Google Gears hangs when capturing (unmanaged resource store) - google-gears

Our code was written based on the example from Google Gears' own docs. We're using an unmanaged resource store. So we declare the files in an array, create the store, and capture all the files.
Trouble is, the capturing process hangs. It always hangs on a random file (no discernible pattern has emerged), and when you reload the page, it always successfully captures.
We're capturing 48 files. It seems to have nothing to do with the files themselves, as it hangs on every file type. I've seen it hang on the 6th file or the 47th. Windows and Mac. FF, IE, and Safari.
We are not using a WorkerPool, and I'm thinking this may be necessary. Any other ideas why it would hang?

I discovered that the problem was in the scope of the variable. The code we had used from Google's own example had the creation of the store, and the capture happening in separate functions, and since we were downloading so many files along the way, the object was getting destroyed by the browser's own trash collector.
That's why the callback was producing no errors, and it was instead just hanging.

Related

How to save PDF from HTML in Azure Functions

I'm developing an application which will have a web crawler for some sites.
The application will trigger a Azure Function by URL where the crawler will start the work.
So far, so good, but, we'll have to save some evidence that the crawler passed though the site. We're thinking of save a PDF file with the screen that the crawler passed, but, as Azure Functions doesn't have GDI+, it won't work with Selenium or PhantomJS.
One different approach can be download the HTML content and somehow save this HTML string (with all the JS and CSS dependency) into a PDF file.
i'd like of some library which can work with Azure Functions to make the screenshot of some URL (or HTML string) and save to PDF.
Thanks.
Unfortunately the App Service Sandbox whose rules Azure Functions live by is going to block most GDI+ API calls. We have had success with one third party library (ByteScout) for some PDF generation needs but I think in your case that type of operation is explicitly blocked. You can find out more details here https://github.com/projectkudu/kudu/wiki/Azure-Web-App-sandbox#win32ksys-user32gdi32-restrictions
There is no workaround that I'm aware of because at the end of the day most of these solutions are relying on GDI+ in the underlying OS (directly or indirectly).
Your only real option is to offload that workload to virtual machine without the restriction on the API.That could take the form of a dedicated VM or something like an Azure Container Instance whose life-cycle you can manage more dynamically as needed. We do something similar today where we have a message queue being monitored on a VM and our azure function drops the request into the queue for processing.

Remove A URL Scheme Handler from Launch Services

I am developing a Cocoa Mac app which dynamically generates and registers itself for URL schemes. However, when the application registers itself to handle a newly generated URL scheme (e.g. myscheme1423://), I would like to prevent the application from responding to any previously registered URL schemes.
I am using LSSetDefaultHandlerForURLScheme() for the purpose of registering a URL scheme; in conjunction, the application automatically overwrites it's Info.plist to contain the new scheme. As you may know, the LSSetDefaultHandlerForURLScheme() function adds the given bundleID/scheme to a Launch Services database. However, I couldn't find an equivalent Launch Services function to remove the same bundleID/scheme pair from the database.
I know that I could simply ignore any external events which originated from a URL scheme other than the one for which the app is actively registered, but it feels to me that there should be a simple way to completely wipe out the system's knowledge of the previous scheme. If my application goes through the process of registering for a new scheme more than a few hundred times, a point will come where a significant amount of space (for a Plist, at least) is being taken up on disk by a plethora of pointless pieces of data (i.e. the old Launch Services entries).
I just fired up a playground and began playing. This is utterly undocumented but it appears to work.
Try passing ("None" as CFString) for the second parameter of
LSSetDefaultHandlerForURLScheme()

