Sunday, 23 December 2012

Ubuntu 11.10 Shortcuts


  • Hold Super – Show launcher.
  • Hold Super, then 1 or 2 or 3 and so on until 0 – Opens or puts focus to an application. The number actually corresponds to the location of the icon on the launcher from top to bottom.
  • Adding Shift will open a new instance of the application if it’s already open.
  • Super+T – Opens the trash can.
  • Alt+F1 – Put keyboard focus on the Launcher, use arrow keys to navigate, Enter launches an application, Right arrow exposes the quick lists if an application has them.
  • Ctrl+Alt+T – Launch a terminal window.

  • Tap Super(Press, don’t hold) – Opens the Dash.
  • Super+A opens the Dash in Applications Len
  • Tab -  Move to the next lens (When the dash is open)
  • Shift+Tab – 11.10+ only – Move to the previous lens (when the dash is open)
  • Alt+F2 – Invokes the Dash in a “special mode” to run a command. Typing in a Folder Name will find that folder in Nautilus, you can also use ~ as a shortcut in the field. Typing an application name will show different settings of that application with that application itself.

  • F10 – Open the first menu on the panel, use the arrows keys to move along to the end of that list or to the last menu, which is ‘Session’ by default.
  • Press Esc to close the menus without choosing anything.

Window Management
  • Super+W – Spread mode, zoom out on all windows in all workspaces.

Spread Mode
  • Super+D – Minimize or restore all windows; (Show Desktop.)
  • Alt+Tab – Switch to other applications, you can hold Alt down and then hit tab to switch to the next application.
  • Alt-` (The key to the left of 1 on US layouts, by default Unity will take it as any key above the Tab key.)- Switch between an application’s windows. Hitting this combo when you’re already focused on an application will automatically switch only between the windows for that application.

Window Placement
Cycling through the same key Unity will cycle through different placement widths, so experiment by hitting the NUM key multiple times, for example Ctrl-Alt-numpad 5 5 5:
  • Ctrl+Alt+Numpad 7 – Place window in top left corner of screen.
  • Ctrl+Alt+Numpad 8 – Place window in top half of screen.
  • Ctrl+Alt+Numpad 9 – Place window in top right corner of screen.
  • Ctrl+Alt+Numpad 4 – Place window on the left side of the screen.
  • Ctrl+Alt+Numpad 5 – Center/Maximize the window in the middle of the screen.
  • Ctrl+Alt+Numpad 6 – Place window on the right side of the screen.
  • Ctrl+Alt+Numpad 1 – Place window in the bottom left corner of the screen.
  • Ctrl+Alt+Numpad 2 – Place window in the bottom half of the screen.
  • Ctrl+Alt+Numpad 3 – Place window in the bottom right corner of the screen.
  • Ctrl+Alt+Numpad 0 – Maximize window.
  • Alt + F7 with Arrow keys – Moves the current window on the screen in the current workspace. Use Arrow keys to change its position fast, and use Arrow keys (on NUMpad  when NumLock is off) to change it slowly.

Workspace Management
  • Super+S – Expo mode (for everything), zooms out on all the workspaces and lets you manage windows.
  • Shift+Alt+↑ – Expo mode for all windows in the current workspace only.
  • Ctrl+Alt+← / → / ↑ / ↓ – Change to a new workspace.
  • Ctrl+Alt+Shift-← / → / ↑ / ↓ – Place window to a new workspace.
  • Alt + F10 to resize current window between normal size and/or maximize.
  • Ctrl+Alt+L - Lock the screen.

Unresponsive Script on browsers and some settings for firefox.

Warning Unresponsive script

When JavaScript code runs for longer than a predefined amount of time, Firefox will display a dialog that says Warning: Unresponsive Script. This time is given by the settings dom.max_script_run_time and dom.max_chrome_script_run_time. Increasing the values of those settings will cause the warning to appear less often, but will defeat the purpose: to inform you of a problem with an extension or web site so you can stop the runaway script.
Complete Error Message: “A script on this page may be busy, or It may have stopped responding. You can stop the script now, or you can continue to see if the script will complete.”
Sometimes you may be able to identify the extension:
"Script: chrome://fastdial/content/storage.js:71" 
This error is telling you that Firefox thinks that a script may be running out of control and would make Firefox hang if nothing is done. The script could be something on a web page you're accessing, in an extension you installed, or even Firefox itself. 

