MVC批量更新,使用jQuery Template

时间：2014-05-09 08:09:21 收藏：0 阅读：572

在"MVC批量更新,可验证并解决集合元素不连续控制器接收不完全的问题"中，当点击"添加"按钮的时候，通过部分视图，在界面上添加新行。本篇体验使用jQuery Template，在界面上添加新行。

□ 思路

→引用jQuery Template所需要的js文件：jquery.tmpl.min.js
→在<script type="text/x-jquery-tmpl" id="movieTemplate"></script>中生成模版内容，里面包含占位符
→点击添加按钮的时候，把模版内容追加到界面上，并给占位符赋值

□ jQuery Template的内容大致是这样：

<script type="text/x-jquery-tmpl" id="movieTemplate">

<li style="padding-bottom:15px">

    <input autocomplete="off" name="FavouriteMovies.Index" type="hidden" value="${index}" />

    <img src="/Content/images/draggable-icon.png" style="cursor: move" alt=""/>

    <label>Title</label>

    <input name="FavouriteMovies[${index}].Title" type="text" value="" />

    <label>Rating</label>

    <input name="FavouriteMovies[${index}].Rating" type="text" value="0" />

    <a href="#" onclick="$(this).parent().remove();">Delete</a>

</li>

</script>

为了得到以上内容，由帮助类方法获得：

帮助类CollectionEditingHtmlExtensions：
模版内容同样是通过MovieEntryEditor.cshtml这个部分视图生成的，只不过生成的内容中包含了占位符。

using System;

using System.Collections.Generic;

using System.Web;

using System.Web.Mvc;

using System.Web.Mvc.Html;

namespace VariableCollection.Extension

    public static class CollectionEditingHtmlExtensions

        /// <summary>

        /// 目标是生成如下格式

        ///<input autocomplete="off" name="FavouriteMovies.Index" type="hidden" value="6d85a95b-1dee-4175-bfae-73fad6a3763b" />

        ///<label>Title</label>

        ///<input class="text-box single-line" name="FavouriteMovies[6d85a95b-1dee-4175-bfae-73fad6a3763b].Title" type="text" value="Movie 1" />

        ///<span class="field-validation-valid"></span>

        /// </summary>

        /// <typeparam name="TModel"></typeparam>

        /// <param name="html"></param>

        /// <param name="collectionName">集合属性的名称</param>

        /// <returns></returns>

        public static IDisposable BeginCollectionItem<TModel>(this HtmlHelper<TModel> html, string collectionName)

            if (string.IsNullOrEmpty(collectionName))

                throw new ArgumentException("collectionName is null or empty","collectionName");

            string collectionIndexFieldName = String.Format("{0}.Index", collectionName);//FavouriteMovies.Index

            string itemIndex = null;

            if (html.ViewData.ContainsKey(JQueryTemplatingEnabledKey))

                itemIndex = "${index}";

            else

                itemIndex = GetCollectionItemIndex(collectionIndexFieldName);

            //比如，FavouriteMovies[6d85a95b-1dee-4175-bfae-73fad6a3763b]

            string collectionItemName = string.Format("{0}[{1}]", collectionName, itemIndex);

            TagBuilder indexField = new TagBuilder("input");

            indexField.MergeAttributes(new Dictionary<string, string>() {

                { "name", String.Format("{0}.Index", collectionName) }, //name="FavouriteMovies.Index"

                { "value", itemIndex },//value="6d85a95b-1dee-4175-bfae-73fad6a3763b"

                { "type", "hidden" },

                { "autocomplete", "off" }

});

            html.ViewContext.Writer.WriteLine(indexField.ToString(TagRenderMode.SelfClosing));

            return new CollectionItemNamePrefixScope(html.ViewData.TemplateInfo, collectionItemName);

         private class CollectionItemNamePrefixScope : IDisposable

             private readonly TemplateInfo _templateInfo;

             private readonly string _previousPrefix;

             public CollectionItemNamePrefixScope(TemplateInfo templateInfo, string collectionItemName)

                 this._templateInfo = templateInfo;

                 _previousPrefix = templateInfo.HtmlFieldPrefix;

                 templateInfo.HtmlFieldPrefix = collectionItemName;

             public void Dispose()

                 _templateInfo.HtmlFieldPrefix = _previousPrefix;

        /// <summary>

        /// 以FavouriteMovies.Index为键，把Guid字符串存放在上下文中

        /// 如果是添加进入部分视图，就直接生成一个Guid字符串

        /// 如果是更新，为了保持和ModelState的一致，就遍历原先的Guid

        /// </summary>

        /// <param name="collectionIndexFieldName">FavouriteMovies.Index</param>

        /// <returns>返回Guid字符串</returns>

        private static string GetCollectionItemIndex(string collectionIndexFieldName)

