How to modify Solution/Project object? - c#

I have defined attribute MyAttribute : Attribute that is supposed to be used exactly once within a class (only one constructor per class may have it and it can appear only once on ctor’s attribute list).
I have created a Roslyn analyzer to check this which marks every usage of such attribute (if used more than once) and allows user to pick fixture called "Leave this attribute occurrence and delete all others".
Now within FixProvider I need to return new modified Solution. It's not difficult to modify every Document that requires the fix (by using SyntaxRewriter to modify SyntaxTree inside). However, I have no idea how to modify Solution or Project - they don't have any method like "ReplaceProject"/"ReplaceDocument".
How to do that?

You could replace the text of a document using the following method:
solution = solution.WithDocumentText(currentDocument.Id,
currentDocumentSyntaxTree.GetText());

Related

What's the easiest way to create a managed visualiser in C#?

I have a background in C++ and recently I started working in C#.
I have written following pieces of code (in Visual Studio):
var list_Loads = database.GetData<Load>().ToList();
var test_list = list_Loads.Where(o => (o.Name.Substring(0, 3) == "123")).ToList();
When I run the program and I move my mouse over both lists, first I get the count, which is very useful, but when I ask for the entries, this is what I get:
0 : namespace.Load
1 : namespace.Load
2 : namespace.Load
...
Not very useful, as you can imagine :-)
So my question: how can I show the Name attributes of those objects?
I thought: no problem. I have a background in native visualisers, so it should be rather easy to turn this into useful information, but then it comes:
In order to alter the way that those objects are represented, there is the first proposal to add a [DebuggerDisplay] "tag" to the definition of that class in source code.
However, as those classes are part of a framework I'm just referring to, I don't have access to the source code and hence I can't modify this.
Then I found another solution, which comes down to: "Write an entire C# project, debug, test and install it and it might work" (see documentation on "Custom visualisers of data" on the Microsoft website).
I almost choked in my coffee: writing an entire project, just for altering the view of an object??? (While, in C++, you just create a simple .natvis file, mention the classname and some configuration, launch .nvload and that's it.
Does anybody know a simple way to alter the appearance of C# object, without needing to pass through the whole burden of creating an entire C# project?
By the way, when I try to load a natvis file in Visual Studio immediate window, this is what I get:
.nvload "C:\Temp_Folder\test.natvis"
error CS1525: Invalid expression term '.'
What am I doing wrong?
Thanks in advance
OP (my emphasis):
In order to alter the way that those objects are represented, there is the first proposal to add a [DebuggerDisplay] "tag" to the definition of that class in source code.
However, as those classes are part of a framework I'm just referring to, I don't have access to the source code and hence I can't modify this.
Does anybody know a simple way to alter the appearance of C# object, without needing to pass through the whole burden of creating an entire C# project?
If you just want to specify [DebuggerDisplay] on a type, you don't have to have access to the source code. You can make use of [assembly:DebuggerDisplay()] and control how a type appears in the debugger. The only downside is that [assembly:DebuggerDisplay()] naturally only affects the current assembly whose code your mouse is hovering over. If you wish to use the customised display in other assemblies that you own, then you must repeat the [assembly:DebuggerDisplay()] definition.
Here's an easy before-and-after example with DateTime. I picked DateTime because we generally don't have access to the source code and it has some interesting properties:
var items = new List<DateTime>
{
DateTime.Now.AddDays(-2),
DateTime.Now.AddDays(-1),
DateTime.Now
};
...which on my machine defaults to:
Maybe I'm fussy and I just want to see:
Day of the week and
Day of the year
...I can do that via:
using System.Diagnostics;
[assembly: DebuggerDisplay("{DayOfWeek} {DayOfYear}", Target = typeof(DateTime))]
...which results in:
Example:
namespace DebuggerDisplayTests
{
public class DebuggerDisplayTests
{
public DebuggerDisplayTests()
{
var items = new List<DateTime>
{
DateTime.Now.AddDays(-2),
DateTime.Now.AddDays(-1),
DateTime.Now
};
}
}
.
.
.
}
Overrides
[assembly:DebuggerDisplay()] can also be used as a means to override pre-existing [DebuggerDisplay] on a 3-rd party type. Don't like what style they have chosen? Is the type showing far too much information? Change it with [assembly:DebuggerDisplay()].

Having the same attribute on multiple places (NOT copy paste methodd)

I need to have the same attribute on properties of different classes, e.g. :
[Display( Name = "Last Name" )]
is there a way not to copy paste the same line on different classes/interfaces? instead have a construct that refers to that line and copy paste the reference everywhere instead?
You probably will find AOP helpfull. Search for best framework yourself.
you could create a script in something simple like ruby or powershell to add in that line in the same place on every page, or to add it after a regex match. A simpler method would be to create a parent class and have every class you want to implement this attribute extend the parent class.
If you end up needing to make the same change in so many places that copy and pasting is too much work, then you should look at your project and try to decide if a relationship exists there or if there truly are that many unrelated fields that end up having the same value
I ended up using a constant instead:
[Display( Name = Constants.LastName )]
where Constants.LastName = "Last Name" ); is a defined string constant.

