);
foreach (QueryNode value in values)
{
if (value is SingleValueNode singleValue)
{
ProcessNode(singleValue, level + 1, parentName);
}
}
}
/// <inheritdoc cref="ProcessNode(SingleValueNode, int, string?)" path="param"/>
/// <summary>
/// Handles a binary operator, such as 'eq', 'ne', 'and', 'or', etc.
/// </summary>
private static void ProcessBinaryOperatorNode
(
BinaryOperatorNode node,
int level,
string? parentName
)
{
ProcessSingleValueNode(node, level);
WriteLine(level, FormatOperator(node.OperatorKind));
ProcessNode(node.Left, level + 1, parentName);
ProcessNode(node.Right, level + 1, parentName);
}
#endregion
#region Property name formatting methods
/// <summary>
/// Appends name of the parent to the given name if needed.
/// </summary>
/// <param name="name">
/// Name of the property.
/// </param>
/// <param name="parentName">
/// Name of the parent collection property (to which the 'Any' operation is applied).
/// </param>
/// <returns>
/// Property name.
/// </returns>
private static string GetPropertyName
(
string name,
string? parentName
)
{
return string.IsNullOrEmpty(parentName)
? name
: parentName + _separator + name;
}
/// <inheritdoc cref="GetPropertyName(string, string)" path="param|returns"/>
/// <summary>
/// Generates the name of the complex (i.e. nested) property that includes the names of all parents.
/// </summary>
/// <param name="node">
/// Property node.
/// </param>
private static string GetPropertyName
(
SingleValuePropertyAccessNode node,
string? parentName
)
{
string path = "";
string parent;
if (node.Source == null)
{
return GetPropertyName(node.Property.Name, parentName);
}
// The source property point to the parent object referencing this property.
var source = node.Source;
while (source != null)
{
// There may be a couple of types used as sources.
// In our example, UserFilter.Name is a SingleComplexNode,
// while UserFilter.Sponsor.Name is a SingleNavigationNode.
// There may be other case, but I'm not sure how to test.
if (source is SingleComplexNode singleComplexNode &&
!string.IsNullOrEmpty(singleComplexNode.Property?.Name))
{
parent = singleComplexNode.Property.Name ?? "";
source = singleComplexNode.Source;
}
else if (source is SingleNavigationNode singleNavigationNode &&
!string.IsNullOrEmpty(singleNavigationNode.NavigationProperty?.Name))
{
parent = singleNavigationNode.NavigationProperty?.Name ?? "";
source = singleNavigationNode.Source;
}
else
{
break;
}
path = string.IsNullOrEmpty(path)
? parent
: parent + _separator + path;
}
return string.IsNullOrEmpty(path)
? GetPropertyName(node.Property.Name, parentName)
: GetPropertyName(GetPropertyName(node.Property.Name, path), parentName);
}
/// <inheritdoc cref="GetPropertyName(SingleValuePropertyAccessNode, string)" path="param|returns"/>
private static string GetPropertyName
(
SingleValueOpenPropertyAccessNode node,
string? parentName
)
{
string path = "";
string parent;
if (node.Source == null)
{
return GetPropertyName(node.Name, parentName);
}
// The source property point to the parent object referencing this property.
var source = node.Source;
while (source != null)
{
// There may be a couple of types used as sources.
// In our example, UserFilter.Name is a SingleComplexNode,
// while UserFilter.Sponsor.Name is a SingleNavigationNode.
// There may be other case, but I'm not sure how to test.