            Queue<string> previousIndices = (Queue<string>)HttpContext.Current.Items[collectionIndexFieldName];

            if (previousIndices == null)

                HttpContext.Current.Items[collectionIndexFieldName] = previousIndices = new Queue<string>();

                string previousIndicesValues = HttpContext.Current.Request[collectionIndexFieldName];

                if (!string.IsNullOrWhiteSpace(previousIndicesValues))

                    foreach (string index in previousIndicesValues.Split(‘,‘))

                        previousIndices.Enqueue(index);

            return previousIndices.Count > 0 ? previousIndices.Dequeue() : Guid.NewGuid().ToString();

        private const string JQueryTemplatingEnabledKey = "__BeginCollectionItem_jQuery";

        public static MvcHtmlString CollectionItemJQueryTemplate<TModel, TCollectionItem>(this HtmlHelper<TModel> html,

                                                                                    string partialViewName,

                                                                                    TCollectionItem modelDefaultValues)

            ViewDataDictionary<TCollectionItem> viewData = new ViewDataDictionary<TCollectionItem>(modelDefaultValues);

            viewData.Add(JQueryTemplatingEnabledKey, true);

            return html.Partial(partialViewName, modelDefaultValues, viewData);

□ MovieEntryEditor.cshtm部分视图与上篇相同

@using VariableCollection.Extension

@model VariableCollection.Models.Movie

<li style="padding-bottom: 15px;">

    @using (Html.BeginCollectionItem("FavouriteMovies"))

        <img src="@Url.Content("~/Content/images/draggable-icon.png")" style="cursor: move" alt=""/>

        @Html.LabelFor(model => model.Title)

        @Html.EditorFor(model => model.Title)

        @Html.ValidationMessageFor(model => model.Title)

        @Html.LabelFor(model => model.Rating)

        @Html.EditorFor(model => model.Rating)

        @Html.ValidationMessageFor(model => model.Rating)

        <a href="#" onclick=" $(this).parent().remove(); ">删除行</a>

</li>

□ HomeController

        public ActionResult EditJqueryTemplate()

            return View(CurrentUser);

        [HttpPost]

        public ActionResult EditJqueryTemplate(User user)

            if (!this.ModelState.IsValid)

                return View(user);

            CurrentUser = user;

            return RedirectToAction("Display");

□ EditJqueryTemplate.cshtml完整代码如下：

@using VariableCollection.Extension

@using VariableCollection.Models

@model VariableCollection.Models.User

@{

    ViewBag.Title = "EditJqueryTemplate";

    Layout = "~/Views/Shared/_Layout.cshtml";

<h2>EditJqueryTemplate</h2>

@using (Html.BeginForm())

    @Html.ValidationSummary(true)

    <fieldset>

        <legend>最喜欢看的电影</legend>

        @Html.HiddenFor(model => model.Id)

        <div class="editor-label">

            @Html.LabelFor(model => model.Name)

        </div>

        <div class="editor-field">

            @Html.EditorFor(model => model.Name)

            @Html.ValidationMessageFor(model => model.Name)

        </div>

    </fieldset>

    <fieldset>

        <legend>最喜欢看的电影</legend>

        @if (Model.FavouriteMovies == null || Model.FavouriteMovies.Count == 0)

            <p>没有喜欢看的电影~~</p>

        <ul id="movieEditor" style="list-style-type: none">

            @if (Model.FavouriteMovies != null)

                foreach (Movie movie in Model.FavouriteMovies)

                    Html.RenderPartial("MovieEntryEditor", movie);

        </ul>

        <a id="addAnother" href="#" >添加</a>

    </fieldset>

<p>

        <input type="submit" value="提交" />

    </p>

@section scripts

    <script src="~/Scripts/jquery.tmpl.min.js"></script>

    <script type="text/x-jquery-tmpl" id="movieTemplate">

            @Html.CollectionItemJQueryTemplate("MovieEntryEditor", new Movie())

    </script>

    <script type="text/javascript">

            $(function () {

                $("#movieEditor").sortable();

                $(‘#addAnother‘).click(function() {

                    viewModel.addNew();

});

});

            var viewModel = {

                addNew: function () {

                    $("#movieEditor").append($("#movieTemplate").tmpl({ index: viewModel._generateGuid() }));

},

                _generateGuid: function () {

                    // Source: http://stackoverflow.com/questions/105034/how-to-create-a-guid-uuid-in-javascript/105074#105074

                    return ‘xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx‘.replace(/[xy]/g, function (c) {

                        var r = Math.random() * 16 | 0, v = c == ‘x‘ ? r : (r & 0x3 | 0x8);

                        return v.toString(16);

});

};

    </script>

参考资料：
※ Editing Variable Length Reorderable Collections in ASP.NET MVC – Part 2: jQuery Templates

MVC批量更新,使用jQuery Template,布布扣,bubuko.com