I have a simple string that I would like to save for later use on an ASP.NET server. It is an authorization string for a web service. It mostly stays the same, but may expire every few months. It will be saved programmatically from a code-behind file. Is there a simple place I can save it?
Initial thoughts are:
File - seems reasonable
Database - we don't have one setup and it seems like a lot of overhead to hold a string
Session - this would be too short lived
Config file - Based on answer from MK_Dev this would require a web app restart. No go then.
Somewhere else that I don't know about, but would be perfect?
Another possibility is to create a custom registry key. Here is an article with some code examples: Manipulating and Editing Registry with .NET.
If you don't mind restarting the app when the value changes, then config file is the way to go. If you need it to be fully dynamic, you can add a config table to the database and update it when changes.
How about server side cache?
Check this out: http://msdn.microsoft.com/en-us/library/18c1wd61%28v=vs.71%29.aspx
If the string remains static for the most part, I would store it in Cache with an expiration and/or dependency. If you go the dependency route, you can use a file or store the string in the database, and it will update automatically if and when it's changed.
See this article for details: Caching Application Data
How about System.Environment variables?
System.Environment.SetEnvironmentVariable("mystring","asdf");
System.Environment.GetEnvironmentVariable("mystring");
Related
I read this article. I was planning on creating a setup page that runs and allows the user to change the sql connection strings which is stored in the web.config file. With some changes this may help in deployment or even development. My question is is it possible to change the connection string in the web.config file based on user input and is this advisable. N.B The connection string must be contained in the web.config
THank you
You may find helpful this blogpost on this topic.
hmmmm. Changing the web.config file would cause the app to restart. At least that's what would normally happen and from my understanding of the dependencies involved would happen if you did it from code.
That might be acceptable to you though & it is the best way to do it if the restart is acceptable.
Simon
It's possible to modify web.config based upon user input. It's just an XML file.
We do this as part of a custom action in an installer (MSI).
Modifying a web.config will cause the application pool to recycle though. Depending on your site, this (recycling) may or may not be a big deal.
Can I change access or edit the values specified in Global.asax from IIS?? The reason is that I don't have the source code and the only change we need right now is to change the connection strings (database) specified in Global.asax.vb file.
Thanks!!
Usually, connection strings are specified in the Web.config for this very reason. If the values are hardcoded, there's no way for you to modify them unless you can change the code. You can setup an identical database (name, creds) and change some config settings so that your database server resolves to the same machine name. That's all I can think of...
Well, I was able to circumvent the issue. Not very elegant and might add to performance load, but was the simplest considering the work involved to recreate the project.
I created another aspx page and set the connection variables using the Application object in the Page's Page_Load, and then did a response.redirect to the previous default file. I was lucky as all code referred to the Application Object, and this was set only in Global.asax - had there been any code which directly specified the connection string - then I would be screwed!
The only overhead was that the Application_Start would be called only once - but overwriting those values with Page_Load will be called every time a request is made. Kind of trade-off I am ready to do.
I could not agree the previous answer as it mentioned the "Ideal" Case and the best practices - it did not solve my problem. The previous solution should be adopted if the previous sql server can be completely demoted.
Thanks Guys!
I'm working with ASP.NET and c#.
I don't know where to store the configuration setting for my web app.
Every time a page loads the app reads the master page. On the master page, everytime I need to get the following data:
Meta Tags for the site
The users have to be able to change this data in their CMS, so I think the best for this is to store in the database. So every time a user request a page the web app is going to query the database.
Some configuration like the master page we are using (we use several for several templates), and some other config. We think we can store this in the web.config since users can't modify these values.
In the past we used an xml file to read the Meta Tags, but we ythink is better to use the database.
Also, does it cost a lot for the web app to access the web.config in every page? I mean, to do "ConfigurationManager.AppSettings["variable"];"
Thanks a lot !!!
ConfigurationManager.AppSettings["variable"] value is remained and picked from cache, until web.config changes.
you can also store application setting in xml file in App_Data folder, and mentioned in web.config like:
<appSettings configSource="App_Data\Config\siteConfig.xml" />
For Metatags a database storage will be better. You could use the ASP.NET cache object to improve performance so you don't have to get the info from DB on every request. You could use a time based expiration for the data or even sql based expiration trigger.
The web.config file is not accessed every time an item is read. It's stored on memory so there is no performance hit on using it.