Letting the script run longer

If you find that pressing the Continue button brings up the same dialog again, letting the script run longer won't help you; it will just make Firefox hang for longer. However, if you can use Firefox normally after pressing Continue, then the script may just needs extra time to complete.
To tell Firefox to let the script run longer:
  1. In the Location bar, (URL Bar)type about:config and press Enter.
    • The about:config "This might void your warranty!" warning page may appear. Click I'll be careful, I promise!, to continue to the about:config page.
  2. In the about:config page, search for the preference dom.max_script_run_time, and double-click on it.
  3. In the Enter integer value prompt, type 20.
  4. Press OK
With scripts now allowed to run for longer times, you may no longer receive the prompt.
If you still receive the prompt (or if you want to see it again), you should set that preference back to the default value.
  1. In the Location bar, type about:config and press Enter.
    • The about:config "This might void your warranty!" warning page may appear. Click I'll be careful, I promise!, to continue to the about:config page.
  2. In the about:config page, search for the preference dom.max_script_run_time.
  3. Right-click on it and choose Reset.

Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Some problems with Firefox are caused by extensions, themes or hardware acceleration. This article will help you determine whether one of these is causing your problem and, if it is, describe how to make Firefox run normally again. 

 Note: The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Consider using it before going though a lengthy troubleshooting process. 

Start Firefox in Safe Mode

When you start in Firefox's Troubleshoot Firefox issues using Safe Mode, all extensions are temporarily disabled, hardware acceleration is turned off and the default theme is used. This will help determine whether one of these is causing your problem.
  1. At the top of the Firefox window, click the Help menu and select Restart with Add-ons Disabled.... Firefox will start up with the Firefox Safe Mode dialog.
    Note: You can also start Firefox in Safe Mode by quitting Firefox and then going to your Terminal and running: firefox -safe-mode
    You may need to specify the Firefox installation path (e.g. /usr/lib/firefox-4)
  2. When the Firefox Safe Mode window appears, press the button Continue in Safe Mode.
After Firefox starts in Safe Mode, test for your problem.

The problem still occurs in Safe Mode

If your problem persists in Safe Mode, it is not being caused by an extension, theme or hardware acceleration. Other possible causes could be plugins or changes made to Firefox preference settings, which are not disabled in Safe Mode.

The problem does not occur in Safe Mode

If your problem did not occur in Safe Mode, it is most likely because of an extension, theme or hardware acceleration. Continue following the steps in this article to determine the cause of your problem.

Turn off hardware acceleration

With some graphics card and graphics driver setups, Firefox may crash or have trouble showing text or objects on pages when using hardware acceleration. You can try turning off hardware acceleration to see if it fixes the problem.
  1. At the top of the Firefox window, click on the Edit menu and select Preferences
  2. Select the Advanced panel and the General tab.
  3. Uncheck Use hardware acceleration when available.
  4. At the top of the Firefox window, click on the File menu and select Quit.
  5. Start Firefox the way you normally do.
If the problem is no longer happening, then hardware acceleration was likely the cause. You can try updating your graphics drivers to see if that fixes it or simply run without hardware acceleration. Otherwise, your problem is likely related to extensions or themes. Continue with the steps in this article to see if they help.

Switch to the default theme

If you are using a theme other than the default Firefox theme:
  1. At the top of the Firefox window, click on the Tools menu, and then click Add-ons. The Add-ons Manager tab will open.
  2. In the Add-ons Manager tab, select the Appearance panel.
  3. Select the default theme, then click the Enable button, to make Firefox switch to that theme.
  4. Click Restart Firefox if necessary.
After you restart Firefox, test for your problem. If it no longer occurs, the theme you were using was causing it. If it still occurs, continue following the steps in this article.

Disable all extensions

To determine whether a faulty extension is causing your problem, you can disable all of your installed extensions:
  1. At the top of the Firefox window, click on the Tools menu, and then click Add-ons. The Add-ons Manager tab will open.
  2. In the Add-ons Manager tab, select the Extensions panel.
  3. Click the name of an extension in the list to select it.
  4. Click Disable to disable the selected extension.
  5. Repeat this for each of the other extensions in the list.
  6. Click Restart Firefox.
After you restart Firefox, all extensions will be disabled. Test for your problem.
  • If the problem still occurs with all extensions disabled, it is most likely that the localstore.rdf file in your Firefox profile is corrupt. You can Reset toolbars and controls to resolve the problem.
If the problem no longer occurs with all extensions disabled, one of your extensions was causing it. To find the extension that was causing your problem, continue as follows:

