Determining when database zip is unpacked

I am fetching a db zip on initial startup of an AIR app (after 1st install), which I then unpack via FZip. After this operation I immediately need to load data from the genera开发者_运维问答ted sqlite db, which fails since I seem not able to determine when the zip is completely unpacked and/or the sqlite has been created.

Any suggestions? Thx!

• For clarity: I am dispatching an event within Cairngorm after my result operation's been done of course, but this doesn't seem sufficient.

Well you kind of have the answer in the question.

I had a quick look at the FZip docs and noticed there's an event dispatched when the zip file is loaded.

Just scanning through the code, in FZipLibrary.as there's the processNext() method which contains a while loop to traverse the files in the archive. You could add a FILE_PARSED constant to FZipEvent and dispatch such an event from there, after the while loop is finished.

I can't try test this at the moment, but here's what I mean:

/*
 * Copyright (C) 2006 Claus Wahlers and Max Herkender
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */

package deng.fzip
{
    import deng.fzip.FZipFile;
    import flash.events.Event;

    /**
     * FZip dispatches FZipEvent objects when a file contained in the
     * ZIP archive has finished loading and can be accessed. There is 
     * only one type of FZipEvent: FZipErrorEvent.FILE_LOADED.
     */     
    public class FZipEvent extends Event
    {
        /**
        * The file that has finished loading.
        */      
        public var file:FZipFile;

        /**
        * Defines the value of the type property of a FZipEvent object.
        */      
        public static const FILE_LOADED:String = "fileLoaded";

        /**
        * Zip contents were parsed
        */      
        public static const FILE_PARSED:String = "fileParsed";

        /**
         * Constructor
         * 
         * @param type The type of the event. Event listeners can 
         * access this information through the inherited type property. 
         * There is only one type of FZipEvent: 
         * FZipEvent.PARSE_ERROR.
         * 
         * @param file The file that has finished loading.
         * 
         * @param bubbles Determines whether the Event object participates 
         * in the bubbling stage of the event flow. Event listeners can 
         * access this information through the inherited bubbles property.
         * 
         * @param cancelable Determines whether the Event object can be 
         * canceled. Event listeners can access this information through 
         * the inherited cancelable property.
         */     
        public function FZipEvent(type:String, file:FZipFile = null, bubbles:Boolean = false, cancelable:Boolean = false) {
            this.file = file;
            super(type, bubbles, cancelable);
        }

        /**
         * Creates a copy of the FZipEvent object and sets the value 
         * of each property to match that of the original.
         * 
         * @return A new FZipEvent object with property values that 
         * match those of the original.
         */     
        override public function clone():Event {
            return new FZipEvent(type, file, bubbles, cancelable);
        }
    }
}

That would be just adding the constant for the event.

/*
 * Copyright (C) 2006 Claus Wahlers and Max Herkender
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */

package deng.fzip {
    import flash.events.*;
    import flash.display.Bitmap;
    import flash.display.BitmapData;
    import flash.display.DisplayObject;
    import flash.display.Loader;
    import flash.utils.ByteArray;

    /**
     * Dispatched when all pending files have been processed. 
     *
     * @eventType flash.events.Event.COMPLETE 
     */
    [Event(name="complete", type="flash.events.Event")]

    /**
     * <p>FZipLibrary works with a FZip instance to load files as
     * usable instances, like a DisplayObject or BitmapData. Each file
     * from a loaded zip is processed based on their file extentions.
     * More than one FZip instance can be supplied, and if it is
     * currently loading files, then FZipLibrary will wait for incoming
     * files before it completes.</p>
     * 
     * <p>Flash's built-in Loader class is used to convert formats, so the
     * only formats currently supported are ones that Loader supports.
     * As of this writing they are SWF, JPEG, GIF, and PNG.</p>
     * 
     * <p>The following example loads an external zip file, outputs the
     * width and height of an image and then loads a sound from a SWF file.</p>
     * 
     * <pre>
     * package {
     *  import flash.events.*;
     *  import flash.display.BitmapData;
     *  import deng.fzip.FZip;
     *  import deng.fzip.FZipLibrary;
     *  
     *  public class Example {
     *      private var lib:FZipLibrary;
     *      
     *      public function Example(url:String) {
     *          lib = new FZipLibrary();
     *          lib.formatAsBitmapData(".gif");
     *          lib.formatAsBitmapData(".jpg");
     *          lib.formatAsBitmapData(".png");
     *          lib.formatAsDisplayObject(".swf");
     *          lib.addEventListener(Event.COMPLETE,onLoad);
     *          
     *          var zip:FZip = new FZip();
     *          zip.load(url);
     *          lib.addZip(zip);
     *      }
     *      private function onLoad(evt:Event) {
     *          var image:BitmapData = lib.getBitmapData("test.png");
     *          trace("Size: " + image.width + "x" + image.height);
     *          
     *          var importedSound:Class = lib.getDefinition("data.swf", "SoundClass") as Class;
     *          var snd:Sound = new importedSound() as Sound;
     *      }
     *  }
     * }</pre>
     * 
     * @see http://livedocs.macromedia.com/flex/201/langref/flash/display/Loader.html
     */
    public class FZipLibrary extends EventDispatcher {
        static private const FORMAT_BITMAPDATA:uint = (1 << 0);
        static private const FORMAT_DISPLAYOBJECT:uint = (1 << 1);

