public override void Process(TagHelperContext context, TagHelperOutput output)
{
var builder = new TagBuilder("img");
builder.Attributes["src"] = "/pictures/" + UrlHelperThumbnailExtensions.GetThumbnail(null, Src, Size);
output.MergeAttributes(builder);
}
public override void Process(TagHelperContext context, TagHelperOutput output)
{
var builder = new TagBuilder("li");
if (ViewContext.ActionDescriptor.RouteValues["controller"] == Controller)
builder.AddCssClass("active");
output.MergeAttributes(builder);
}
/// <summary>
/// Synchronously executes the <see cref="TagHelper" /> with the given <paramref name="context" /> and
/// <paramref name="output" />.
/// </summary>
/// <param name="context">Contains information associated with the current HTML tag.</param>
/// <param name="output">A stateful HTML element used to generate an HTML tag.</param>
public override void Process(TagHelperContext context, TagHelperOutput output)
{
// Generate the list.
var selectListItems = GenerateListForEnumType();
// Get current value for model expression.
var currentValues = Generator.GetCurrentValues(ViewContext, EnumFor.ModelExplorer, EnumFor.Name, false);
var tag = Generator.GenerateSelect(ViewContext, EnumFor?.ModelExplorer, null, EnumFor?.Name, selectListItems,
currentValues, false,
null);
if (tag != null)
{
output.MergeAttributes(tag);
output.PostContent.AppendHtml(tag.InnerHtml);
}
}
/// <inheritdoc />
/// <remarks>Does nothing if <see cref="For"/> is <c>null</c>.</remarks>
public override async Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (output == null)
{
throw new ArgumentNullException(nameof(output));
}
var tagBuilder = Generator.GenerateLabel(
ViewContext,
For.ModelExplorer,
For.Name,
labelText: null,
htmlAttributes: null);
if (tagBuilder != null)
{
output.MergeAttributes(tagBuilder);
// We check for whitespace to detect scenarios such as:
// <label for="Name">
// </label>
if (!output.IsContentModified)
{
var childContent = await output.GetChildContentAsync();
if (childContent.IsEmptyOrWhiteSpace)
{
// Provide default label text since there was nothing useful in the Razor source.
output.Content.SetHtmlContent(tagBuilder.InnerHtml);
}
else
{
output.Content.SetHtmlContent(childContent);
}
}
}
}
/// <inheritdoc />
/// <remarks>
/// Does nothing if user provides an <c>action</c> attribute and <see cref="Antiforgery"/> is <c>null</c> or
/// <c>false</c>.
/// </remarks>
/// <exception cref="InvalidOperationException">
/// Thrown if <c>action</c> attribute is provided and <see cref="Action"/> or <see cref="Controller"/> are
/// non-<c>null</c> or if the user provided <c>asp-route-*</c> attributes.
/// </exception>
public override void Process(TagHelperContext context, TagHelperOutput output)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (output == null)
{
throw new ArgumentNullException(nameof(output));
}
if (Method != null)
{
output.CopyHtmlAttribute(nameof(Method), context);
}
var antiforgeryDefault = true;
// If "action" is already set, it means the user is attempting to use a normal <form>.
if (output.Attributes.ContainsName(HtmlActionAttributeName))
{
if (Action != null || Controller != null || Area != null || Route != null || RouteValues.Count != 0)
{
// User also specified bound attributes we cannot use.
throw new InvalidOperationException(
Resources.FormatFormTagHelper_CannotOverrideAction(
"<form>",
HtmlActionAttributeName,
ActionAttributeName,
ControllerAttributeName,
AreaAttributeName,
RouteAttributeName,
RouteValuesPrefix));
}
// User is using the FormTagHelper like a normal <form> tag. Antiforgery default should be false to
// not force the antiforgery token on the user.
antiforgeryDefault = false;
}
else
{
IDictionary<string, object> routeValues = null;
if (_routeValues != null && _routeValues.Count > 0)
{
// Convert from Dictionary<string, string> to Dictionary<string, object>.
routeValues = new Dictionary<string, object>(_routeValues.Count, StringComparer.OrdinalIgnoreCase);
foreach (var routeValue in _routeValues)
{
routeValues.Add(routeValue.Key, routeValue.Value);
}
}
if (Area != null)
{
if (routeValues == null)
{
routeValues = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);
}
// Unconditionally replace any value from asp-route-area.
routeValues["area"] = Area;
}
TagBuilder tagBuilder;
if (Route == null)
{
tagBuilder = Generator.GenerateForm(
ViewContext,
Action,
Controller,
routeValues,
method: null,
htmlAttributes: null);
}
else if (Action != null || Controller != null)
{
// Route and Action or Controller were specified. Can't determine the action attribute.
