[cross_file] An abstraction to allow working with files across multiple platforms.

[mvanbeusekom]

Description

This PR copies the x_file type from the file_selector package into its own package. This will allow us to easily reuse this cross platform file abstraction in other plugins that are dealing with files, without having to duplicate the code.

At the moment there is a requirement to use this type in the camera plugin to be able to add the web implementation (suggestion to use x_file originated from @ditman, see here). Additional interest has been shown to use it in the image_picker plugin and cache_manager package.

Note: I took the liberty of renaming XFile to CrossFile since a package with the name "XFile" already exists on pub.dev but with a different purpose.

If this PR is accepted and the package is published, I will make sure to also migrate the file_selector plugin to use this new package and delete the internal implementation.

Checklist

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• My PR includes unit or integration tests for all changed/updated/fixed behaviors (See Contributor Guide).
• All existing and new tests are passing.
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• The title of the PR starts with the name of the plugin surrounded by square brackets, e.g. [shared_preferences]
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Breaking Change

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• Yes, this is a breaking change (please indicate a breaking change in CHANGELOG.md and increment major revision).
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[ditman]

Is there a way that we can preserve @jasonpanelli's authorship on this package? Can we maybe add him as a co-author of one of your commits, and then ensure that when we merge he stays as a co-author?

Thanks!

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[mvanbeusekom]

@googlebot I consent.

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[mvanbeusekom]

@ditman thanks for the review. I have added the missing copyrights and immediately added @jasonpanelli as co-author. This however resulted in the CLA step failing since Jason now needs to also give his consent (which makes sense, but didn't think about it earlier).

Also I did a git mv when copying all files from the file_selector plugin, so if one would run for example git log --follow packages/cross-file/lib/src/types/base.dart you can still see the full history including all commits by @jasonpanelli.

[ditman]

Thanks for the extra effort @mvanbeusekom!

@jasonpanelli, when you have time, can you please tell googlebot you consent to this change? Thanks!

[ditman]

/cc @tugorez can you please also take a look at the new CrossFile, and see if it fits future usages or the ability to add extra metadata? Thanks!!

[ditman]

Quick note @mvanbeusekom: there's already some implementations coming for the file_selector plugin example.

I understand that the package name conflicts with something already in pub, and I think CrossFile is a good name for it; but could we maintain the name of the class that this package exports as XFile, so we can introduce the new package through the platform_interface in a backwards-compatible way?

(If we decide to go through with naming the class CrossFile, we'd need to bump the major version of the platform_interface package interface to introduce the new class name; this bump cascades to the implementations as well, because those would have an implementation that return an XFile, which then gets migrated to CrossFile)

[google-cla]

All (the pull request submitter and all commit authors) CLAs are signed, but one or more commits were authored or co-authored by someone other than the pull request submitter.

We need to confirm that all authors are ok with their commits being contributed to this project. Please have them confirm that by leaving a comment that contains only @googlebot I consent. in this pull request.

Note to project maintainer: There may be cases where the author cannot leave a comment, or the comment is not properly detected as consent. In those cases, you can manually confirm consent of the commit author(s), and set the cla label to yes (if enabled on your project).

ℹ️ Googlers: Go here for more info.

[mvanbeusekom]

Quick note @mvanbeusekom: there's already some implementations coming for the file_selector plugin example.

I understand that the package name conflicts with something already in pub, and I think CrossFile is a good name for it; but could we maintain the name of the class that this package exports as XFile, so we can introduce the new package through the platform_interface in a backwards-compatible way?

(If we decide to go through with naming the class CrossFile, we'd need to bump the major version of the platform_interface package interface to introduce the new class name; this bump cascades to the implementations as well, because those would have an implementation that return an XFile, which then gets migrated to CrossFile)

This is a good point. I have renamed the classes (and file names) back to XFile while keeping the package name CrossFile.

[ditman]

(I've pinged @jasonpanelli to get his approval!)

[google-cla]

All (the pull request submitter and all commit authors) CLAs are signed, but one or more commits were authored or co-authored by someone other than the pull request submitter.

We need to confirm that all authors are ok with their commits being contributed to this project. Please have them confirm that by leaving a comment that contains only @googlebot I consent. in this pull request.

Note to project maintainer: There may be cases where the author cannot leave a comment, or the comment is not properly detected as consent. In those cases, you can manually confirm consent of the commit author(s), and set the cla label to yes (if enabled on your project).

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[jasonpanelli]

@googlebot I consent.

[ditman]

Ah yes, I forgot to mention this check:

* The name of "lib/x_file.dart", "x_file", should match the name of the package, "cross_file".
  This helps users know what library to import.

[mvanbeusekom]

Ah yes, I forgot to mention this check:

* The name of "lib/x_file.dart", "x_file", should match the name of the package, "cross_file".
  This helps users know what library to import.

Should be fixed now, CI is all green

[ditman]

This is going to be great. If there's any issue with the merge, feel free to add me to the CODEOWNERS for this package!

[ditman]

Note to all: package: cross_file is now a thing:

https://pub.dev/packages/cross_file