        private var pendingFiles:Array = [];
        private var pendingZips:Array = [];
        private var currentState:uint = 0;
        private var currentFilename:String;
        private var currentZip:FZip;
        private var currentLoader:Loader;

        private var bitmapDataFormat:RegExp = /[]/;
        private var displayObjectFormat:RegExp = /[]/;
        private var bitmapDataList:Object = {};
        private var displayObjectList:Object = {};

        /**
         * Constructor
         */
        public function FZipLibrary() {
        }
        /**
         * Use this method to add an FZip instance to the processing queue.
         * If the FZip instance specified is not active (currently receiving files)
         * when it is processed than only the files already loaded will be processed.
         * 
         * @param zip An FZip instance to process
         */
        public function addZip(zip:FZip):void {
            pendingZips.unshift(zip);
            processNext();
        }
        /**
         * Used to indicate a file extension that triggers formatting to BitmapData.
         * 
         * @param ext A file extension (".jpg", ".png", etc)
         */
        public function formatAsBitmapData(ext:String):void {
            bitmapDataFormat = addExtension(bitmapDataFormat,ext);
        }
        /**
         * Used to indicate a file extension that triggers formatting to DisplayObject.
         * 
         * @param ext A file extension (".swf", ".png", etc)
         */
        public function formatAsDisplayObject(ext:String):void {
            displayObjectFormat = addExtension(displayObjectFormat,ext);
        }
        /**
         * @private
         */
        private function addExtension(original:RegExp,ext:String):RegExp {
            return new RegExp(ext.replace(/[^A-Za-z0-9]/,"\\$&")+"$|"+original.source);
        }

        /**
         * Request a file that has been formatted as BitmapData.
         * A ReferenceError is thrown if the file does not exist as a
         * BitmapData.
         * 
         * @param filename The filename of the BitmapData instance.
         */
        public function getBitmapData(filename:String):BitmapData {
            if (!bitmapDataList[filename] is BitmapData) {
                throw new Error("File \""+filename+"\" was not found as a BitmapData");
            }
            return bitmapDataList[filename] as BitmapData;
        }
        /**
         * Request a file that has been formatted as a DisplayObject.
         * A ReferenceError is thrown if the file does not exist as a
         * DisplayObject.
         * 
         * @param filename The filename of the DisplayObject instance.
         */
        public function getDisplayObject(filename:String):DisplayObject {
            if (!displayObjectList.hasOwnProperty(filename)) {
                throw new ReferenceError("File \""+filename+"\" was not found as a DisplayObject");
            }
            return displayObjectList[filename] as DisplayObject;
        }
        /**
         * Retrieve a definition (like a class) from a SWF file that has
         * been formatted as a DisplayObject.
         * A ReferenceError is thrown if the file does not exist as a
         * DisplayObject, or the definition does not exist.
         * 
         * @param filename The filename of the DisplayObject instance.
         */
        public function getDefinition(filename:String,definition:String):Object {
            if (!displayObjectList.hasOwnProperty(filename)) {
                throw new ReferenceError("File \""+filename+"\" was not found as a DisplayObject, ");
            }
            var disp:DisplayObject = displayObjectList[filename] as DisplayObject;
            try {
                return disp.loaderInfo.applicationDomain.getDefinition(definition);
            } catch (e:ReferenceError) {
                throw new ReferenceError("Definition \""+definition+"\" in file \""+filename+"\" could not be retrieved: "+e.message);
            }
            return null;
        }

