Are strings in web.config compiled into the executable? - c#

The storage admins where I work have bought and configured a new huge NAS system.
Over time all current storage will migrate over there. This means that various network paths will change and this will break some in-house applications. We are reviewing a bunch of old apps the find the ones that use current paths like: \\old-file-system.company.com\Users so that we can modify them.
The old apps I have found all set these paths as strings in the project web.config file. My question is: are these paths compiled into the executable or are they read at runtime from this config file? Can we just modify the paths in the config files and not have to potentially rebuild them or upgrade them to newer .Net versions?
Cheers

The values are read from the config file.
That is precisely the point of config files: to provide the ability to alter these values without needing to redeploy the application.
Note that this may need you to restart the app pool on IIS after making changes. Usually, it should automatically do that when it detects changes to the config file, but from historical experience this sometimes breaks without you noticing.
As an aside: don't forget about alternative config storage methods such as databases.

yes, they are!
it will then depend on the code.
So, As a general rule no.
However, if you added new config items, then they may well not show up.
And if the code used the built in class in place of often used configuration manager to get values?
then you have to re-compile.
But, we also might use this:
vb.net:
Dim rstData As New DataTable
Using cmdSQL As New SqlCommand(strSQL, New SqlConnection(My.Settings.TEST3))
cmdSQL.Connection.Open()
rstData.Load(cmdSQL.ExecuteReader)
End Using
So, in place of config manager, I often use My.Settings.TEST3.
(you get intel-sense). So on build, a class is created for some of those web config files.)
In c#, the above is:
Properties.Settings.Default.TEST3
And again often used due to intel-sense in place of configuration manager.
That class is re-build at compile time. So, if the code used to get web.config values is always configuration manager, then you would/should be ok.
However, if code used the built-in class like above?
The values ARE pulled from web.config at compile (build) time.
the class is called
c#
Settings.Desinger.Cs
vb.net
Settings.Desinger.vb
So, I would check the above two files. That class tends to come from here:
Now the above when we add say a connection string to the project?
The above DOES update and put the above settings into web.config.
However, the class created (settings.Desing.cs/vb?
It is re-generated each time, and it DOES COPY the values from web.config.
So this means that after changing the settings in that project, you REALLY do have to re-build.
As noted, if one came from desktop land, then we just add settings to above, and use them. They actually are created in web config, but we often use the above - since as noted ANY new setting we add to the project now has intel-sense.
So, I would search the source code for:
vb:
My.Settings.TEST3
(search for My.Settings.)
or
c#
Properties.Settings.Default.TEST3
(search for Properties.Settings.)
if either of above are used in the code?
Then yes, you have to re-build since they are re-created at compile time into a class, and the values ARE pulled from web.config at compile time.
If configuration manager was used in all cases, then you are ok.
however, if the designer class was used, then a re-build is required, and worse a change in web.config will not be reflected in that class until a re-build.

Related

How to use environment dependent app.config file

We are a group of C#/.NET 4.5 developers working on the same application.
The application has a set of configurations related to each developer machine, like the connection string to the DB, network related settings (proxies, IPs, credentials) and a LOT MORE.
Because the application has grown we are incurring in a lot of environment related configurations like for example:
If this is MyPC then load the connection string for my PC.
If this is the XDeveloperPC then specify proxy’s settings.
Also if new developers leaves or join the group, then the process to update the file becomes a total head ache. Maintaining the file has become very hard and is a possible source of bug and errors.
I was thinking in having specific app.config files related to each developer environment like:
app_MyPC.config
app_XDeveloperPC.config
And when the application builds or executes then specify which one to load as if it where the default app.config of the application. Then, when the application or any class or method refers to a given configuration (like the connection string) is access to this configuration file as if it where accessing to the app.config default file.
I would not want to create a Configuration class that builds immediately when the application starts because then I should have references from every place to this class and the application is quite large, with a bunch of projects and dlls.
I rather prefer to hear some opinions and what do you think should be the best way to achieve this.
Is it possible to achieve this?
How?
Do you know a better approach?
FYI, please note that .NET only loads one config file for the whole application. You could try multiple config files something as like specified here,
Multiple App.Config Files in .NET Class library project
Hope this helps...
You can specify sections of app.config to be loaded from another file. See this answer
However, you might have to customize the above solution, the app.config files and the way configs are organized.
Another approach is to use a custom settings file instead of app.config. This will need some code change to use the config file. This config can either be an XML or a JSON file (JSON is easy to deal with). You can use an inheritance model wherein generic settings come from one file, specific settings come from another file and so on. Also, you can load settings from such file at runtime and change application behavior on the fly.
If you decide to use custom config file, and if you already have lot of code written considering App.config file, you can abstract the app.config calls to a method and let that method deal with where to pull the settings value from. That way you can minimize the code change and keep everything tidy.
Maybe you can use the machine.config file (C:\Windows\Microsoft.NET\Framework\your Framework version\Config\machine.config)

