/// <summary>
/// Initializes a new instance of the <see cref="TagHelperContentWrapperTextWriter"/> class.
/// </summary>
/// <param name="encoding">The <see cref="Encoding"/> in which output is written.</param>
/// <param name="content">The <see cref="TagHelperContent"/> to write to.</param>
public TagHelperContentWrapperTextWriter(Encoding encoding, TagHelperContent content)
{
if (encoding == null)
{
throw new ArgumentNullException(nameof(encoding));
}
if (content == null)
{
throw new ArgumentNullException(nameof(content));
}
Content = content;
Encoding = encoding;
}
private void AppendAttribute(TagHelperContent content, string key, object value, bool escapeQuotes)
{
content
.AppendHtml(" ")
.AppendHtml(key);
if (escapeQuotes)
{
// Passed only JavaScript-encoded strings in this case. Do not perform HTML-encoding as well.
content
.AppendHtml("=\\\"")
.AppendHtml((string)value)
.AppendHtml("\\\"");
}
else
{
// HTML-encoded the given value if necessary.
content
.AppendHtml("=\"")
.Append(HtmlEncoder, ViewContext.Writer.Encoding, value)
.AppendHtml("\"");
}
}
private void BuildScriptTag(
TagHelperAttributeList attributes,
TagHelperContent builder)
{
builder.AppendHtml("<script");
foreach (var attribute in attributes)
{
var attributeValue = attribute.Value;
if (AppendVersion == true &&
string.Equals(attribute.Name, SrcAttributeName, StringComparison.OrdinalIgnoreCase))
{
// "src" values come from bound attributes and globbing. So anything but a non-null string is
// unexpected but could happen if another helper targeting the same element does something odd.
// Pass through existing value in that case.
var attributeStringValue = attributeValue as string;
if (attributeStringValue != null)
{
attributeValue = _fileVersionProvider.AddFileVersionToPath(attributeStringValue);
}
}
AppendAttribute(builder, attribute.Name, attributeValue, escapeQuotes: false);
}
builder.AppendHtml("></script>");
}
private void BuildGlobbedScriptTags(
TagHelperAttributeList attributes,
TagHelperContent builder)
{
EnsureGlobbingUrlBuilder();
// Build a <script> tag for each matched src as well as the original one in the source file
var urls = GlobbingUrlBuilder.BuildUrlList(null, SrcInclude, SrcExclude);
foreach (var url in urls)
{
// "url" values come from bound attributes and globbing. Must always be non-null.
Debug.Assert(url != null);
if (string.Equals(url, Src, StringComparison.OrdinalIgnoreCase))
{
// Don't build duplicate script tag for the original source url.
continue;
}
attributes[SrcAttributeName] = url;
BuildScriptTag(attributes, builder);
}
}
private void BuildLinkTag(TagHelperAttributeList attributes, TagHelperContent builder)
{
builder.AppendHtml("<link ");
foreach (var attribute in attributes)
{
var attributeValue = attribute.Value;
builder
.AppendHtml(attribute.Name)
.AppendHtml("=\"")
.Append(HtmlEncoder, ViewContext.Writer.Encoding, attribute.Value)
.AppendHtml("\" ");
}
builder.AppendHtml("/>");
}
private void BuildGlobbedLinkTags(TagHelperAttributeList attributes, TagHelperContent builder)
{
EnsureGlobbingUrlBuilder();
// Build a <link /> tag for each matched href.
var staticUrl = HostingEnvironment.IsDevelopment() ? String.Format("http://localhost:{0}{1}", devSettings.WebpackDevServerPort, HrefInclude) : "";
var includePattern = HostingEnvironment.IsDevelopment() ? "" : HrefInclude;
var urls = GlobbingUrlBuilder.BuildUrlList(staticUrl, includePattern, "");
foreach (var url in urls)
{
// "url" values come from bound attributes and globbing. Must always be non-null.
