JSON: forward slashes (e.g. in URL) are getting escaped

Hello,

When I am trying to capture the url of my asp.net core application using JsonLayout the url of the site is being escaped.

NLog version: 4.5.11

NLog.Web.AspNetCore version: 4.8.0

Platform: .NET Core 2.2

Current NLog config (xml or C#, if relevant)

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      autoReload="true"
      internalLogLevel="Info"
      internalLogFile="c:\temp\internal-nlog.txt">

  <!-- enable asp.net core layout renderers -->
  <extensions>
    <add assembly="NLog.Web.AspNetCore"/>
  </extensions>

  <!-- the targets to write to -->
  <targets async="true">
    <!-- Write logs as Json into a file -->
    <target name="json-file" 
      xsi:type="File" 
      fileName="${basedir}/application-logs.json"
      archiveAboveSize="50000000" 
      archiveEvery="Day" 
      maxArchiveFiles="9"
      concurrentWrites="False">
      <layout xsi:type="JsonLayout">
        <attribute name="date" layout="${longdate}" />
        <attribute name="level" layout="${level:upperCase=true}"/>
        <attribute name="logger" layout="${logger}"/>
        <attribute name="identity" layout="${aspnet-user-identity}"/>
        <attribute name="url" layout="${aspnet-request-url:IncludePort=true:IncludeQueryString=true}" encode="true"/>
        <attribute name="host" layout="${aspnet-Request-Host}"/>
        <attribute name="userAgent" layout="${aspnet-Request-UserAgent}"/>
        <attribute name="referrer" layout="${aspnet-Request-Referrer}"/>
        <attribute name="action" layout="${aspnet-mvc-action}"/>
        <attribute name="clientIp" layout="${aspnet-request-ip}"/>
        <attribute name="message" layout="${message}" />
        <attribute name="exception" layout="${onexception:|${exception:format=ToString}}" />
      </layout>
    </target>

  </targets>
  <rules>
    <!--Skip non-critical Microsoft logs and so log only own logs-->
    <logger name="Microsoft.*" maxlevel="Info" final="true" /> <!-- BlackHole without writeTo -->
    
    <!-- Log all events to the json-file target -->
    <logger name="*" writeTo="json-file" minlevel="Trace" />
  </rules>
</nlog>

• What is the current result? The output line looks like the following, notice the escaped slashes in the url:

{ "date": "2019-09-08 14:06:51.4229", "level": "DEBUG", "logger": "API.Controllers.ValuesController", "url": "https:\/\/localhost:5001\/api\/values", "action": "Get", "clientip": "::1", "message": "Some Log Goes Here", "exception": "|System.Exception: An exception" }

• What is the expected result? The url would not be escaped.

{ "date": "2019-09-08 14:06:51.4229", "level": "DEBUG", "logger": "Miovision.QAP.API.Controllers.ValuesController", "url": "https://localhost:5001/api/values", "action": "Get", "clientip": "::1", "message": "Some Log Goes Here", "exception": "|System.Exception: An exception" }

I have tried to set the encoding to false but then the url is no longer wrapped in quotes, which is needed for me to consume the url correctly in a later step.

[snakefoot]

@kylelaverty + @sagebind NLog 4.6.8 has been released

https://www.nuget.org/packages/NLog

New setting EscapeForwardSlash has been added to JsonLayout.

[snakefoot]

Created PR #3743 to resolve this. But it will only apply to sub-attributes.

If a nested attribute embeds a JsonLayout using encode="false", then it will not inherit the configuration from the top-JsonLayout (There is no guaranteed of the order of initializing NLog Layouts)