Web.Config
Ok, but if web.config is stored in memory and the site has tons of visits, is this good for performance?
Meta Tags
can you give me an example on how to use ASP.NET cache object to store META-TAGS?
In this case with a lot of visits is also better to use cache instead of access to database on every request?
The cache object is for every user/session on all the users share that object? It'd be better that all the users use the same cache object. This way the firsat one access to the database and the rest get the cache object. Is possible to do this way?
Thanks a lot for you answers
Is it possible to clear the output cache of one asp.net web application from inside another asp.net web application?
Reason being... We have several wep applications structured like...
http://www.website.com/intranet/cms/
http://www.website.com/area1/
http://www.website.com/area2/
Pages in /area1/ and /area2/ are cached and are managed through /intranet/cms/. When a page is edited using /intranet/cms/ I want to clear it out of the cache in the appropriate /area#/ application.
I already tried using a VaryByCustom that looks up a guid stored in the HttpContext.Cache but that seems to be cached per web application, that doesn't work.
Really if there were any way of passing data between web applications on a single server, that would solve my problem, since I can use that + VaryByCustom.
Thanks!
-Mike Thomas
The way I've done this in the past is to have a "hidden" page (in each of the /areaX sites) that does the flushing, reloading, etc. The page validates a shared secret query parameter before doing anything (to avoid DoS attacks). If valid the page would output an "OK" message once the operation is complete; generates a 404 error if the secret is invalid.
If you want the flush to be on a per-item or per-group basis then add a second parameter that identifies that item/group.
This method is also server technology independent, and can be triggered by other management tools if required.
One way I know of doing this is by using a shared resource as a dependency, usually a file. When the file is changed, the cache is cleared. I think you can use HttpResponse.AddFileDependency for this.
However, in these cases it's usually better to use an out-of-process cache such as memcached. I haven't tested it myself, but this link deals on using memcached with OutputCache.
What is a good way to edit a Web.config file programmatically?
I looked into System.Xml but couldn't find any obvious answers.
This fellow shows sample code if you still want to do it after all the caveats:
protected void EditConfigButton(object sender, EventArgs e)
{
Configuration objConfig = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("~");
AppSettingsSection objAppsettings = (AppSettingsSection)objConfig.GetSection("appSettings");
//Edit
if (objAppsettings != null)
{
objAppsettings.Settings["test"].Value = "newvalueFromCode";
objConfig.Save();
}
}
One valid reason for editing a web.config is to encrypt it, which is what that article is about.
You can use the WebConfigurationManager to read specific configuration sections. This will return a ConfigurationSection object. You can use this to read/modify the ConfigurationElements in the section. Once you have updated them, you can Save the ConfigurationSection and it will update the file with your changes.
I use this to automatically encrypt the appSettings and connectionStrings on Application_Start if they aren't already encrypted. I haven't actually changed any settings this way, but it seems like you ought to be able to do so.
Saving the updated configuration file may cause the app to recycle depending on how it is built.
Depending on what you are doing, the method is really a bit different in each situation. However the most robust method is to load it as an XmlDocument and modify it as needed via that method, but you MUST be careful to only modify it in the needed manner.
In theory; you could just generate a web config file programmatically and with some templating to make it easy.
However, if you're trying to edit your web.config from within the site; it's highly recommended you don't. At the very least; you'd trigger an app reset every time you updated it; which would be especially bad if you're using in-process sessions.
As Anders asked, what is it you're trying to do?
Yes I agree with Josh. I have tried this before and I've had two negative effects:
Slow loading if the current page after postback because ASP.NET is loading the web.config and all related resources
If you change the web.config early enough in the load cycle (e.g. global.asax events) the site may never load or fail in unpredictable ways
Agree with others, editing the webconfig is achievable, but has knock on effects are just to dangerous / risk involved
If its a value that is application specific, then it should be in an application specific config file
Lot of time you want to modify application specific settings after deployment like say when something is wrong e.g. switching the database connection in case current DB goes down. Moreover sometimes you want to create your own XML based configuration file which you want o modify programatically.
Try XML Webpad - http://xmlwebpad.codeplex.com/
Its a framework to view an edit XML files. Once you integrate it with your web app, editing web.config ill be as simple as viewing the web.config page, making the required changes and hitting the save button (all from within your application).