C# TagHelperOutput.CopyHtmlAttribute方法代码示例

        /// <inheritdoc />
        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 attribute that is also a well-known HTML attribute.
            if (Src != null)
            {
                output.CopyHtmlAttribute(SrcAttributeName, context);
            }

            // If there's no "src" attribute in output.Attributes this will noop.
            ProcessUrlAttribute(SrcAttributeName, output);

            // Retrieve the TagHelperOutput variation of the "src" attribute in case other TagHelpers in the
            // pipeline have touched the value. If the value is already encoded this ScriptTagHelper may
            // not function properly.
            Src = output.Attributes[SrcAttributeName]?.Value as string;

            var modeResult = AttributeMatcher.DetermineMode(context, ModeDetails);

            modeResult.LogDetails(Logger, this, context.UniqueId, ViewContext.View.Path);

            if (!modeResult.FullMatches.Any())
            {
                // No attributes matched so we have nothing to do
                return;
            }

            // NOTE: Values in TagHelperOutput.Attributes may already be HTML-encoded.
            var attributes = new TagHelperAttributeList(output.Attributes);

            if (AppendVersion == true)
            {
                EnsureFileVersionProvider();

                if (Src != null)
                {
                    output.Attributes[SrcAttributeName].Value = _fileVersionProvider.AddFileVersionToPath(Src);
                }
            }

            var builder = new DefaultTagHelperContent();

            // Get the highest matched mode
            var mode = modeResult.FullMatches.Select(match => match.Mode).Max();

            if (mode == Mode.GlobbedSrc || mode == Mode.Fallback && !string.IsNullOrEmpty(SrcInclude))
            {
                BuildGlobbedScriptTags(attributes, builder);
                if (string.IsNullOrEmpty(Src))
                {
                    // Only SrcInclude is specified. Don't render the original tag.
                    output.TagName = null;
                    output.Content.SetContent(string.Empty);
                }
            }

            if (mode == Mode.Fallback)
            {
                string resolvedUrl;
                if (TryResolveUrl(FallbackSrc, encodeWebRoot: false, resolvedUrl: out resolvedUrl))
                {
                    FallbackSrc = resolvedUrl;
                }

                BuildFallbackBlock(attributes, builder);
            }

            output.PostElement.SetContent(builder);
        }

        /// <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["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.
//.........这里部分代码省略.........

        /// <inheritdoc />
        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 attribute that is also a well-known HTML attribute.
            if (Href != null)
            {
                output.CopyHtmlAttribute(HrefAttributeName, context);
            }

            // If there's no "href" attribute in output.Attributes this will noop.
            ProcessUrlAttribute(HrefAttributeName, output);

            // Retrieve the TagHelperOutput variation of the "href" attribute in case other TagHelpers in the
            // pipeline have touched the value. If the value is already encoded this LinkTagHelper may
            // not function properly.
            Href = output.Attributes[HrefAttributeName]?.Value as string;

            // NOTE: Values in TagHelperOutput.Attributes may already be HTML-encoded.
            var attributes = new TagHelperAttributeList(output.Attributes);

            var builder = new DefaultTagHelperContent();

            if (!string.IsNullOrEmpty(HrefInclude))
            {
                BuildGlobbedLinkTags(attributes, builder);
                if (string.IsNullOrEmpty(Href))
                {
                    // Only HrefInclude is specified. Don't render the original tag.
                    output.TagName = null;
                    output.Content.SetContent(HtmlString.Empty);
                }
            }

