Search Results

Search found 26523 results on 1061 pages for 'jack back'.

Page 80/1061 | < Previous Page | 76 77 78 79 80 81 82 83 84 85 86 87  | Next Page >

  • Mod_rewrite delete parameter in 301 Redirect

    - by Jack
    Hi, How would I go about rewriting: http://www.example.com/foo.html?order=desc&limit=all&something=else to http://www.example.com/foo.html?order=desc&something=else I want to remove all instances on limit=all regardless of how many other parameters in the url. I have tried: RewriteCond %{QUERY_STRING} ^(.*&)&limit=all(&.*)?$ [NC] RewriteRule ^foo\.html$ /foo\.html\?%1%2 [R=301,L]

    Read the article

  • How can I read PDFs with e-reader on a Lenovo tablet?

    - by Jack M
    This is my first time using a tablet and I'm totally lost - this must be what computers look like to old people. This is a Lenovo Thinkpad tablet. I don't see a specific model number on it (it was passed down to me second hand). What I'd like to do is read a PDF. I'm fairly certain I successfully transferred the PDF onto the tablet via an SD card, and I noticed this thing has an app called "eReader" on it, so I started that up. All I see are empty bookshelves, and no obvious buttons or settings anywhere. I saw in multiple places that you have to, as one site puts it: ...copy and paste the relevant files into the eBooks folder and they will appear on the eReader shelf for your consumption... But I have no idea how to: Access the file system. Locate the eBooks folder. Copy and paste files. Will I need a file explorer app? If so, how can I install that given that my only method of getting data onto this tablet is an SD card (no wireless internet).

    Read the article

  • Hidden bootloader

    - by Jack
    I need a bootloader that will work as described: I want my computer to boot Windows, that is my main OS installed on a primary bootable partition. However, I'd like to have a 2-3 second span with blinking cursor, before Windows starts. If I press any key in that period it should launch Ubuntu from a small Truecrypt-encoded partition, upon providing a correct password. In other words I'm looking for a hidden bootloader that would expose itself only when a key is pressed during a certain time. Do you happen to know anything like that?

    Read the article

  • GNU Emacs is crashing with -nw

    - by Jack
    When I run emacs with -nw option, the emacs really open, but I can't do more nothing. As if the user input is blocked and no keyboard signal is received and/or interpreted. I've tried run without load .emacs file and some other behaviors: emacs -nw -Q --no-desktop --debug-ini foo.c But makes no difference and strangely the GUI-version(using Gtk) is working fine. My gnu-emacs version is GNU Emacs 23.3.1 Any help to help to fix it is very appreciated.

    Read the article

  • Windows 7 Tray Application

    - by Cpt. Jack
    When I launch an application in Windows 7, it shows up in the tray but no where on my main screen. When I hover over it and select the application, nothing shows up. In order to make the application visible, I need to hover over it, right click and select maximize. Anytime I maximize the screen and then select to make it a smaller window, it also disappears. This is an awfully painful process in judst trying to launch the application. Please help me figure out how to change this to make sure th applicationalways opens into a maximized screen.

    Read the article

  • Convert Chinese character .wav song into .mp3 or .wma on English OS

    - by Jack
    I have bunch of Chinese .wav files on my hard disk that I'm trying to convert into .mp3 with Audacity but it appear that Audacity can not read Chinese character songs but the .wav file display correctly on my 32 bits Win7 Ultimate(English) pc. I have to rename these Chinese character songs into English file name in order to convert them. Does anyone know if there is any software (prefer open source) that will take Chinese character file name(.wav) and convert it into .mp3 without renaming the file?

    Read the article

  • Looking for algorithms regarding scaling and moving

    - by user1806687
    I've been bashing my head for the past couple of weeks trying to find algorithms that would help me accomplish, on first look very easy task. So, I got this one object currently made out of 5 cuboids (2 sides, 1 top, 1 bottom, 1 back), this is just for an example, later on there will be whole range of different set ups. I have included three pictures of this object(as said this is just for an example). Now, the thing is when the user scales the whole object this is what should happen: X scale: top and bottom cuboids should get scaled by a scale factor, sides should get moved so they are positioned just like they were before(in this case at both ends of top and bottom cuboids), back should get scaled so it fits like before(if I simply scale it by a scale factor it will leave gaps on each side). Y scale: sides should get scaled by a scale factor, top and bottom cuboid should get moved, and back should also get scaled. Z scale: sides, top and bottom cuboids should get scaled, back should get moved. Here is an image of the example object (a thick walled box, with one face missing, where each wall is made by a cuboid): Front of the object: Hope you can help,

    Read the article

  • Missing files when Windows 7 returns from hibernate w/ dual boot

    - by Arthur N
    I have a dual-boot setup with Ubuntu (lucid) and Windows 7. I have the Windows file system shared on Ubuntu through Samba. Occasionally, I am working on Windows and my machine will go into hibernate (i.e. when the battery level is critical). By default, my GRUB settings boot me into Ubuntu. So when I get back to my PC, sometimes I just hop into Ubuntu instead of going back to Windows. However, if I write any files to the Windows file system during that Ubuntu session, the next time I do go back to Windows (which resumes from hibernate), those files are missing. Obviously, the state of the actual file system and the hibernate snapshot become out of sync, and Windows chooses the hibernate snapshot, overriding any changes I may have made thru Ubuntu. For now, I've disabled the hibernate option in the Windows power settings, but is there any utility I can use to get back some of those missing files?

    Read the article

  • Problem with java on Windows

    - by Jack
    I had installed jdk-6u18-windows-i586 on my machine. Later on I uninstalled it and installed jdk 1.5.0_13 instead. Now when I do javac -version I get jdk 1.5.0_13 But when I do java -version I get java version "1.6.0_19" How do I fix this?

    Read the article

  • Missing files when Windows 7 returns from hibernate w/ dual boot

    - by Arthur N
    I have a dual-boot setup with Ubuntu (lucid) and Windows 7. I have the Windows file system shared on Ubuntu through Samba. Occasionally, I am working on Windows and my machine will go into hibernate (i.e. when the battery level is critical). By default, my GRUB settings boot me into Ubuntu. So when I get back to my PC, sometimes I just hop into Ubuntu instead of going back to Windows. However, if I write any files to the Windows file system during that Ubuntu session, the next time I do go back to Windows (which resumes from hibernate), those files are missing. Obviously, the state of the actual file system and the hibernate snapshot become out of sync, and Windows chooses the hibernate snapshot, overriding any changes I may have made thru Ubuntu. For now, I've disabled the hibernate option in the Windows power settings, but is there any utility I can use to get back some of those missing files?

