I'm writing a CmdLet in C# and use the Powershell-Class and invoke different commands. Here my Code:
PowerShell poswershell;
public Construcor()
{
powershell = PowerShell.Create()
}
public Collection<PSObject> InvokeRestMethod(string uri)
{
return InvokePSCommand("Invoke-RestMethod", new[] { uri });
}
public Collection<PSObject> InvokePSCommand(string command, string[] args)
{
var execute = command;
execute = GetExecuteCommand(args, execute);
powershell.Commands.AddScript(execute);
return powershell.Invoke();
}
private static string GetExecuteCommand(string[] args, string execute)
{
if (args == null) return execute;
for (var i = 0; i < args.Count(); i++)
{
execute += " " + args[i];
}
return execute;
}
It works like I want, but really slowly. I want the same function, which gives me a Collection<PSObject> back. But when I call the InvokeRestMehtod several times, it takes a long time to get trough this.
Why I use this just for a simple WebRequest you ask?
The answer is, that I have to read from an uri (which returns json) some information. Fact is that the json structure is always different. Therefor the Invoke-RestMehtod gives me exactly what I need, a dynamic object(PSObject). I have to have this kind of object, because after that process I need to give this in the powershell user back, so he can pipeline the object and use it furhter.
My question is now, how could I get the same result, which I can pass into powershell, from an uri which return json?
EDIT
I found this dll=> Microsoft.PowerShell.Commands.Utility.dll, it includes in C# code the InvokeRestMethod-CmdLet what is called by the powershell. If I could read this code well, I could (would) use it in my code. Then I wouldn't create a PowerShell instance and invoke from my powershell-CmdLet an other CmdLet, which I do not like much and takes a way too long. Someone knows this dll and could help me to customize this code for my project?
I found dottrace and analyzed the process, here a screenshot I can't get any useful information out of that, perhaps someone of you? But I'm pretty sure Powershell.Invoke() takes most of the time while executing.
Why don't you reuse the same PowerShell object rather than create a new one each time? Each instantiation causes the PowerShell to have to initialize again. Just be sure to call powershell.Commands.Clear() between Invoke() calls.
I solved the problem now, here is the basic code which reads an uri (returns JSON) and returns an object:
private object InvokeRest(string uri)
{
return InvokeRest(uri, null);
}
private object InvokeRest(string uri, NetworkCredential networkCredential)
{
var webRequest = WebRequest.Create(uri);
if (networkCredential!=null)
webRequest.Credentials = networkCredential;
_webResponse = webRequest.GetResponse();
var streamReader = new StreamReader(_webResponse.GetResponseStream());
var str = streamReader.ReadToEnd();
ErrorRecord exRef;
var doc = JsonObject.ConvertFromJson(str, out exRef);
return doc;
}
Because I found out that every object you output in the powershell, converts in a PSObject and formats it.
Related
Hi I am trying to use C# reflection to call a method that is passed a parameter and in return passes back a result. How can I do that? I've tried a couple of things but with no success. I'm used to PHP and Python where this can be done on a single line so this is very confusing to me.
In essence this is how the call would be made without reflection:
response = service.CreateAmbience(request);
request has these objects:
request.UserId = (long)Constants.defaultAmbience["UserId"];
request.Ambience.CountryId = (long[])Constants.defaultAmbience["CountryId"];
request.Ambience.Name.DefaultText = (string)Constants.defaultAmbience["NameDefaultText"];
request.Ambience.Name.LanguageText = GetCultureTextLanguageText((string)Constants.defaultAmbience["NameCulture"], (string)Constants.defaultAmbience["NameText"]);
request.Ambience.Description.DefaultText = (string)Constants.defaultAmbience["DescriptionText"];
request.Ambience.Description.LanguageText = GetCultureTextLanguageText((string)Constants.defaultAmbience["DescriptionCulture"], (string)Constants.defaultAmbience["DescriptionDefaultText"]);
This is my function to implement the reflection where serviceAction for the case above would be "CreateAmbience":
public static R ResponseHelper<T,R>(T request, String serviceAction)
{
ICMSCoreContentService service = new ContentServiceRef.CMSCoreContentServiceClient();
R response = default(R);
response = ???
}
Something along the lines of:
MethodInfo method = service.GetType().GetMethod(serviceAction);
object result = method.Invoke(service, new object[] { request });
return (R) result;
You may well want to add checks at each level though, to make sure the method in question is actually valid, that it has the right parameter types, and that it's got the right return type. This should be enough to get you started though.