if (source is SingleComplexNode singleComplexNode &&
!string.IsNullOrEmpty(singleComplexNode.Property?.Name))
{
parent = singleComplexNode.Property.Name ?? "";
source = singleComplexNode.Source;
}
else if (source is SingleNavigationNode singleNavigationNode &&
!string.IsNullOrEmpty(singleNavigationNode.NavigationProperty?.Name))
{
parent = singleNavigationNode.NavigationProperty?.Name ?? "";
source = singleNavigationNode.Source;
}
else
{
break;
}
path = string.IsNullOrEmpty(path)
? parent
: parent + _separator + path;
}
return string.IsNullOrEmpty(path)
? GetPropertyName(node.Name, parentName)
: GetPropertyName(GetPropertyName(node.Name, path), parentName);
}
/// <inheritdoc cref="GetPropertyName(SingleValuePropertyAccessNode, string)" path="param|returns"/>
private static string GetPropertyName
(
CollectionComplexNode node,
string? parentName
)
{
string path = "";
string parent;
if (node.Source == null)
{
return GetPropertyName(node.Property.Name, parentName);
}
// The source property point to the parent object referencing this property.
var source = node.Source;
while (source != null)
{
// There may be a couple of types used as sources.
// In our example, UserFilter.Name is a SingleComplexNode,
// while UserFilter.Sponsor.Name is a SingleNavigationNode.
// There may be other case, but I'm not sure how to test.
if (source is SingleComplexNode singleComplexNode &&
!string.IsNullOrEmpty(singleComplexNode.Property?.Name))
{
parent = singleComplexNode.Property.Name ?? "";
source = singleComplexNode.Source;
}
else if (source is SingleNavigationNode singleNavigationNode &&
!string.IsNullOrEmpty(singleNavigationNode.NavigationProperty?.Name))
{
parent = singleNavigationNode.NavigationProperty?.Name ?? "";
source = singleNavigationNode.Source;
}
else
{
break;
}
path = string.IsNullOrEmpty(path)
? parent
: parent + _separator + path;
}
return string.IsNullOrEmpty(path)
? GetPropertyName(node.Property.Name, parentName)
: GetPropertyName(GetPropertyName(node.Property.Name, path), parentName);
}
/// <inheritdoc cref="GetPropertyName(SingleValuePropertyAccessNode, string)" path="param|returns"/>
private static string GetPropertyName
(
CollectionPropertyAccessNode node,
string? parentName
)
{
string path = "";
string parent;
if (node.Source == null)
{
return GetPropertyName(node.Property.Name, parentName);
}
// The source property point to the parent object referencing this property.
var source = node.Source;
while (source != null)
{
// There may be a couple of types used as sources.
// In our example, UserFilter.Name is a SingleComplexNode,
// while UserFilter.Sponsor.Name is a SingleNavigationNode.
// There may be other case, but I'm not sure how to test.
if (source is SingleComplexNode singleComplexNode &&
!string.IsNullOrEmpty(singleComplexNode.Property?.Name))
{
parent = singleComplexNode.Property.Name ?? "";
source = singleComplexNode.Source;
}
else if (source is SingleNavigationNode singleNavigationNode &&
!string.IsNullOrEmpty(singleNavigationNode.NavigationProperty?.Name))
{
parent = singleNavigationNode.NavigationProperty?.Name ?? "";
source = singleNavigationNode.Source;
}
else
{
break;
}
path = string.IsNullOrEmpty(path)
? parent
: parent + _separator + path;
}
return string.IsNullOrEmpty(path)
? GetPropertyName(node.Property.Name, parentName)
: GetPropertyName(GetPropertyName(node.Property.Name, path), parentName);
}
#endregion
#region Output formatting methods
/// <summary>
/// Formats node message.
/// </summary>
/// <param name="name">
/// Name of the node.
/// </param>
/// <returns>
/// Formatted node message.
/// </returns>
private static string FormatNode
(
object name
)
{
return "NODE: " + name;
}
/// <summary>
/// Formats operator message.
/// </summary>
/// <param name="name">
/// Name of the operator.
/// </param>
/// <returns>
/// Formatted operator message.
/// </returns>
private static string FormatOperator
(
object name
)
{
return "OPERATOR: " + name;
}
/// <summary>
/// Formats property message.
/// </summary>
/// <param name="name">
/// Name of the property.
/// </param>
/// <returns>
/// Formatted property message.
/// </returns>
private static string FormatProperty
(
object name
)
{
return "PROPERTY: " + name;
}
/// <summary>
/// Formats value message.
/// </summary>
/// <param name="name">
/// Name of the value.
/// </param>
/// <returns>
/// Formatted value message.
/// </returns>
private static string FormatValue
(
object name
)
{
return "VALUE: " + name;
}
#endregion
#region Print functions
/// <summary>
/// Prints text with appropriate indentation.
/// </summary>
/// <param name="indentLevel">
/// Indentation level.
/// </param>
/// <param name="message">
/// Message text.
/// </param>
/// <param name="args">
/// Optional message parameters.
/// </param>
private static void WriteLine
(
int indentLevel,
string message,
params object[] args
)
{
string indent = new(' ', indentLevel * _indentLength);
Console.WriteLine(indent + message, args);
}
#endregion
}
#region Data models used by the OData filter
/// <summary>
/// Defines types of users.
/// </summary>
public enum UserType
{
Employee,
Contractor,
Guest
}
/// <summary>
/// Defines name parts.
/// </summary>
public class PersonName
{
public string? GivenName
{
get; set;
}
public string? NickName
{
get; set;
}
public string? Surname
{
get; set;
}
public char? MiddleInitial
{
get; set;
}
}
/// <summary>
/// Defines social login info.
/// </summary>
public class SocialLogin
{
public string? Name
{
get; set;
}
public string? Url
{
get; set;
}
}
/// <summary>
/// Primary filter object (it may not necessarily correspond to the corresponding backend entity).
/// </summary>
public class User
{
public int? Id
{
get; set;
}
public UserType? Type
{
get; set;
}
public PersonName? Name
{
get; set;
}
public string? DisplayName
{
get; set;
}
public string? Email
{
get; set;
}
public bool? Enabled
{
get; set;
}
// Use this property to test complex properties (it can be nested indefinitely).
public User? Sponsor
{
get; set;
}
public string[]? PhoneNumbers
{
get; set;
}
public List<SocialLogin>? SocialLogins
{
get; set;
}
}
#endregion
Here is the program output:
ODATA SCHEMA ELEMENTS:
- TestOData1.User: TypeDefinition
- TestOData1.PersonName: TypeDefinition
- TestOData1.SocialLogin: TypeDefinition
- TestOData1.UserType: TypeDefinition
- Default.Container: EntityContainer
------------------------------------------------------------------------
EXPRESSION: not(enabled)
------------------------------------------------------------------------
OPERATOR: Not
PROPERTY: Enabled
------------------------------------------------------------------------
EXPRESSION: not(true)
------------------------------------------------------------------------
OPERATOR: Not
VALUE: True
------------------------------------------------------------------------
EXPRESSION: email eq null
------------------------------------------------------------------------
OPERATOR: Equal
PROPERTY: Email
VALUE: (null)
------------------------------------------------------------------------
EXPRESSION: email ne null
------------------------------------------------------------------------
OPERATOR: NotEqual
PROPERTY: Email
VALUE: (null)
------------------------------------------------------------------------
EXPRESSION: email eq 'john@mail.com'
------------------------------------------------------------------------
OPERATOR: Equal
PROPERTY: Email
VALUE: john@mail.com
------------------------------------------------------------------------
EXPRESSION: email ne 'john@mail.com'
------------------------------------------------------------------------
OPERATOR: NotEqual
PROPERTY: Email
VALUE: john@mail.com
------------------------------------------------------------------------
EXPRESSION: email eq displayName
------------------------------------------------------------------------
OPERATOR: Equal
PROPERTY: Email
PROPERTY: DisplayName
------------------------------------------------------------------------
EXPRESSION: email ne displayName
------------------------------------------------------------------------
OPERATOR: NotEqual
PROPERTY: Email
PROPERTY: DisplayName
------------------------------------------------------------------------
EXPRESSION: contains(email, '@')
------------------------------------------------------------------------
OPERATOR: contains
PROPERTY: Email
VALUE: @
------------------------------------------------------------------------
EXPRESSION: not contains(email, '@')
------------------------------------------------------------------------
OPERATOR: Not
OPERATOR: contains
PROPERTY: Email
VALUE: @
------------------------------------------------------------------------
EXPRESSION: contains(email, displayName)
------------------------------------------------------------------------
OPERATOR: contains
PROPERTY: Email
PROPERTY: DisplayName
------------------------------------------------------------------------
EXPRESSION: not contains(email, displayName)
------------------------------------------------------------------------
OPERATOR: Not
OPERATOR: contains
PROPERTY: Email
PROPERTY: DisplayName
------------------------------------------------------------------------
EXPRESSION: startsWith(email, 'john')
------------------------------------------------------------------------
OPERATOR: startswith
PROPERTY: Email
VALUE: john
------------------------------------------------------------------------
EXPRESSION: not startsWith(email, 'john')
------------------------------------------------------------------------
OPERATOR: Not
OPERATOR: startswith
PROPERTY: Email
VALUE: john
------------------------------------------------------------------------
EXPRESSION: endsWith(email, '@mail.com')
------------------------------------------------------------------------
OPERATOR: endswith
PROPERTY: Email
VALUE: @mail.com
------------------------------------------------------------------------
EXPRESSION: not endsWith(email, '@mail.com')
------------------------------------------------------------------------
OPERATOR: Not
OPERATOR: endswith
PROPERTY: Email
VALUE: @mail.com
------------------------------------------------------------------------
EXPRESSION: email in ('john@mail.com', 'mary@mail.com')
------------------------------------------------------------------------
OPERATOR: In
PROPERTY: Email
VALUE: john@mail.com
VALUE: mary@mail.com
------------------------------------------------------------------------
EXPRESSION: not (email in ('john@mail.com', 'mary@mail.com'))
------------------------------------------------------------------------
OPERATOR: Not
OPERATOR: In
PROPERTY: Email
VALUE: john@mail.com
VALUE: mary@mail.com
------------------------------------------------------------------------
EXPRESSION: id eq 0
------------------------------------------------------------------------
OPERATOR: Equal
PROPERTY: Id
VALUE: 0
------------------------------------------------------------------------
EXPRESSION: id gt 0
------------------------------------------------------------------------
OPERATOR: GreaterThan
PROPERTY: Id
VALUE: 0
------------------------------------------------------------------------
EXPRESSION: id lt 2000
------------------------------------------------------------------------
OPERATOR: LessThan
PROPERTY: Id
VALUE: 2000
------------------------------------------------------------------------
EXPRESSION: id ge 1
------------------------------------------------------------------------
OPERATOR: GreaterThanOrEqual
PROPERTY: Id
VALUE: 1
------------------------------------------------------------------------
EXPRESSION: id le 2000
------------------------------------------------------------------------
OPERATOR: LessThanOrEqual
PROPERTY: Id
VALUE: 2000
------------------------------------------------------------------------
EXPRESSION: name eq null
------------------------------------------------------------------------
OPERATOR: Equal
PROPERTY: Name
VALUE: (null)
------------------------------------------------------------------------
EXPRESSION: name ne null
------------------------------------------------------------------------
OPERATOR: NotEqual
PROPERTY: Name
VALUE: (null)
------------------------------------------------------------------------
EXPRESSION: name/givenName eq null
------------------------------------------------------------------------
OPERATOR: Equal
PROPERTY: Name/GivenName
VALUE: (null)
------------------------------------------------------------------------
EXPRESSION: sponsor/name/givenName eq null
------------------------------------------------------------------------
OPERATOR: Equal
PROPERTY: Sponsor/Name/GivenName
VALUE: (null)
------------------------------------------------------------------------
EXPRESSION: name/surname ne sponsor/name/surname
------------------------------------------------------------------------