    Read the article

  • Can I reprogram a microphone input to be used as an audio output? (on XP)

    - by qftme
    I have a five year old Sony Vaio laptop (vgn-fw31m) that has had impact damage to the audio-output mini-jack for about the last year or so. In a recent discussion with my brother, we wondered whether it would be possible to write a program that would enable windows to use the microphone mini-jack input as the audio-output? As I currently use this laptop for work I am not keen to risk pulling it apart in order to replace the components comprising the audio-out. I therefore 'hope' that a programming solution exists. I would really appreciate any advice on this and eagerly await your response. Kind regards, qftme :)

    Read the article

  • Is it necessary for a Windows Server 2008 R2 to join a domain so that its IIS can communicate correctly?

    - by Jack
    I have a Windows Server 2008 R2 that is not join to any domain. I have developed an web application that will display the domain name and the username on the server itself. However, when I publish my web application to IIS, it always fail and display different types of error messages (because I change settings such as Enabled ASP.NET Impersonation, Disable Anonymous Authentication, Set Application Pool to Classic and so on) So, I was wondering if it is necessary for the Server to join in a domain so that I can reduce any unnecessary error message and be able to zoom into the correct direction?

    Read the article

  • Performance problems - Jira running on Ubuntu over VMware ESX 4.0 maxing out all 4 vCPUs.

    - by Jack T
    We are running Jira on a box under VMware ESX 4.0 and performance is vaiable to say the least. The physical box has 12 Gig RAM and 4x Xeon 2.26 GHz CPUs. vCentre is telling us the CPUs are not maxed out at any time, RAM is fine too. When we issue a request to the host it sometimes maxes out all 4 vCPUs. Sometimes it's quick, sometimes very very slow. There doesn't seem to be a pattern. Any ideas?

    Read the article

  • Clarify git stash for me in switching branches

    - by EmmyS
    I've been working on branch A. My work there is not finished, but I need to switch to branch B for a while. It looks like stash is the command to use. I've found a number of references showing how to use stash to save your changes, but I'm a bit confused. All of the references say something like, when you're ready to go back, just do git stash pop. They don't, however, tell me if I need to switch back to branch A before doing that, though. So, do I manually go back to branch A before running stash pop, or do I stay in branch B, and the actual act of running stash pop will send me back to branch A where I left off with it?

    Read the article

  • After turning off my monitor, the computer won't display again

    - by Nick Lassonde
    If I physically turn off the monitor (DVI connection) and then turn it back on, the connection does not wake back up. The monitor enters "Power Saving" mode. I've tried unplugging the DVI cable and plugging back in, I've tried updating the video card drivers (it's Windows Vista; Windows 7 failed to install on this machine). I can use VNC to connect to the machine again, and after a reboot, the monitor works again. Does anyone have any idea?

    Read the article

  • Logging in over ssh in a different session?

    - by Jordan Reiter
    I don't know exactly what the correct term is, but I notice if I log in to a remote SSH server, then close the window, open a new one, and log into that server again, my bash history and user processes appear to be different. For instance, if I started a background process I can't get back into it, or something I typed won't show up in my bash history. The problem is for some reason occasionally something happens to my remote session and instead of being disconnected the session just hangs; I have to close the window and open a new one to reconnect. As a result sometimes it means a long running process basically is "lost" since I can't get back into it. Is there any way to set it up so that when I log back in I log back in to the same "session"? This is using OS X Terminal.

    Read the article

  • dist-upgrade broke my insatll HELP

    - by diefuchsjagden
    so I ran apt-get update; apt-get dist-upgrade the upgrade failed and I lost the gui, I have an encrypted /home drive. When I run apt-get * (any command) I have all kinds of errors mostly missing depends and thats because apparently my network stack is gone. I have no NIC if I run ifconfig. It doesn't even show up with lspci If I were to do a "clean" install of 10.04 LTS which is what I had on my on my build, will I lose all my data? BTW I was just using Ubuntu's default encryption to manage the encryption using my PSWD as the key so if I were to use the same user name and PSWD would my data be accessible? I can see my data from command line, when or if Xorg does start it just loads a basic window with nothing but a black X in the middle of the screen which I can only assume is my mouse cursor but it doesn't move! Reddit /r/linux had some ideas none of which worked was, no help. And apparently /r/ubuntu is full of jerks because all they did was ridicule me. If I can get my install back I probably will be switching back to either Slackware or Gentoo. The Ubuntu forums were of no help they had the same suggestion as /r/linux. I am about to just run my back up script to my back up drives and nuke everything else but I'd rather not.

    Read the article

  • A new day has dawned in my SharePoint world.

    - by SPTales
    Until I started working with SharePoint, I never thought I would be blogging.  I am usually a pretty private individual, but this thing called the SharePoint community pulls you in and makes you feel like you should be a part of it, contributing to it and giving something back.  So here I am blogging for the first time – and so begins my tale. I started my work life as a Systems admin, but was given a chance to start working with SharePoint 2007 back in - ironically enough - January of 2007.  It has been downhill from there or uphill depending on your perspective!  I jumped in with both feet and haven’t looked back.  Lucky for me Microsoft gave us a new version to work with.  A new job a couple years ago gave me the chance to work with that new version.  Now I spend my days weaving a tale of SharePoint for a Sales based organization. So why this blog?  To give something back. I spend most days toggling between administration, InfoPath, Branding and design, HTML, JQuery, and XSLT depending on the need.  The blog will detail these projects and solutions as best I can.  Hopefully they will be of use to someone who may be trying to accomplish similar things, just as many of the blogs that I have referenced over the last 5 years have been a huge help and resource for me.

    Read the article

  • Where do I read more about building an architecture like Google has? [on hold]

    - by user107148
    I want to develop a program that watches and traverses a rather big network for data. This data should then be available to search through with my program, maybe through a web interface or something. My intuitive thought at the moment is to build an architecture kind of like the one Google has. One "front-end" (the Google Search page) which is essentially a regular web application and one "back-end" (which in Google's case traverses the web). Now for the hard part: If I decide to make such a system, how should communication be done between these parts? One idea I had is to use some kind of database that both the back-end and front-end can access, but then comes the issues of concurrent writes and reads. Another issue with just using a database to communicate is that it makes it hard to "notify" the other part when something changes. Let's say that I want the "front-end" part to push changes to the UI when a change is noticed in the back-end. Then the back-end would have to have some way of notifying the front-end of this.

    Read the article

  • Reinstallation or redeployment after hardware crash?

