使用编辑器/显示模板中的部分

时间:2011-03-25 14:06:37

标签: html asp.net-mvc asp.net-mvc-3 razor

我希望将所有JavaScript代码保存在一个部分中;就在我的主布局页面中关闭body标签之前,只是想知道最好的,MVC风格。

例如,如果我创建一个使用jQuery UI的DateTime Picker的DisplayTemplate\DateTime.cshtml文件,而不是将JavaScript直接嵌入到该模板中,那么它将在页面中间呈现。

在我的普通视图中,我可以在主布局中使用@section JavaScript { //js here }然后@RenderSection("JavaScript", false),但这似乎不适用于显示/编辑器模板 - 任何想法?

8 个答案:

答案 0 :(得分:180)

你可以继续两个帮手的结合:

public static class HtmlExtensions
{
    public static MvcHtmlString Script(this HtmlHelper htmlHelper, Func<object, HelperResult> template)
    {
        htmlHelper.ViewContext.HttpContext.Items["_script_" + Guid.NewGuid()] = template;
        return MvcHtmlString.Empty;
    }

    public static IHtmlString RenderScripts(this HtmlHelper htmlHelper)
    {
        foreach (object key in htmlHelper.ViewContext.HttpContext.Items.Keys)
        {
            if (key.ToString().StartsWith("_script_"))
            {
                var template = htmlHelper.ViewContext.HttpContext.Items[key] as Func<object, HelperResult>;
                if (template != null)
                {
                    htmlHelper.ViewContext.Writer.Write(template(null));
                }
            }
        }
        return MvcHtmlString.Empty;
    }
}

然后在_Layout.cshtml

<body>
...
@Html.RenderScripts()
</body>

以及某个模板中的某处:

@Html.Script(
    @<script src="@Url.Content("~/Scripts/jquery-1.4.4.min.js")" type="text/javascript"></script>
)

答案 1 :(得分:38)

Darin的修改版本的答案,以确保订购。也适用于CSS:

public static IHtmlString Resource(this HtmlHelper HtmlHelper, Func<object, HelperResult> Template, string Type)
{
    if (HtmlHelper.ViewContext.HttpContext.Items[Type] != null) ((List<Func<object, HelperResult>>)HtmlHelper.ViewContext.HttpContext.Items[Type]).Add(Template);
    else HtmlHelper.ViewContext.HttpContext.Items[Type] = new List<Func<object, HelperResult>>() { Template };

    return new HtmlString(String.Empty);
}

public static IHtmlString RenderResources(this HtmlHelper HtmlHelper, string Type)
{
    if (HtmlHelper.ViewContext.HttpContext.Items[Type] != null)
    {
        List<Func<object, HelperResult>> Resources = (List<Func<object, HelperResult>>)HtmlHelper.ViewContext.HttpContext.Items[Type];

        foreach (var Resource in Resources)
        {
            if (Resource != null) HtmlHelper.ViewContext.Writer.Write(Resource(null));
        }
    }

    return new HtmlString(String.Empty);
}

您可以像这样添加JS和CSS资源:

@Html.Resource(@<script src="@Url.Content("~/Scripts/jquery-1.4.4.min.js")" type="text/javascript"></script>, "js")
@Html.Resource(@<link rel="stylesheet" href="@Url.Content("~/CSS/style.css")" />, "css")

并像这样呈现JS和CSS资源:

@Html.RenderResources("js")
@Html.RenderResources("css")

您可以进行字符串检查以查看它是否以脚本/链接开头,因此您无需明确定义每个资源的内容。

答案 2 :(得分:31)

我遇到了同样的问题,但是这里提出的解决方案仅适用于添加对资源的引用,并且不适合内联JS代码。我找到了一个非常有用的article并将所有内联JS(以及脚本标记)包装在

@using (Html.BeginScripts())
{
    <script src="@Url.Content("~/Scripts/jquery-ui-1.8.18.min.js")" type="text/javascript"></script>
    <script>
    // my inline scripts here
    <\script>
}

