File: Construction\ProjectItemDefinitionElement.cs
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Project: ..\..\..\src\Build\Microsoft.Build.csproj (Microsoft.Build)
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Collections.Generic;
using System.Diagnostics;
using System.Xml;
using Microsoft.Build.ObjectModelRemoting;
using Microsoft.Build.Shared;
 
#nullable disable
 
namespace Microsoft.Build.Construction
{
    /// <summary>
    /// ProjectItemDefinitionElement class represents the Item Definition element in the MSBuild project.
    /// </summary>
    [DebuggerDisplay("{ItemType} #Metadata={Count} Condition={Condition}")]
    public class ProjectItemDefinitionElement : ProjectElementContainer
    {
        /// <summary>
        /// External projects support
        /// </summary>
        internal ProjectItemDefinitionElement(ProjectItemDefinitionElementLink link)
            : base(link)
        {
        }
 
        /// <summary>
        /// Initialize a ProjectItemDefinitionElement instance from a node read from a project file
        /// </summary>
        internal ProjectItemDefinitionElement(XmlElement xmlElement, ProjectItemDefinitionGroupElement parent, ProjectRootElement containingProject)
            : base(xmlElement, parent, containingProject)
        {
            ErrorUtilities.VerifyThrowArgumentNull(parent, nameof(parent));
        }
 
        /// <summary>
        /// Initialize a ProjectItemDefinitionElement instance from a node read from a project file
        /// </summary>
        private ProjectItemDefinitionElement(XmlElement xmlElement, ProjectRootElement containingProject)
            : base(xmlElement, null, containingProject)
        {
        }
 
        /// <summary>
        /// Gets the definition's type.
        /// </summary>
        public string ItemType => ElementName;
 
        /// <summary>
        /// Get any child metadata definitions.
        /// </summary>
        public ICollection<ProjectMetadataElement> Metadata => GetChildrenOfType<ProjectMetadataElement>();
 
        /// <summary>
        /// Convenience method to add a piece of metadata to this item definition.
        /// Adds after any existing metadata. Does not modify any existing metadata.
        /// </summary>
        public ProjectMetadataElement AddMetadata(string name, string unevaluatedValue)
        {
            return AddMetadata(name, unevaluatedValue, false);
        }
 
        /// <summary>
        /// Convenience method to add a piece of metadata to this item definition.
        /// Adds after any existing metadata. Does not modify any existing metadata.
        /// </summary>
        /// <param name="name">The name of the metadata to add</param>
        /// <param name="unevaluatedValue">The value of the metadata to add</param>
        /// <param name="expressAsAttribute">If true, then the metadata will be expressed as an attribute instead of a child element, for example
        /// &lt;Content CopyToOutputDirectory="PreserveNewest" /&gt;
        /// </param>
        public ProjectMetadataElement AddMetadata(string name, string unevaluatedValue, bool expressAsAttribute)
        {
            ErrorUtilities.VerifyThrowArgumentLength(name, nameof(name));
            ErrorUtilities.VerifyThrowArgumentNull(unevaluatedValue, nameof(unevaluatedValue));
 
            if (expressAsAttribute)
            {
                ProjectMetadataElement.ValidateValidMetadataAsAttributeName(name, ElementName, Location);
            }
 
            ProjectMetadataElement metadata = ContainingProject.CreateMetadataElement(name);
            metadata.Value = unevaluatedValue;
            metadata.ExpressedAsAttribute = expressAsAttribute;
 
            AppendChild(metadata);
 
            return metadata;
        }
 
        /// <summary>
        /// Creates an unparented ProjectItemDefinitionElement, wrapping an unparented XmlElement.
        /// Caller should then ensure the element is added to a parent.
        /// </summary>
        internal static ProjectItemDefinitionElement CreateDisconnected(string itemType, ProjectRootElement containingProject)
        {
            XmlUtilities.VerifyThrowArgumentValidElementName(itemType);
 
            // Orcas inadvertently did not check for reserved item types (like "Choose") in item definitions,
            // as we do for item types in item groups. So we do not have a check here.
            // Although we could perhaps add one, as such item definitions couldn't be used
            // since no items can have the reserved itemType.
            XmlElementWithLocation element = containingProject.CreateElement(itemType);
 
            return new ProjectItemDefinitionElement(element, containingProject);
        }
 
        /// <summary>
        /// Overridden to verify that the potential parent and siblings
        /// are acceptable. Throws InvalidOperationException if they are not.
        /// </summary>
        internal override void VerifyThrowInvalidOperationAcceptableLocation(ProjectElementContainer parent, ProjectElement previousSibling, ProjectElement nextSibling)
        {
            ErrorUtilities.VerifyThrowInvalidOperation(parent is ProjectItemDefinitionGroupElement, "OM_CannotAcceptParent");
        }
 
        /// <inheritdoc />
        protected override ProjectElement CreateNewInstance(ProjectRootElement owner)
        {
            return owner.CreateItemDefinitionElement(ItemType);
        }
 
        /// <summary>
        /// Do not clone attributes which can be metadata. The corresponding expressed as attribute project elements are responsible for adding their attribute
        /// </summary>
        protected override bool ShouldCloneXmlAttribute(XmlAttribute attribute) => !ProjectMetadataElement.AttributeNameIsValidMetadataName(attribute.LocalName);
 
        internal override bool ShouldCloneXmlAttribute(XmlAttributeLink attributeLink) => !ProjectMetadataElement.AttributeNameIsValidMetadataName(attributeLink.LocalName);
    }
}