throw new InvalidOperationException(
Resources.FormatFormTagHelper_CannotDetermineActionWithRouteAndActionOrControllerSpecified(
"<form>",
RouteAttributeName,
ActionAttributeName,
ControllerAttributeName,
HtmlActionAttributeName));
}
else
{
tagBuilder = Generator.GenerateRouteForm(
ViewContext,
Route,
routeValues,
method: null,
htmlAttributes: null);
}
if (tagBuilder != null)
{
output.MergeAttributes(tagBuilder);
output.PostContent.AppendHtml(tagBuilder.InnerHtml);
}
if (string.Equals(Method, FormMethod.Get.ToString(), StringComparison.OrdinalIgnoreCase))
{
antiforgeryDefault = false;
}
}
if (Antiforgery ?? antiforgeryDefault)
{
var antiforgeryTag = Generator.GenerateAntiforgery(ViewContext);
if (antiforgeryTag != null)
{
output.PostContent.AppendHtml(antiforgeryTag);
}
}
}
/// <inheritdoc />
/// <remarks>Does nothing if <see cref="ValidationSummary"/> is <see cref="ValidationSummary.None"/>.</remarks>
public override void Process(TagHelperContext context, TagHelperOutput output)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (output == null)
{
throw new ArgumentNullException(nameof(output));
}
if (ValidationSummary == ValidationSummary.None)
{
return;
}
var tagBuilder = Generator.GenerateValidationSummary(
ViewContext,
excludePropertyErrors: ValidationSummary == ValidationSummary.ModelOnly,
message: null,
headerTag: null,
htmlAttributes: null);
if (tagBuilder != null)
{
output.MergeAttributes(tagBuilder);
output.PostContent.AppendHtml(tagBuilder.InnerHtml);
}
}
/// <inheritdoc />
/// <remarks>Does nothing if <see cref="For"/> is <c>null</c>.</remarks>
/// <exception cref="InvalidOperationException">
/// Thrown if <see cref="Format"/> is non-<c>null</c> but <see cref="For"/> is <c>null</c>.
/// </exception>
public override void Process(TagHelperContext context, TagHelperOutput output)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (output == null)
{
throw new ArgumentNullException(nameof(output));
}
// Pass through attributes that are also well-known HTML attributes. Must be done prior to any copying
// from a TagBuilder.
if (InputTypeName != null)
{
output.CopyHtmlAttribute("type", context);
}
if (Value != null)
{
output.CopyHtmlAttribute(nameof(Value), context);
}
// Note null or empty For.Name is allowed because TemplateInfo.HtmlFieldPrefix may be sufficient.
// IHtmlGenerator will enforce name requirements.
var metadata = For.Metadata;
var modelExplorer = For.ModelExplorer;
if (metadata == null)
{
throw new InvalidOperationException(Resources.FormatTagHelpers_NoProvidedMetadata(
"<input>",
ForAttributeName,
nameof(IModelMetadataProvider),
For.Name));
}
string inputType;
string inputTypeHint;
if (string.IsNullOrEmpty(InputTypeName))
{
// Note GetInputType never returns null.
inputType = GetInputType(modelExplorer, out inputTypeHint);
}
else
{
inputType = InputTypeName.ToLowerInvariant();
inputTypeHint = null;
}
// inputType may be more specific than default the generator chooses below.
if (!output.Attributes.ContainsName("type"))
{
output.Attributes.SetAttribute("type", inputType);
}
TagBuilder tagBuilder;
switch (inputType)
{
case "checkbox":
GenerateCheckBox(modelExplorer, output);
return;
case "hidden":
tagBuilder = Generator.GenerateHidden(
ViewContext,
modelExplorer,
For.Name,
value: For.Model,
useViewData: false,
htmlAttributes: null);
break;
case "password":
tagBuilder = Generator.GeneratePassword(
ViewContext,
modelExplorer,
For.Name,
value: null,
htmlAttributes: null);
break;
case "radio":
tagBuilder = GenerateRadio(modelExplorer);
break;
default:
tagBuilder = GenerateTextBox(modelExplorer, inputTypeHint, inputType);
break;
}
if (tagBuilder != null)
{
// This TagBuilder contains the one <input/> element of interest. Since this is not the "checkbox"
// special-case, output is a self-closing element no longer guaranteed.
output.MergeAttributes(tagBuilder);
output.Content.AppendHtml(tagBuilder.InnerHtml);
}
}
/// <inheritdoc />
/// <remarks>Does nothing if <see cref="For"/> is <c>null</c>.</remarks>
public override void Process(TagHelperContext context, TagHelperOutput output)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (output == null)
{
throw new ArgumentNullException(nameof(output));
}
// Ensure GenerateSelect() _never_ looks anything up in ViewData.
var items = Items ?? Enumerable.Empty<SelectListItem>();
if (For == null)
{
var options = Generator.GenerateGroupsAndOptions(optionLabel: null, selectList: items);
output.PostContent.AppendHtml(options);
return;
}
var tagBuilder = Generator.GenerateSelect(
ViewContext,
For.ModelExplorer,
optionLabel: null,
expression: For.Name,
selectList: items,
currentValues: _currentValues,
allowMultiple: _allowMultiple,
htmlAttributes: null);
if (tagBuilder != null)
{
output.MergeAttributes(tagBuilder);
output.PostContent.AppendHtml(tagBuilder.InnerHtml);
}
}
/// <inheritdoc />
/// <remarks>Does nothing if <see cref="For"/> is <c>null</c>.</remarks>
public override void Process(TagHelperContext context, TagHelperOutput output)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (output == null)
{
throw new ArgumentNullException(nameof(output));
}
var tagBuilder = Generator.GenerateTextArea(
ViewContext,
For.ModelExplorer,
For.Name,
rows: 0,
columns: 0,
htmlAttributes: null);
if (tagBuilder != null)
{
// Overwrite current Content to ensure expression result round-trips correctly.
output.Content.SetHtmlContent(tagBuilder.InnerHtml);
output.MergeAttributes(tagBuilder);
}
}