Gaining Root Access w/ Elevated Helper & SMJobBless

I'm working on something that needs to install files periodically into a folder in /Library.
I understand that in the past I could have used one of the Authenticate methods but those have since been deprecated in 10.7.
What I've understood from my reading so far:
I should create a helper that somehow gets authenticated and have that helper do all of the moving tasks. I've taken a look at some of the sample code, including some involving XPC and one called Elevator but I'm a bit confused.
A lot of it seems to deal with setting up some sort of client / server model but I'm not sure how this would translate into me actually installing my files into the correct directories. Most of the examples are just passing strings.
My question simply: How can I create my folder in /Library programmatically and periodically write files to it while only prompting the user for a password ONCE and never again? I'm really not sure how to approach this and there doesn't seem to be much documentation.
You are correct that there isn't much documentation for this. You'll basically write another app, the helper app, which will get installed with SMJobBless(). Not surprisingly,
the tricky part here is the code signing. The least obvious part for me was that the SMAuthorizedClients and SMPrivilegedExecutables entries in the info plist files of each app are dependent on the identity/certificate that you used to sign the app with. There is also a trick with the compiler/linker to getting the info plist file compiled into the helper tool, which will be a single executable file, rather than a bundle.
Once you get the helper app up and running then you have to devise a way to communicate with it since these are two different processes. XPC is one option, perhaps the easiest. XPC is typically used with server processes, but what you are using here is the communication side of XPC only. Basically it passes dictionaries back and forth between the two apps. Create a standard format for the dictionary. I used #"action", #"source", and #"destination" with 3 different action values, #"filemove", #"filecopy", and #"makedirectory". Those are the 3 things that my helper app can do and I can easily add more if necessary.
The helper app will basically setup the XPC connection and event handler stuff and wait for a connection and commands. The commands will just be a dictionary so you check for the appropriate keys/values and do whatever.
I can provide more details and code if you need more help, but this question is 9 months old so I don't want to waste time giving you details you've already figured out.

Selenium RC drops error when it tries open the popup

When selenium tries to open popup window I'm getting JS error permission denied in file
file:///C:/DOCUME~1//LOCALS~1/Temp/customProfileDir8708f7f69e14482ba857f4b2e74775c1/core/RemoteRunner.hta
So this break script execution, could you assist? I saw a related topic at MSDN and openqa but didn't find resolution that could help me.
I've just encountered this error. In the end it was because I was running IE in 'Offline' mode. Open the File menu and make sure that "Work Offline" does not have a tick next to it.
I've just updated a section about that in the Selenium docs. The website build is not working right now, so if you go to the site you will find the old version.
I'll paste the raw text here, I think your case is the second: JS trying to access sections that are still not loaded, so your solution would be a waitForPopUp command:
Why am I getting a permission denied
error?
The most common reason for this error
is that your session is attempting to
violate the same-origin policy by
crossing domain boundaries (e.g.,
accesses a page from http://domain1
and then accesses a page from
http://domain2) or switching protocols
(moving from http://domainX to
https://domainX). For this to be
solved, try using the Heightened
Privileges Browsers if you're working
with the Proxy Injection browsers.
This is covered in some detail in the
tutorial. Make sure you read the
sections about The Same Origin Policy
and Proxy Injection carefully.
If the previous situation was not your
case, it can also occur when
JavaScript attempts to look at
objects which are not yet available
(before the page has completely
loaded), or tries to look at objects
which are no longer available (after
the page has started to be unloaded).
This is most typically encountered
with AJAX pages which are working with
sections of a page or subframes that
load and/or reload independently of
the larger page. For this type of
problem, it is common that the error
is intermittent. Often it is
impossible to reproduce the problem
with a debugger because the trouble
stems from race conditions which are
not reproducible when the debugger's
overhead is added to the system. Try
first adding a static pause to make
sure this is the situation and then
moving on to the waitFor kind of
commands.

IIS/Cache problem?

I have a program that checks if a file is present every 3 seconds, using webrequest and webresponse. If that file is present it does something if not, ect, that part works fine. I have a web page that controls the program by creating the file with a message and other variables as entered into the page, and then creates it and shoots it over to the folder that the program is checking. There is also a "stop" button that deletes that file.
This works well except that after one message is launched and then deleted, when it is launched the second time with a different message the program still sees the old message. I watch the file be deleted in IIS, so that is not the issue.
I've thought about meta tags to prevent caching, but would having the file be dynamically named solve this issue also? How would I make the program be able to check for a file where only the first part of the filename is known? I've found solutions for checking directories on local machines, but that won't work here.
Any ideas welcome, thanks.
I'm not that used to IIS, but in Apache you can create a .htaccess and set/modify HTTP-Headers.
With 'Cache-Control' you can tell a proxy/browser not to cache a file.
http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html
A solution like this may work in IIS too if it is really a cache problem.
(To test this, open using your preffered browser with caching turned off
A simple hack is to add something unique to the url each time
http://www.yourdomain.com/yourpage.aspx?random=123489797
Adding a random number to the URL forces it to be fresh. Even if you don't use the querystring param, IIS doesnt know that, so executes the page again anyways.