Here's a quick example of calling an object method by name using reflection:
Type thisType = <your object>.GetType();
MethodInfo theMethod = thisType.GetMethod(<The Method Name>);
theMethod.Invoke(this, <an object [] of parameters or null>);
If you're on .NET 4, use dynamic:
dynamic dService = service;
var response = dService.CreateAmbience(request);
You can use Delegate.CreateDelegate to obtain a delegate to the method by name:
public static R ResponseHelper<T,R>(T request, string serviceAction)
{
var service = new ContentServiceRef.CMSCoreContentServiceClient();
var func = (Func<T,R>)Delegate.CreateDelegate(typeof(Func<T,R>),
service,
serviceAction);
return func(request);
}
I have below command and it returns me null object . When I run the command separately in PowerShell window I get the right result. Below is my PowerShell method which is calling the command and the also the PowerShell command which I have defined. I am basically looking to return a string value. Please let me know what wrong am I doing?
C# method:
public string RunScript( string contentScript, Dictionary<string, EntityProperty> parameters)
{
List<string> parameterList = new List<string>();
foreach( var item in parameters )
{
parameterList.Add( item.Value.ToString() );
}
using( PowerShell ps = PowerShell.Create() )
{
ps.AddScript( contentScript );
// in ContentScript I get "Get-RowAndPartitionKey" on debugging
ps.AddParameters( parameterList );//I get list of strings
IAsyncResult async = ps.BeginInvoke();
StringBuilder stringBuilder = new StringBuilder();
foreach( PSObject result in ps.EndInvoke( async ) )
// here i get result empty in ps.EndInvoke(async)
{
stringBuilder.AppendLine( result.ToString() );
}
return stringBuilder.ToString();
}
}
}
My Powershell GetRowAndPartitionKey cmdlet definition, which the code above is trying to call:
public abstract class GetRowAndPartitionKey : PSCmdlet
{
[Parameter]
public List<string> Properties { get; set; } = new List<string>();
}
[Cmdlet( VerbsCommon.Get, "RowAndPartitionKey" )]
public class GetRowAndPartitionKeyCmd : GetRowAndPartitionKey
{
protected override void ProcessRecord()
{
string rowKey = string.Join( "_", Properties );
string pKey = string.Empty;
WriteObject( new
{
RowKey = rowKey,
PartitionKey = pKey
} );
}
}
}
When using the PowerShell SDK, if you want to pass parameters to a single command with .AddParameter() / .AddParameters() / AddArgument(), use .AddCommand(), not .AddScript()
.AddScript() is for passing arbitrary pieces of PowerShell code that is executed as a script block to which the parameters added with .AddParameters() are passed.
That is, your invocation is equivalent to & { Get-RowAndPartitionKey } <your-parameters>, and as you can see, your Get-RowAndPartitionKey command therefore doesn't receive the parameter values.
See this answer or more information.
Note: As a prerequisite for calling your custom Get-RowAndPartitionKey cmdlet, you may have to explicitly import the module (DLL) that contains it, which you can do:
either: with a separate, synchronous Import-Module call executed beforehand (for simplicity, I'm using .AddArgument() here, with passes an argument positionally, which binds to the -Name parameter (which also accepts paths)):
ps.AddCommand("Import-Module").AddArgument(#"<your-module-path-here>").Invoke();
or: as part of a single (in this case asynchronous) invocation - note the required .AddStatement() call to separate the two commands:
IAsyncResult async =
ps.AddCommand("Import-Module").AddArgument(#"<your-module-path-here>")
.AddStatement()
.AddCommand("GetRowAndPartitionKey").AddParameter("Properties", parameterList)
.BeginInvoke();
"<your-module-path-here>" refers to the full file-system path of the module that contains the Get-RowAndPartitionKey cmdlet; depending on how that module is implemented, it is either a path to the module's directory, its .psd1 module manifest, or to its .dll, if it is a stand-alone assembly.
Alternative import method, using the PowerShell SDK's dedicated .ImportPSModule() method:
This method obviates the need for an in-session Import-Module call, but requires extra setup:
Create a default session state.
Call .ImportPSModule() on it to import the module.
Pass this session state to PowerShell.Create()
var iss = InitialSessionState.CreateDefault();
iss.ImportPSModule(new string[] { #"<your-module-path-here>" });
var ps = PowerShell.Create(iss);
// Now the PowerShell commands submitted to the `ps` instance
// will see the module's exported commands.
