The Drupal 5 version lacks explanation that flagging users, and comments, is almost useless.

This is a major documentation flaw.

I've just created a handbook page explaining this:

Limitations of the Drupal 5 version.

Indeed, being able to flag users in the Drupal 5 version is not very useful.

I'm not yet closing this issue: I'll right away put an explanation in the UI of the module itself.

(It's possible to use some custom code to generate a list of flagged users, but I don't think it's worth the bother.)

I use tpl files for user pages and all node types so am not seeing any links on user pages.

BTW, this is a different issue, which you'd have encountered even if you used Drupal 6. In these cases you can display the link manually, as explained in Placing a flag link on a page.

I added explanation to the UI. The "Add flag" screen now contains a collapsed fieldset titled "Important note concerning the limitation of Views 1.x".

http://drupal.org/cvs?commit=137801

Oops. I haven't noticed your new reply. I'll soon answer.

I just have this in all my node templates for the standard node bookmarking:

a href="/flag/flag/bookmarks/node/ ?php print [...]

You shouldn't. It's best to simply do:

print flag_create_link('bookmarks', $node->nid);

You don't need to know the URL for bookmarking a node (or any other object).

The flag_create_link() also adds some Javascript magic to the page.

but then your first answer makes me think that because of the views 1.x limitations, the fact you can flag users even in D5 can't be exploited, correct?

Sort of.

For most admins, the ability to flag users, in D5, indeed can't be exploited, because there isn't a very easy way to list flagged users.

But if you know some SQL you can generate the list of flagged users yourself.

HOWEVER,

Drupal 5 admins usually use modules such as Bio or NodeProfile. So they can still flag and list "users": you flag, and list, their "profile" nodes instead. I should add this to the documentation.

[...] modules such as Bio or NodeProfile. So they can still flag and list "users": you flag, and list, their "profile" nodes instead. I should add this to the documentation.

I added this info to both the handbook and the UI.

http://drupal.org/cvs?commit=137823

Thanks for listing this information. I have just spent ages trying to figure out what I was doing wrong with Flag & 5x & Views!

Giving up on trying to flag comments!

Is there a way of finding out the nid of a user's nodeprofile

Yes, that's the only challenge.

Put the following in your template:

// Find the user ID
$uid = $account->uid

// Load the profile node
$node = node_load(array('type' => 'bio', 'uid' => $uid));

if ($node) {
  print "The NID of user number $uid is $node->nid";
}
else {
  print "Can't find the node of user number $uid";
}

Let me know if it works. The rest is easy.

However, you need to change two things in the code:

1. I assumed the "machine name" of the node's content-type is "bio". Change it to whatever name you use for it.

2. I assumed the user ID can be reached by doing `$account->uid`. If you don't have a variable `$account` in your template, change that line to read `$uid = arg(1);`

===

Note that you should arrange for every user to have a profile node. (If you have several node types serving as profile nodes, you should pick the one you consider the primary.) Modules such as 'bio' and 'usernode' can enforce the creation of such node, but, IIRC, Node Profile doesn't have this feature. So you should either put that node form on the user registration page (so it gets created), or install usernode. There might be other options; It's been a long time since I touched these modules, so the information I give here may not be accurate.

Oops. The line before is missing a semicolon.

Chnage:

$uid = $account->uid

to:

$uid = $account->uid;

And if you get "Can't find the node of user number" ---note the user number is missing-- it means that the variable $account doesn't exist in your template. In that case, change:

$uid = $account->uid;

to:

$uid = arg(1); 

(Here we assume the user ID is the second argument in the URL.)

it will be those usernodes that are going to get flagged, right?

Yes.

they are pretty much empty pages
[...] I can jazz them up

You can leave them empty. Their only purpose is to get listed by Views.

Let's suppose you named your flag "friends". You now have a "My friends" menu item and if you click it you'll see all users you've flagged. What you're seeing is the titles of these 'usernode' nodes.

=======

The next step it to print the flag/unflag link.

The easiest solution is to simply add the following (after the existing code):

// I assume the name of the flag is 'bookmarks'. It could be
// 'friends', but you first have to create a flag by that name.

print flag_create_link('bookmarks', $node->nid);

(Make sure this works.)

Now, you want to change the appearance of the link. There are two ways to do this:

1. You can theme the link to show however you like.

2. But if you want to go the "old" way of doing things, you can do:

// Change this to the name of the flag.
$flag_name = 'bookmarks';

$flag = flag_get_flag($flag_name);

if (!$flag) {
  print "No such flag exists";
}

if ($flag->is_flagged($node->nid)) {
  print l(t('Remove from friends'), "flag/unflag/$flag_name/$node->nid", array(), drupal_get_destination());
}
else {
  print l(t('Add to friends'), "flag/flag/$flag_name/$node->nid", array(), drupal_get_destination());
}

Is there a way of using views to list out all content created by the users I've managed to flag using this method?

It's easily doable in Views 2.

As for Views 1: it might be doable, but it's not very trivial. You'll have to use NodeFusion/NodeFamily. If you're using 'bio' it might be easier: that module duplicates, in the Views interface, all the fields/filters so you can operate on the usernode.