ExtJS 4.1 - 在 Model.Save() 响应中返回关联数据

Question

我很好奇为什么 Model.save() 响应的结果集中包含的记录没有正确返回更新的关联数据，尽管更新的数据包含在服务器响应中...

示例模型和商店定义：

Ext.define("App.model.test.Parent",{
    extend: 'Ext.data.Model',
    requires: ['App.model.test.Child'],
    fields: [
            {name: 'id', type: 'int' },
            {name: 'name', type: 'string'},
            {name: 'kids', type: 'auto', defaultValue: []}
    ],
    idProperty: 'id',

    hasMany: [{
            foreignKey: 'parent_id',
            model: 'App.model.test.Child', 
            associationKey: 'kids',
            name: 'getKids'   
    }],

    proxy: {
        type: 'ajax',
        api : {
            create: '/service/test/create/format/json',
            read : '/service/test/read/format/json',
            update : '/service/test/update/format/json'
        },

        reader: {
            idProperty      : 'id',
            type            : 'json',
            root            : 'data',        
            successProperty : 'success',       
            messageProperty : 'message'
        },

        writer: {
            type            : 'json',
            writeAllFields  : true
        }
    }
});

Ext.define("App.model.test.Child",{
    extend: 'Ext.data.Model',
    fields: [
        {name: 'id', type: 'int' },
        {name: 'name', type: 'string'},
        {name: 'parent_id', type: 'int'}
    ]
});

Ext.define("App.store.test.Simpson",{
    storeId: 'TheSimpsons',
    extend: 'Ext.data.Store',
    model : 'App.model.test.Parent',
    autoLoad: true,
    autoSync: false
});

应用服务器对代理的READ 请求的响应使用单个模型及其相关数据。这一切都在起作用！

服务器对读取请求的响应

{
"data":{
    "id":1,
    "name":"Homer Simpson",
    "children":{
        "1":{
            "id":1,
            "name":"Bart Simpson"
        },
        "2":{
            "id":2,
            "name":"Lisa Simpson"
        },
        "3":{
            "id":3,
            "name":"Maggie Simpson"
        }
    }
},
"success":true,
"message":null
}

到目前为止，一切都在按计划进行......

store = Ext.create("App.store.test.Simpson");
homer = store.getById(1);
kids  = homer.getKids().getRange();
console.log("The Simpson Kids", kids);  // [>constructor, >constructor, >constructor]

不希望的行为始于保存和更新请求

这是我对 UPDATE 请求的测试响应...

/** Server UPDATE Response */
{
"data":{
    "id":1,
    "name":"SAVED Homer Simpson",
    "kids":[{
        "id":1,
        "name":"SAVED Bart Simpson",
        "parent_id":1
    },{
        "id":2,
        "name":"SAVED Lisa Simpson",
        "parent_id":1
    },{
        "id":3,
        "name":"SAVED Maggie Simpson",
        "parent_id":1
    }]
},
"success":true,
"message":null
}


/** Will call proxy UPDATE, response is above */
homer.save({
    success: function(rec, op){
        var savedRec = op.getRecords().pop(),
            kidNames = '';
        console.log(savedRec.get('name')); // SAVED Homer Simpson = CORRECT!
        Ext.each(savedRec.getKids().getRange(), function(kid){
            kidNames += kid.get('name') + ", ";
        });
        console.log(kids); 
        //Outputs: Bart Simpson, Lisa Simpson, Maggie Simpson = WRONG!!
    }
})

我注意到，如果我检查服务器返回的记录，生成的关联存储（即getKidsStore）包含的记录是原始记录，即它们的名称中没有“SAVED”。然而，返回记录的kids 属性确实包含正确的数据。

如果我正确理解了这个问题，那是Ext.data.reader.Reader 没有使用.save() 响应中包含的关联数据正确更新关联存储。如果是这样，在我看来，这是非常不直观的，因为我希望与处理 store.load() 请求并首先填充生成的关联存储的读取器具有相同的行为。

谁能指出我实现我所追求的行为的正确方向？

免责声明： 此处提出了同样的问题：ExtJs 4 - Load nested data on record save，但没有任何回应。我觉得我的问题更彻底..