    - by HAY
    What is the best way to bring back the server online after hardware crash. I suppose image won't work after hardware change. So I like to know what is the fastest way to bring everything back. I've the following software running on the server: MSSQL IIS Custom Server Software FTP Server Then there is configuration: Registering asp.net 4.0 Configuration files for server software (these can be put back from backup) Configuration if windows firewall. Thanks in advance

    Read the article

  • Feedback Filtration&ndash;Processing Negative Comments for Positive Gains

    - by D'Arcy Lussier
    After doing 7 conferences, 5 code camps, and countless user group events, I feel that this is a post I need to write. I actually toyed with other names for this post, however those names would just lend itself to the type of behaviour I want people to avoid – the reactionary, emotional response that speaks to some deeper issue beyond immediate facts and context. Humans are incredibly complex creatures. We’re also emotional, which serves us well in certain situations but can hinder us in others. Those of us in leadership build up a thick skin because we tend to encounter those reactionary, emotional responses more often, and we’re held to a higher standard because of our positions. While we could react with emotion ourselves, as the saying goes – fighting fire with fire just makes a bigger fire. So in this post I’ll share my thought process for dealing with negative feedback/comments and how you can still get value from them. The Thought Process Let’s take a real-world example. This week I held the Prairie IT Pro & Dev Con event. We’ve gotten a lot of session feedback already, most of it overwhelmingly positive. But some not so much – and some to an extreme I rarely see but isn’t entirely surprising to me. So here’s the example from a person we’ll refer to as Mr. Horrible: How was the speaker? Horrible! Worst speaker ever! Did the session meet your expectations? Hard to tell, speaker ruined it. Other Comments: DO NOT bring this speaker back! He was at this conference last year and I hoped enough negative feedback would have taught you to not bring him back...obviously not...I will not return to this conference next year if this speaker is brought back. Now those are very strong words. “Worst speaker ever!” “Speaker ruined it” “I will not return to this conference next year if the speaker is brought back”. The speakers I invite to speak at my conference are not just presenters but friends and colleagues. When I see this, my initial reaction is of course very emotional: I get defensive, I get angry, I get offended. So that’s where the process kicks in. Step 1 – Take a Deep Breath Take a deep breath, calm down, and walk away from the keyboard. I didn’t do that recently during an email convo between some colleagues and it ended up in my reacting emotionally on Twitter – did I mention those colleagues follow my Twitter feed? Yes, I ate some crow. Ok, now that we’re calm, let’s move on to step 2. Step 2 – Strip off the Emotion We need to take off the emotion that people wrap their words in and identify the root issues. For instance, if I see: “I hated this session, the presenter was horrible! He spoke so fast I couldn’t make out what he was saying!” then I drop off the personal emoting (“I hated…”) and the personal attack (“the presenter was horrible”) and focus on the real issue this person had – that the speaker was talking too fast. Now we have a root cause of the displeasure. However, we’re also dealing with humans who are all very different. Before I call up the speaker to talk about his speaking pace, I need to do some other things first. Back to our Mr. Horrible example, I don’t really have much to go on. There’s no details of how the speaker “ruined” the session or why he’s the “worst speaker ever”. In this case, the next step is crucial. Step 3 – Validate the Feedback When I tell people that we really like getting feedback for the sessions, I really really mean it. Not just because we want to hear what individuals have to say but also because we want to know what the group thought. When a piece of negative feedback comes in, I validate it against the group. So with the speaker Mr. Horrible commented on, I go to the feedback and look at other people’s responses: 2 x Excellent 1 x Alright 1 x Not Great 1 x Horrible (our feedback guy) That’s interesting, it’s a bit all over the board. If we look at the comments more we find that the people who rated the speaker excellent liked the presentation style and found the content valuable. The one guy who said “Not Great” even commented that there wasn’t anything really wrong with the presentation, he just wasn’t excited about it. In that light, I can try to make a few assumptions: - Mr. Horrible didn’t like the speakers presentation style - Mr. Horrible was expecting something else that wasn’t communicated properly in the session description - Mr. Horrible, for whatever reason, just didn’t like this presenter Now if the feedback was overwhelmingly negative, there’s a different pattern – one that validates the negative feedback. Regardless, I never take something at face value. Even if I see really good feedback, I never get too happy until I see that there’s a group trend towards the positive. Step 4 – Action Plan Once I’ve validated the feedback, then I need to come up with an action plan around it. Let’s go back to the other example I gave – the one with the speaker going too fast. I went and looked at the feedback and sure enough, other people commented that the speaker had spoken too quickly. Now I can go back to the speaker and let him know so he can get better. But what if nobody else complained about it? I’d still mention it to the speaker, but obviously one person’s opinion needs to be weighed as such. When we did PrDC Winnipeg in 2011, I surveyed the attendees about the food. Everyone raved about it…except one person. Am I going to change the menu next time for that one person while everyone else loved it? Of course not. There’s a saying – A sure way to fail is to try to please everyone. Let’s look at the Mr. Horrible example. What can I communicate to the speaker with such limited information provided in the feedback from Mr. Horrible? Well looking at the groups feedback, I can make a few suggestions: - Ensure that people understand in the session description the style of the talk - Ensure that people understand the level of detail/complexity of the talk and what prerequisite knowledge they should have I’m looking at it as possibly Mr. Horrible assumed a much more advanced talk and was disappointed, while the positive feedback by people who – from their comments – suggested this was all new to them, were thrilled with the session level. Step 5 – Follow Up For some feedback, I follow up personally. Especially with negative or constructive feedback, its important to let the person know you heard them and are making changes because of their comments. Even if their comments were emotionally charged and overtly negative, it’s still important to reach out personally and professionally. When you remove the emotion, negative comments can be the best feedback you get. Also, people have bad days. We’ve all had one of “those days” where we talked more sternly than normal to someone, or got angry at something we’d normally shrug off. We have various stresses in our lives and sometimes they seep out in odd ways. I always try to give some benefit of the doubt, and re-evaluate my view of the person after they’ve responded to my communication. But, there is such a thing as garbage feedback. What Mr. Horrible wrote is garbage. It’s mean spirited. It’s hateful. It provides nothing constructive at all. And a tell-tale sign that feedback is garbage – the person didn’t leave their name even though there was a field for it. Step 6 – Delete It Feedback must be processed in its raw form, and the end products should drive improvements. But once you’ve figured out what those things are, you shouldn’t leave raw feedback lying around. They are snapshots in time that taken alone can be damaging. Also, you should never rest on past praise. In a future blog post, I’m going to talk about how we can provide great feedback that, even when its critical, can still be constructive.

