Add configuration-based variable expansion for snippets

README.md

@@ -85,3 +85,31 @@ Enables snippets you declare in XML syntax. The `FilePath` is a path to the root
 ### Snippets
 
 In addition to the XML snippets, you can declare some snippets using `Snippets` object. The probably main difference is that the XML is more readable for longer snippets and better escapes special characters in CDATA sections. Use these as you wish.
+
+### Variables
+
+The `Variables` section lets you declare named values that are substituted into snippet text at apply/copy time. This makes it easy to share snippets across machines or operating systems.
+
+**Syntax:** use `{VariableName}` placeholders inside any snippet text.
+
+**Configuration example:**
+
+```json
+{
+  "Variables": {
+    "ShellExt": "ps1"
+  },
+  "Snippets": {
+    "Install": "Run install.{ShellExt} to get started."
+  }
+}
+```
+
+On macOS/Linux you would set `"ShellExt": "sh"`, on Windows `"ShellExt": "ps1"`. The snippet text `"Run install.{ShellExt} to get started."` expands to the correct value at apply/copy time, while the snippet source stays unchanged.
+
+**Notes:**
+- Variable names are matched exactly as declared (case-sensitive).
+- Unknown tokens (variables not declared in `Variables`) are left verbatim in the expanded text — you typically don't need to escape literal `{Name}` content unless `Name` happens to match a declared variable.
+- To prevent a `{Name}` span from being expanded (when the name collides with a declared variable), wrap it as `{{Name}}`. The braces are preserved in the output.
+- If a snippet text fails to parse (e.g. contains JSON-like `{...}` syntax), the text is returned unchanged.
+- Snippet search always runs against the raw (unexpanded) template text.

src/Directory.Packages.props

@@ -3,6 +3,7 @@
     <FrameworkPackageVersion>10.0.0</FrameworkPackageVersion>
   </PropertyGroup>
   <ItemGroup>
+    <PackageVersion Include="Neptuo" Version="6.0.2" />
     <PackageVersion Include="Neptuo.Windows.Converters" Version="1.0.0" />
     <PackageVersion Include="Neptuo.Windows.HotKeys" Version="2.0.0" />
     <PackageVersion Include="Neptuo.Windows.Threading" Version="1.0.1" />

src/Neptuo.Productivity.SnippetManager.Avalonia/App.axaml.cs

@@ -6,6 +6,7 @@
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
 using Avalonia.Threading;
+using Neptuo.Productivity.SnippetManager.Variables;
 
 namespace Neptuo.Productivity.SnippetManager;
 
@@ -68,7 +69,8 @@ public override void OnFrameworkInitializationCompleted()
         enabled => configurationWatcher?.EnableRaisingEventsFromConfigurationWatcher(enabled),
         shutdown,
         GetExampleConfiguration,
-        GetCurrentHotkey
+        GetCurrentHotkey,
+        configuration.Variables
     );
 
     private void RequestShutdown(IClassicDesktopStyleApplicationLifetime desktop)
@@ -119,6 +121,7 @@ private Configuration GetExampleConfiguration()
     {
         var example = new Configuration();
         example.General = GeneralConfiguration.Example;
+        example.Variables = VariablesConfiguration.Example;
         snippetProviders.AddExampleConfigurations(example.Providers);
         return example;
     }

src/Neptuo.Productivity.SnippetManager.Avalonia/Navigator.cs

@@ -8,6 +8,7 @@
 using Avalonia.Media;
 using Avalonia.Threading;
 using Neptuo.Productivity.SnippetManager.Services;
+using Neptuo.Productivity.SnippetManager.Variables;
 using Neptuo.Productivity.SnippetManager.ViewModels;
 using Neptuo.Productivity.SnippetManager.ViewModels.Commands;
 using Neptuo.Productivity.SnippetManager.Views;
@@ -24,9 +25,10 @@ public class Navigator : IClipboardService, ISendTextService
     private readonly Func<Configuration> getExampleConfiguration;
     private readonly Func<string> getCurrentHotkey;
     private readonly ConfigurationRepository configurationRepository;
+    private readonly SnippetExpansionPipeline expansionPipeline;
     private int? lastExternalProcessId;
 