在关闭&#39; body&#39;之前的_Layout视图中放置@Html.PageScripts()标签。对我来说就像一个魅力。

<小时/> 帮助者自己:

public static class HtmlHelpers
{
    private class ScriptBlock : IDisposable
    {
        private const string scriptsKey = "scripts";
        public static List<string> pageScripts
        {
            get
            {
                if (HttpContext.Current.Items[scriptsKey] == null)
                    HttpContext.Current.Items[scriptsKey] = new List<string>();
                return (List<string>)HttpContext.Current.Items[scriptsKey];
            }
        }

        WebViewPage webPageBase;

        public ScriptBlock(WebViewPage webPageBase)
        {
            this.webPageBase = webPageBase;
            this.webPageBase.OutputStack.Push(new StringWriter());
        }

        public void Dispose()
        {
            pageScripts.Add(((StringWriter)this.webPageBase.OutputStack.Pop()).ToString());
        }
    }

    public static IDisposable BeginScripts(this HtmlHelper helper)
    {
        return new ScriptBlock((WebViewPage)helper.ViewDataContainer);
    }

    public static MvcHtmlString PageScripts(this HtmlHelper helper)
    {
        return MvcHtmlString.Create(string.Join(Environment.NewLine, ScriptBlock.pageScripts.Select(s => s.ToString())));
    }
}

答案 3 :(得分:13)

我喜欢@ john-w-harding发布的solution,所以我将其与@ {darin-dimitrov的answer结合使用,以制作以下可能过于复杂的解决方案,让您延迟渲染任何HTML (也是脚本)在使用块中。

USAGE

在重复的局部视图中,仅包括块一次:

@using (Html.Delayed(isOnlyOne: "MYPARTIAL_scripts")) {
    <script>
        someInlineScript();
    </script>
}

在(重复的?)局部视图中,每次使用部分时都包括块:

@using (Html.Delayed()) {
    <b>show me multiple times, @Model.Whatever</b>
}

在(重复的?)局部视图中,包括块一次,然后专门按名称one-time呈现:

@using (Html.Delayed("one-time", isOnlyOne: "one-time")) {
    <b>show me once by name</b>
    <span>@Model.First().Value</span>
}

渲染:

@Html.RenderDelayed(); // the "default" unidentified blocks
@Html.RenderDelayed("one-time", false); // render the specified block by name, and allow us to render it again in a second call
@Html.RenderDelayed("one-time"); // render the specified block by name
@Html.RenderDelayed("one-time"); // since it was "popped" in the last call, won't render anything

CODE

public static class HtmlRenderExtensions {

    /// <summary>
    /// Delegate script/resource/etc injection until the end of the page
    /// <para>@via https://stackoverflow.com/a/14127332/1037948 and http://jadnb.wordpress.com/2011/02/16/rendering-scripts-from-partial-views-at-the-end-in-mvc/ </para>
    /// </summary>
    private class DelayedInjectionBlock : IDisposable {
        /// <summary>
        /// Unique internal storage key
        /// </summary>
        private const string CACHE_KEY = "DCCF8C78-2E36-4567-B0CF-FE052ACCE309"; // "DelayedInjectionBlocks";

        /// <summary>
        /// Internal storage identifier for remembering unique/isOnlyOne items
        /// </summary>
        private const string UNIQUE_IDENTIFIER_KEY = CACHE_KEY;

        /// <summary>
        /// What to use as internal storage identifier if no identifier provided (since we can't use null as key)
        /// </summary>
        private const string EMPTY_IDENTIFIER = "";

        /// <summary>
        /// Retrieve a context-aware list of cached output delegates from the given helper; uses the helper's context rather than singleton HttpContext.Current.Items
        /// </summary>
        /// <param name="helper">the helper from which we use the context</param>
        /// <param name="identifier">optional unique sub-identifier for a given injection block</param>
        /// <returns>list of delayed-execution callbacks to render internal content</returns>
        public static Queue<string> GetQueue(HtmlHelper helper, string identifier = null) {
            return _GetOrSet(helper, new Queue<string>(), identifier ?? EMPTY_IDENTIFIER);
        }

