/// <summary>
/// Sets an attribute value by name to 'value.ToString()'. If 'replace' is false, the attribute is only set if not
/// already set. If 'value' is null, the entry is removed from the list instead.
/// </summary>
/// <exception cref="ArgumentException"> Thrown if 'name' is null or empty. </exception>
/// <param name="list"> The TagHelperAttributeList to merge an attribute value with. </param>
/// <param name="name"> The key to set a value for. </param>
/// <param name="value">
/// The value to set for the specified key, which will be converted to a string first. If null, any existing entry is
/// removed instead (if 'replace' is true).
/// </param>
/// <param name="replace">
/// (Optional) If true (the default) adds a new entry or replaces an existing entry, otherwise the request is ignored.
/// If this is false, nothing is removed, and any merge requests with existing keys will be ignored.
/// </param>
/// <param name="removeOnEmptyOrWhitespace">
/// (Optional) If true (default) any empty or whitespace-only values will remove the attribute. This is in addition to
/// 'null', which always removes values.
/// </param>
/// <param name="replaceIfValueNotEmpty">
/// (Optional) If true, any existing entry is only replaced if the given value is not empty or whitespace only. Default
/// is false. This setting has no affect if the 'replace' parameter is false.
/// </param>
public static void MergeAttribute(this TagHelperAttributeList list, string name, object value, bool replace = true, bool removeOnEmptyOrWhitespace = true, bool replaceIfValueNotEmpty = false)
{
if (name == null)
{
throw new ArgumentException("Value cannot be null.", nameof(name));
}
else if (name is string && string.IsNullOrEmpty((string)(object)name))
{
throw new ArgumentException("Value cannot be null or empty.", nameof(name));
}
if (replace || value != null && !list.ContainsName(name))
{
var valueStr = value?.ToString().Trim();
var isEmpty = string.IsNullOrWhiteSpace(valueStr);
if (valueStr == null || removeOnEmptyOrWhitespace && isEmpty)
{
list.RemoveAll(name);
}
else if (!replaceIfValueNotEmpty || !isEmpty)
{
list.Add(name, valueStr);
}
}
}
public override void Process(TagHelperContext context, TagHelperOutput output)
{
if (ShouldAddActive())
{
TagHelperAttributeList attrs = output.Attributes;
attrs.RemoveAll("active-if-route");
attrs.Add("class", "active");
}
}
public void ApplyTo(TagHelperAttributeList target)
{
Guard.NotNull(target, nameof(target));
if (_list.Count == 0)
{
target.RemoveAll("class");
}
else
{
target.SetAttribute("class", string.Join(' ', _list));
}
}
public void RemoveAll_RemovesAllExpectedAttributes(
IEnumerable <TagHelperAttribute> initialAttributes,
string keyToRemove,
IEnumerable <TagHelperAttribute> expectedAttributes,
bool expectedRemoval)
{
// Arrange
var attributes = new TagHelperAttributeList(initialAttributes);
// Act
var removed = attributes.RemoveAll(keyToRemove);
// Assert
Assert.Equal(expectedRemoval, removed);
Assert.Equal(expectedAttributes, attributes, CaseSensitiveTagHelperAttributeComparer.Default);
}
/// <summary>
/// Moves the html attribute <paramref name="name"/> from source <paramref name="attributes"/> to <see cref="TagBuilder"/> <paramref name="target"/>.
/// </summary>
/// <param name="attributes">The source to find attribute to move.</param>
/// <param name="target">The target <see cref="TagBuilder"/> instance to move found attribute to.</param>
/// <param name="name">Name of attribute to find in source.</param>
/// <param name="replaceExisting">Whether to replace existing attribute in <paramref name="target"/>.</param>
/// <param name="ignoreNull">Whether to skip moving if source attribute's value is <see langword="null"/>.</param>
/// <returns><see langword="true"/> if an attribute has been moved, <see langword="false"/> otherwise.</returns>
public static bool MoveAttribute(this TagHelperAttributeList attributes, TagBuilder target, string name, bool replaceExisting = true, bool ignoreNull = true)
{
Guard.NotEmpty(name, nameof(name));
Guard.NotNull(target, nameof(target));
if (attributes.TryGetAttribute(name, out var attribute))
{
if (target.MergeAttribute(name, () => attribute.Value?.ToString(), replaceExisting, ignoreNull))
{
attributes.RemoveAll(name);
return(true);
}
}
return(false);
}
public static bool RemoveAll(this TagHelperAttributeList attributeList, params string[] attributeNames)
{
return(attributeNames.Aggregate(false, (current, name) => attributeList.RemoveAll(name) || current));
}
public void RemoveAll_RemovesAllExpectedAttributes(
IEnumerable<TagHelperAttribute> initialAttributes,
string keyToRemove,
IEnumerable<TagHelperAttribute> expectedAttributes,
bool expectedRemoval)
{
// Arrange
var attributes = new TagHelperAttributeList(initialAttributes);
// Act
var removed = attributes.RemoveAll(keyToRemove);
// Assert
Assert.Equal(expectedRemoval, removed);
Assert.Equal(expectedAttributes, attributes, CaseSensitiveTagHelperAttributeComparer.Default);
}
