使用自定义标签帮助程序更新相关电话实体

如果我理解正确,一个appuser可能有3个电话号码,每个用户的每种电话类型的计数将为零或一。

如果是这样,我们可以简单地使用phoneType作为索引,换句话说,不需要使用自定义索引来迭代 Phones 财产,以及 ProcessAsync() 方法可以是:

    public override async Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
    {
        output.TagName = null; //DO NOT WANT AN OUTTER HTML ELEMENT

        var props = typeof(UserPhones).GetProperties();

        // display editable tags for phones
        foreach (var pt in this.TypesToEdit) {
            var phone = Phones.SingleOrDefault(p=>p.Type == pt);
            var index = (int) pt;
            foreach (var pi in props)
            {
                // if phone==null , then the pv should be null too
                var pv = phone==null? null: pi.GetValue(phone);
                var tag = GenerateFieldForProperty(pi.Name, pv, index, pt);
                output.Content.AppendHtml(tag);
            }
        }
        // generate hidden input tags for phones
        var phones= Phones.Where(p => !this.TypesToEdit.Contains((p.Type)));
        foreach (var p in phones) {
            var index = (int)p.Type;
            foreach (var pi in props) {
                var pv = pi.GetValue(p);
                var tag = GenerateFieldForProperty(pi.Name,pv,index,p.Type);
                output.Content.AppendHtml(tag);
            }
        }
    }

这里 GenerateFieldForProperty 是为特定属性生成标记生成器的简单帮助器方法:

    private TagBuilder GenerateFieldForProperty(string propName,object propValue,int index, EnumPhoneType eType )
    {
        // whether current UserPhone is editable (check the PhoneType)
        var editable = TypesToEdit.Contains(eType);
        var expression = this.ExpressionFilter(For.Name + $"[{index}].{propName}");
        var explorer = For.ModelExplorer.GetExplorerForExpression(typeof(IList<UserPhones>), o => propValue);

        //IF REQUESTED TYPE AND PROPERTY SPECIFIED
        if (pi.Name.NormalizeString() == PropNameToEdit.NormalizeString() && editable)
        {
            TagBuilder gridItem = new TagBuilder("div");
            gridItem.Attributes.Add("class", "rvt-grid__item");
            var labelText = this.GetLabelTextByPhoneType(eType);
            gridItem.InnerHtml.AppendHtml(BuildLabel(explorer, expression, labelText));
            gridItem.InnerHtml.AppendHtml(BuildTextBox(explorer, expression, propValue?.ToString()));
            return gridItem;
        }
        else //ADD HIDDEN FIELD SO BOUND PROPERLY
            return BuildHidden(explorer, expression, propValue?.ToString());
    }


    private string GetLabelTextByPhoneType(EnumPhoneType eType) {
        string lVal = null;
        switch (eType)
        {
            case EnumPhoneType.Home:
                lVal = "Home Phone";
                break;
            case EnumPhoneType.Mobile:
                lVal = "Mobile Phone";
                break;
            case EnumPhoneType.Other:
                lVal = "Other Phone";
                break;
            default:
                break;
        }
        return lVal;
    }

当发布到服务器时,如果有人没有为 other PhoneType,实际有效负载如下:

AppUser.UserPhones[0].UserPhoneId=....&AppUser.UserPhones[0].PhoneNumber=911&....
&AppUser.UserPhones[2].UserPhoneId=&AppUser.UserPhones[2].PhoneNumber=&AppUser.UserPhones[2].Type=&AppUser.UserPhones[2].AppUserId=&AppUser.UserPhones[2].AppUser=
&AppUser.UserPhones[1].UserPhoneId=...&AppUser.UserPhones[1].PhoneNumber=119&....

由于我们使用电话类型作为索引,因此我们可以得出以下结论: UserPhones[0] 将用作 Mobile 电话和 UserPhones[2] 将被视为 Home 电话。

页处理程序或操作方法

服务器端的模型绑定器将为每个用户电话创建一个空字符串。 为了删除这些空输入并防止过度发布攻击,我们可以使用LINQ过滤用户电话,以便在不使用空电话的情况下创建或更新用户电话记录:

    var editables = new[] {
        EnumPhoneType.Mobile,
        EnumPhoneType.Other,
    };
    AppUser.UserPhones = AppUser.UserPhones
        .Where(p => !string.IsNullOrEmpty(p.PhoneNumber))  // remove empty inputs
        .Where(p => editables.Contains(p.Type) )           // remove not editable inputs
        .ToList();
    // now the `UserPhones` will be clean for later use
    // ... create or update user phones as you like 

假设您要创建电话:

public IActionResult OnPostCreate() {
    var editables = new[] {
        EnumPhoneType.Mobile,
        EnumPhoneType.Other,
    };
    AppUser.UserPhones = AppUser.UserPhones
        .Where(p => !string.IsNullOrEmpty(p.PhoneNumber))
        .Where(p => editables.Contains(p.Type) )
        .Select(p => {                   // construct relationship for inputs
            p.AppUser = AppUser;
            p.AppUserId = AppUser.Id;
            return p;
        })
        .ToList();

    this._dbContext.Set<UserPhones>().AddRange(AppUser.UserPhones);
    this._dbContext.SaveChanges();

    return Page();
}

测试用例:

<form method="post">
    <div class="row">

    <user-phones 
        phones="@Model.AppUser.UserPhones" 
        asp-for="@Model.AppUser.UserPhones" 
        prop-name-to-edit="PhoneNumber"
        types-to-edit="new EnumPhoneType[] { EnumPhoneType.Mobile, EnumPhoneType.Other}"
        >
    </user-phones>
    </div>

    <button type="submit">submit</button>
</form>

拥有手机和家庭电话号码的用户1:

想要创建新手机号码的用户2: