Interface support

DEVELOPER.md

@@ -0,0 +1,233 @@
+# Developer Guide
+
+This document provides comprehensive guidance for developers working on the Linq2GraphQL.Client project, particularly when modifying T4 templates and the code generation system.
+
+## Table of Contents
+
+- [Prerequisites](#prerequisites)
+- [Project Structure](#project-structure)
+- [T4 Template Development](#t4-template-development)
+- [Code Generation Workflow](#code-generation-workflow)
+- [Troubleshooting](#troubleshooting)
+- [Best Practices](#best-practices)
+
+## Prerequisites
+
+- **Visual Studio 2022** (recommended) or Visual Studio 2019/2022
+- **.NET 8.0 SDK** or later
+- **T4 Template Support** - Ensure the "Text Template Transformation" workload is installed in Visual Studio
+
+## Project Structure
+
+```
+src/
+├── Linq2GraphQL.Generator/           # Main code generation project
+│   ├── Templates/                     # T4 template files
+│   │   ├── Client/                    # Client generation templates
+│   │   ├── Class/                     # Class generation templates
+│   │   ├── Interface/                 # Interface generation templates
+│   │   ├── Methods/                   # Method generation templates
+│   │   └── Enum/                      # Enum generation templates
+│   ├── GraphQLSchema/                 # Schema parsing and processing
+│   └── ClientGenerator.cs             # Main generation orchestration
+└── Linq2GraphQL.Client/              # Core client library
+```
+
+## T4 Template Development
+
+### Understanding T4 Templates
+
+This project uses **T4 (Text Template Transformation Toolkit)** for code generation. T4 templates are `.tt` files that generate C# source code based on GraphQL schema information.
+
+#### Template File Types
+
+- **`.tt`** - Source T4 template files (human-editable)
+- **`.tt.cs`** - Partial class definitions for template variables and helper methods
+- **`.cs`** - Preprocessed T4 templates (auto-generated, contains the actual `TransformText()` method)
+
+### Template Development Workflow
+
+#### 1. Modifying T4 Templates
+
+When modifying `.tt` files:
+
+1. **Edit the `.tt` file** with your changes
+2. **Manually regenerate the `.cs` file** using Visual Studio's custom tool
+3. **Build the project** to ensure compilation
+4. **Test the generation** by running the client generator
+
+#### 2. Manual Template Regeneration
+
+**⚠️ IMPORTANT: After modifying any `.tt` file, you MUST manually regenerate the corresponding `.cs` file.**
+
+**In Visual Studio 2022:**
+
+1. Right-click on the `.tt` file in Solution Explorer
+2. Select **"Run Custom Tool"**
+3. This will regenerate the `.cs` file with your changes
+4. Verify the `.cs` file contains your updated template logic
+
+**Alternative method:**
+1. Right-click on the `.tt` file
+2. Select **"Properties"**
+3. Set **"Custom Tool"** to `TextTemplatingFilePreprocessor`
+4. Set **"Custom Tool Namespace"** to your desired namespace
+5. Save the file to trigger regeneration
+
+#### 3. Template File Dependencies
+
+Each T4 template requires:
+
+- **`.tt` file** - Contains the template logic and output format
+- **`.tt.cs` file** - Provides the partial class with constructor parameters and helper methods
+- **`.cs` file** - Auto-generated preprocessed template (regenerated from `.tt`)
+
+### Template Syntax
+
+#### Basic T4 Directives
+
+```t4
+<#@ template language="C#" #>
+<#@ assembly name="System.Core" #>
+<#@ import namespace="System.Linq" #>
+```
+
+#### Template Expressions
+
+```t4
+<#= variableName #>                    <!-- Output variable value -->
+<# if (condition) { #>                 <!-- Conditional blocks -->
+    // C# code here
+<# } #>
+<# foreach (var item in collection) { #> <!-- Loops -->
+    // Process each item
+<# } #>
+```
+
+#### Helper Methods
+
+Define helper methods in the `.tt.cs` file:
+
+```csharp
+public partial class TemplateName
+{
+    private readonly string variableName;
+
+    public TemplateName(string variableName)
+    {
+        this.variableName = variableName;
+    }
+
+    private string HelperMethod()
+    {
+        return "Helper logic here";
+    }
+}
+```
+
+## Code Generation Workflow
+
+### 1. Development Cycle
+
+```
+Edit .tt file → Run Custom Tool → Build Project → Test Generation → Repeat
+```
+
+### 2. Testing Changes
+
+After modifying templates:
+
+1. **Build the project** to ensure no compilation errors
+2. **Run the client generator** to test template output
+3. **Verify generated code** matches your expectations
+4. **Test the generated client** in a sample application
+
+### 3. Command Line Generation
+
+```bash
+# Build the generator project
+dotnet build src/Linq2GraphQL.Generator
+
+# Generate a client
+dotnet run --project src/Linq2GraphQL.Generator -- <endpoint> [options]
+```
+
+## Troubleshooting
+
+### Common Issues
+
+#### T4 Templates Not Regenerating
+
+**Problem:** Changes to `.tt` files not reflected in generated output.
+
+**Solution:**
+1. Ensure you've run the **"Run Custom Tool"** on the `.tt` file
+2. Check that the `.cs` file was updated with your changes
+3. Clean and rebuild the project
+4. Verify the T4 preprocessor is working in Visual Studio
+
+#### Missing TransformText Method
+
+**Problem:** Compilation error "does not contain a definition for 'TransformText'".
+
+**Solution:**
+1. The `.cs` file is missing or outdated
+2. Run **"Run Custom Tool"** on the corresponding `.tt` file
+3. Ensure the `.tt.cs` file exists and has the correct partial class definition
+
+#### Template Variables Not Available
+
+**Problem:** Template variables like `namespaceName` or `name` are undefined.
+
+**Solution:**
+1. Check the `.tt.cs` file has the correct constructor parameters
+2. Verify the partial class has `readonly` fields for all template variables
+3. Ensure the `ClientGenerator.cs` passes the correct parameters when instantiating templates
+
+### Debugging Tips
+
+1. **Check the `.cs` file content** - It should contain your template logic in the `TransformText()` method
+2. **Verify template compilation** - Build errors often indicate template syntax issues
+3. **Use Visual Studio's T4 debugging** - Set breakpoints in the generated `.cs` files
+4. **Check build output** - Look for T4-related error messages
+
+## Best Practices
+
+### Template Design
+
+1. **Keep templates focused** - Each template should handle one specific aspect of code generation
+2. **Use helper methods** - Move complex logic to the `.tt.cs` file
+3. **Maintain readability** - Use clear variable names and consistent formatting
+4. **Handle edge cases** - Always check for null values and empty collections
+
+### Code Organization
+
+1. **Separate concerns** - Keep template logic separate from business logic
+2. **Use partial classes** - Leverage C# partial classes for template organization
+3. **Consistent naming** - Follow the project's naming conventions
+4. **Documentation** - Include XML comments in generated code
+
+### Testing
+
+1. **Test with various schemas** - Ensure templates work with different GraphQL schemas
+2. **Validate generated code** - Check that generated code compiles and works correctly
+3. **Regression testing** - Ensure changes don't break existing functionality
+4. **Integration testing** - Test the complete generation pipeline
+
+### Version Control
+
+1. **Commit `.tt` and `.tt.cs` files** - These are source files
+2. **Ignore generated `.cs` files** - Add `**/*.cs` to `.gitignore` for auto-generated files
+3. **Document template changes** - Include clear commit messages for template modifications
+4. **Review generated output** - Verify that template changes produce the expected results
+
+## Getting Help
+
+- **Check existing templates** - Review similar templates for examples
+- **T4 documentation** - Microsoft's T4 documentation provides comprehensive guidance
+- **Project issues** - Search existing GitHub issues for similar problems
+- **Community support** - Reach out to the project maintainers or community
+
+---
+
+**Note:** T4 template development requires careful attention to the regeneration workflow. Always remember to run the custom tool after modifying `.tt` files to ensure your changes are applied to the generated code.

