cascadingdropdownbehavior.js

AJAX 应用 实现页面的无刷新

            this._setOptions(null, inInit);
            return;
        }

        // Show the loading text (if any)
        this._setOptions(null, inInit, true);

        if (this._servicePath && this._serviceMethod) {
            // Raise the populating event and optionally cancel the web service invocation
            var eventArgs = new Sys.CancelEventArgs();
            this.raisePopulating(eventArgs);
            if (eventArgs.get_cancel()) {
                return;
            }
            
            // Create the service parameters and optionally add the context parameter
            // (thereby determining which method signature we're expecting...)
            var params = { knownCategoryValues:knownCategoryValues, category:this._category };
            if (this._useContextKey) {
                params.contextKey = this._contextKey;
            }
        
            // Call the helper web service
            Sys.Net.WebServiceProxy.invoke(this._servicePath, this._serviceMethod, false, params,
                Function.createDelegate(this, this._onMethodComplete), Function.createDelegate(this, this._onMethodError));
            $common.updateFormToRefreshATDeviceBuffer();
        }
    },

    _onMethodComplete : function(result, userContext, methodName) {
        // Success, update the DropDownList
        this._setOptions(result);
    },

    _onMethodError : function(webServiceError, userContext, methodName) {
        // Indicate failure
        if (webServiceError.get_timedOut()) {
            this._setOptions( [ this._makeNameValueObject(AjaxControlToolkit.Resources.CascadingDropDown_MethodTimeout) ] );
        } else {
            this._setOptions( [ this._makeNameValueObject(String.format(AjaxControlToolkit.Resources.CascadingDropDown_MethodError, webServiceError.get_statusCode())) ] );
        }
    },

    _makeNameValueObject : function(message) {
        /// <summary>
        /// Create an object with name and value properties set to the provided message
        /// </summary>
        /// <param name="message" type="String">
        /// Message
        /// </param>
        /// <returns type="Object">
        /// Object with name and value properties set to the message
        /// </returns>

        return { 'name': message, 'value': message };
    },

    get_ParentControlID : function() {
        /// <value type="String">
        /// ID of the parent drop down in a hierarchy of drop downs
        /// </value>
       return this._parentControlID;
    },
    set_ParentControlID : function(value) {
        if (this._parentControlID != value) {
            this._parentControlID = value;
            this.raisePropertyChanged('ParentControlID');
        }
    },

    get_Category : function() {
        /// <value type="String">
        /// Category of this drop down
        /// </value>
        return this._category;
    },
    set_Category : function(value) {
        if (this._category != value) {
            this._category = value;
            this.raisePropertyChanged('Category');
        }
    },

    get_PromptText : function() {
        /// <value type="String">
        /// Prompt text displayed as the first entry in the drop down
        /// </value>
        return this._promptText;
    },
    set_PromptText : function(value) {
        if (this._promptText != value) {
            this._promptText = value;
            this.raisePropertyChanged('PromptText');
        }
    },

    get_PromptValue : function() {
        /// <value type="String">
        /// Value for the option displayed by a DropDownList showing the PromptText
        /// </value>
        return this._promptValue;
    },
    set_PromptValue : function(value) {
        if (this._promptValue != value) {
            this._promptValue = value;
            this.raisePropertyChanged('PromptValue');
        }
    },

    get_EmptyText : function() {
        /// <value type="String">
        /// Text for the option displayed when the list is empty
        /// </value>
        return this._emptyText;
    },
    set_EmptyText : function(value) {
        if (this._emptyText != value) {
            this._emptyText = value;
            this.raisePropertyChanged('EmptyText');
        }
    },

    get_EmptyValue : function() {
        /// <value type="String">
        /// Value for the option displayed when the list is empty
        /// </value>
        return this._emptyValue;
    },
    set_EmptyValue : function(value) {
        if (this._emptyValue != value) {
            this._emptyValue = value;
            this.raisePropertyChanged('EmptyValue');
        }
    },

    get_LoadingText : function() {
        /// <value type="String">
        /// Loading text to to be displayed when getting the drop down's values from the web service
        /// </value>
        return this._loadingText;
    },
    set_LoadingText : function(value) {
        if (this._loadingText != value) {
            this._loadingText = value;
            this.raisePropertyChanged('LoadingText');
        }
    },

    get_SelectedValue : function() {
         /// <value type="String">
         /// Selected value of the drop down
         /// </value>
        return this._selectedValue;
    },
    set_SelectedValue : function(value, text) {
        if (this._selectedValue != value) {
            if (!text) {
                // Initial population by server; look for "value:::text" pair
                var i = value.indexOf(':::');
                if (-1 != i) {
                    text = value.slice(i + 3);
                    value = value.slice(0, i);
                }
            }
            var oldValue = this._selectedValue;
            this._selectedValue = value;
            this.raisePropertyChanged('SelectedValue');
            this.raiseSelectionChanged(new AjaxControlToolkit.CascadingDropDownSelectionChangedEventArgs(oldValue, value));
        }
        AjaxControlToolkit.CascadingDropDownBehavior.callBaseMethod(this, 'set_ClientState', [ this._selectedValue+':::'+text ]);
    },

    get_ServicePath : function() {
        /// <value type="String" mayBeNull="true">
        /// Path to the web service
        /// </value>
        return this._servicePath;
    },
    set_ServicePath : function(value) {
        if (this._servicePath != value) {
            this._servicePath = value;
            this.raisePropertyChanged('ServicePath');
        }
    },