    Read the article

  • Camera Preview App in Android throwing many errors (Nexus 4)

    - by Jagatheesan Jack
    I am trying to develop a camera app that takes a picture and saves it in a SQLite database. I get a lot of errors when executing the application. My code is as below. Any idea? CameraActivity.java private Camera mCamera; private CameraPreview mPreview; private int CAMERA_RETURN_CODE=100; private static final String TAG = "Take_Picture"; public static final int MEDIA_TYPE_IMAGE = 1; public static final int MEDIA_TYPE_VIDEO = 2; private Bitmap cameraBmp; private int MAX_FACES = 1; private Face[] faceList; public RectF[] rects; private Canvas canvas; private Drawable pictureDataDrawable; private MySQLiteHelper database; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.camera_activity); //this.requestWindowFeature(Window.FEATURE_NO_TITLE); //Create an instance of Camera mCamera = getCameraInstance(); setCameraDisplayOrientation(this, 0, mCamera); // Create our Preview view and set it as the content of our activity. mPreview = new CameraPreview(this, mCamera); FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview); preview.addView(mPreview); database = new MySQLiteHelper(getApplicationContext()); Button captureButton = (Button) findViewById(R.id.button_capture); captureButton.setOnClickListener( new View.OnClickListener() { private PictureCallback mPicture; @Override public void onClick(View v) { //mCamera.startPreview(); // get an image from the camera mCamera.takePicture(null, null, mPicture); PictureCallback mPicture = new PictureCallback() { @Override public void onPictureTaken(byte[] data, Camera camera) { try{ if (data != null) database.addEntry(data); //mCamera.startPreview(); } catch(Exception e){ Log.d(TAG, e.getMessage()); } } } ); } /** A safe way to get an instance of the Camera object. */ public static Camera getCameraInstance(){ Camera c = null; try { c = Camera.open(c.getNumberOfCameras()-1); // attempt to get a Camera instance } catch (Exception e){ // Camera is not available (in use or does not exist) } return c; // returns null if camera is unavailable } public static void setCameraDisplayOrientation(Activity activity, int cameraId, android.hardware.Camera camera) { android.hardware.Camera.CameraInfo info = new android.hardware.Camera.CameraInfo(); android.hardware.Camera.getCameraInfo(cameraId, info); int rotation = activity.getWindowManager().getDefaultDisplay() .getRotation(); int degrees = 360; /*switch (rotation) { case Surface.ROTATION_0: degrees = 0; break; case Surface.ROTATION_90: degrees = 90; break; case Surface.ROTATION_180: degrees = 180; break; case Surface.ROTATION_270: degrees = 270; break; }*/ int result; if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) { result = (info.orientation + degrees) % 360; result = (360 - result) % 360; // compensate the mirror } else { // back-facing result = (info.orientation - degrees + 360) % 360; } camera.setDisplayOrientation(result); } @Override protected void onPause() { super.onPause(); //releaseMediaRecorder(); // if you are using MediaRecorder, release it first releaseCamera(); // release the camera immediately on pause event } private void releaseCamera(){ if (mCamera != null){ mCamera.release(); // release the camera for other applications mCamera = null; } } public void startFaceDetection(){ // Try starting Face Detection Camera.Parameters params = mCamera.getParameters(); // start face detection only *after* preview has started if (params.getMaxNumDetectedFaces() > 0){ // camera supports face detection, so can start it: mCamera.startFaceDetection(); } } CameraPreview.java public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback { private SurfaceHolder mHolder; private Camera mCamera; private String TAG; private List<Size> mSupportedPreviewSizes; public CameraPreview(Context context, Camera camera) { super(context); mCamera = camera; // Install a SurfaceHolder.Callback so we get notified when the // underlying surface is created and destroyed. mHolder = getHolder(); mHolder.addCallback(this); // deprecated setting, but required on Android versions prior to 3.0 mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } public void surfaceCreated(SurfaceHolder holder) { // The Surface has been created, now tell the camera where to draw the preview. try { mCamera.setPreviewDisplay(holder); mCamera.setDisplayOrientation(90); mCamera.startPreview(); } catch (IOException e) { Log.d(TAG, "Error setting camera preview: " + e.getMessage()); } } public void surfaceDestroyed(SurfaceHolder holder) { // empty. Take care of releasing the Camera preview in your activity. } public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { // If your preview can change or rotate, take care of those events here. // Make sure to stop the preview before resizing or reformatting it. if (mHolder.getSurface() == null){ // preview surface does not exist return; } // stop preview before making changes try { mCamera.stopPreview(); } catch (Exception e){ // ignore: tried to stop a non-existent preview } try { mCamera.setPreviewDisplay(mHolder); mCamera.startPreview(); } catch (Exception e){ Log.d(TAG, "Error starting camera preview: " + e.getMessage()); } } public void setCamera(Camera camera) { if (mCamera == camera) { return; } mCamera = camera; if (mCamera != null) { List<Size> localSizes = mCamera.getParameters().getSupportedPreviewSizes(); mSupportedPreviewSizes = localSizes; requestLayout(); try { mCamera.setPreviewDisplay(mHolder); } catch (IOException e) { e.printStackTrace(); } /* Important: Call startPreview() to start updating the preview surface. Preview must be started before you can take a picture. */ mCamera.startPreview(); } } MySQLiteHelper.java private static final int count = 0; public static final String TABLE_IMAGE = "images"; public static final String COLUMN_ID = "_id"; public static final String PICTURE_DATA = "picture"; public static final String DATABASE_NAME = "images.db"; public static final int DATABASE_VERSION = 1; public static final String DATABASE_CREATE = "create table " + TABLE_IMAGE + "(" + COLUMN_ID + " integer primary key autoincrement, " + PICTURE_DATA + " blob not null);"; public static SQLiteDatabase database; private static String TAG = "test"; public MySQLiteHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); // TODO Auto-generated constructor stub } public MySQLiteHelper(Context context, String name, CursorFactory factory, int version, DatabaseErrorHandler errorHandler) { super(context, name, factory, version, errorHandler); // TODO Auto-generated constructor stub } @Override public void onCreate(SQLiteDatabase database) { database.execSQL(DATABASE_CREATE); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { Log.w(MySQLiteHelper.class.getName(), "Upgrading database from version " + oldVersion + " to " + newVersion + ", which will destroy all old data"); db.execSQL("DROP TABLE IF EXISTS " + TABLE_IMAGE); onCreate(db); } /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub } public void addEntry(byte [] array) throws SQLiteException{ ContentValues cv = new ContentValues(); //cv.put(KEY_NAME, name); cv.put(PICTURE_DATA, array); database.insert( TABLE_IMAGE, null, cv ); Log.w(TAG , "added " +count+ "images"); database.close(); } Errors 11-07 23:28:39.050: E/mm-libcamera2(176): PROFILE HAL: stopPreview(): E: 1383838119.067589459 11-07 23:28:39.050: E/mm-camera(201): config_MSG_ID_STOP_ACK: streamon_mask is not clear. Should not call PP_Release_HW 11-07 23:28:39.090: E/QCameraHWI(176): android::status_t android::QCameraHardwareInterface::setPreviewWindow(preview_stream_ops_t*):Received Setting NULL preview window 11-07 23:28:39.090: E/QCameraHWI(176): android::status_t android::QCameraHardwareInterface::setPreviewWindow(preview_stream_ops_t*): mPreviewWindow = 0x0x0, mStreamDisplay = 0x0xb8a9df90 11-07 23:28:39.090: E/mm-camera(201): config_shutdown_pp Camera not in streaming mode. Returning. 11-07 23:28:39.090: E/mm-camera(201): vfe_ops_deinit: E 11-07 23:28:39.120: E/qcom_sensors_hal(533): hal_process_report_ind: Bad item quality: 11 11-07 23:28:39.310: E/qcom_sensors_hal(533): hal_process_report_ind: Bad item quality: 11 11-07 23:28:39.330: E/mm-camera(201): sensor_load_chromatix: libchromatix_imx119_preview.so: 30 11-07 23:28:39.340: E/mm-camera(201): vfe_ops_init: E 11-07 23:28:39.360: E/mm-camera(201): vfe_legacy_stats_buffer_init: AEC_STATS_BUFNUM 11-07 23:28:39.360: E/mm-camera(201): vfe_legacy_stats_buffer_init: AEC_STATS_BUFNUM 11-07 23:28:39.360: E/mm-camera(201): mctl_init_stats_proc_info: snap_max_line_cnt =25776 11-07 23:28:39.440: E/QCameraHWI(176): android::status_t android::QCameraHardwareInterface::setPreviewWindow(preview_stream_ops_t*): mPreviewWindow = 0x0xb8aa1780, mStreamDisplay = 0x0xb8a9df90 11-07 23:28:39.440: E/mm-camera(201): config_proc_CAMERA_SET_INFORM_STARTPREVIEW 11-07 23:28:39.450: E/mm-camera(201): config_update_stream_info Storing stream parameters for video inst 1 as : width = 640, height 480, format = 1 inst_handle = 810081 cid = 0 11-07 23:28:39.490: E/mm-camera(201): config_update_stream_info Storing stream parameters for video inst 3 as : width = 640, height 480, format = 1 inst_handle = 830083 cid = 0 11-07 23:28:39.490: E/mm-camera(201): config_update_stream_info Storing stream parameters for video inst 4 as : width = 512, height 384, format = 1 inst_handle = 840084 cid = 0 11-07 23:28:39.500: E/mm-camera(201): config_decide_vfe_outputs: Ports Used 3, Op mode 1 11-07 23:28:39.500: E/mm-camera(201): config_decide_vfe_outputs Current mode 0 Full size streaming : Disabled 11-07 23:28:39.500: E/mm-camera(201): config_decide_vfe_outputs: Primary: 640x480, extra_pad: 0x0, Fmt: 1, Type: 1, Path: 1 11-07 23:28:39.500: E/mm-camera(201): config_decide_vfe_outputs: Secondary: 640x480, extra_pad: 0x0, Fmt: 1, Type: 3, Path: 4 11-07 23:28:39.510: E/mm-camera(201): config_update_inst_handles Updated the inst handles as 810081, 830083, 0, 0 11-07 23:28:39.631: E/mm-camera(201): sensor_load_chromatix: libchromatix_imx119_preview.so: 30 11-07 23:28:39.631: E/mm-camera(201): camif_client_set_params: camif has associated with obj mask 0x1 11-07 23:28:39.631: E/mm-camera(201): config_v2_CAMERA_START_common CAMIF_PARAMS_ADD_OBJ_ID failed -1 11-07 23:28:39.641: E/mm-camera(201): vfe_operation_config: format 3 11-07 23:28:39.641: E/mm-camera(201): vfe_operation_config:vfe_op_mode=5 11-07 23:28:39.641: E/mm-camera(201): Invalid ASD Set Params Type 11-07 23:28:39.641: E/mm-camera(201): vfe_set_bestshot: Bestshot mode not changed