T4 Text Templates Pass object to included Template

I am using Preprocessed Text Templates (.tt) . How can I pass object to another included Preprocessed Text Template? I checked the documentation but didn't find any sample to do that.
Thanks
If you look at the generated code from your preprocessed template, you'll see that it is just a partial class. A great way to pass in data is simply to add another partial of the class, and provide a member and Getter/Setter pair for it. If you then include some further code in that preprocessed template, it will contribute to the same class, so your added member will still be available. If on the other hand, your included code is just class feature clocks (<#+ #>), then you'll likely be defining methods that you can call, in which case you can simply add your data to pass as an extra parameter to those methods.

Move method to new file and keep it in the same class(make it partial)

I have a lot of classes with several methods.
And i need to separate each method of the class in its own file, but kept they in the same class( make it partial).
Exploring the R# 6.1 options i haven't found linear possibility. May be there are hidden options?
Thanks
Added:
This refactoring is not usual because this code is UI tests, that grouped in class by the part of functionality.
We need to separate them to be able to work on them separately from source control.
I'm using ReSharper 5.1 and do not know such refatoring in one step.
The fastest way I know is:
Create partial classes
Write a second declaration of partial class with empty body and copy/paste or
double (Ctl+D) it so often as the count of different files should be.
Create files
Go to every class declaration, press Ctrl+Shift+R and select Move To Another File...,
enter a new file name and press OK.
Move methods
Do for every method to move: Go to method, press Alt+Enter,
select Move declaration(s) to another type part and select file.

C# property attributes

I have seen the following code:
[DefaultValue(100)]
[Description("Some descriptive field here")]
public int MyProperty{...}
The functionality from the above snippit seems clear enough, I have no idea as to how I can use it to do useful things. Im not even sure as to what name to give it!
Does anyone know where I can find more information/a tutorial on these property attributes?
I would be also interested in any novel / useful tasks this feature can do.
The functionality from the above
snippit seems clear enough,
Maybe not, as many people think that [DefaultValue()] sets the value of the property. Actually, all it does to tell some visual designer (e.g. Visual Studio), what the code is going to set the default value to. That way it knows to bold the value in the Property Window if it's set to something else.
People have already covered the UI aspect - attributes have other uses, though... for example, they are used extensively in most serialization frameworks.
Some attributes are given special treatment by the compiler - for example, [PrincipalPermission(...)] adds declarative security to a method, allowing you to (automatically) check that the user has suitable access.
To add your own special handling, you can use PostSharp; there are many great examples of using PostSharp to do AOP things, like logging - or just code simplification, such as with automatic INotifyPropertyChanged implementation.
They are called Attributes, there is a lot of information in msdn, e.g. http://msdn.microsoft.com/en-us/library/z0w1kczw.aspx
In general they don't "do" anything on their own, they are used by some other code that will use your class. XmlSerialization is a good example: XmlSerializer (provided by Microsoft as part of the framework) can almost any class (there are a number of requirements on the class though) - it uses reflection to see what data is contained in the class. You can use attributes (defined together with XmlSerializer) to change the way XmlSerializer will serialize your class (e.g. tell it to save the data as attribute instead of an element).
The ones in your example is used by the visual designer (i.e. MS Expression Blend and Visual Studio designer) to give hints in the designer UI.
Note that they are metadata and will not affect the property logic. Setting DefaultValue for instance will not set the property to that value by default, you have to do that manually.
If you for some reason want to access these attributes, you would have to use reflection.
See MSDN for more information about designer attributes.
We use it to define which graphical designer should be loaded to configure
an instance of a specific type.
That is to say, we have a kind of workflow designer which loads all possible command
types from an assembly. These command types have properties that need to be configured,
so every command type has the need for a different designer (usercontrol).
For example, consider the following command type (called a composite in our solution)
[CompositeMetaData("Delay","Sets the delay between commands",1)]
[CompositeDesigner(typeof(DelayCompositeDesigner))]
public class DelayComposite : CompositeBase
{
// code here
}
This is information is used in two places
1) When the designer creates a list of commands, it uses the CompositeMetaData
to display more information about the command.
2) When the user adds a command to the designer and the designer creates
an instance of that class, it looks at the CompositeDesigner property,
creates a new instance of the specified type (usercontrol) and adds it
to the visual designer.
Consider the following code, we use to load the commands into our "toolbar":
foreach (Type t in assembly.GetExportedTypes())
{
Console.WriteLine(t.Name);
if (t.Name.EndsWith("Composite"))
{
var attributes = t.GetCustomAttributes(false);
ToolboxListItem item = new ToolboxListItem();
CompositeMetaDataAttribute meta = (CompositeMetaDataAttribute)attributes
.Where(a => a.GetType() == typeof(Vialis.LightLink.Attributes.CompositeMetaDataAttribute)).First();
item.Name = meta.DisplayName;
item.Description = meta.Description;
item.Length = meta.Length;
item.CompositType = t;
this.lstCommands.Items.Add(item);
}
}
As you can see, for every type in the assembly of which the name ends with "Composite",
we get the custom attributes and use that information to populate our ToolboxListItem instance.
As for loading the designer, the attribute is retreived like this:
var designerAttribute = (CompositeDesignerAttribute)item.CompositType.GetCustomAttributes(false)
.Where(a => a.GetType() == typeof(CompositeDesignerAttribute)).FirstOrDefault();
This is just one example of how you might be able to use custom attributes,
I hope this gives you a place to start.
These attributes customize the design time experience.
http://msdn.microsoft.com/en-us/library/a19191fh.aspx

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