threads / patch / 39412

patchsubmodule documentation: Reorder introductory paragraphs

Subject: [PATCH] submodule documentation: Reorder introductory paragraphs

## tl;dr

5 messages between May 22, 2015 and May 26, 2015. Diffs are folded; open one to read it.

replies: 4people: 4as markdown or json

Stefan Beller· May 22, 2015, 19:38 UTC · lore

It's better to start the man page with a description of what submodules actually are instead of saying what they are not.

Reorder the paragraphs such that the first short paragraph introduces the submodule concept, the second paragraph highlights the usage of the submodule command, the third paragraph giving background information, and finally the fourth paragraph discusing alternatives such as subtrees and remotes, which we don't want to be confused with.

This ordering deepens the knowledge on submodules with each paragraph. First the basic questions like "How/what" will be answered, while the underlying concepts will be taught at a later time.

Making sure it is not confused with subtrees and remotes is not really enhancing knowledge of submodules itself, but rather painting the big picture of git concepts, so you could also argue to have it as the second paragraph. Personally I think this may confuse readers, specially newcomers though.

Additionally to reordering the paragraphs, they have been slightly reworded.

Signed-off-by: Stefan Beller <sbeller@google.com>
---
For now I used a part of Junios suggestion
    Submodules are not to be confused with remotes, which are other
    repositories of the same project;
    
I like the "are not to be confused" part, as they warn the reader
that there will be a paragraph not as concise but touching other
commands and topics.
 Documentation/git-submodule.txt | 50 ++++++++++++++++++-----------------------
 1 file changed, 22 insertions(+), 28 deletions(-)
Show changes to Documentation/git-submodule.txt +22 −28
diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 2c25916..d126c86 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -25,22 +25,17 @@ SYNOPSIS
 
 DESCRIPTION
 -----------
-Submodules allow foreign repositories to be embedded within
-a dedicated subdirectory of the source tree, always pointed
-at a particular commit.
+This command will inspect, update and manage submodules.
 
-They are not to be confused with remotes, which are meant mainly
-for branches of the same project; submodules are meant for
-different projects you would like to make part of your source tree,
-while the history of the two projects still stays completely
-independent and you cannot modify the contents of the submodule
-from within the main project.
-If you want to merge the project histories and want to treat the
-aggregated whole as a single project from then on, you may want to
-add a remote for the other project and use the 'subtree' merge strategy,
-instead of treating the other project as a submodule. Directories
-that come from both projects can be cloned and checked out as a whole
-if you choose to go that route.
+Submodules allow you to keep another Git repository in a subdirectory
+of your repository. The other repository has its own history, which does not
+interfere with the history of the current repository. This can be used to
+have external dependencies such as libraries for example.
+
+When cloning or pulling a repository containing submodules however,
+these will not be checked out by default; the 'init' and 'update'
+subcommands will maintain submodules checked out and at
+appropriate revision in your working tree.
 
 Submodules are composed from a so-called `gitlink` tree entry
 in the main repository that refers to a particular commit object
@@ -51,19 +46,18 @@ describes the default URL the submodule shall be cloned from.
 The logical name can be used for overriding this URL within your
 local repository configuration (see 'submodule init').
 
-This command will manage the tree entries and contents of the
-gitmodules file for you, as well as inspect the status of your
-submodules and update them.
-When adding a new submodule to the tree, the 'add' subcommand
-is to be used.  However, when pulling a tree containing submodules,
-these will not be checked out by default;
-the 'init' and 'update' subcommands will maintain submodules
-checked out and at appropriate revision in your working tree.
-You can briefly inspect the up-to-date status of your submodules
-using the 'status' subcommand and get a detailed overview of the
-difference between the index and checkouts using the 'summary'
-subcommand.
-
+Submodules are not to be confused with remotes, which are other
+repositories of the same project; submodules are meant for
+different projects you would like to make part of your source tree,
+while the history of the two projects still stays completely
+independent and you cannot modify the contents of the submodule
+from within the main project.
+If you want to merge the project histories and want to treat the
+aggregated whole as a single project from then on, you may want to
+add a remote for the other project and use the 'subtree' merge strategy,
+instead of treating the other project as a submodule. Directories
+that come from both projects can be cloned and checked out as a whole
+if you choose to go that route.
 