Test for faulty extensions

To determine which of your disabled extensions was causing your problem, you can re-enable each extension one at a time.
  1. At the top of the Firefox window, click on the Tools menu, and then click Add-ons. The Add-ons Manager tab will open.
  2. In the Add-ons Manager tab, select the Extensions panel.
  3. Click the name of an extension in the list to select it.
  4. Click Enable to enable the selected extension.
  5. Click Restart Firefox.
After you restart Firefox, test for your problem. If the problem comes back, the extension you just enabled was causing it.
Note: If you have a large number of extensions, it may be quicker to enable more than one extension at a time. The method with the fewest number of restarts required is: Enable half the extensions in this list, then restart Firefox and test for the problem. If the problem reoccurs, you know that the faulty extension is one of the ones you just enabled. If the problem does not occur, you know the faulty extension is one of the disabled ones. Repeat the process until the faulty extension is found.
After you find the extension that was causing your problem, disable or uninstall the faulty extension and re-enable the other extensions in the Add-ons window.

Updating extensions

If an extension was causing your problem, it may have an update available that will fix it:
  1. At the top of the Firefox window, click on the Tools menu, and then click Add-ons. The Add-ons Manager tab will open.
  2. In the Add-ons Manager tab, select the Extensions panel.
  3. Click Find Updates.
  4. If updates are found, install them by clicking Install Updates.
  5. When the installation is complete, click Restart Firefox.
After Firefox restarts, your extensions will be updated. If the extension that was causing your problem had an update, re-enable it and test for your problem again.

Checking extension settings

Some problems are caused if the settings of an extension override Firefox settings (e.g. problems with toolbars). Therefore you may want to check the extension's settings to see if you can find the option that is causing your problem:
  1. At the top of the Firefox window, click on the Tools menu, and then click Add-ons. The Add-ons Manager tab will open.
  2. In the Add-ons Manager tab, select the Extensions panel.
  3. For the extension that is causing your problem click the Preferences button.
  4. Click your way through the settings to see if there is an option that may solve your problem.
  5. If you found a suitable option, click Save and Restart Firefox
Content refers to following links.

Thursday, 20 December 2012

OpenERP 7.0

OpenERP has lots of new feature and completely new user friendly UI and with viral features, I am damn sure it will rock the world of ERP.

Here following are some analysis of mine on 7.0, how it works and how everything initialized and how instance of OpenERP webclient initiated, hope you will like this.

Before going further let us see OpenERP client-server architecture, how OpenERP user, client, server and database interacts with each other., which clarify above descriptions.

I will start with starting procedure of OpenERP Server from terminal with command-line arguments, I will also describes some method call, what that method do in short description. Here I have explained the flow of server, how each job got initialized, Still these is not the perfect flow but I'll update and improve this day by day,  for better understanding follow the flow with your system and "CORRECT ME" if I am wrong, please share your views for points on which you have better ideas with comment on this post.

Before starting flow let's see directory structure for OpenERP Server Version 7.0, so that whenever I take some reference of module or method so you can have better idea.

Note :- OpenERP server now runs in Embedded mode only, so now when you run OpenERP what process goes in background, openerp-server will call main method with command-line arguments, this main method will sets os environment, will check root user for POSIX system, parses config file where all options are stored by calling parse_config method(Parse the configuration file (if any) and the command-line arguments.), also checks postgres user(Exit if the configured database user is 'postgres'), will initalize logger, set babel path(Mainly user for internationalization), setup signal handler(need explanation), runs test files(YAML), it also setups pidfile this file contains process ids. this methos will also imports/exports the translation based on translate_in/translate_out option of config, Config file may have workers defined in it either statically defined in config file or from command line, so this main method will starts the OpenERP service with workers(to provide multi cron environment), if there is no worker defined the it starts the serivces simply(there is start_services_workers and start_services methods defined for this) .

Now its start_service which starts service of http, netrpc, and cron, following is the description regarding all this.

1. start internal:
       start_internal method will initializes logger where log related OpenERP going to store, after that it will initiate object proxy, this object proxy will create a global object of self, so that object proxy service can be use globally(see init of object_proxy in osv.osv for detail), after starting and creating global object of objcet proxy service this will starts web service, the web service is the module which contains db, common, objects_proxy, report_spool classes, the start service method of web_service will creates instantiate this classes, the init methods of this classes will register their service with ExportService object, ExportService is a proxy class for exported service(as services of db, common and etc exported to it) this contains a dict of services so when we need to call particular service(i.e. particular object) we will call getService method of ExportService class.

Important Note :- This will also add openerp modules in sys.modules so that we can access our openerp modules .py file from anywhere by accessing sys.modules['openerp.module .py file']

After that this method will loads server wide modules by calling load_server_wide_modules, this method will read the addons path provided in config file or provided at terminal options(ultimately command line options are updates config file, see load_openerp_module method modules.modules).

load_openerp_module:// remain to write details

So in short the role of start_internal is to instantiate internal resource and export their service and load server modules.

