Ext JS 6 Proxy that supports JSON Request Data and preserves GET parameters

Ext.ux.data.proxy.JsonAjaxProxy.js

Ext.define('Ext.ux.data.proxy.JsonAjaxProxy', {
    extend:'Ext.data.proxy.Ajax',
    alias:'proxy.jsonajax',

    /**
     * proxy: {
     *     type:'jsonajax',
     *     api: {
     *         read:'/api'
     *     },
     *     extraParams: {
     *         extra:'param'
     *     }
     * }
     *     
     * call:
     * store.load({
     *     params: {
     *         foo: 'bar',
     *         foobar: 'barfoo'
     *     },
     *     jsonData: {
     *         uids: [ 1, 2, 3, 4, 5, 6, 7, 8, 9 ],
     *         action: 'killthemall'
     *     }
     * });
     * 
     * result:
     * https://cooljsonapi.example/api?foo=bar&foobar=barfoo&extra=param
     * { uids: [1, 2, 3, 4, 5, 6, 7, 8, 9 ], action: 'killthemall' }
     */

    actionMethods : {
        create: "POST",
        read: "POST",
        update: "POST",
        destroy: "POST"
    },
    
    headers: { 
        'Content-Type': 'application/json' 
    },

    buildRequest:function (operation) {
        var request = this.callParent(arguments);

        // For documentation on jsonData see Ext.Ajax.request
        request.setJsonData(operation.jsonData);
        
        // Do not change params to support GET params
        // and extra params from proxy
        // request.setParams(operation.getParams());

        return request;
    },

    /*
     * @override
     * Inherit docs. We don't apply any encoding here because
     * all of the direct requests go out as jsonData
     */
    applyEncoding: function(value){
        return value;
    }

});