Question

我想在breeze dataService（客户端）中获取下面提到的自定义属性。

namespace Tam.Framework.Web.Models
{
    [ViewAttribute("app/views/Employee.html")]//this custom class attribute
    public class Employee : BaseEntity
    {
        protected override string OnGetDescriptor()
        {
            return "some description";
        }

        public string FirstName { get; set; }

        [Display(Name = "LAST NAME")]//this custom property attribute
        public string LastName { get; set; }
    }
}

Answer 1

在服务器上，将逻辑添加到元数据控制器操作以使用显示属性属性补充标准元数据：

[HttpGet]
public virtual string Metadata()
{
    // Extend metadata with extra attributes
    var metadata = JObject.Parse(this.ContextProvider.Metadata());
    var ns = metadata["schema"]["namespace"].ToString();
    foreach (var breezeEntityType in metadata["schema"]["entityType"])
    {
        var typeName = ns + "." + breezeEntityType["name"].ToString();
        var entityType = BuildManager.GetType(typeName, true);

        foreach (var propertyInfo in entityType.GetProperties())
        {
            var attributes = propertyInfo.GetAllAttributes();
            var breezePropertyInfo = breezeEntityType["property"].SingleOrDefault(p => p["name"].ToString() == propertyInfo.Name);
            if (breezePropertyInfo == null)
                continue;

            // handle display attribute...
            var displayAttribute = attributes.OfType<DisplayAttribute>().FirstOrDefault();
            if (displayAttribute != null)
            {
                var displayName = displayAttribute.GetName();
                if (displayName != null)
                    breezePropertyInfo["displayName"] = displayName;
                var displayOrder = displayAttribute.GetOrder();
                if (displayOrder != null)
                    breezePropertyInfo["displayOrder"] = displayOrder;
                var autogenerateField = displayAttribute.GetAutoGenerateField();
                if (autogenerateField != null)
                    breezePropertyInfo["autoGenerateField"] = autogenerateField;
            }

            // allowEmptyStrings.
            if (propertyInfo.PropertyType == typeof(string))
            {
                breezePropertyInfo["allowEmptyStrings"] = true;
                var requiredAttribute = attributes.OfType<RequiredAttribute>().FirstOrDefault();
                if (requiredAttribute != null && !requiredAttribute.AllowEmptyStrings)
                    breezePropertyInfo["allowEmptyStrings"] = false;
            }

            // todo: handle other types of attributes...
        }
    }

    return metadata.ToString();
}

在客户端上，获取元数据并使用自定义元数据补充breeze实体类型。

function initializeMetadataStore(metadataStore, metadata) {
    var metadataType, metadataProperty, entityProperty, i, j;
    for (i = 0; i < metadata.schema.entityType.length; i++) {
        metadataType = metadata.schema.entityType[i];
        var entityType = metadataStore.getEntityType(metadataType.name);
        for (j = 0; j < metadataType.property.length; j++) {
            metadataProperty = metadataType.property[j];
            entityProperty = entityType.getProperty(metadataProperty.name);
            if (entityProperty) {
                if (typeof metadataProperty.displayName !== 'undefined') {
                    entityProperty.displayName = metadataProperty.displayName;
                }
                if (typeof metadataProperty.displayOrder !== 'undefined') {
                    entityProperty.displayOrder = metadataProperty.displayOrder;
                }
                if (typeof metadataProperty.autoGenerateField !== 'undefined') {
                    entityProperty.autoGenerateField = metadataProperty.autoGenerateField;
                }
                if (typeof metadataProperty.allowEmptyStrings !== 'undefined') {
                    entityProperty.allowEmptyStrings = metadataProperty.allowEmptyStrings;
                }
            }
        }
    }
}

var entityManager = ....something...;
entityManager.fetchMetadata(function (metadata) {
    return initializeMetadataStore(entityManager.metadataStore, metadata);
});

现在，breeze实体类型中提供了额外的元数据......

var propertyDisplayName = myEntity.entityType.getProperty('lastName').displayName;

Answer 2

var manager = configureBreezeManager();

        function configureBreezeManager() {

        breeze.NamingConvention.camelCase.setAsDefault();
        var mgr = new breeze.EntityManager('api/breeze');
        model.configureMetadataStore(mgr.metadataStore);
        mgr.fetchMetadata(function (metadata) {
            return initializeMetadataStore(mgr.metadataStore, metadata);
        });
        return mgr;
    };




       function initializeMetadataStore(metadataStore, metadata) {
        breeze.NamingConvention.defaultInstance = breeze.NamingConvention.none;
        var metadataType, metadataProperty, entityProperty, i, j;
        for (i = 0; i < metadata.schema.entityType.length; i++) {
            metadataType = metadata.schema.entityType[i];
            var entityType = metadataStore.getEntityType(metadataType.name);
            for (j = 0; j < metadataType.property.length; j++) {
                metadataProperty = metadataType.property[j];

                    entityProperty = entityType.getProperty(metadataProperty.name);

                if (entityProperty) {
                    if (typeof metadataProperty.displayName !== 'undefined') {
                        entityProperty.displayName = metadataProperty.displayName;
                    }
                    if (typeof metadataProperty.displayOrder !== 'undefined') {
                        entityProperty.displayOrder = metadataProperty.displayOrder;
                    }
                    if (typeof metadataProperty.autoGenerateField !== 'undefined') {
                        entityProperty.autoGenerateField = metadataProperty.autoGenerateField;
                    }
                    if (typeof metadataProperty.allowEmptyStrings !== 'undefined') {
                        entityProperty.allowEmptyStrings = metadataProperty.allowEmptyStrings;
                    }
                }
            }
        }

    }





        var readData = function (entityName, observableResults, showLog) {

        if (!entityName || !observableResults)
            return null;

        var query = new breeze.EntityQuery()
            .from(entityName);


        return manager.executeQuery(query)
         .then(querySucceeded)
         .fail(queryFailed);
    }

    function readEmployee() {
    return breezeDataService.readData("Employees", employees, true).then(function () {

        var propertyDisplayName = employees()[0].entityType.getProperty('lastName').displayName;//error displayName undefined
     }
    }

当我通过readData函数得到实体列表时，list（observableResults [0]）没有任何displayName但是我添加displayName并通过initializeMetadataStore函数检查它是否正确

最后!!!!!我发现它是因为breeze.NamingConvention.camelCase.setAsDefault（）;

如何使用从属性属性中提取的元数据添加extend breeze实体类型

2 个答案: