UpdatePList.targets

<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

  
  <UsingTask TaskName="UpdatePListEntries" TaskFactory="RoslynCodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.Core.dll">
    <ParameterGroup>
      <TargetFile ParameterType="System.String" Required="true" />
      <Entries ParameterType="Microsoft.Build.Framework.ITaskItem[]" Required="true" />
      <IconFile ParameterType="System.String" Output="true" />
    </ParameterGroup>
    <Task>
      <Reference Include="netstandard" />
      <Code Type="Class" Language="cs"><![CDATA[
    using System;
    using System.IO;
    using System.Xml;
    using System.Text;
    using Microsoft.Build.Framework;
    using Microsoft.Build.Utilities;

    public class UpdatePListEntries : Task
    {
      [Required]
      public string TargetFile { get; set; }
      [Required]
      public Microsoft.Build.Framework.ITaskItem[] Entries { get; set; }
      [Output]
      public string IconFile { get; set; }

      XmlDocument xml;
      XmlNode dict;

      class NullSubsetXmlTextWriter : XmlTextWriter
      {
        XmlWriterSettings _settings;
        public NullSubsetXmlTextWriter(string inputFileName, Encoding encoding)
          : base(inputFileName, encoding)
        {
          Formatting = Formatting.Indented;
          IndentChar = ' ';
          Indentation = 2;
          _settings = new XmlWriterSettings();
          _settings.Encoding = Encoding.UTF8;
          _settings.Indent = true;
          _settings.IndentChars = "  ";
          _settings.NewLineChars = "\n";
          _settings.NewLineHandling = NewLineHandling.Entitize;
        }

        public override XmlWriterSettings Settings { get { return _settings; } }

        public override void WriteDocType(string name, string pubid, string sysid, string subset)
        {
          // fix issue writing doctype
          if (subset == string.Empty)
            subset = null;
          base.WriteDocType(name, pubid, sysid, subset);
        }
      }

      string GetStringProperty(string name)
      {
        var location = dict.SelectSingleNode("key[.='" + name + "']/following-sibling::string[1]");
        return location.InnerText;
      }

      void AddStringProperty(string name, string value, bool force = false)
      {
        XmlNode node;
      
        var exists = dict.SelectSingleNode("key[text()='" + name + "']") != null;
        if (exists && !force)
          return;
      
        dict.AppendChild(node = xml.CreateNode(XmlNodeType.Element, "key", null));
        node.InnerText = name;
        dict.AppendChild(node = xml.CreateNode(XmlNodeType.Element, "string", null));
        node.InnerText = value;
      }
      
      public override bool Execute()
      {
        xml = new XmlDocument();
        xml.Load(TargetFile);

        dict = xml.SelectSingleNode("plist/dict") as XmlElement;

        foreach (var entry in Entries)
        {
          if (!bool.TryParse(entry.GetMetadata("Force"), out var force))
            force = false;
            
          AddStringProperty(entry.ItemSpec, entry.GetMetadata("Value"), force);
        }
        
        IconFile = GetStringProperty("CFBundleIconFile");

        using (var sw = new NullSubsetXmlTextWriter(TargetFile, Encoding.UTF8))
          xml.Save(sw);
          
        return true;
      }
    }
]]></Code>
    </Task>
  </UsingTask>
  

</Project>