Edit JSON files from WiX installers

WixJsonFileExtension is a WiX Toolset extension for changing JSON configuration files, such as appsettings.json, during an MSI install, repair or uninstall. It adds a JsonFile element that works like util:XmlFile does for XML: you name the file, a JSONPath and a value, and the extension does the deferred, elevated, rolled-back work. There is no custom action code to write.

• WiX Toolset v4, v5, v6 and v7
• x64, x86 and ARM64 installers
• Set, read, delete and replace values; append, insert and remove array items
• Windows Installer properties in values ([DB_SERVER]), typed values (number, boolean, JSON)
• Automatic rollback, optional backups, JSON schema validation
• MIT licensed, on NuGet

Quick start

Add the package to your .wixproj:

<PackageReference Include="WixJsonFileExtension" Version="7.1.0" />

Declare the namespace and add JsonFile elements to the component that installs the file:

<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs"
     xmlns:Json="http://schemas.hegsie.com/wix/JsonExtension">
  ...
  <Component Id="AppConfig">
    <File Id="AppSettings" Name="appsettings.json" Source="appsettings.json" />

    <Json:JsonFile Id="SetConnection" File="[#AppSettings]"
                   ElementPath="$.ConnectionStrings.DefaultConnection"
                   Value="Server=[DB_SERVER];Database=[DB_NAME];Trusted_Connection=True"
                   Action="setValue" />
  </Component>

Guides

• Update appsettings.json from a WiX installer
• Keep user settings in appsettings.json across upgrades
• Cookbook: connection strings, logging, feature flags, API endpoints and more
• IntelliSense for the JsonFile element (XSD schema)
• Full reference (README)

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