            output.PostElement.SetContent(builder);
        }

        //
        public override async Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
        {
            bool useSiteMinJs = UseSiteMinJs?.Contains(HostingEnvironment.EnvironmentName, StringComparison.OrdinalIgnoreCase) == true;
            if (WarnIfTestIsInvalid?.Contains(HostingEnvironment.EnvironmentName, StringComparison.OrdinalIgnoreCase) == true)
            {
                var x = await output.GetChildContentAsync();
                if (!useSiteMinJs)
                    output.PreElement.AppendHtml(string.Format(_preTest, FallbackTest, $"Script `{RemotePath}` already loaded. Did you create the correct test"));
                output.PostElement.AppendHtml(string.Format(_postTest, FallbackTest, $"Script `{RemotePath}` still not loaded. Did you create the correct test"));
            }
            var LocalRelPath = "";
            if (CopySrcToFallback?.Contains(HostingEnvironment.EnvironmentName, StringComparison.OrdinalIgnoreCase) == true)
            {
                try
                {
                    var scheme = Context.HttpContext.Request.Scheme;
                    RemotePath = RemotePath.StartsWith("//")
                        ? scheme + ":" + RemotePath
                        : RemotePath.ToLower().StartsWith("/") || RemotePath.ToLower().StartsWith("~/")
                        ? scheme + "://" + Context.HttpContext.Request.Host + RemotePath.Replace("~", "")
                        : RemotePath;

                    LocalRelPath = (useSiteMinJs == false) ?
                        "/js/" + new Uri(RemotePath).Segments.Last()
                        : FallbackSrc ?? "/fallback/js/" + new Uri(RemotePath).Segments.Last();
                    var localPath = HostingEnvironment.MapPath(LocalRelPath.TrimStart('/'));
                    var pathHelper = new PathHelper(RemotePath, localPath);
                    if (!File.Exists(localPath))
                    {
                        using (var webClient = new HttpClient())
                        {
                            var file = await webClient.GetStringAsync(new Uri(RemotePath));
                            Directory.CreateDirectory(pathHelper.LocalDirectory);
                            File.WriteAllText(localPath, file);
                            if (RemotePath.Contains(".min.") && UseSiteMinJs != null)//copy full version to let gulp minify this verion to site.css
                            {
                                file = await webClient.GetStringAsync(new Uri(RemotePath.Replace(".min", "")));
                                File.WriteAllText(localPath, file);
                            }
                            if (!RemotePath.Contains(".min.") && UseMinified != null)
                            {
                                file = await webClient.GetStringAsync(new Uri(RemotePath.Replace(".js", ".min.js")));
                                File.WriteAllText(localPath, file);
                            }

                        }
                    }
                }
                catch (HttpRequestException ex)
                {
                    throw new FileNotFoundException($"The remote file:{RemotePath} cannot be found.", ex);
                }
            }
            if (context.AllAttributes.ContainsName("src"))
            {
                output.CopyHtmlAttribute("src", context);
                if (UseLocal?.Contains(HostingEnvironment.EnvironmentName, StringComparison.OrdinalIgnoreCase) == true)
                    output.Attributes["src"].Value = LocalRelPath;
                string href = output.Attributes["src"].Value.ToString();
                if (UseMinified?.Contains(HostingEnvironment.EnvironmentName, StringComparison.OrdinalIgnoreCase) == true && !href.Contains(".min."))
                    output.Attributes["src"] = href.Replace(".js", ".min.js");
                if (useSiteMinJs)
                    output.Attributes["src"].Value = "";
            }
        }

        /// <inheritdoc />
        public override void Process(TagHelperContext context, TagHelperOutput output)
        {
            if (context == null)
            {
                throw new ArgumentNullException(nameof(context));
            }

            if (output == null)
            {
                throw new ArgumentNullException(nameof(output));
            }

            output.CopyHtmlAttribute(SrcAttributeName, context);
            ProcessUrlAttribute(SrcAttributeName, output);

            if (AppendVersion)
            {
                EnsureFileVersionProvider();

                // Retrieve the TagHelperOutput variation of the "src" attribute in case other TagHelpers in the
                // pipeline have touched the value. If the value is already encoded this ImageTagHelper may
                // not function properly.
                Src = output.Attributes[SrcAttributeName].Value as string;

                output.Attributes[SrcAttributeName] = _fileVersionProvider.AddFileVersionToPath(Src);
            }
        }