Caveat: A PowerShell instance reflects its initial session state in .Runspace.InitialSessionState, but as a conceptually read-only property; the tricky part is that it is technically still modifiable, so that mistaken attempts to modify it are quietly ignored rather than resulting in exceptions.
To troubleshoot these calls:
Check ps.HadErrors after .Invoke() / .EndInvoke() to see if the PowerShell commands reported any (non-terminating) errors.
Enumerate ps.Streams.Errors to inspect the specific errors that occurred.
See this answer to a follow-up question for self-contained sample code that demonstrates these techniques.
What am I doing wrong here? I have the following that actually calls the PowerCLI commands via PowerShell that then returns the data via c# to asp.net. I am not getting any data returned from this even though the command looks correct. Any ideas?
public List<string> ReturnVMsToStrings(string VCENTER_NAME, PSCredential credential)
{
InitialSessionState PS_ISS;
VI_SERVER_NAME = VCENTER_NAME;
string[] IMPORT_MODULES = { "VMWare.PowerCLI", "NimblePowerShellToolkit" };
PS_ISS = InitialSessionState.CreateDefault();
PS_ISS.ImportPSModule(IMPORT_MODULES);
PowerShell PSINSTANCE = PowerShell.Create(PS_ISS);
Collection<PSObject> result;
PSINSTANCE.Commands.AddCommand("Connect-VIServer");
PSINSTANCE.Commands.AddParameter("Server", VI_SERVER_NAME);
PSINSTANCE.Commands.AddParameter("Credential", credential);
PSINSTANCE.Invoke();
// Get the VMs
PSINSTANCE.Commands.AddCommand("Get-VM");
result = PSINSTANCE.Invoke();
List<string> sorted_list = new List<string>();
if (result.Count > 0)
{
foreach (PSObject obj in result)
{
sorted_list.Add(obj.Properties["Name"].Value.ToString());
}
sorted_list.Sort();
}
else
{
Exception e = new Exception("Result is empty");
throw e;
}
return sorted_list;
}
Result has no data in it. Running this command from PowerShell returns a bunch of objects from my vCenter. This is really odd with no real reason why this is not working so any pointers would help.
The code was fine. What wasn't happy was the variable passing through within the asp. Net session. Viewstate to the rescue. Thanks everyone for taking the time to answer.
You're calling PSINSTANCE.Invoke() twice, remove the first call and retry.
The only solution I could find was using:
mshtml.HTMLDocument htmldocu = new mshtml.HTMLDocument();
htmldocu .createDocumentFromUrl(url, "");
and I am not sure about the performance, it should be better than loading the html file in a WebBrowser and then grab the HtmlDocument from there. Anyhow, that code does not work on my machine. The application crashes when it tries to execute the second line.
Has anyone an approach to achieve this efficiently or any other way?
NOTE: Please understand that I need the HtmlDocument object for DOM processing. I do not need the html string.
Use the DownloadString method of the WebClient object. e.g.
WebClient client = new WebClient();
string reply = client.DownloadString("http://www.google.com");
In the above example, after executed, reply will contain the html markup of the endpoint http://www.google.com.
WebClient.DownloadString MSDN
In an attempt to answer your actual question from four years ago (at the time of me posting this answer), I'm providing a working solution. I wouldn't be surprised if you found another way to do this, either, so this is mostly for other people searching for a similar solution. Keep in mind, however, that this is considered
somewhat obsolete (the actual use of HtmlDocument)
not the best way to handle HTML DOM parsing (the preferred solution is to use HtmlAgilityPack or CsQuery or some other method using actual parsing and not regular expressions)
extremely hacky and therefore not the safest/most compatible way to do it
you really should not be doing what I'm about to show
Additionally, keep in mind that HtmlDocument is really just a wrapper for mshtml.HTMLDocument2, so it is technically slower than just using a COM wrapper directly, but I completely understand the use case simply for ease of coding.