Debug.Assert(url != null);
if (string.Equals(Href, url, StringComparison.OrdinalIgnoreCase))
{
// Don't build duplicate link tag for the original href url.
continue;
}
attributes[HrefAttributeName] = url;
BuildLinkTag(attributes, builder);
}
}
private void BuildLinkTag(TagHelperAttributeList attributes, TagHelperContent builder)
{
builder.AppendHtml("<link ");
foreach (var attribute in attributes)
{
var attributeValue = attribute.Value;
if (AppendVersion == true &&
string.Equals(attribute.Name, HrefAttributeName, StringComparison.OrdinalIgnoreCase))
{
// "href" values come from bound attributes and globbing. So anything but a non-null string is
// unexpected but could happen if another helper targeting the same element does something odd.
// Pass through existing value in that case.
var attributeStringValue = attributeValue as string;
if (attributeStringValue != null)
{
attributeValue = _fileVersionProvider.AddFileVersionToPath(attributeStringValue);
}
}
builder
.AppendHtml(attribute.Name)
.AppendHtml("=\"")
.Append(HtmlEncoder, ViewContext.Writer.Encoding, attributeValue)
.AppendHtml("\" ");
}
builder.AppendHtml("/>");
}
private void BuildFallbackBlock(TagHelperContent builder)
{
EnsureGlobbingUrlBuilder();
var fallbackHrefs =
GlobbingUrlBuilder.BuildUrlList(FallbackHref, FallbackHrefInclude, FallbackHrefExclude).ToArray();
if (fallbackHrefs.Length > 0)
{
if (AppendVersion == true)
{
for (var i = 0; i < fallbackHrefs.Length; i++)
{
// fallbackHrefs come from bound attributes and globbing. Must always be non-null.
Debug.Assert(fallbackHrefs[i] != null);
fallbackHrefs[i] = _fileVersionProvider.AddFileVersionToPath(fallbackHrefs[i]);
}
}
builder.Append(HtmlString.NewLine);
// Build the <meta /> tag that's used to test for the presence of the stylesheet
builder
.AppendHtml("<meta name=\"x-stylesheet-fallback-test\" class=\"")
.Append(FallbackTestClass)
.AppendHtml("\" />");
// Build the <script /> tag that checks the effective style of <meta /> tag above and renders the extra
// <link /> tag to load the fallback stylesheet if the test CSS property value is found to be false,
// indicating that the primary stylesheet failed to load.
builder
.AppendHtml("<script>")
.AppendHtml(
string.Format(
CultureInfo.InvariantCulture,
JavaScriptResources.GetEmbeddedJavaScript(FallbackJavaScriptResourceName),
JavaScriptEncoder.JavaScriptStringEncode(FallbackTestProperty),
JavaScriptEncoder.JavaScriptStringEncode(FallbackTestValue),
JavaScriptStringArrayEncoder.Encode(JavaScriptEncoder, fallbackHrefs)))
.AppendHtml("</script>");
}
}
private void BuildGlobbedLinkTags(TagHelperAttributeList attributes, TagHelperContent builder)
{
EnsureGlobbingUrlBuilder();
// Build a <link /> tag for each matched href.
var urls = GlobbingUrlBuilder.BuildUrlList(null, HrefInclude, HrefExclude);
foreach (var url in urls)
{
// "url" values come from bound attributes and globbing. Must always be non-null.
Debug.Assert(url != null);
if (string.Equals(Href, url, StringComparison.OrdinalIgnoreCase))
{
// Don't build duplicate link tag for the original href url.
continue;
}
attributes[HrefAttributeName] = url;
BuildLinkTag(attributes, builder);
}
}
private void BuildScriptTag(
TagHelperAttributeList attributes,
TagHelperContent builder)
{
builder.AppendHtml("<script");
foreach (var attribute in attributes)
{
AppendAttribute(builder, attribute.Name, attribute.Value, escapeQuotes: false);
}
builder.AppendHtml("></script>");
}