Can I track the use of ConfigurationManager settings

I am trying to clean up the web.config in multiple projects, but am worried that I may remove an appsetting/connectionstring that is being used somewhere.
For example, I want to know if ConfigurationManager.AppSettings["MySetting"]) is used.
I can of course do a global find for ConfigurationManager or Appsettings, but that doesn't check in compiled dlls (this project has some dlls referenced that i know are looking for certain keys).
I would love to be able to 'log' (text file, db, anywhere) the use of the .config file, minimally logging the key name, but ideally the namespace/method that called it. If this is possible, I could come back in some amount of time and check the log to see what is used.
Deleting the settings and seeing if the app throws an exception is tempting :), but not a realistic option.
Thanks in advance!
You can try to use aspect to log that a method was called.
I'm not sure if you will be able to get which configuration or key was retrieved but having all the places that's called is already a starting point.
Hope that helps.
Give a try for PostSharp or Unity.

Best way to store settings (special requirements)

I found a lot of information for saving different kinds of application/user settings in different places but getting confused what could be the best way for me.
My problem has different dimensions:
The application will have some User-Roles (Admin, StandardUser, ...), where every User (based on Windows-Logon) will belong to one role.
The Admin is allowed to setup everything for everyone.
The settings have different categories:
Application settings (should be the same for every user on the computer)
User-Role-specific settings
User-specific settings
The application has several projects where different projects have to access the settings.
(4. The application is written in C#)
I don't want to mention the things that I have read because I don't want to steer your thoughts into a (maybe wrong) direction.
So, how would you handle this scenario?
Thanks a lot!!
Joerg
EDIT 1
Some more things after the first answers that I hope can clarify my question:
my question doesn't focus on the authentication of the users, it focusses on create/edit/save settings
my first attempts for solving the problem were:
using the Visual Studio Settings.Settings file
... doesn't work because I have several projects that have to have access to the settings AND I couldn't find a way to make the ApplicationSettings writeable (they are readonly)
use the ConfigurationManager-Class
... I am not experienced with this one but as far as I understand this class it is just another class that gives me access to my ApplicationSettings (and has the same problems like #1)
... maybe a link to a good tutorial will help
invent something on my own
... I still hope to find something ready-to-use
I guess in this kind of scenarios you probably have a database. When you incorporate users, user rights, etc in there it is probably also a good place to save your application settings.
I always love the database centric solutions, since there are widely available (when you want to create a new UI based on the same system, you can reuse the settings there).
I think the entity–attribute–value model is a good design strategy to consider.
You can create a view with triggers on them hiding system only properties, enabling the admin to change all, and the user to only change theirs.
By your description I'd say you want Role Based Authentication. It's something that has been asked before. I'd go to the link specified in that answer to find an overview and some code samples of how to approach this problem.
Microsoft has done a great job adding some abstractions with the Membership Providers and now the ASP.NET Identity Framework (in case you have a Web Application). Regardless of what you choose to do, database or config files are going to be involved (take a look here to learn how to manage those) and some sort of claim derived system.
Assumption: You already have figured out how you are going to handle roles, and your question is only about storage/retrieval of settings.
Point #3 means you can't use a Settings file for Application and User scoped settings combined with a custom configuration section for holding the role specific settings (optionally encrypted).
My next suggestion would be a WCF endpoint that exposes the settings, either in their entirety (security trimmed contents of Application + User specific + Role specific) or by some sort of dictionary lookup equivalent. Additionally:
The endpoint would need to require Windows Authentication (or possibly Claims) so that it could determine the user specific/role specific part.
Each application would then need to have knowledge of the WCF endpoint, either through configuration or potentially through WCF Discovery.
Update:
Note that WCF doesn't solve your storage question, but it helps with your point #3 - multiple projects that need to use the same settings. A WCF endpoint allows a single project that encapsulates the storage/retrieval of settings to be re-used by multiple clients. WCF can be complicated to read about, but in practice it's pretty easy to setup - you just decorate an interface and host it in IIS. You could also host it yourself in something like a windows service if you were adverse to using IIS, but deploying it to IIS would be a lot easier. You can then consume it in your other applications by adding a Service Reference to your project, and then you call the interface code as if the code was in your own project.
In case you are talking about a single application with multiple class libraries:
What I'm describing above assumes you are making multiple applications that all need to share settings. If you are actually talking about a single application with multiple class library projects, the built-in Settings can still be used - there is just one manual step you need to do to make it work across projects. After adding settings to both your application project and your class library project(s), you should copy the app.config section containing the settings in your class library and copy/paste it into your application's app.config. Visual Studio isn't very clever and it will only sync the class library Settings changes to an app.config within the class library project, even though an app.config for a class library isn't a "real thing", since only the app.config for the application consuming the class library is actually used by default (which is why you need to merge it into your application's app.config).
If you need multiple class libraries (including the main application project) to use the same settings, you could make a dedicated class library project just to hold the settings (note you can add multiple Settings files to this project to make the settings more modular), and then all the other projects could reference the common settings project (to avoid circular dependencies, you wouldn't hold any Settings in the main application project that a class library needed).
Overriding a user's settings
The Settings object has a mechanism you could use to override settings (say, with value's specified by an administrator). When you add a Settings object to your project, it creates a Settings partial class with some example code for wiring into the SettingsLoaded event. In this event, you could load your administrative settings (either through a WCF call, or perhaps from a know location on the file system) and apply any overrides.