        /// <summary>
        /// Retrieve a context-aware list of cached output delegates from the given helper; uses the helper's context rather than singleton HttpContext.Current.Items
        /// </summary>
        /// <param name="helper">the helper from which we use the context</param>
        /// <param name="defaultValue">the default value to return if the cached item isn't found or isn't the expected type; can also be used to set with an arbitrary value</param>
        /// <param name="identifier">optional unique sub-identifier for a given injection block</param>
        /// <returns>list of delayed-execution callbacks to render internal content</returns>
        private static T _GetOrSet<T>(HtmlHelper helper, T defaultValue, string identifier = EMPTY_IDENTIFIER) where T : class {
            var storage = GetStorage(helper);

            // return the stored item, or set it if it does not exist
            return (T) (storage.ContainsKey(identifier) ? storage[identifier] : (storage[identifier] = defaultValue));
        }

        /// <summary>
        /// Get the storage, but if it doesn't exist or isn't the expected type, then create a new "bucket"
        /// </summary>
        /// <param name="helper"></param>
        /// <returns></returns>
        public static Dictionary<string, object> GetStorage(HtmlHelper helper) {
            var storage = helper.ViewContext.HttpContext.Items[CACHE_KEY] as Dictionary<string, object>;
            if (storage == null) helper.ViewContext.HttpContext.Items[CACHE_KEY] = (storage = new Dictionary<string, object>());
            return storage;
        }


        private readonly HtmlHelper helper;
        private readonly string identifier;
        private readonly string isOnlyOne;

        /// <summary>
        /// Create a new using block from the given helper (used for trapping appropriate context)
        /// </summary>
        /// <param name="helper">the helper from which we use the context</param>
        /// <param name="identifier">optional unique identifier to specify one or many injection blocks</param>
        /// <param name="isOnlyOne">extra identifier used to ensure that this item is only added once; if provided, content should only appear once in the page (i.e. only the first block called for this identifier is used)</param>
        public DelayedInjectionBlock(HtmlHelper helper, string identifier = null, string isOnlyOne = null) {
            this.helper = helper;

            // start a new writing context
            ((WebViewPage)this.helper.ViewDataContainer).OutputStack.Push(new StringWriter());

            this.identifier = identifier ?? EMPTY_IDENTIFIER;
            this.isOnlyOne = isOnlyOne;
        }

        /// <summary>
        /// Append the internal content to the context's cached list of output delegates
        /// </summary>
        public void Dispose() {
            // render the internal content of the injection block helper
            // make sure to pop from the stack rather than just render from the Writer
            // so it will remove it from regular rendering
            var content = ((WebViewPage)this.helper.ViewDataContainer).OutputStack;
            var renderedContent = content.Count == 0 ? string.Empty : content.Pop().ToString();

            // if we only want one, remove the existing
            var queue = GetQueue(this.helper, this.identifier);

            // get the index of the existing item from the alternate storage
            var existingIdentifiers = _GetOrSet(this.helper, new Dictionary<string, int>(), UNIQUE_IDENTIFIER_KEY);

            // only save the result if this isn't meant to be unique, or
            // if it's supposed to be unique and we haven't encountered this identifier before
            if( null == this.isOnlyOne || !existingIdentifiers.ContainsKey(this.isOnlyOne) ) {
                // remove the new writing context we created for this block
                // and save the output to the queue for later
                queue.Enqueue(renderedContent);

                // only remember this if supposed to
                if(null != this.isOnlyOne) existingIdentifiers[this.isOnlyOne] = queue.Count; // save the index, so we could remove it directly (if we want to use the last instance of the block rather than the first)
            }
        }
    }