    Read the article

  • Using the West Wind Web Toolkit to set up AJAX and REST Services

    - by Rick Strahl
    I frequently get questions about which option to use for creating AJAX and REST backends for ASP.NET applications. There are many solutions out there to do this actually, but when I have a choice - not surprisingly - I fall back to my own tools in the West Wind West Wind Web Toolkit. I've talked a bunch about the 'in-the-box' solutions in the past so for a change in this post I'll talk about the tools that I use in my own and customer applications to handle AJAX and REST based access to service resources using the West Wind West Wind Web Toolkit. Let me preface this by saying that I like things to be easy. Yes flexible is very important as well but not at the expense of over-complexity. The goal I've had with my tools is make it drop dead easy, with good performance while providing the core features that I'm after, which are: Easy AJAX/JSON Callbacks Ability to return any kind of non JSON content (string, stream, byte[], images) Ability to work with both XML and JSON interchangeably for input/output Access endpoints via POST data, RPC JSON calls, GET QueryString values or Routing interface Easy to use generic JavaScript client to make RPC calls (same syntax, just what you need) Ability to create clean URLS with Routing Ability to use standard ASP.NET HTTP Stack for HTTP semantics It's all about options! In this post I'll demonstrate most of these features (except XML) in a few simple and short samples which you can download. So let's take a look and see how you can build an AJAX callback solution with the West Wind Web Toolkit. Installing the Toolkit Assemblies The easiest and leanest way of using the Toolkit in your Web project is to grab it via NuGet: West Wind Web and AJAX Utilities (Westwind.Web) and drop it into the project by right clicking in your Project and choosing Manage NuGet Packages from anywhere in the Project.   When done you end up with your project looking like this: What just happened? Nuget added two assemblies - Westwind.Web and Westwind.Utilities and the client ww.jquery.js library. It also added a couple of references into web.config: The default namespaces so they can be accessed in pages/views and a ScriptCompressionModule that the toolkit optionally uses to compress script resources served from within the assembly (namely ww.jquery.js and optionally jquery.js). Creating a new Service The West Wind Web Toolkit supports several ways of creating and accessing AJAX services, but for this post I'll stick to the lower level approach that works from any plain HTML page or of course MVC, WebForms, WebPages. There's also a WebForms specific control that makes this even easier but I'll leave that for another post. So, to create a new standalone AJAX/REST service we can create a new HttpHandler in the new project either as a pure class based handler or as a generic .ASHX handler. Both work equally well, but generic handlers don't require any web.config configuration so I'll use that here. In the root of the project add a Generic Handler. I'm going to call this one StockService.ashx. Once the handler has been created, edit the code and remove all of the handler body code. Then change the base class to CallbackHandler and add methods that have a [CallbackMethod] attribute. Here's the modified base handler implementation now looks like with an added HelloWorld method: using System; using Westwind.Web; namespace WestWindWebAjax { /// <summary> /// Handler implements CallbackHandler to provide REST/AJAX services /// </summary> public class SampleService : CallbackHandler { [CallbackMethod] public string HelloWorld(string name) { return "Hello " + name + ". Time is: " + DateTime.Now.ToString(); } } } Notice that the class inherits from CallbackHandler and that the HelloWorld service method is marked up with [CallbackMethod]. We're done here. Services Urlbased Syntax Once you compile, the 'service' is live can respond to requests. All CallbackHandlers support input in GET and POST formats, and can return results as JSON or XML. To check our fancy HelloWorld method we can now access the service like this: http://localhost/WestWindWebAjax/StockService.ashx?Method=HelloWorld&name=Rick which produces a default JSON response - in this case a string (wrapped in quotes as it's JSON): (note by default JSON will be downloaded by most browsers not displayed - various options are available to view JSON right in the browser) If I want to return the same data as XML I can tack on a &format=xml at the end of the querystring which produces: <string>Hello Rick. Time is: 11/1/2011 12:11:13 PM</string> Cleaner URLs with Routing Syntax If you want cleaner URLs for each operation you can also configure custom routes on a per URL basis similar to the way that WCF REST does. To do this you need to add a new RouteHandler to your application's startup code in global.asax.cs one for each CallbackHandler based service you create: protected void Application_Start(object sender, EventArgs e) { CallbackHandlerRouteHandler.RegisterRoutes<StockService>(RouteTable.Routes); } With this code in place you can now add RouteUrl properties to any of your service methods. For the HelloWorld method that doesn't make a ton of sense but here is what a routed clean URL might look like in definition: [CallbackMethod(RouteUrl="stocks/HelloWorld/{name}")] public string HelloWorld(string name) { return "Hello " + name + ". Time is: " + DateTime.Now.ToString(); } The same URL I previously used now becomes a bit shorter and more readable with: http://localhost/WestWindWebAjax/HelloWorld/Rick It's an easy way to create cleaner URLs and still get the same functionality. Calling the Service with $.getJSON() Since the result produced is JSON you can now easily consume this data using jQuery's getJSON method. First we need a couple of scripts - jquery.js and ww.jquery.js in the page: <!DOCTYPE html> <html> <head> <link href="Css/Westwind.css" rel="stylesheet" type="text/css" /> <script src="scripts/jquery.min.js" type="text/javascript"></script> <script src="scripts/ww.jquery.min.js" type="text/javascript"></script> </head> <body> Next let's add a small HelloWorld example form (what else) that has a single textbox to type a name, a button and a div tag to receive the result: <fieldset> <legend>Hello World</legend> Please enter a name: <input type="text" name="txtHello" id="txtHello" value="" /> <input type="button" id="btnSayHello" value="Say Hello (POST)" /> <input type="button" id="btnSayHelloGet" value="Say Hello (GET)" /> <div id="divHelloMessage" class="errordisplay" style="display:none;width: 450px;" > </div> </fieldset> Then to call the HelloWorld method a little jQuery is used to hook the document startup and the button click followed by the $.getJSON call to retrieve the data from the server. <script type="text/javascript"> $(document).ready(function () { $("#btnSayHelloGet").click(function () { $.getJSON("SampleService.ashx", { Method: "HelloWorld", name: $("#txtHello").val() }, function (result) { $("#divHelloMessage") .text(result) .fadeIn(1000); }); });</script> .getJSON() expects a full URL to the endpoint of our service, which is the ASHX file. We can either provide a full URL (SampleService.ashx?Method=HelloWorld&name=Rick) or we can just provide the base URL and an object that encodes the query string parameters for us using an object map that has a property that matches each parameter for the server method. We can also use the clean URL routing syntax, but using the object parameter encoding actually is safer as the parameters will get properly encoded by jQuery. The result returned is whatever the result on the server method is - in this case a string. The string is applied to the divHelloMessage element and we're done. Obviously this is a trivial example, but it demonstrates the basics of getting a JSON response back to the browser. AJAX Post Syntax - using ajaxCallMethod() The previous example allows you basic control over the data that you send to the server via querystring parameters. This works OK for simple values like short strings, numbers and boolean values, but doesn't really work if you need to pass something more complex like an object or an array back up to the server. To handle traditional RPC type messaging where the idea is to map server side functions and results to a client side invokation, POST operations can be used. The easiest way to use this functionality is to use ww.jquery.js and the ajaxCallMethod() function. ww.jquery