编辑：我已经在 Sencha 论坛上发布了这个问题：http://www.sencha.com/forum/showthread.php?270336-Associated-Data-in-Model.save()-Response

编辑（2013 年 8 月 23 日）：我用一个完整的例子重写了这篇文章，以及其他发现......

Answer 1

我发现了问题，或者更确切地说，困惑在于Ext.data.Operation 的getRecords() 方法。此方法返回“将返回操作的初始配置记录，尽管代理可能会在操作初始化后的某个时候修改这些记录的数据。” 根据文档。

这让 IMO 相当困惑，因为返回的记录确实已更新，但生成的关联存储以及关联的数据并未更新！这就是导致我困惑的原因，看起来好像记录包含来自应用程序服务器的更新数据，但事实并非如此。

为了帮助我简单的头脑从响应中获取FULLY更新的数据，我在Ext.data.Operation类中添加了一个方法...我只是写了这个方法并没有对其进行了测试，而不是确保我正在寻找的功能，所以使用风险自负！

请记住，我不调用 store.sync()，而是实例化一个模型并调用 model.save() 方法，因此我的 resultSet 通常只包含一条记录...

Ext.override(Ext.data.Operation,{
    getSavedRecord: function(){
        var me = this, // operation
            resultSet = me.getResultSet();

        if(resultSet.records){
            return resultSet.records[0];
        }else{
            throw "[Ext.data.Operation] EXCEPTION: resultSet contains no records!";
        }

    }
});

现在我能够实现我所追求的功能......

// Get the unsaved data
store = Ext.create('App.store.test.Simpson');
homer = store.getById(1);
unsavedChildren = '';

Ext.each(homer.getKids().getRange(), function(kid){
    unsavedChildren += kid.get('name') + ",";
});

console.log(unsavedChildren); // Bart Simpson, Lisa Simpson, Maggie Simpson

// Invokes the UPDATE Method on the proxy
// See original post for server response
home.save({
    success: function(rec, op){
        var savedRecord = op.getSavedRecord(), // the magic! /sarcasm
            savedKids   = '';

        Ext.each(savedRecord.getKids().getRange(), function(kid){
            savedKids += kid.get('name') + ',';
        });

        console.log("Saved Children", savedKids);

        /** Output is now Correct!!
            SAVED Bart Simpson, SAVED Lisa Simpson, SAVED Maggie Simpson
          */
    }
});

编辑 2013 年 12 月 10 日 我还向Ext.data.Model 添加了一个方法，我称之为updateTo，它处理将记录更新到提供的记录，它还处理关联。我将它与上述getSavedRecord 方法结合使用。请注意，这不处理任何 belongsTo 关联，因为我没有在我的应用程序中使用它们，但该功能很容易添加。

/**
 * Provides a means to update to the provided model, including any associated data
 * @param {Ext.data.Model} model The model instance to update to. Must have the same modelName as the current model
 * @return {Ext.data.Model} The updated model
 */
updateTo: function(model){
    var me = this,
    that = model,
    associations = me.associations.getRange();

    if(me.modelName !== that.modelName)
    throw TypeError("updateTo requires a model of the same type as the current instance ("+ me.modelName +"). " + that.modelName + " provided.");

    // First just update the model fields and values
    me.set(that.getData());

    // Now update associations
    Ext.each(associations, function(assoc){
    switch(assoc.type){
        /**
         * hasOne associations exist on the current model (me) as an instance of the associated model.
         * This instance, and therefore the association, can be updated by retrieving the instance and
         * invoking the "set" method, feeding it the updated data from the provided model.
         */
        case "hasOne":
            var instanceName  = assoc.instanceName,
                currentInstance = me[instanceName],
                updatedInstance = that[instanceName];

