Extract strings from LocalizedString and LocalizedHtmlString constructors and Create calls

[MikeAlhayek]

Summary

Some code creates localizable strings directly, without a localizer:

var displayName = new LocalizedString("Foo", "Foo");
var html = new LocalizedHtmlString("Foo", "Foo");

// Single argument form, where the name is also the value.
var shortForm = new LocalizedString("Foo");
var shortHtml = new LocalizedHtmlString("Foo");

// Factory methods, for example C# 14 static extension members.
var created = LocalizedString.Create("Foo");
var createdHtml = LocalizedHtmlString.Create("Foo");

Before this change, the extractor found only S["Foo"], H["Foo"], and T["Foo"]. Strings created with the LocalizedString (Microsoft.Extensions.Localization) or LocalizedHtmlString (Microsoft.AspNetCore.Mvc.Localization) constructors were not added to the POT file.

This PR adds a LocalizedStringExtractor for C# and VB and registers it in CSharpProjectProcessor and VisualBasicProjectProcessor.

Behavior

• The extractor uses the first (name) argument as the msgid. This is the key that the string is localized by. The second (value) argument and any other arguments are ignored.
• It matches only when the name argument is a string literal. nameof(...), variables, and other expressions are skipped.
• It accepts one or more arguments. The single argument form (new LocalizedString("Foo")) is not in .NET today. It is supported so that the extractor is ready for a helper or a future constructor where the name is also the value. A call with no arguments is skipped.
• It accepts simple, qualified, and global:: type names, for example new Microsoft.Extensions.Localization.LocalizedString(...).
• It also extracts LocalizedString.Create("...") and LocalizedHtmlString.Create("...") calls, and the LocalizedStringExtensions.Create("...") and LocalizedHtmlStringExtensions.Create("...") forms for callers that do not use C# 14. The type and method names are in LocalizedStringTypes in OrchardCoreContrib.PoExtractor.DotNet, so the C# and VB extractors share them.
• C#: string concatenation ("a " + "b") is supported. The concatenation logic moved from SingularStringExtractor to an internal ExpressionSyntaxExtensions helper, so both extractors use it.
• VB: the type name check is case-insensitive, like VB identifiers.
• Target-typed new("Foo", "Foo") is not supported, because the type cannot be known from syntax alone.

The README "Limitations" section documents the new convention.

Tests

• New LocalizedStringExtractorTests in the C# and VB test projects, with positive and negative cases for both types, the single argument form, and the Create calls.
• dotnet test -c Release: all 89 tests pass.
• Manual end-to-end run: new LocalizedString("From constructor", "From constructor") shows in the generated POT file with the correct msgctxt. LocalizedString.Create("...") and LocalizedHtmlString.Create("...") are also extracted. new LocalizedString(nameof(C), "...") and LocalizedString.Create(nameof(E)) are skipped.

Related

The LocalizedString.Create and LocalizedHtmlString.Create helpers are proposed for Orchard Core in OrchardCMS/OrchardCore#19933

🤖 Generated with Claude Code

[hishamco]

Why have these been introduced or is it Claude :)

[MikeAlhayek]

To allow LocalizedString.Create("...") and LocalizedHtmlString.Create("...") so we are not typing the same string twice.

[hishamco]

I'm curious about the Create method, AFAIK, LocalizedString doesn't have such a method

[MikeAlhayek]

It does not. I added it in OC. OrchardCMS/OrchardCore#19933

[sebastienros]

We talked about it during triage and that is a sound approach.

[hishamco]

OrchardCMS/OrchardCore#19933 (comment)

[hishamco]

I think we need to close this after merging OrchardCMS/OrchardCore#19972, right?

[MikeAlhayek]

Yes.

[hishamco]

I have something to add to what you did guys on these PR, hope to join tonight