    /// <summary>
    /// <para>Start a delayed-execution block of output -- this will be rendered/printed on the next call to <see cref="RenderDelayed"/>.</para>
    /// <para>
    /// <example>
    /// Print once in "default block" (usually rendered at end via <code>@Html.RenderDelayed()</code>).  Code:
    /// <code>
    /// @using (Html.Delayed()) {
    ///     <b>show at later</b>
    ///     <span>@Model.Name</span>
    ///     etc
    /// }
    /// </code>
    /// </example>
    /// </para>
    /// <para>
    /// <example>
    /// Print once (i.e. if within a looped partial), using identified block via <code>@Html.RenderDelayed("one-time")</code>.  Code:
    /// <code>
    /// @using (Html.Delayed("one-time", isOnlyOne: "one-time")) {
    ///     <b>show me once</b>
    ///     <span>@Model.First().Value</span>
    /// }
    /// </code>
    /// </example>
    /// </para>
    /// </summary>
    /// <param name="helper">the helper from which we use the context</param>
    /// <param name="injectionBlockId">optional unique identifier to specify one or many injection blocks</param>
    /// <param name="isOnlyOne">extra identifier used to ensure that this item is only added once; if provided, content should only appear once in the page (i.e. only the first block called for this identifier is used)</param>
    /// <returns>using block to wrap delayed output</returns>
    public static IDisposable Delayed(this HtmlHelper helper, string injectionBlockId = null, string isOnlyOne = null) {
        return new DelayedInjectionBlock(helper, injectionBlockId, isOnlyOne);
    }

    /// <summary>
    /// Render all queued output blocks injected via <see cref="Delayed"/>.
    /// <para>
    /// <example>
    /// Print all delayed blocks using default identifier (i.e. not provided)
    /// <code>
    /// @using (Html.Delayed()) {
    ///     <b>show me later</b>
    ///     <span>@Model.Name</span>
    ///     etc
    /// }
    /// </code>
    /// -- then later --
    /// <code>
    /// @using (Html.Delayed()) {
    ///     <b>more for later</b>
    ///     etc
    /// }
    /// </code>
    /// -- then later --
    /// <code>
    /// @Html.RenderDelayed() // will print both delayed blocks
    /// </code>
    /// </example>
    /// </para>
    /// <para>
    /// <example>
    /// Allow multiple repetitions of rendered blocks, using same <code>@Html.Delayed()...</code> as before.  Code:
    /// <code>
    /// @Html.RenderDelayed(removeAfterRendering: false); /* will print */
    /// @Html.RenderDelayed() /* will print again because not removed before */
    /// </code>
    /// </example>
    /// </para>

    /// </summary>
    /// <param name="helper">the helper from which we use the context</param>
    /// <param name="injectionBlockId">optional unique identifier to specify one or many injection blocks</param>
    /// <param name="removeAfterRendering">only render this once</param>
    /// <returns>rendered output content</returns>
    public static MvcHtmlString RenderDelayed(this HtmlHelper helper, string injectionBlockId = null, bool removeAfterRendering = true) {
        var stack = DelayedInjectionBlock.GetQueue(helper, injectionBlockId);

        if( removeAfterRendering ) {
            var sb = new StringBuilder(
#if DEBUG
                string.Format("<!-- delayed-block: {0} -->", injectionBlockId)
#endif
                );
            // .count faster than .any
            while (stack.Count > 0) {
                sb.AppendLine(stack.Dequeue());
            }
            return MvcHtmlString.Create(sb.ToString());
        } 

        return MvcHtmlString.Create(
#if DEBUG
                string.Format("<!-- delayed-block: {0} -->", injectionBlockId) + 
#endif
            string.Join(Environment.NewLine, stack));
    }


}

答案 4 :(得分:10)

安装 Forloop.HtmlHelpers nuget包 - 它添加了一些帮助程序来管理部分视图和编辑器模板中的脚本。

在布局的某个地方,您需要致电

@Html.RenderScripts()

这将是页面中输出任何脚本文件和脚本块的位置,因此我建议将其放在布局中的主脚本之后以及脚本部分之后(如果有的话)。

如果您正在使用捆绑的Web优化框架,则可以使用重载

@Html.RenderScripts(Scripts.Render)

