使用directjngine在ext-js中无限滚动

Question

首先，我请求你对我宽宏大量:我只是一个可怜的ext-js和javascript新手……

我正在努力适应我对ext-js中的infinite scroll grid example的需求。我在sencha ext-js中定义了以下存储：

Ext.define('AM.store.M2MResources', {
    extend: 'Ext.data.Store',
    requires: 'Ext.direct.*', //  use ext-direct for binding
    model: 'AM.model.M2MResource',
    autoLoad: true,

    paramsAsHash:false,
    autoSave: false,

    pageSize: 25,
    // allow the grid to interact with the paging scroller by buffering
    buffered: true,

    proxy: {
        type: 'direct',
        api: {
            // create  : undefined,
            read    : M2MResourceServlet.getM2Mresources,
            // update  : undefined,
            // destroy : undefined 
        },      
        extraParams: {
              total: 100
        },
        root: 'data',
        fields: [{name:'label'}, {name:'address_unique'}, {name:'address_network'}, {name:'status'}],
        paramOrder: 'page, start, limit',
        reader: {       
            type: 'json',           
            root: 'data',
            successProperty: 'success',
            totalProperty: 'totalCount'
        },
        writer: new Ext.data.JsonWriter({
            encode: false,
            writeAllFields: true,
            listful: true
        }
        )
    }
});

使用此directJNgine服务器副本：

public class M2MResourceServlet {
    public static class ResourceData{       
        public String label;
        public String address_unique;
        public String address_network;
        public String status;
    }

    public static class DirectStoreResult{
        ResourceData[] data;
        public int totalCount;
        public boolean success = true;

        public DirectStoreResult(ResourceData[] data, int totalCount) {
            super();
            this.data = data;
            this.totalCount = totalCount;
        }
    }

    static int counter = 0;
    @DirectMethod
    public DirectStoreResult getM2Mresources( Integer page, Integer start, Integer limit ) {
        ArrayList<ResourceData> result = new ArrayList<ResourceData>();

        // fill result list...

        DirectStoreResult r = new DirectStoreResult(result.toArray(new ResourceData []{}),limit);
        return r;
    }
}

然后我指定了以下模型：

Ext.define('AM.model.M2MResource', {
    extend: 'Ext.data.Model',
    fields: [
        {name:'label' },
        {name:'address_unique' },
        {name:'address_network' },
        {name:'status' }
     ]
});

因此，我想将数据加载到下面的网格中：

Ext.define('AM.view.resgrid.M2MResources', {
    extend: 'Ext.grid.Panel',
    alias: 'widget.m2mresources',

    title: 'All Resources Here',    

    verticalScrollerType: 'paginggridscroller',

    store: 'M2MResources',

  initComponent: function() {

      console.log('initComponent function in View has been called...');

      this.columns = [
                      {header: 'friendly name',dataIndex: 'label',flex: 1, sortable: true},
                      {header: 'address unique', dataIndex: 'address_unique',flex: 1},
                      {header: 'address network', dataIndex: 'address_network', flex: 1},
                      {header: 'node status',dataIndex: 'status',flex: 1}
                      ];

      this.callParent(arguments);

      Ext.getStore('M2MResources').guaranteeRange(0, 100);
  }
});

不幸的是，该存储似乎从未加载过数据:网格面板显示“正在加载...”不显示符号和数据项。我怀疑问题出在我的直接方法返回的json中。在客户端，我得到了以下json数据记录：

​

​

你能建议一下如何解决这个问题吗？谢谢!

Answer 1

好的，这个问题的合理答案可以在here找到。基本上，服务器端直接方法的形式必须是

@DirectMethod
public PartialResult<ResourceData> getM2Mresources(int start, int limit) {
        ResourceData[] m2mResources = ...
    //...
        return new PartialResult<ResourceData>(Arrays.asList(m2mResources), 
    m2mResources.length);
}

其中，PartialResult类如下所示：

public class PartialResult<T> {

    /** the partial result set */
    private Collection<T> result;

    /** the size of the complete result set */
    private int total;

    public Collection<T> getResult() {
       return this.result;
    }

    public int getTotal() {
       return this.total;
    }

    public void setResult(Collection<T> result) {
       this.result = result;
    }

    public void setTotal(int total) {
       this.total = total;
    }

    public PartialResult(Collection<T> result, int total) {
       super();
       this.result = result;
       this.total = total;
    }

}

我在ResourceData类中添加了一些getter，就像在原始示例中一样。

js存储是

Ext.define('AM.store.M2MResources', {
    extend: 'Ext.data.DirectStore',
    requires: 'Ext.direct.*', //  use ext-direct for binding
    model: 'AM.model.M2MResource',

    autoLoad: true,
    buffered: true,
    pageSize: 20,
    purgePageCount: 0,
    leadingBufferZone: 60,
    trailingBufferZone: 0,

    constructor : function(config) {
        config = config || {};

        config.proxy = {
            type: 'direct',
            directFn : M2MResourceServlet.getM2Mresources,
            reader: {
                type: 'json',
                root: 'result'
            },
            paramOrder: 'start,limit',
            paramsAsHash: false
        };

        this.callParent([config]);
    },

    toString: function() {
        return 'M2MResources: count = ' + this.getCount() + ', totalCount = ' 
                + this.getTotalCount();
    }
});

显然，这正是我想要做的。所以谢谢你亚当·戴维斯！无论如何，如果有人能解释为什么必须使用directFn元素而不是api元素，我将不胜感激……

Answer 2

响应数据与您的读卡器配置不匹配。您已经为您的阅读器配置了一个数据根目录：‘’，但我在响应中看到的是没有数据节点。您显示的展开节点是：根：'result.data'。我也看不到属性successProperty和totalProperty。