OPERATOR: NotEqual
PROPERTY: Name/Surname
PROPERTY: Sponsor/Name/Surname
------------------------------------------------------------------------
EXPRESSION: name/givenName in ('John', 'Mary')
------------------------------------------------------------------------
OPERATOR: In
PROPERTY: GivenName
VALUE: John
VALUE: Mary
------------------------------------------------------------------------
EXPRESSION: name/givenName ne name/nickName
------------------------------------------------------------------------
OPERATOR: NotEqual
PROPERTY: Name/GivenName
PROPERTY: Name/NickName
------------------------------------------------------------------------
EXPRESSION: startsWith(displayName, 'J')
------------------------------------------------------------------------
OPERATOR: startswith
PROPERTY: DisplayName
VALUE: J
------------------------------------------------------------------------
EXPRESSION: type eq 'Employee'
------------------------------------------------------------------------
OPERATOR: Equal
PROPERTY: Type
VALUE: Employee
------------------------------------------------------------------------
EXPRESSION: type eq 'Guest' and name/Surname eq 'Johnson'
------------------------------------------------------------------------
OPERATOR: And
OPERATOR: Equal
PROPERTY: Type
VALUE: Guest
OPERATOR: Equal
PROPERTY: Name/Surname
VALUE: Johnson
------------------------------------------------------------------------
EXPRESSION: type eq 'Contractor' and not(endsWith(email, '@mail.com'))
------------------------------------------------------------------------
OPERATOR: And
OPERATOR: Equal
PROPERTY: Type
VALUE: Contractor
OPERATOR: Not
OPERATOR: endswith
PROPERTY: Email
VALUE: @mail.com
------------------------------------------------------------------------
EXPRESSION: enabled eq false and type in ('Employee', 'Contractor')
------------------------------------------------------------------------
OPERATOR: And
OPERATOR: Equal
PROPERTY: Enabled
VALUE: False
OPERATOR: In
PROPERTY: Type
VALUE: Employee
VALUE: Contractor
------------------------------------------------------------------------
EXPRESSION: (enabled eq true and type eq 'Employee') or (enabled eq false and (type eq 'Guest' or endsWith(email, '@mail.com')))
------------------------------------------------------------------------
OPERATOR: Or
OPERATOR: And
OPERATOR: Equal
PROPERTY: Enabled
VALUE: True
OPERATOR: Equal
PROPERTY: Type
VALUE: Employee
OPERATOR: And
OPERATOR: Equal
PROPERTY: Enabled
VALUE: False
OPERATOR: Or
OPERATOR: Equal
PROPERTY: Type
VALUE: Guest
OPERATOR: endswith
PROPERTY: Email
VALUE: @mail.com
------------------------------------------------------------------------
EXPRESSION: phoneNumbers/any(p: p eq '123-456-6789')
------------------------------------------------------------------------
OPERATOR: Any
PROPERTY: PhoneNumbers
OPERATOR: Equal
PROPERTY: PhoneNumbers
VALUE: 123-456-6789
------------------------------------------------------------------------
EXPRESSION: socialLogins/any(s: s/name eq 'Facebook')
------------------------------------------------------------------------
OPERATOR: Any
PROPERTY: SocialLogins
OPERATOR: Equal
PROPERTY: SocialLogins/Name
VALUE: Facebook
------------------------------------------------------------------------
EXPRESSION: socialLogins/any(s: s/name eq 'Facebook' or endsWith(s/url, 'google.com'))
------------------------------------------------------------------------
OPERATOR: Any
PROPERTY: SocialLogins
OPERATOR: Or
OPERATOR: Equal
PROPERTY: SocialLogins/Name
VALUE: Facebook
OPERATOR: endswith
PROPERTY: SocialLogins/Url
VALUE: google.com
------------------------------------------------------------------------
EXPRESSION: sponsor/phoneNumbers/any(p: p eq '123-456-6789')
------------------------------------------------------------------------
OPERATOR: Any
PROPERTY: Sponsor/PhoneNumbers
OPERATOR: Equal
PROPERTY: Sponsor/PhoneNumbers
VALUE: 123-456-6789
------------------------------------------------------------------------
EXPRESSION: sponsor/socialLogins/any(s: s/name eq 'Facebook')
------------------------------------------------------------------------
OPERATOR: Any
PROPERTY: Sponsor/SocialLogins
OPERATOR: Equal
PROPERTY: Sponsor/SocialLogins/Name
VALUE: Facebook
Enjoy!