How to use partial config files

I am involved in a project where development and testing is going on in different locations. There are a few entries in the app.config that are "local" to the different locations (hence, "config"). Therefore, everyone tends to keep his own app.config, which always makes it difficult for a new setting to be introduced.
I'm looking for an idea, something like partial classes, where the bulk of an app.config can be in one place, and a few items in another, and yet all wind up in the proper exe.config after a build.
First of all you can split up config file using the configSource attribute. For example, in web.config you could write:
<authentication configSource="ConfigFiles\authentication.config" />
.. and have your authentication config in another file. This may be of use to you, with local variations (eg. DB settings).
Secondly, and more importantly, you probably want to watch this video to learn about deploying to different environments (using web.debug.config and web.release.config)
http://www.hanselman.com/blog/WebDeploymentMadeAwesomeIfYoureUsingXCopyYoureDoingItWrong.aspx

c# pattern for two applications sharing a configuration file

I have two applications that have many common configuration properties. When a configuration property of one changes, I want the other to change as well. Does anyone have a sensible way to accomplish this before I start off down the wrong track?
EDIT: I'm using .NET 2.0
You can create and reference a common configSource for the configuration section(s) involved. For instance, if you wanted a common set of AppSettings, copy your current appSettings to a new file (say appSettings.shared.config) and replace them in both app configs with this:
<appSettings configSource="appSettings.shared.config"/>
Here's more documentation: http://sunali.com/2008/01/23/configsource-property-dividing-configuration-files-into-pieces/
Far as I know, this cannot be done for an entire file, only sections, and each section will need its own file (and the section must still be declared in the configurationsections element of the app.config). But, this has a number of really cool uses; for instance, you can separate your connection strings into files geared towards different environments (local, development, testing, staging, production) and by changing one filename in one place you've now pointed your app at the different environment.
One easy way to accomplish this is to use the configSource attribute in the app.config in both applications, and point this to a common file. Bingo, change one file, all apps are updated.
Check the MSDN documentation on it here.
there are a couple of different ways you could do this:
use the registry
use a config file in a common location
use a configuration table in a database

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