这样该方法用于写出脚本文件。

现在,只要您想在视图,局部视图或模板中添加脚本文件或块,只需使用

@using (Html.BeginScriptContext())
{
  Html.AddScriptFile("~/Scripts/jquery.validate.js");
  Html.AddScriptBlock(
    @<script type="text/javascript">
       $(function() { $('#someField').datepicker(); });
     </script>
  );
}

帮助程序确保如果多次添加,则只呈现一个脚本文件引用,并且还确保脚本文件以预期顺序呈现出来,即

  1. 布局
  2. 部分和模板(按照它们在视图中显示的顺序,从上到下)

答案 5 :(得分:5)

这篇文章真的对我有所帮助,所以我想我会发布我的基本想法的实现。我已经介绍了一个可以返回脚本标记的辅助函数,以便在@ Html.Resource函数中使用。

我还添加了一个简单的静态类,以便我可以使用类型变量来识别JS或CSS资源。

public static class ResourceType
{
    public const string Css = "css";
    public const string Js = "js";
}

public static class HtmlExtensions
{
    public static IHtmlString Resource(this HtmlHelper htmlHelper, Func<object, dynamic> template, string Type)
    {
        if (htmlHelper.ViewContext.HttpContext.Items[Type] != null) ((List<Func<object, dynamic>>)htmlHelper.ViewContext.HttpContext.Items[Type]).Add(template);
        else htmlHelper.ViewContext.HttpContext.Items[Type] = new List<Func<object, dynamic>>() { template };

        return new HtmlString(String.Empty);
    }

    public static IHtmlString RenderResources(this HtmlHelper htmlHelper, string Type)
    {
        if (htmlHelper.ViewContext.HttpContext.Items[Type] != null)
        {
            List<Func<object, dynamic>> resources = (List<Func<object, dynamic>>)htmlHelper.ViewContext.HttpContext.Items[Type];

            foreach (var resource in resources)
            {
                if (resource != null) htmlHelper.ViewContext.Writer.Write(resource(null));
            }
        }

        return new HtmlString(String.Empty);
    }

    public static Func<object, dynamic> ScriptTag(this HtmlHelper htmlHelper, string url)
    {
        var urlHelper = new UrlHelper(htmlHelper.ViewContext.RequestContext);
        var script = new TagBuilder("script");
        script.Attributes["type"] = "text/javascript";
        script.Attributes["src"] = urlHelper.Content("~/" + url);
        return x => new HtmlString(script.ToString(TagRenderMode.Normal));
    }
}

并在使用中

@Html.Resource(Html.ScriptTag("Areas/Admin/js/plugins/wysiwyg/jquery.wysiwyg.js"), ResourceType.Js)

感谢@Darin Dimitrov,他在my question here中提供了答案。

答案 6 :(得分:2)

使用RequireScript HtmlHelper在Populate a Razor Section From a Partial中给出的答案遵循相同的模式。它还具有检查和抑制对同一Javascript URL的重复引用的好处,并且它具有可用于控制排序的显式priority参数。

我通过添加以下方法扩展了此解决方案:

// use this for scripts to be placed just before the </body> tag
public static string RequireFooterScript(this HtmlHelper html, string path, int priority = 1) { ... }
public static HtmlString EmitRequiredFooterScripts(this HtmlHelper html) { ... }

// use this for CSS links
public static string RequireCSS(this HtmlHelper html, string path, int priority = 1) { ... }
public static HtmlString EmitRequiredCSS(this HtmlHelper html) { ... }

我喜欢Darin&amp; eth0的解决方案,因为他们使用HelperResult模板,它允许脚本和CSS块,而不仅仅是Javascript和CSS文件的链接。

答案 7 :(得分:1)

@Darin Dimitrov和@ eth0回答用于捆绑扩展用法:

@Html.Resources(a => new HelperResult(b => b.Write( System.Web.Optimization.Scripts.Render("~/Content/js/formBundle").ToString())), "jsTop")