2. netrpc server(service)

      netrpc_server module has start_service method which starts netrpc service on specified domain and port, it instantiates TinySocketServerThread class.
TinySocketServerThread: it extends Threading and Server class. this will create main thread for netrpc interface, and initialize Server class(Here we mostly played with Threads for Server and socket instance).
Server class: // remain to write details

3. wsgi server

        wsgi_server.start_service() will start the WSGI server,this is the point where WSGI(Web Server Gateway Interface) is initialized using werkzeug library, creates a thread of serve, serve will creates WSGI server by calling werkzeug.serving.make_server, as we have creates a separate thread for this so for each server we will create and instantiate separate thread which will server forever, make_server takes application as a parameter(application to serve), for fetch application we have application method, this application method will returns instance of application either with Proxy or without proxy(based on options given in config, there is --proxy-mode to run OpnERP behind proxy to run OpenERP behind apache proxy read, there is application_unproxied method which returns application handler (Question why again openerp.service.start_internal() called internal services are already initialized in openerp.service.start_service()), there are list of handler as follow:

wsgi_xmlrpc_1 : //TODO

wsgi_xmlrpc : //TODO

wsgi_xmlrpc_legacy : //TODO

wsgi_webdav : //TODO

The above all are the handlers which handles every requests, request like for access common service, object service or access any method, all of the above calls xmlrpc_return method which calls dispatch_rpc method a common gateway method which handles each and every RPC calls and returns result which in turn returned as a response in str format, if dispatch_rpc fails it will gives exception,
there is method xmlrpc_handle_exception which handles all kind of xmlrpc exceptions.

     Up to this we will have a WSGI server listening to our XMLRPC requests, now further we will see how any request initiated from web and how it is reaches to OpenERP Server and response given to client.

You will have question that how all modules are loaded and how web modules are loaded, so for this I will discuss load_openerp_module method of modules.modules.

4. cron

        Note:- For threading you can refer

        Start the above runner function in a daemon thread.

    The thread is a typical daemon thread: it will never quit and must be
    terminated when the main process exits.

The start service of cron module will create max_cron_threads(config option), by calling thread.Thread with target=cron_runner(Note:- cron will be a daemon thread as we have set t.setDaemon(True)),
We have set sleep interval to 60 seconds + number(index) of thread which is Steve Reich timing style that is first thread will have sleep time 61 second and second thread will have 62 and so on.

cron_runner :- this mainly checks for acquire job, This selects in database all the jobs that should be processed. It then tries to lock each of them and, if it succeeds, run the cron job (if it doesn't succeed, it means the job was already locked to be taken care of by another thread) and return.

In short this is basically cron module and cron_runner are responsible for run corn jobs by fetching from ir_cron model and runs it forever at particular interval.

If there is 60 cron threads then each one is wake up at the difference of 1 second as I discussed above time interval style of Steve Reich and at each second cron jobs got run.

Note :- Please share your views regarding the points in which you have better ideas.

Up to this We have seen how server starts, parse options and based on that options starts services as described above, now we will see how all modules got registered in pool(pool a directory of objects instances, with key as object name so when you get any object from pool like self.pool.get('some object') then you will have instance of that object and you can use datas and methods of that object) and how web is initialized.

As we already seen that  start_internal of service module will call load_server_wide_modules, this method will read the addons path provided in config file or provided at terminal options, as we have given server addons as well as web addons path from either terminal or in config file.

There will be web module always available to load in load_server_wide_modules because this is the module which is going to load always, whether user logged in or not, after login process, server will load database specific modules in which user logged in but web will always going to load, if you want some other modules to be pre-loaded then you can just set config setting or either you can give comma separated modules in terminal, -load is the option for it.

Note :- Let me clarify(as it is obvious) that loading of server addons is post procedure of login by default only web module is loaded, as user going to use web interface to interact with OpenERP.

This is the point where web module going to load

openerp.modules.module.load_openerp_module(m(web by default)) will load web module.

load_openerp_module :-Load an OpenERP module, if not already loaded. This loads the module and register all of its models, thanks to either the MetaModel metaclass, or the explicit instantiation of the model. This is also used to load server-wide module (i.e. it is also used when there is no model to register).

This method will find the path of module and imports it(See __import__ used to import modules whose name is known at runtime))

After importing this module this function will load all descriptions from manifest file( or in old case), it will load all static files, xmls, demo files(all attributes of manifest file) by reading this file, after loading module and importing it it will appends it in loaded gloabl variable.