        /// <inheritdoc />
        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 attribute that is also a well-known HTML attribute.
            if (Href != null)
            {
                output.CopyHtmlAttribute(HrefAttributeName, context);
            }

            // If there's no "href" attribute in output.Attributes this will noop.
            ProcessUrlAttribute(HrefAttributeName, output);

            // Retrieve the TagHelperOutput variation of the "href" attribute in case other TagHelpers in the
            // pipeline have touched the value. If the value is already encoded this LinkTagHelper may
            // not function properly.
            Href = output.Attributes[HrefAttributeName]?.Value as string;

            Mode mode;
            if (!AttributeMatcher.TryDetermineMode(context, ModeDetails, Compare, out mode))
            {
                // No attributes matched so we have nothing to do
                return;
            }

            // NOTE: Values in TagHelperOutput.Attributes may already be HTML-encoded.
            var attributes = new TagHelperAttributeList(output.Attributes);

            if (AppendVersion == true)
            {
                EnsureFileVersionProvider();

                if (Href != null)
                {
                    output.Attributes[HrefAttributeName].Value = _fileVersionProvider.AddFileVersionToPath(Href);
                }
            }

            var builder = new DefaultTagHelperContent();
            if (mode == Mode.GlobbedHref || mode == Mode.Fallback && !string.IsNullOrEmpty(HrefInclude))
            {
                BuildGlobbedLinkTags(attributes, builder);
                if (string.IsNullOrEmpty(Href))
                {
                    // Only HrefInclude is specified. Don't render the original tag.
                    output.TagName = null;
                    output.Content.SetContent(HtmlString.Empty);
                }
            }

            if (mode == Mode.Fallback)
            {
                string resolvedUrl;
                if (TryResolveUrl(FallbackHref, resolvedUrl: out resolvedUrl))
                {
                    FallbackHref = resolvedUrl;
                }

                BuildFallbackBlock(builder);
            }

            output.PostElement.SetContent(builder);
        }

        /// <inheritdoc />
        /// <remarks>
        /// Does nothing unless <see cref="TagHelperContext.Items"/> contains a
        /// <see cref="SelectTagHelper"/> <see cref="Type"/> entry and that entry is a non-empty
        /// <see cref="ICollection{string}"/> instance. Also does nothing if the associated &lt;option&gt; is already
        /// selected.
        /// </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));
            }

            // Pass through attributes that are also well-known HTML attributes.
            if (Value != null)
            {
                output.CopyHtmlAttribute(nameof(Value), context);
            }

            // Nothing to do if this <option/> is already selected.
            if (!output.Attributes.ContainsName("selected"))
            {
                // Is this <option/> element a child of a <select/> element the SelectTagHelper targeted?
                object formDataEntry;
                context.Items.TryGetValue(typeof(SelectTagHelper), out formDataEntry);

                // ... And did the SelectTagHelper determine any selected values?
                var selectedValues = formDataEntry as ICollection<string>;
                if (selectedValues != null && selectedValues.Count != 0)
                {
                    // Encode all selected values for comparison with element content.
                    var encodedValues = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
                    foreach (var selectedValue in selectedValues)
                    {
                        encodedValues.Add(Generator.Encode(selectedValue));
                    }

                    // Select this <option/> element if value attribute or content matches a selected value. Callers
                    // encode values as-needed while executing child content. But TagHelperOutput itself
                    // encodes attribute values later, when start tag is generated.
                    bool selected;
                    if (Value != null)
                    {
                        selected = selectedValues.Contains(Value);
                    }
                    else if (output.IsContentModified)
                    {
                        selected = encodedValues.Contains(output.Content.GetContent());
                    }
                    else
                    {
                        var childContent = await output.GetChildContentAsync();
                        selected = encodedValues.Contains(childContent.GetContent());
                    }

                    if (selected)
                    {
                        output.Attributes.Add("selected", "selected");
                    }
                }
            }
        }