[Feature Request]: Common Task for Creating and Modifying URIs (BuildUri)

[jrdodds]

Summary

A common task that can create and modify collections of URIs.

This issue is replacing the "Proposed 'BuildUri' Common Task" discussion.

A PR will be added to this issue with a proposed implementation. [Update: PR is #8614]

Background and Motivation

There is an existing FormatUrl task that can accept and output a string. FormatUrl is a specialized task that was written for a specific use case. It canonicalizes a URL and will replace 'localhost' with the current machine name. Replacing 'localhost' can easily be counter-productive for many scenarios including creating a test configuration that is meant to be distributed to multiple hosts and run locally.

FormatUrl doesn't support general construction and modification of URIs and there isn't other support currently provided in MSBuild.

A project that needs to generate or manipulate a URI may use string functions, a custom task, or an external script or tool. All three of these approaches can be flawed if the code used doesn't correctly understand URIs.

Proposed Feature

The BuildUri task wraps the UriBuilder class and operates on Item collections. Providing useful access to the UriBuilder class is new¹. Providing for Item collections makes the task very flexible.

BuildUri has an optional input parameter for an ItemGroup of URIs (InputUri), a set of optional input parameters that map to the properties of UriBuilder, and an output parameter for an ItemGroup of URIs (OutputUri).

For an empty set of InputUri, the other input parameters are used to create a new URI.

For a set of 1 or more InputUri, the other input parameters are applied to each member of the set, e.g. a set of http URIs can be changed to used https.

For the OutputUri, each item is set with custom metadata that reflects the properties of the UriBuilder class. A set of URIs could be passed through the BuildUri task to add the metadata and the results could then be task or target batched by the added metadata, e.g. the collection could be batched by UriScheme.

Creating a URI might look like the following:

    <BuildUri UriScheme="https" UriHost="example.com" UriPath="test">
      <Output TaskParameter="OutputUri" PropertyName="ExampleUri" />
    </BuildUri>

Creating URIs for a set of hosts might look like the following:

    <ItemGroup>
      <template Include="http://example.com/" />
      <template Include="http://example.com/api" />
      <template Include="http://example.com/config" />
      <host Include="dev01-01;dev01-02;dev02-01;dev02-02" />
    </ItemGroup>
    <BuildUri InputUri="@(template)" UriScheme="https" UriHost="%(host.Identity)">
      <Output TaskParameter="OutputUri" ItemName="node" />
    </BuildUri>

Alternative Designs

No response

Footnotes

1. System.UriBuilder is a supported type for static property functions but doesn't have any public static members. ↩

[AR-May]

Team triage: Let's keep this issue open and see if there is community interest in it.