If you're cool with all of the above, here's how to accomplish what you want.
public class HtmlDocumentFactory
{
private static Type htmlDocType = typeof(System.Windows.Forms.HtmlDocument);
private static Type htmlShimManagerType = null;
private static object htmlShimSingleton = null;
private static ConstructorInfo docCtor = null;
public static HtmlDocument Create()
{
if (htmlShimManagerType == null)
{
// get a type reference to HtmlShimManager
htmlShimManagerType = htmlDocType.Assembly.GetType(
"System.Windows.Forms.HtmlShimManager"
);
// locate the necessary private constructor for HtmlShimManager
var shimCtor = htmlShimManagerType.GetConstructor(
BindingFlags.NonPublic | BindingFlags.Instance, null, new Type[0], null
);
// create a new HtmlShimManager object and keep it for the rest of the
// assembly instance
htmlShimSingleton = shimCtor.Invoke(null);
}
if (docCtor == null)
{
// get the only constructor for HtmlDocument (which is marked as private)
docCtor = htmlDocType.GetConstructors(
BindingFlags.NonPublic | BindingFlags.Instance
)[0];
}
// create an instance of mshtml.HTMLDocument2 (in the form of
// IHTMLDocument2 using HTMLDocument2's class ID)
object htmlDoc2Inst = Activator.CreateInstance(Type.GetTypeFromCLSID(
new Guid("25336920-03F9-11CF-8FD0-00AA00686F13")
));
var argValues = new object[] { htmlShimSingleton, htmlDoc2Inst };
// create a new HtmlDocument without involving WebBrowser
return (HtmlDocument)docCtor.Invoke(argValues);
}
}
To use it:
var htmlDoc = HtmlDocumentFactory.Create();
htmlDoc.Write("<html><body><div>Hello, world!</body></div></html>");
Console.WriteLine(htmlDoc.Body.InnerText);
// output:
// Hello, world!
I have not tested this code directly -- I have translated it from an old Powershell script that needed the same functionality you're requesting. If it fails, let me know. The functionality is there but the code might need very minor tweaking to get working.
In my WinForms application I need to call javascript function from my WebBrowser control. I used Document.InvokeScript and it works perfect with functions alone e.g
Document.InvokeScript("function").
But when i want to call javascript object method e.g.
Document.InvokeScript("obj.method")
it doesn't work. Is there a way to make it work? Or different solution to this problem? Without changing anything in the javascript code!
Thanks in advance :)
The example in the documentation does NOT include the parenthesis.
private void InvokeScript()
{
if (webBrowser1.Document != null)
{
HtmlDocument doc = webBrowser1.Document;
String str = doc.InvokeScript("test").ToString() ;
Object jscriptObj = doc.InvokeScript("testJScriptObject");
Object domOb = doc.InvokeScript("testElement");
}
}
Try
Document.InvokeMethod("obj.method");
Note that you can pass arguments if you use HtmlDocument.InvokeScript Method (String, Object[]).
Edit
Looks like you aren't the only one with this issue: HtmlDocument.InvokeScript - Calling a method of an object . You can make a "Proxy function" like the poster of that link suggests. Basically you have a function that invokes your object's function. It's not an ideal solution, but it'll definitely work. I'll continue looking to see if this is possible.
Another post on same issue: Using WebBrowser.Document.InvokeScript() to mess around with foreign JavaScript . Interesting solution proposed by C. Groß on CodeProject:
private string sendJS(string JScript) {
object[] args = {JScript};
return webBrowser1.Document.InvokeScript("eval",args).ToString();
}
You could make that an extension method on HtmlDocument and call that to run your function, only using this new function you WOULD include parenthesis, arguments, the whole nine yards in the string you pass in (since it is just passed along to an eval).
Looks like HtmlDocument does not have support for calling methods on existing objects. Only global functions. :(
Unfortunately you can't call object methods out of the box using WebBrowser.Document.InvokeScript.
The solution is to provide a global function on the JavaScript side which can redirect your call. In the most simplistic form this would look like:
function invoke(method, args) {
// The root context is assumed to be the window object. The last part of the method parameter is the actual function name.
var context = window;
var namespace = method.split('.');
var func = namespace.pop();
// Resolve the context
for (var i = 0; i < namespace.length; i++) {
context = context[namespace[i]];
}
// Invoke the target function.
result = context[func].apply(context, args);
}
In your .NET code you would use this as follows:
var parameters = new object[] { "obj.method", yourArgument };
var resultJson = WebBrowser.Document.InvokeScript("invoke", parameters);
As you mention that you cannot change anything to your existing JavaScript code, you'll have to inject the above JavaScript method in some how. Fortunately the WebBrowser control can also do for you by calling the eval() method:
WebBrowser.Document.InvokeScript("eval", javaScriptString);
For a more robust and complete implementation see the WebBrowser tools I wrote and the article explaining the ScriptingBridge which specifically aims to solve the problem you describe.
webBrowser.Document.InvokeScript("execScript", new object[] { "this.alert(123)", "JavaScript" })
for you supposed to be like this
webBrowser.Document.InvokeScript("execScript", new object[] { "obj.method()", "JavaScript" })