wraps jQuery's AJAX functions and knows implicitly how to call a CallbackServer method with parameters and parse the result. Let's look at another simple example that posts a simple value but returns something more interesting. Let's start with the service method: [CallbackMethod(RouteUrl="stocks/{symbol}")] public StockQuote GetStockQuote(string symbol) { Response.Cache.SetExpires(DateTime.UtcNow.Add(new TimeSpan(0, 2, 0))); StockServer server = new StockServer(); var quote = server.GetStockQuote(symbol); if (quote == null) throw new ApplicationException("Invalid Symbol passed."); return quote; } This sample utilizes a small StockServer helper class (included in the sample) that downloads a stock quote from Yahoo's financial site via plain HTTP GET requests and formats it into a StockQuote object. Lets create a small HTML block that lets us query for the quote and display it: <fieldset> <legend>Single Stock Quote</legend> Please enter a stock symbol: <input type="text" name="txtSymbol" id="txtSymbol" value="msft" /> <input type="button" id="btnStockQuote" value="Get Quote" /> <div id="divStockDisplay" class="errordisplay" style="display:none; width: 450px;"> <div class="label-left">Company:</div> <div id="stockCompany"></div> <div class="label-left">Last Price:</div> <div id="stockLastPrice"></div> <div class="label-left">Quote Time:</div> <div id="stockQuoteTime"></div> </div> </fieldset> The final result looks something like this:   Let's hook up the button handler to fire the request and fill in the data as shown: $("#btnStockQuote").click(function () { ajaxCallMethod("SampleService.ashx", "GetStockQuote", [$("#txtSymbol").val()], function (quote) { $("#divStockDisplay").show().fadeIn(1000); $("#stockCompany").text(quote.Company + " (" + quote.Symbol + ")"); $("#stockLastPrice").text(quote.LastPrice); $("#stockQuoteTime").text(quote.LastQuoteTime.formatDate("MMM dd, HH:mm EST")); }, onPageError); }); So we point at SampleService.ashx and the GetStockQuote method, passing a single parameter of the input symbol value. Then there are two handlers for success and failure callbacks.  The success handler is the interesting part - it receives the stock quote as a result and assigns its values to various 'holes' in the stock display elements. The data that comes back over the wire is JSON and it looks like this: { "Symbol":"MSFT", "Company":"Microsoft Corpora", "OpenPrice":26.11, "LastPrice":26.01, "NetChange":0.02, "LastQuoteTime":"2011-11-03T02:00:00Z", "LastQuoteTimeString":"Nov. 11, 2011 4:20pm" } which is an object representation of the data. JavaScript can evaluate this JSON string back into an object easily and that's the reslut that gets passed to the success function. The quote data is then applied to existing page content by manually selecting items and applying them. There are other ways to do this more elegantly like using templates, but here we're only interested in seeing how the data is returned. The data in the object is typed - LastPrice is a number and QuoteTime is a date. Note about the date value: JavaScript doesn't have a date literal although the JSON embedded ISO string format used above  ("2011-11-03T02:00:00Z") is becoming fairly standard for JSON serializers. However, JSON parsers don't deserialize dates by default and return them by string. This is why the StockQuote actually returns a string value of LastQuoteTimeString for the same date. ajaxMethodCallback always converts dates properly into 'real' dates and the example above uses the real date value along with a .formatDate() data extension (also in ww.jquery.js) to display the raw date properly. Errors and Exceptions So what happens if your code fails? For example if I pass an invalid stock symbol to the GetStockQuote() method you notice that the code does this: if (quote == null) throw new ApplicationException("Invalid Symbol passed."); CallbackHandler automatically pushes the exception message back to the client so it's easy to pick up the error message. Regardless of what kind of error occurs: Server side, client side, protocol errors - any error will fire the failure handler with an error object parameter. The error is returned to the client via a JSON response in the error callback. In the previous examples I called onPageError which is a generic routine in ww.jquery that displays a status message on the bottom of the screen. But of course you can also take over the error handling yourself: $("#btnStockQuote").click(function () { ajaxCallMethod("SampleService.ashx", "GetStockQuote", [$("#txtSymbol").val()], function (quote) { $("#divStockDisplay").fadeIn(1000); $("#stockCompany").text(quote.Company + " (" + quote.Symbol + ")"); $("#stockLastPrice").text(quote.LastPrice); $("#stockQuoteTime").text(quote.LastQuoteTime.formatDate("MMM dd, hh:mmt")); }, function (error, xhr) { $("#divErrorDisplay").text(error.message).fadeIn(1000); }); }); The error object has a isCallbackError, message and  stackTrace properties, the latter of which is only populated when running in Debug mode, and this object is returned for all errors: Client side, transport and server side errors. Regardless of which type of error you get the same object passed (as well as the XHR instance optionally) which makes for a consistent error retrieval mechanism. Specifying HttpVerbs You can also specify HTTP Verbs that are allowed using the AllowedHttpVerbs option on the CallbackMethod attribute: [CallbackMethod(AllowedHttpVerbs=HttpVerbs.GET | HttpVerbs.POST)] public string HelloWorld(string name) { … } If you're building REST style API's this might be useful to force certain request semantics onto the client calling. For the above if call with a non-allowed HttpVerb the request returns a 405 error response along with a JSON (or XML) error object result. The default behavior is to allow all verbs access (HttpVerbs.All). Passing in object Parameters Up to now the parameters I passed were very simple. But what if you need to send something more complex like an object or an array? Let's look at another example now that passes an object from the client to the server. Keeping with the Stock theme here lets add a method called BuyOrder that lets us buy some shares for a stock. Consider the following service method that receives an StockBuyOrder object as a parameter: [CallbackMethod] public string BuyStock(StockBuyOrder buyOrder) { var server = new StockServer(); var quote = server.GetStockQuote(buyOrder.Symbol); if (quote == null) throw new ApplicationException("Invalid or missing stock symbol."); return string.Format("You're buying {0} shares of {1} ({2}) stock at {3} for a total of {4} on {5}.", buyOrder.Quantity, quote.Company, quote.Symbol, quote.LastPrice.ToString("c"), (quote.LastPrice * buyOrder.Quantity).ToString("c"), buyOrder.BuyOn.ToString("MMM d")); } public class StockBuyOrder { public string Symbol { get; set; } public int Quantity { get; set; } public DateTime BuyOn { get; set; } public StockBuyOrder() { BuyOn = DateTime.Now; } } This is a contrived do-nothing example that simply echoes back what was passed in, but it demonstrates how you can pass complex data to a callback method. On the client side we now have a very simple form that captures the three values on a form: <fieldset> <legend>Post a Stock Buy Order</legend> Enter a symbol: <input type="text" name="txtBuySymbol" id="txtBuySymbol" value="GLD" />&nbsp;&nbsp; Qty: <input type="text" name="txtBuyQty" id="txtBuyQty" value="10" style="width: 50px" />&nbsp;&nbsp; Buy on: <input type="text" name="txtBuyOn" id="txtBuyOn" value="<%= DateTime.Now.ToString("d") %>" style="width: 70px;" /> <input type="button" id="btnBuyStock" value="Buy Stock" /> <div id="divStockBuyMessage" class="errordisplay" style="display:none"></div> </fieldset> The completed form and demo then looks something like this:   The client side code that picks up the input values and assigns them to object properties and sends the AJAX request looks like this: $("#btnBuyStock").click(function () { // create an object map that matches StockBuyOrder signature var buyOrder = { Symbol: $("#txtBuySymbol").val(), Quantity: $("#txtBuyQty").val() * 1, // number Entered: new Date() } ajaxCallMethod("SampleService.ashx", "BuyStock", [buyOrder], function (result) { $("#divStockBuyMessage").text(result).fadeIn(1000); }, onPageError); }); The code creates an object and attaches the properties that match the server side object passed to the BuyStock method. Each property that you want to update needs to be included and the type must match (ie. string, number, date in this case). Any missing properties will not be set but also not cause any errors. Pass POST data instead of Objects In the last example I collected a bunch of values from form variables and stuffed them into object variables in JavaScript code. While that works, often times this isn't really helping - I end up converting my types on the client and then doing another conversion on the server. If lots of input controls are on a page and you just want to pick up the values on the server via plain POST variables - that can be done too - and it makes sense especially if you're creating and filling the client side object only to push data to the server. Let's add another method to the server that once again lets us buy a stock. But this time let's not accept a parameter but rather send POST data to the server. Here's the server method receiving POST data: [CallbackMethod] public string BuyStockPost() { StockBuyOrder buyOrder = new StockBuyOrder(); buyOrder.Symbol = Request.Form["txtBuySymbol"]; ; int qty; int.TryParse(Request.Form["txtBuyQuantity"], out qty); buyOrder.Quantity = qty; DateTime time; DateTime.TryParse(Request.Form["txtBuyBuyOn"], out time); buyOrder.BuyOn = time; // Or easier way yet //FormVariableBinder.Unbind(buyOrder,null,"txtBuy"); var server = new StockServer(); var quote = server.GetStockQuote(buyOrder.Symbol); if (quote == null) throw new ApplicationException("Invalid or missing stock symbol."); return string.Format("You're buying {0} shares of {1} ({2}) stock at {3} for a total of {4} on {5}.", buyOrder.Quantity, quote.Company, quote.Symbol, quote.LastPrice.ToString("c"), (quote.LastPrice * buyOrder.Quantity).ToString("c"), buyOrder.BuyOn.ToString("MMM d")); } Clearly we've made this server method take more code than it did with the object parameter. We've basically moved the parameter assignment logic from the client to the server. As a result the client code to call this method is now a bit shorter since there's no client side shuffling of values from the controls to an object. $("#btnBuyStockPost").click(function () { ajaxCallMethod("SampleService.ashx", "BuyStockPost", [], // Note: No parameters - function (result) { $("#divStockBuyMessage").text(result).fadeIn(1000); }, onPageError, // Force all page Form Variables to be posted { postbackMode: "Post" }); }); The client simply calls the BuyStockQuote method and pushes all the form variables from the page up to the server which parses them instead. The feature that makes this work is one of the options you can pass to the ajaxCallMethod() function: { postbackMode: "Post" }); which directs the function to include form variable POST data when making the service call. Other options include PostNoViewState (for WebForms to strip out WebForms crap vars), PostParametersOnly (default), None. If you pass parameters those are always posted to the server except when None is set. The above code can be simplified a bit by using the FormVariableBinder helper, which can unbind form variables directly into an object: FormVariableBinder.Unbind(buyOrder,null,"txtBuy"); which replaces the manual Request.Form[] reading code. It receives the object to unbind into, a string of properties to skip, and an optional prefix which is stripped off form variables to match property names. The component is similar to the MVC model binder but it's independent of MVC. Returning non-JSON Data CallbackHandler also supports returning non-JSON/XML data via special return types. You can return raw non-JSON encoded strings like this: [CallbackMethod(ReturnAsRawString=true,ContentType="text/plain")] public string HelloWorldNoJSON(string name) { return "Hello " + name + ". Time is: " + DateTime.Now.ToString(); } Calling this method results in just a plain string - no JSON encoding with quotes around the result. This can be useful if your server handling code needs to return a string or HTML result that doesn't fit well for a page or other UI component. Any string output can be returned. You can also return binary data. Stream, byte[] and Bitmap/Image results are automatically streamed back to the client. Notice that you should set the ContentType of the request either on the CallbackMethod attribute or using Response.ContentType. This ensures the Web Server knows how to display your binary response. Using a stream response makes it possible to return any of data. Streamed data can be pretty handy to return bitmap data from a method. The following is a method that returns a stock history graph for a particular stock over a provided number of years: [CallbackMethod(ContentType="image/png",RouteUrl="stocks/history/graph/{symbol}/{years}")] public Stream GetStockHistoryGraph(string symbol, int years = 2,int width = 500, int height=350) { if (width == 0) width = 500; if (height == 0) height = 350; StockServer server = new StockServer(); return server.GetStockHistoryGraph(symbol,"Stock History for " + symbol,width,height,years); } I can now hook this up into the JavaScript code when I get a stock quote. At the end of the process I can assign the URL to the service that returns the image into the src property and so force the image to display. Here's the changed code: $("#btnStockQuote").click(function () { var symbol = $("#txtSymbol").val(); ajaxCallMethod("SampleService.ashx", "GetStockQuote", [symbol], function (quote) { $("#divStockDisplay").fadeIn(1000); $("#stockCompany").text(quote.Company + " (" + quote.Symbol + ")"); $("#stockLastPrice").text(quote.LastPrice); $("#stockQuoteTime").text(quote.LastQuoteTime.formatDate("MMM dd, hh:mmt")); // display a stock chart $("#imgStockHistory").attr("src", "stocks/history/graph/" + symbol + "/2"); },onPageError); }); The resulting output then looks like this: The charting code uses the new ASP.NET 4.0 Chart components via code to display a bar chart of the 2 year stock data as part of the StockServer class which you can find in the sample download. The ability to return arbitrary data from a service is useful as you can see - in this case the chart is clearly associated with the service and it's nice that the graph generation can happen off a handler rather than through a page. Images are common resources, but output can also be PDF reports, zip files for downloads etc. which is becoming increasingly more common to be returned from REST endpoints and other applications. Why reinvent? Obviously the examples I've shown here are pretty basic in terms of functionality. But I hope they demonstrate the core features of AJAX callbacks that you need to work through in most applications which is simple: return data, send back data and potentially retrieve data in various formats. While there are other solutions when it comes down to making AJAX callbacks and servicing REST like requests, I like the flexibility my home grown solution provides. Simply put it's still the easiest solution that I've found that addresses my common use cases: AJAX JSON RPC style callbacks Url based access XML and JSON Output from single method endpoint XML and JSON POST support, querystring input, routing parameter mapping UrlEncoded POST data support on callbacks Ability to return stream/raw string data Essentially ability to return ANYTHING from Service and pass anything All these features are available in various solutions but not together in one place. I've been using this code base for over 4 years now in a number of projects both for myself and commercial work and it's served me extremely well. Besides the AJAX functionality CallbackHandler provides, it's also an easy way to create any kind of output endpoint I need to create. Need to create a few simple routines that spit back some data, but don't want to create a Page or View or full blown handler for it? Create a CallbackHandler and add a method or multiple methods and you have your generic endpoints.  It's a quick and easy way to add small code pieces that are pretty efficient as they're running through a pretty small handler implementation. I can have this up and running in a couple of minutes literally without any setup and returning just about any kind of data. Resources Download the Sample NuGet: Westwind Web and AJAX Utilities (Westwind.Web) ajaxCallMethod() Documentation Using the AjaxMethodCallback WebForms Control West Wind Web Toolkit Home Page West Wind Web Toolkit Source Code © Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET  jQuery  AJAX   Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

    Read the article

< Previous Page | 76 77 78 79 80 81 82 83 84 85 86 87  | Next Page >