             // Update the current model's hasOne instance with data from the provided model
             currentInstance.set(updatedInstance.getData());

            break;

        /** 
         * hasMany associations operate from a store, so we need to retrieve the updated association
         * data from the provided model (that) and feed it into the current model's (me) assocStore
         */
        case "hasMany":
            var assocStore = me[assoc.storeName],
                getter     = assoc.name,
                newData    = that[getter]().getRange();

            // Update the current model's hasMany association store with data from the provided model's hasMany store
            assocStore.loadData(newData);
            break;

        // If for some reason a bogus association type comes through, throw a type error
        // At this time I have no belongsTo associations in my application, so this TypeError
        // may one day appear if I decide to implement them.
        default:
            throw TypeError("updateTo does not know how to handle association type: " + assoc.type);
            break;
    }
    });

    // Commit these changes
    me.commit();

    return me;
}

所以基本上我会做这样的事情（理论上这将在 Order 控制器中）

doSaveOrder: function(order){
    var me = this,                       // order controller 
        orderStore = me.getOrderStore(); // magic method

    // Save request
    order.save({
        scope: me,
        success: function(responseRecord, operation){ 
            // note: responseRecord does not have updated associations, as per post
            var serverRecord = operation.getSavedRecord(),
                storeRecord  = orderStore.getById(order.getId());

            switch(operation.action){
                case 'create':
                    // Add the new record to the client store
                    orderStore.add(serverRecord);
                break;

                case 'update':
                    // Update existing record, AND associations, included in server response
                    storeRecord.updateTo(serverRecord);
                break;
            }
        }
    });
}

我希望这对像我一样困惑的人有所帮助！

Answer 2

完全同意你的看法。真是奇怪的行为。它应该更新记录上的关联存储。这就是我解决这个问题的方法（基本上只是通过阅读器运行响应！）：

 success: function(record, operation) {
     var newRecord= me.getMyModel().getProxy().reader.read(operation.response).records[0];
 }

Answer 3

在 ExtJS 6.2 中问题仍然存在（或再次存在）。 我的解决方案：

/**
 * In Ext.data.reader.Reader::extractRecord the call readAssociated reads out the hasMany associations and processes them.
 * This works perfectly for Model.load() since internally a Model is used as record variable in extractRecord. 
 * For Model.save() record extractRecord contains just the Object with the received data from the PUT request, 
 *  therefore readAssociated is never called and no associations are initialized or updated.
 * The following override calls readAssociated if necessary in the save callback.
 */
Ext.override(Ext.data.Model, {
    save: function(options) {
        options = Ext.apply({}, options);
        var me = this,
            includes = me.schema.hasAssociations(me),
            scope  = options.scope || me,
            callback,
            readAssoc = function(record) {
                //basicly this is the same code as in readAssociated to loop through the associations
                var roles = record.associations,
                    key, role;
                for (key in roles) {
                    if (roles.hasOwnProperty(key)) {
                        role = roles[key];
                        // The class for the other role may not have loaded yet
                        if (role.cls) {
                            //update the assoc store too                            
                            record[role.getterName]().loadRawData(role.reader.getRoot(record.data));
                            delete record.data[role.role];
                        }
                    }
                }

            };

        //if we have includes, then we can read the associations
        if(includes) {
            //if there is already an success handler, we have to call both
            if(options.success) {
                callback = options.success;
                options.success = function(rec, operation) {
                    readAssoc(rec);
                    Ext.callback(callback, scope, [rec, operation]);
                };
            }
            else {
                options.success = readAssoc;
            }
        }
        this.callParent([options]);
    }
});

Answer 4

如果您的 ID 字段有值，那么 ExtJS 将始终调用更新。如果您没有向 id 字段写入任何值或将其设置为 null，则应调用 create。我猜您正在尝试使用现有记录调用保存，因此它将始终调用更新。这是一种期望的行为。