 COMMANDS
 --------
-- 
2.4.1.233.g3f9b614.dirty
Philip Oakley· May 22, 2015, 21:18 UTC · re: Stefan Beller · lore

Re: [PATCH] submodule documentation: Reorder introductory paragraphs

From: "Stefan Beller" <sbeller@google.com>
Show 101 quoted lines
> It's better to start the man page with a description of what 
> submodules
> actually are instead of saying what they are not.
>
> Reorder the paragraphs such that
> the first short paragraph introduces the submodule concept,
> the second paragraph highlights the usage of the submodule command,
> the third paragraph giving background information,
> and finally the fourth paragraph discusing alternatives such
> as subtrees and remotes, which we don't want to be confused with.
>
> This ordering deepens the knowledge on submodules with each paragraph.
> First the basic questions like "How/what" will be answered, while the
> underlying concepts will be taught at a later time.
>
> Making sure it is not confused with subtrees and remotes is not really
> enhancing knowledge of submodules itself, but rather painting the big
> picture of git concepts, so you could also argue to have it as the 
> second
> paragraph. Personally I think this may confuse readers, specially
> newcomers though.
>
> Additionally to reordering the paragraphs, they have been slightly
> reworded.
>
> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
>
> For now I used a part of Junios suggestion
>    Submodules are not to be confused with remotes, which are other
>    repositories of the same project;
>
> I like the "are not to be confused" part, as they warn the reader
> that there will be a paragraph not as concise but touching other
> commands and topics.
>
> Documentation/git-submodule.txt | 50 
> ++++++++++++++++++-----------------------
> 1 file changed, 22 insertions(+), 28 deletions(-)
>
> diff --git a/Documentation/git-submodule.txt 
> b/Documentation/git-submodule.txt
> index 2c25916..d126c86 100644
> --- a/Documentation/git-submodule.txt
> +++ b/Documentation/git-submodule.txt
> @@ -25,22 +25,17 @@ SYNOPSIS
>
> DESCRIPTION
> -----------
> -Submodules allow foreign repositories to be embedded within
> -a dedicated subdirectory of the source tree, always pointed
> -at a particular commit.
> +This command will inspect, update and manage submodules.
>
> -They are not to be confused with remotes, which are meant mainly
> -for branches of the same project; submodules are meant for
> -different projects you would like to make part of your source tree,
> -while the history of the two projects still stays completely
> -independent and you cannot modify the contents of the submodule
> -from within the main project.
> -If you want to merge the project histories and want to treat the
> -aggregated whole as a single project from then on, you may want to
> -add a remote for the other project and use the 'subtree' merge 
> strategy,
> -instead of treating the other project as a submodule. Directories
> -that come from both projects can be cloned and checked out as a whole
> -if you choose to go that route.
> +Submodules allow you to keep another Git repository in a subdirectory
> +of your repository. The other repository has its own history, which 
> does not
> +interfere with the history of the current repository. This can be 
> used to
> +have external dependencies such as libraries for example.
> +
> +When cloning or pulling a repository containing submodules however,
> +these will not be checked out by default; the 'init' and 'update'
> +subcommands will maintain submodules checked out and at
> +appropriate revision in your working tree.
>
> Submodules are composed from a so-called `gitlink` tree entry
> in the main repository that refers to a particular commit object
> @@ -51,19 +46,18 @@ describes the default URL the submodule shall be 
> cloned from.
> The logical name can be used for overriding this URL within your
> local repository configuration (see 'submodule init').
>
> -This command will manage the tree entries and contents of the
> -gitmodules file for you, as well as inspect the status of your
> -submodules and update them.
> -When adding a new submodule to the tree, the 'add' subcommand
> -is to be used.  However, when pulling a tree containing submodules,
> -these will not be checked out by default;
> -the 'init' and 'update' subcommands will maintain submodules
> -checked out and at appropriate revision in your working tree.
> -You can briefly inspect the up-to-date status of your submodules
> -using the 'status' subcommand and get a detailed overview of the
> -difference between the index and checkouts using the 'summary'
> -subcommand.
> -
> +Submodules are not to be confused with remotes, which are other
> +repositories of the same project;