-    public Navigator(ISnippetProvider snippetProvider, ConfigurationRepository configurationRepository, Action<bool> setConfigChangeEnabled, Action shutdown, Func<Configuration> getExampleConfiguration, Func<string> getCurrentHotkey)
+    public Navigator(ISnippetProvider snippetProvider, ConfigurationRepository configurationRepository, Action<bool> setConfigChangeEnabled, Action shutdown, Func<Configuration> getExampleConfiguration, Func<string> getCurrentHotkey, VariablesConfiguration? variables)
     {
         this.snippetProvider = snippetProvider;
         this.configurationRepository = configurationRepository;
@@ -36,6 +38,11 @@ public Navigator(ISnippetProvider snippetProvider, ConfigurationRepository confi
         this.getCurrentHotkey = getCurrentHotkey;
         this.snippetProviderContext = new();
         this.snippetProviderContext.Changed += OnModelsChanged;
+        this.expansionPipeline = new SnippetExpansionPipeline(
+            new TokenSnippetVariableScanner(),
+            new ConfigurationVariableValueResolver(variables),
+            new TokenSnippetTextExpander()
+        );
 
         snippetProviderInitializeTask = snippetProvider.InitializeAsync(snippetProviderContext);
     }
@@ -58,7 +65,7 @@ public void OpenMain(bool stickToActiveCaret = true)
         {
             main = new MainWindow();
             main.Closed += (sender, e) => { main = null; };
-            main.ViewModel = new MainViewModel(snippetProviderContext, new ApplySnippetCommand(this), new CopySnippetCommand(this));
+            main.ViewModel = new MainViewModel(snippetProviderContext, new ApplySnippetCommand(this, expansionPipeline), new CopySnippetCommand(this, expansionPipeline));
             UpdateWindowPositionAnchor(main, stickToActiveCaret);
             shouldRefreshSnippets = true;
         }

src/Neptuo.Productivity.SnippetManager.Avalonia/Views/DesignData/ViewModelLocator.cs

@@ -1,11 +1,18 @@
 using Neptuo.Productivity.SnippetManager.Models;
+using Neptuo.Productivity.SnippetManager.Variables;
 using Neptuo.Productivity.SnippetManager.ViewModels;
 using Neptuo.Productivity.SnippetManager.ViewModels.Commands;
 
 namespace Neptuo.Productivity.SnippetManager.Views.DesignData;
 
 internal class ViewModelLocator
 {
+    private static readonly SnippetExpansionPipeline emptyPipeline = new SnippetExpansionPipeline(
+        new TokenSnippetVariableScanner(),
+        new ConfigurationVariableValueResolver(null),
+        new TokenSnippetTextExpander()
+    );
+
     private static MainViewModel? mainViewModel;
     public static MainViewModel MainViewModel
     {
@@ -17,8 +24,8 @@ public static MainViewModel MainViewModel
 
                 mainViewModel = new MainViewModel(
                     tree,
-                    new ApplySnippetCommand(InteropService.Instance),
-                    new CopySnippetCommand(InteropService.Instance)
+                    new ApplySnippetCommand(InteropService.Instance, emptyPipeline),
+                    new CopySnippetCommand(InteropService.Instance, emptyPipeline)
                 );
 
                 mainViewModel.Snippets.AddRange(tree.GetRoots());

src/Neptuo.Productivity.SnippetManager.UI/App.xaml.cs

@@ -2,6 +2,7 @@
 using System.IO;
 using System.Text.Json;
 using System.Windows;
+using Neptuo.Productivity.SnippetManager.Variables;
 using Application = System.Windows.Application;
 using MessageBox = System.Windows.MessageBox;
 
@@ -55,7 +56,8 @@ protected override void OnStartup(StartupEventArgs e)
             configurationRepository,
             enabled => configurationWatcher.EnableRaisingEventsFromConfigurationWatcher(enabled),
             Shutdown,
-            GetExampleConfiguration
+            GetExampleConfiguration,
+            configuration.Variables
         );
 
         private string GetXmlConfigurationPath() 
@@ -73,6 +75,7 @@ private Configuration GetExampleConfiguration()
         {
             var example = new Configuration();
             example.General = GeneralConfiguration.Example;
+            example.Variables = VariablesConfiguration.Example;
             snippetProviders.AddExampleConfigurations(example.Providers);
 
             return example;

src/Neptuo.Productivity.SnippetManager.UI/Navigator.cs

@@ -4,6 +4,7 @@
 using System.Windows.Forms;
 using System.Windows.Input;
 using Neptuo.Productivity.SnippetManager.Services;
+using Neptuo.Productivity.SnippetManager.Variables;
 using Neptuo.Productivity.SnippetManager.ViewModels;
 using Neptuo.Productivity.SnippetManager.ViewModels.Commands;
 using Neptuo.Productivity.SnippetManager.Views;
@@ -24,8 +25,9 @@ public class Navigator : IClipboardService, ISendTextService
     private readonly Action shutdown;
     private readonly Func<Configuration> getExampleConfiguration;
     private readonly ConfigurationRepository configurationRepository;
+    private readonly SnippetExpansionPipeline expansionPipeline;
 
-    public Navigator(ISnippetProvider snippetProvider, ConfigurationRepository configurationRepository, Action<bool> setConfigChangeEnabled, Action shutdown, Func<Configuration> getExampleConfiguration)
+    public Navigator(ISnippetProvider snippetProvider, ConfigurationRepository configurationRepository, Action<bool> setConfigChangeEnabled, Action shutdown, Func<Configuration> getExampleConfiguration, VariablesConfiguration? variables)
     {
         this.snippetProvider = snippetProvider;
         this.configurationRepository = configurationRepository;
@@ -34,6 +36,11 @@ public Navigator(ISnippetProvider snippetProvider, ConfigurationRepository confi
         this.getExampleConfiguration = getExampleConfiguration;
         this.snippetProviderContext = new();
         this.snippetProviderContext.Changed += OnModelsChanged;
+        this.expansionPipeline = new SnippetExpansionPipeline(
+            new TokenSnippetVariableScanner(),
+            new ConfigurationVariableValueResolver(variables),
+            new TokenSnippetTextExpander()
+        );
 
         snippetProviderInitializeTask = snippetProvider.InitializeAsync(snippetProviderContext);
     }
@@ -52,7 +59,7 @@ public void OpenMain(bool stickToActiveCaret = true)
         {
             main = new MainWindow();
             main.Closed += (sender, e) => { main = null; };
-            main.ViewModel = new MainViewModel(snippetProviderContext, new ApplySnippetCommand(this), new CopySnippetCommand(this));
+            main.ViewModel = new MainViewModel(snippetProviderContext, new ApplySnippetCommand(this, expansionPipeline), new CopySnippetCommand(this, expansionPipeline));
             UpdateWindowStickPointToCaret(main, stickToActiveCaret);
 
             _ = UpdateSnippetsAsync(main.ViewModel);

src/Neptuo.Productivity.SnippetManager.UI/Views/DesignData/ViewModelLocator.cs

@@ -1,11 +1,18 @@
 using Neptuo.Productivity.SnippetManager.Models;
+using Neptuo.Productivity.SnippetManager.Variables;
 using Neptuo.Productivity.SnippetManager.ViewModels;
 using Neptuo.Productivity.SnippetManager.ViewModels.Commands;
 
 namespace Neptuo.Productivity.SnippetManager.Views.DesignData;
 
 internal class ViewModelLocator
 {
+    private static readonly SnippetExpansionPipeline emptyPipeline = new SnippetExpansionPipeline(
+        new TokenSnippetVariableScanner(),
+        new ConfigurationVariableValueResolver(null),
+        new TokenSnippetTextExpander()
+    );
+
     private static MainViewModel? mainViewModel;
     public static MainViewModel MainViewModel
     {
@@ -17,8 +24,8 @@ public static MainViewModel MainViewModel
 
                 mainViewModel = new MainViewModel(
                     tree, 
-                    new ApplySnippetCommand(InteropService.Instance), 
-                    new CopySnippetCommand(InteropService.Instance)
+                    new ApplySnippetCommand(InteropService.Instance, emptyPipeline), 
+                    new CopySnippetCommand(InteropService.Instance, emptyPipeline)
                 );
 
                 var gitHub = tree.GetRoots().First(s => s.Title == "GitHub");

src/Neptuo.Productivity.SnippetManager/Configuration.cs

@@ -1,11 +1,14 @@
 using System.Text.Json.Serialization;
+using Neptuo.Productivity.SnippetManager.Variables;
 
 namespace Neptuo.Productivity.SnippetManager;
 
 public class Configuration
 {
     public GeneralConfiguration? General { get; set; }
 
+    public VariablesConfiguration? Variables { get; set; }
+
     [JsonIgnore]
     public Dictionary<string, object> Providers { get; } = new();
 }

src/Neptuo.Productivity.SnippetManager/Neptuo.Productivity.SnippetManager.csproj

@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <ItemGroup>
+    <PackageReference Include="Neptuo" />
     <PackageReference Include="Neptuo.Observables" />
   </ItemGroup>
 

src/Neptuo.Productivity.SnippetManager/Variables/CompositeVariableValueResolver.cs

@@ -0,0 +1,16 @@
+namespace Neptuo.Productivity.SnippetManager.Variables;
+
+public class CompositeVariableValueResolver(IEnumerable<IVariableValueResolver> resolvers) : IVariableValueResolver
+{
+    public bool TryGetValue(string name, out string? value)
+    {
+        foreach (var resolver in resolvers)
+        {
+            if (resolver.TryGetValue(name, out value))
+                return true;
+        }
+
+        value = null;
+        return false;
+    }
+}

src/Neptuo.Productivity.SnippetManager/Variables/ConfigurationVariableValueResolver.cs

@@ -0,0 +1,13 @@
+namespace Neptuo.Productivity.SnippetManager.Variables;
+
+public class ConfigurationVariableValueResolver(VariablesConfiguration? configuration) : IVariableValueResolver
+{
+    public bool TryGetValue(string name, out string? value)
+    {
+        if (configuration != null && configuration.TryGetValue(name, out value))
+            return true;
+
+        value = null;
+        return false;
+    }
+}

src/Neptuo.Productivity.SnippetManager/Variables/ISnippetTextExpander.cs

@@ -0,0 +1,6 @@
+namespace Neptuo.Productivity.SnippetManager.Variables;
+
+public interface ISnippetTextExpander
+{
+    string Expand(string text, IReadOnlyDictionary<string, string?> values);
+}

src/Neptuo.Productivity.SnippetManager/Variables/ISnippetVariableScanner.cs

@@ -0,0 +1,6 @@
+namespace Neptuo.Productivity.SnippetManager.Variables;
+
+public interface ISnippetVariableScanner
+{
+    IReadOnlyList<VariableReference> Scan(string text);
+}

src/Neptuo.Productivity.SnippetManager/Variables/IVariableValueResolver.cs

@@ -0,0 +1,6 @@
+namespace Neptuo.Productivity.SnippetManager.Variables;
+
+public interface IVariableValueResolver
+{
+    bool TryGetValue(string name, out string? value);
+}

src/Neptuo.Productivity.SnippetManager/Variables/SnippetExpansionPipeline.cs

@@ -0,0 +1,23 @@
+namespace Neptuo.Productivity.SnippetManager.Variables;
+
+public class SnippetExpansionPipeline(
+    ISnippetVariableScanner scanner,
+    IVariableValueResolver resolver,
+    ISnippetTextExpander expander)
+{
+    public string Apply(string text)
+    {
+        var references = scanner.Scan(text);
+        if (references.Count == 0)
+            return text;
+
+        var values = new Dictionary<string, string?>();
+        foreach (var reference in references)
+        {
+            resolver.TryGetValue(reference.Name, out var value);
+            values[reference.Name] = value;
+        }
+
+        return expander.Expand(text, values);
+    }
+}

src/Neptuo.Productivity.SnippetManager/Variables/TokenSnippetTextExpander.cs

@@ -0,0 +1,47 @@
+using System.Text;
+using Neptuo.Text.Tokens;
+
+namespace Neptuo.Productivity.SnippetManager.Variables;
+
+public class TokenSnippetTextExpander : ISnippetTextExpander
+{
+    public string Expand(string text, IReadOnlyDictionary<string, string?> values)
+    {
+        var parser = CreateParser();
+        var parsedTokens = new List<TokenEventArgs>();
+        parser.OnParsedToken += (sender, e) => parsedTokens.Add(e);
+
+        if (!parser.Parse(text) || parsedTokens.Count == 0)
+            return text;
+
+        var sb = new StringBuilder();
+        int lastEnd = 0;
+
+        foreach (var tokenEvent in parsedTokens)
+        {
+            sb.Append(text, lastEnd, tokenEvent.StartPosition - lastEnd);
+
+            if (values.TryGetValue(tokenEvent.Token.Fullname, out var value) && value != null)
+                sb.Append(value);
+            else
+                sb.Append(text, tokenEvent.StartPosition, tokenEvent.EndPosition - tokenEvent.StartPosition);
+
+            lastEnd = tokenEvent.EndPosition;
+        }
+
+        sb.Append(text, lastEnd, text.Length - lastEnd);
+
+        return sb.ToString();
+    }
+
+    private static TokenParser CreateParser()
+    {
+        var parser = new TokenParser();
+        parser.Configuration.AllowTextContent = true;
+        parser.Configuration.AllowMultipleTokens = true;
+        parser.Configuration.AllowEscapeSequence = true;
+        parser.Configuration.AllowAttributes = false;
+        parser.Configuration.AllowDefaultAttributes = false;
+        return parser;
+    }
+}