Directory.Packages.props

@@ -1,43 +1,44 @@
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+  <PropertyGroup>
+    <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
+  </PropertyGroup>
+  <ItemGroup>
+    <GlobalPackageReference Include="Nerdbank.GitVersioning" Version="3.7.115" />
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+    <PackageVersion Include="ColorCode.HTML" Version="2.0.15" />
+    <PackageVersion Include="coverlet.collector" Version="6.0.4">
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+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
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+    <PackageVersion Include="HotChocolate.Data" Version="13.9.12" />
+    <PackageVersion Include="HotChocolate.Types.Scalars" Version="13.9.12" />
+    <PackageVersion Include="Macross.Json.Extensions" Version="3.0.0" />
+    <PackageVersion Include="Microsoft.AspNetCore.Components.WebAssembly" Version="8.0.8" />
+    <PackageVersion Include="Microsoft.AspNetCore.Components.WebAssembly.DevServer" Version="8.0.8" />
+    <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="8.0.8" />
+    <PackageVersion Include="Microsoft.Extensions.Caching.Memory" Version="8.0.1" />
+    <PackageVersion Include="Microsoft.Extensions.Configuration" Version="8.0.0" />
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+    <PackageVersion Include="Microsoft.Extensions.Configuration.Json" Version="8.0.1" />
+    <PackageVersion Include="Microsoft.Extensions.DependencyInjection" Version="8.0.1" />
+    <PackageVersion Include="Microsoft.Extensions.Http" Version="8.0.1" />
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+  </ItemGroup>
 </Project>

README.md

@@ -100,6 +100,20 @@ Turning on *SafeMode* will make the client before the first request to do an int
 # Acknowledgments
 Linq2GraphQL is inspired by [GraphQLinq](https://github.com/Giorgi/GraphQLinq) , thank you [Giorgi](https://github.com/Giorgi)
 
+## Contributing
+
+Are you a developer looking to contribute to this project? Please see our [Developer Guide](DEVELOPER.md) for comprehensive information about:
+
+- T4 template development workflow
+- Code generation system architecture
+- Troubleshooting common issues
+- Best practices for template development
+- Manual template regeneration process
+
+## Development Workflow
+
+**⚠️ Important for Developers:** When modifying T4 templates (`.tt` files), you must manually regenerate the corresponding `.cs` files using Visual Studio's "Run Custom Tool" feature. See [DEVELOPER.md](DEVELOPER.md) for detailed instructions.
+
 [![Stargazers repo roster for @linq2graphql/linq2graphql.client](https://reporoster.com/stars/dark/linq2graphql/linq2graphql.client)](https://github.com/linq2graphql/linq2graphql.client/stargazers)
 
 

nuget.config

@@ -2,6 +2,9 @@
 <configuration>
   <packageSources>
     <clear />
-      <add key="Nuget" value="https://api.nuget.org/v3/index.json" />
+    <add key="Nuget" value="https://api.nuget.org/v3/index.json" />
   </packageSources>
+  <packageSourceMapping>
+    <clear />
+  </packageSourceMapping>
 </configuration>

nuget.config.backup

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <packageSources>
+    <clear />
+      <add key="Nuget" value="https://api.nuget.org/v3/index.json" />
+  </packageSources>
+</configuration>