I said (22 May 2015 20:47): "if a nice well understood explanatory phrase can be found " - I'm happy with yours. Many thanks

Show 19 quoted lines
>                                        submodules are meant for
> +different projects you would like to make part of your source tree,
> +while the history of the two projects still stays completely
> +independent and you cannot modify the contents of the submodule
> +from within the main project.
> +If you want to merge the project histories and want to treat the
> +aggregated whole as a single project from then on, you may want to
> +add a remote for the other project and use the 'subtree' merge 
> strategy,
> +instead of treating the other project as a submodule. Directories
> +that come from both projects can be cloned and checked out as a whole
> +if you choose to go that route.
>
> COMMANDS
> --------
> -- 
> 2.4.1.233.g3f9b614.dirty
>
> --
Philip 
Junio C Hamano· May 25, 2015, 22:00 UTC · re: Stefan Beller · lore

Re: [PATCH] submodule documentation: Reorder introductory paragraphs

Stefan Beller <sbeller@google.com> writes:
Show 6 quoted lines
>  DESCRIPTION
>  -----------
> +This command will inspect, update and manage submodules.
>  
> +Submodules allow you to keep another Git repository in a subdirectory
> +of your repository. The other repository has its own history,...

The first line somehow bothered me, so I took a random sample of commands I often use:

    git log
       Shows the commit logs.
    git show
       Shows one or more objects (blobs, trees, tags and commits).
    git commit
       Stores the current contents of the index in a new commit along with a
       log message from the user describing the changes.
    git diff
       Show changes between the working tree and the index or a tree, changes
       between the index and a tree, changes between two trees, changes
       between two blob objects, or changes between two files on disk.
    git push
       Updates remote refs using local refs, while sending objects necessary
       to complete the given refs.

I _think_ what bothered me was "This command" (drawing the reaction "eh, what other command are you going to talk about in the help page for this command?"). Perhaps

    Inspects, updates and manages submodules.
may match the style of other help pages better.

On the other hand, I probably would not have felt such a strong "strangeness" if it were described like this:

    This command can help you inspect, update, and manage
    submodules.

I haven't analized it enough to say why it is, but I suspect it has something to do with (my own) perception that "git submodule" is not very essential to do any of these things (i.e. .gitmodules is a very simple text file), but is primarily a helpful wrapper.

The description of "git config", on which I have a similar perception, seem to match ;-)

    git config
       You can query/set/replace/unset options with this command.
Stefan Beller· May 26, 2015, 17:53 UTC · re: Junio C Hamano · lore