    get_ServiceMethod : function() {
        /// <value type="String">
        /// Name of the method to invoke on the web service
        /// </value>
        return this._serviceMethod;
    },
    set_ServiceMethod : function(value) {
        if (this._serviceMethod != value) {
            this._serviceMethod = value;
            this.raisePropertyChanged('ServiceMethod');
        }
    },
    
    get_contextKey : function() {
        /// <value type="String" mayBeNull="true">
        /// User/page specific context provided to an optional overload of the
        /// web method described by ServiceMethod/ServicePath.  If the context
        /// key is used, it should have the same signature with an additional
        /// parameter named contextKey of type string.
        /// </value>
        return this._contextKey;
    },
    set_contextKey : function(value) {
        if (this._contextKey != value) {
            this._contextKey = value;
            this.set_useContextKey(true);
            this.raisePropertyChanged('contextKey');
        }
    },
    
    get_useContextKey : function() {
        /// <value type="Boolean">
        /// Whether or not the ContextKey property should be used.  This will be
        /// automatically enabled if the ContextKey property is ever set
        /// (on either the client or the server).  If the context key is used,
        /// it should have the same signature with an additional parameter
        /// named contextKey of type string.
        /// </value>
        return this._useContextKey;
    },
    set_useContextKey : function(value) {
        if (this._useContextKey != value) {
            this._useContextKey = value;
            this.raisePropertyChanged('useContextKey');
        }
    },
    
    add_selectionChanged : function(handler) {
        /// <summary>
        /// Add an event handler for the selectionChanged event
        /// </summary>
        /// <param name="handler" type="Function" mayBeNull="false">
        /// Event handler
        /// </param>
        /// <returns />
        this.get_events().addHandler('selectionChanged', handler);
    },
    remove_selectionChanged : function(handler) {
        /// <summary>
        /// Remove an event handler from the selectionChanged event
        /// </summary>
        /// <param name="handler" type="Function" mayBeNull="false">
        /// Event handler
        /// </param>
        /// <returns />
        this.get_events().removeHandler('selectionChanged', handler);
    },
    raiseSelectionChanged : function(eventArgs) {
        /// <summary>
        /// Raise the selectionChanged event
        /// </summary>
        /// <param name="eventArgs" type="AjaxControlToolkit.CascadingDropDownSelectionChangedEventArgs" mayBeNull="false">
        /// Event arguments for the selectionChanged event
        /// </param>
        /// <returns />
        
        var handler = this.get_events().getHandler('selectionChanged');
        if (handler) {
            handler(this, eventArgs);
        }
    },
    
    add_populating : function(handler) {
        /// <summary>
        /// Add an event handler for the populating event
        /// </summary>
        /// <param name="handler" type="Function" mayBeNull="false">
        /// Event handler
        /// </param>
        /// <returns />
        this.get_events().addHandler('populating', handler);
    },
    remove_populating : function(handler) {
        /// <summary>
        /// Remove an event handler from the populating event
        /// </summary>
        /// <param name="handler" type="Function" mayBeNull="false">
        /// Event handler
        /// </param>
        /// <returns />
        this.get_events().removeHandler('populating', handler);
    },
    raisePopulating : function(eventArgs) {
        /// <summary>
        /// Raise the populating event
        /// </summary>
        /// <param name="eventArgs" type="Sys.CancelEventArgs" mayBeNull="false">
        /// Event arguments for the populating event
        /// </param>
        /// <returns />
        /// <remarks>
        /// The populating event can be used to provide custom data to
        /// CascadingDropDown instead of using a web service.  Just cancel the
        /// event (using the CancelEventArgs) and pass your own data to the
        /// _setOptions method.
        /// </remarks>
        
        var handler = this.get_events().getHandler('populating');
        if (handler) {
            handler(this, eventArgs);
        }
    },
    
    add_populated : function(handler) {
        /// <summary>
        /// Add an event handler for the populated event
        /// </summary>
        /// <param name="handler" type="Function" mayBeNull="false">
        /// Event handler
        /// </param>
        /// <returns />
        this.get_events().addHandler('populated', handler);
    },
    remove_populated : function(handler) {
        /// <summary>
        /// Remove an event handler from the populated event
        /// </summary>
        /// <param name="handler" type="Function" mayBeNull="false">
        /// Event handler
        /// </param>
        /// <returns />
        this.get_events().removeHandler('populated', handler);
    },
    raisePopulated : function(eventArgs) {
        /// <summary>
        /// Raise the populated event
        /// </summary>
        /// <param name="eventArgs" type="Sys.EventArgs" mayBeNull="false">
        /// Event arguments for the populated event
        /// </param>
        /// <returns />
        
        var handler = this.get_events().getHandler('populated');
        if (handler) {
            handler(this, eventArgs);
        }
    }
}
AjaxControlToolkit.CascadingDropDownBehavior.registerClass('AjaxControlToolkit.CascadingDropDownBehavior', AjaxControlToolkit.BehaviorBase);
//    getDescriptor : function() {
//        var td = AjaxControlToolkit.CascadingDropDownBehavior.callBaseMethod(this, 'getDescriptor');
//        // Add custom properties
//        td.addProperty('ParentControlID', String);
//        td.addProperty('Category', String);
//        td.addProperty('PromptText', String);
//        td.addProperty('LoadingText', String);
//        td.addProperty('ServicePath', String);
//        td.addProperty('ServiceMethod', String);
//        td.addProperty('SelectedValue', String);
//        return td;
//    },