Here noticable thing is how Root class of Web module is called, from where web module and WSGI dispatching comes into picture ?

load_openerp_module will read description and will find post_load attribute in reference see post_load in manifest file) and will call wsgi_postload method of from server itself.

getattr(sys.modules['openerp.addons.' + module_name], info['post_load'])()

This will read manifest file of web module and reads its info 'post_load' attribute, 'post_load' has value "wsgi_postload" and wsgi_postload is method of in web module which calls openerp.wsgi.register_wsgi_handler(Root()) and gives Root class instance as a argument, this way web application handler instance is added to module registery in server.

So root path request will have a handler available, there will be a serving thread which serves to each and every request(as discussed earlier that server thread calls make_server of werkzeug WSGI and that thread serves forever) as application as handler, application handler is Root instance, so server will call call method of this handler instance from where actual web WSGI dispatched.

So each and every request is handled by appliation handler that is Root class of this class represent as application because each and every request pass through this common gateway, the __call_ method of this claaa will call dispatch where actual dispatching of WSGI happens.

Upto this we have seen basic server process, how web module comes into picture, how application hanlder got registered, so from here we will see Trace of Web-Client how web handles each request, how it call http_request, json_request etc.

Let me give little bit glimpse on directory structure of Web-Client 7.0

As we have seen whenever we request from browser application handler will call dispatch(Actual dispatcher of WSGI), dispatch will analyse the request, its path and will call find_handler for that path, say for example if request path is '/' so handler will be index method of Home class of main controller(Please refer directory structure of Web-Client 7.0), this index method will return html_template, html_template is :

html_template = """<!DOCTYPE html>
<html style="height: 100%%">
        <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/>
        <meta http-equiv="content-type" content="text/html; charset=utf-8" />
        <link rel="shortcut icon" href="/web/static/src/img/favicon.ico"
        <link rel="stylesheet" href="/web/static/src/css/full.css" />

        <script type="text/javascript">
            $(function() {
                var s = new openerp.init(%(modules)s);

        <!--[if lte IE 8]>
        <script src=""></script>
        <script>CFInstall.check({mode: "overlay"});</script>

and see signature of index method :

class Home(openerpweb.Controller):
    _cp_path = '/'

    def index(self, req, s_action=None, db=None, **kw):
        js = "\n        ".join('<script type="text/javascript" src="%s"></script>' % i
                  for i in manifest_list(req, 'js', db=db))
        css = "\n        ".join('<link rel="stylesheet" href="%s">' % i for i in
                  manifest_list(req, 'css', db=db))

        r = html_template % {
            'js': js,
            'css': css,
            'modules': simplejson.dumps(module_boot(req, db=db)),
            'init': 'var wc = new s.web.WebClient();wc.appendTo($(document.body));'
        return r

From here boot strap code is executed, see openerp.init method called from html_template, for better understanding refer boot.js, this boot.js has openerp function which is loaded on document ready (for terms specification of javascript refer, this boot.js will load all other classes and all other files, it will load "pyeval", "corelib", "coresetup", "dates", "formats", "chrome", "data", "views", "search", "list", "form", "list_editable", "web_mobile", "view_tree", "data_export", "data_import".

Very important Note :- 

        JavaScript doesn't have concept of inheritance, doesn't terms related to class etc but we have followed  John Resig's inheritance architecure(Refer, each and every JS object will extends Widget class which in turn extends Class, the Class contains the core logic of constructor, extends, so if you extends Widget class so init method of that class will be automatically called(dummy constructor implementation),all this stuff is defined in corelib.js, so whenever we create any instance of object init method will automatically called, so init method is constructor in terms of OpenERP javascript framework, start method of class which extends openerp.web.widget will be called automatically, this is because of our implementation of corelib.

One more thing to note is that in JavaScript you can create an instance of function like:

helloWorld = function() {
        alert("Hello World");

var hw = new helloWorld();
console.log(hw) //will gives object type
hw.constructor.apply() // will apply function helloWorld

Note:- boot class that is openerp has initialized all other instance, now see html_template given above, we have called s.web.WebClient(); where s is instance of OpenERP(see chrome.js).

Now further we will see, what Webclient object does, as I already  described that when we create any instance of object it's init and start method automatically got called, and start method of Webclient(chrome.js) will check whether user is already logged in or not, if not then we render Login page otherwise will show application page.

For Weg-Client architecture(I'll update this post day by day) ---> To be continue .... 

Note :- Kindly share your views/knowledge if you have better idea on topic described above