Re: [PATCH] submodule documentation: Reorder introductory paragraphs

On Mon, May 25, 2015 at 3:00 PM, Junio C Hamano <gitster@pobox.com> wrote:
Show 38 quoted lines
> Stefan Beller <sbeller@google.com> writes:
>
>>  DESCRIPTION
>>  -----------
>> +This command will inspect, update and manage submodules.
>>
>> +Submodules allow you to keep another Git repository in a subdirectory
>> +of your repository. The other repository has its own history,...
>
> The first line somehow bothered me, so I took a random sample of
> commands I often use:
>
>     git log
>        Shows the commit logs.
>
>     git show
>        Shows one or more objects (blobs, trees, tags and commits).
>
>     git commit
>        Stores the current contents of the index in a new commit along with a
>        log message from the user describing the changes.
>
>     git diff
>        Show changes between the working tree and the index or a tree, changes
>        between the index and a tree, changes between two trees, changes
>        between two blob objects, or changes between two files on disk.
>
>     git push
>        Updates remote refs using local refs, while sending objects necessary
>        to complete the given refs.
>
> I _think_ what bothered me was "This command" (drawing the reaction
> "eh, what other command are you going to talk about in the help page
> for this command?").  Perhaps
>
>     Inspects, updates and manages submodules.
>
> may match the style of other help pages better.
Sounds much better than my patch.
Show 11 quoted lines
>
> On the other hand, I probably would not have felt such a strong
> "strangeness" if it were described like this:
>
>     This command can help you inspect, update, and manage
>     submodules.
>
> I haven't analized it enough to say why it is, but I suspect it has
> something to do with (my own) perception that "git submodule" is not
> very essential to do any of these things (i.e. .gitmodules is a very
> simple text file), but is primarily a helpful wrapper.

My perception is that the submodule man page similar to the subtree man page tries to explain an underlying concept as well. The other man pages you quoted don't do that as the concepts are explained elsewhere(?)

As a side note: In the Gerrit test suite I use the JGit implementation of the config command to write out .gitmodules files. So maybe `git submodule` can be understood as a specialized form of `git config`.

Show 7 quoted lines
>
> The description of "git config", on which I have a similar
> perception, seem to match ;-)
>
>     git config
>        You can query/set/replace/unset options with this command.
>
Heiko Voigt· May 26, 2015, 21:58 UTC · re: Stefan Beller · lore

Re: [PATCH] submodule documentation: Reorder introductory paragraphs

On Tue, May 26, 2015 at 10:53:15AM -0700, Stefan Beller wrote:
Show 20 quoted lines
> On Mon, May 25, 2015 at 3:00 PM, Junio C Hamano <gitster@pobox.com> wrote:
> > Stefan Beller <sbeller@google.com> writes:
> > On the other hand, I probably would not have felt such a strong
> > "strangeness" if it were described like this:
> >
> >     This command can help you inspect, update, and manage
> >     submodules.
> >
> > I haven't analized it enough to say why it is, but I suspect it has
> > something to do with (my own) perception that "git submodule" is not
> > very essential to do any of these things (i.e. .gitmodules is a very
> > simple text file), but is primarily a helpful wrapper.
> 
> My perception is that the submodule man page similar to the subtree
> man page tries to explain an underlying concept as well. The other man
> pages you quoted don't do that as the concepts are explained elsewhere(?)
> 
> As a side note: In the Gerrit test suite I use the JGit implementation of
> the config command to write out .gitmodules files. So maybe `git submodule`
> can be understood as a specialized form of `git config`.

I do not agree here. That view is too limited. Since in the case of e.g. 'git submodule add‘ it does not only change the .gitmodules file but adds a gitlink entry to the index, moves the database into .git/modules, ... .

And even though it is currently not doing much more it might in the future. E.g. it might make sense to add a 'git submodule gc' command which allows the user to purge unused submodule databases from the .git/modules directory.

So I would say it is: "a helper" or "a tool" for submodules. Nothing less nothing more. But on the other hand the same is true for other porcelain commands like e.g. 'git commit'. If you take a look at gitcore-tutorial you could also describe it as a wrapper for write-tree, commit-tree and update-ref to create a commit. Yet the man page says: "Record changes to the repository".

So I am not sure where to draw the line between wrapper and essential command. As a user I would see it as quite essential since for adding a submodule I would need to remember a couple of things:

  * clone the database into .git/modules
  * create the gitlink file
  * checkout the files to the desired directory
  * add the url to the .gitmodules file

So why not go with Junios first suggestion and lets drop the "This command can help you..." and say: "Inspect, update and manage submodules".

Cheers Heiko

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