        /**
         * @private
         */
        private function processNext(evt:Event = null):void {
            while (currentState === 0) {
                if (pendingFiles.length > 0) {
                    var nextFile:FZipFile = pendingFiles.pop();
                    if (bitmapDataFormat.test(nextFile.filename)) {
                        currentState |= FORMAT_BITMAPDATA;
                    }
                    if (displayObjectFormat.test(nextFile.filename)) {
                        currentState |= FORMAT_DISPLAYOBJECT;
                    }
                    if ((currentState & (FORMAT_BITMAPDATA | FORMAT_DISPLAYOBJECT)) !== 0) {
                        currentFilename = nextFile.filename;
                        currentLoader = new Loader();
                        currentLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, loaderCompleteHandler);
                        currentLoader.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, loaderCompleteHandler);
                        var content:ByteArray = nextFile.content;
                        content.position = 0;
                        currentLoader.loadBytes(content);
                        break;
                    }
                } else if (currentZip == null) {
                    if (pendingZips.length > 0) {
                        currentZip = pendingZips.pop();
                        var i:uint = currentZip.getFileCount();
                        while (i > 0) {
                            pendingFiles.push(currentZip.getFileAt(--i));
                        }
                        if (currentZip.active) {
                            currentZip.addEventListener(Event.COMPLETE, zipCompleteHandler);
                            currentZip.addEventListener(FZipEvent.FILE_LOADED, fileCompleteHandler);
                            currentZip.addEventListener(FZipErrorEvent.PARSE_ERROR, zipCompleteHandler);
                            break;
                        } else {
                            currentZip = null;
                        }
                    } else {
                        dispatchEvent(new Event(Event.COMPLETE));
                        break;
                    }
                } else {
                    break;
                }
            }
            dispatchEvent(new FZipEvent(FZipEvent.FILE_PARSED));
        }

        /**
         * @private
         */
        private function loaderCompleteHandler(evt:Event):void {
            if ((currentState & FORMAT_BITMAPDATA) === FORMAT_BITMAPDATA) {
                if (currentLoader.content is Bitmap && (currentLoader.content as Bitmap).bitmapData is BitmapData) {
                    var bitmapData:BitmapData = (currentLoader.content as Bitmap).bitmapData
                    bitmapDataList[currentFilename] = bitmapData.clone();
                    //trace(currentFilename+" -> BitmapData ("+bitmapData.width+"x"+bitmapData.height+")");
                } else if (currentLoader.content is DisplayObject) {
                    var width:uint = uint(currentLoader.content.width);
                    var height:uint = uint(currentLoader.content.height);
                    if (width && height) {
                        var bitmapData2:BitmapData = new BitmapData(width,height,true,0x00000000);
                        bitmapData2.draw(currentLoader);
                        bitmapDataList[currentFilename] = bitmapData2;
                        //trace(currentFilename+" -> BitmapData ("+bitmapData2.width+"x"+bitmapData2.height+")");
                    } else {
                        trace("File \""+currentFilename+"\" could not be converted to BitmapData");
                    }
                } else {
                    trace("File \""+currentFilename+"\" could not be converted to BitmapData");
                }
            }
            if ((currentState & FORMAT_DISPLAYOBJECT) === FORMAT_DISPLAYOBJECT) {
                if (currentLoader.content is DisplayObject) {
                    //trace(currentFilename+" -> DisplayObject");
                    displayObjectList[currentFilename] = currentLoader.content;
                } else {
                    currentLoader.unload();
                    trace("File \""+currentFilename+"\" could not be loaded as a DisplayObject");
                }
            } else {
                currentLoader.unload();
            }
            currentLoader = null;
            currentFilename = "";
            currentState &= ~(FORMAT_BITMAPDATA | FORMAT_DISPLAYOBJECT);
            processNext();
        }
        /**
         * @private
         */
        private function fileCompleteHandler(evt:FZipEvent):void {
            pendingFiles.unshift(evt.file);
            processNext();
        }
        /**
         * @private
         */
        private function zipCompleteHandler(evt:Event):void {
            currentZip.removeEventListener(Event.COMPLETE, zipCompleteHandler);
            currentZip.removeEventListener(FZipEvent.FILE_LOADED, fileCompleteHandler);
            currentZip.removeEventListener(FZipErrorEvent.PARSE_ERROR, zipCompleteHandler);
            currentZip = null;
            processNext();
        }
    }
}

And this would be another line of code added to dispatch the FILE_PARSED event.

The dirty version would be to have a try/catch block and try to access the file repeatedly(in a timer or enter_frame). When the file is finally ready, stop this check loop and carry on.

HTH