2 I am trying to build a template. The compilation of this template results in a weird exception. I have isolated the cause of the exception to the following point:
4 If i have this in the template code:
7 pages="\<TMPL_VAR SEL_PAGES\>"<br/>
8 template=extract-entry<br/>
11 There is no problem at all. I can use the template with the desired result. But if I try to use this (just adding the "show" parameter):
14 pages="\<TMPL_VAR SEL_PAGES>"<br/>
15 template=extract-entry<br/>
16 show=\<TMPL_VAR CNTPG><br/>
19 I get this exception on the Git bash console:
23 Counting objects: 7, done.
24 Delta compression using up to 8 threads.
25 Compressing objects: 100% (4/4), done.
26 Writing objects: 100% (4/4), 410 bytes, done.
27 Total 4 (delta 3), reused 0 (delta 0)
28 remote: From /home/b-odelama-com/source
29 remote: eb1421e..5e1bac5 master -> origin/master
30 remote: Argument "\x{3c}\x{54}..." isn't numeric in numeric lt (<) at /usr/share/perl5/IkiWiki/Plugin/inline.pm line 231.
31 remote: Argument "\x{3c}\x{54}..." isn't numeric in numeric lt (<) at /usr/share/perl5/IkiWiki/Plugin/inline.pm line 231.
32 To ssh://b-odelama-com@odelama-com.branchable.com/
33 eb1421e..5e1bac5 master -> master
36 Please, let me know what to do to avoid this kind of error.
38 > When you add a template page `templates/foo.mdwn` for use
39 > the [[ikiwiki/directive/template]] directive, two things happen:
41 > 1. `\[[!template id=foo ...]]` becomes available;
42 > 2. a wiki page `templates/foo` is built, resulting in a HTML file,
43 > typically `templates/foo/index.html`
45 > The warnings you're seeing are the second of these: when ikiwiki
46 > tries to process `templates/foo.mdwn` as an ordinary page, without
47 > interpreting the `<TMPL_VAR>` directives, `inline` receives invalid
50 > This is a bit of a design flaw in [[plugins/template]] and
51 > [[plugins/edittemplate]], I think - ideally it would be possible to
52 > avoid parts of the page being interpreted when the page is being
53 > rendered normally rather than being used as a template.
55 > There *is* a trick to avoid parts of the page being interpreted when
56 > the page is being used as a template, while having them appear
57 > when it's rendered as a page:
60 > <!-- This part only appears when being used as a page.
61 > It assumes that you never set FALSE to a true value :-) -->
62 > \[[!meta robots="noindex,nofollow"]]
63 > This template is used to describe a thing. Parameters:
64 > * name: the name of the thing
65 > * size: the size of the thing
68 > The thing is called <TMPL_VAR name> and its size is <TMPL_VAR size>
70 > I suppose you could maybe extend that to something like this:
73 > <!-- This part only appears when being used as a page.
74 > It assumes that you never set FALSE to a true value :-) -->
75 > \[[!meta robots="noindex,nofollow"]]
76 > This template is used to describe a thing. Parameters:
77 > * name: the name of the thing
78 > * size: the size of the thing
82 > \[[!if test="included() and !included()" then="""
84 > <!-- This part only appears when being used as a template. It also
85 > assumes that you never set FALSE to a true value, and it
86 > relies on the [[ikiwiki/pagespec]] "included() and !included()"
87 > never being true. -->
88 > The thing is called <TMPL_VAR name> and its size is <TMPL_VAR size>
93 > but that's far harder than it ought to be!
95 > Perhaps the right solution would be to change how the template plugin
96 > works, so that templates are expected to contain a new `definetemplate`
99 > This template is used to describe a thing. Parameters:
100 > * name: the name of the thing
101 > * size: the size of the thing
103 > \[[!definetemplate """
104 > The thing is called <TMPL_VAR name> and its size is <TMPL_VAR size>
107 > with templates not containing a `\[[!definetemplate]]` being treated
108 > as if the whole text of the page was copied into a `\[[!definetemplate]]`,
109 > for backwards compatibility?
113 >> [[!template id=gitbranch author="[[smcv]]" branch=smcv/definetemplate]]
115 >> OK, here is a branch implementing what I said. It adds the `definetemplate`
116 >> directive to [[plugins/goodstuff]] as its last commit.
118 >> Templates with the current strange semantics will still work, until
119 >> IkiWiki breaks compatibility.
121 >> Possible controversies:
123 >> * Should the `definetemplate` plugin be core, or in goodstuff, or neither?
125 >> * Should \[[!definetemplate]] be allowed on any page (with the implementation
126 >> of `template("foo")` looking for a `definetemplate` in `templates/foo`,
127 >> then a `definetemplate` in `foo`, then fall back to the current logic)?
128 >> If not, should \[[!definetemplate]] raise an error when used on a page not
129 >> in `templates/`, since it will have no practical effect there?
131 >> * Is it OK to rely on `definetemplate` being enabled in the basewiki's
134 >> * Should the "use definetemplate" wording in the documentation of
135 >> template and edittemplate be stronger? Should those plugins automatically
136 >> load definetemplate?
140 >>> this looks like a good idea to me.
142 >>> * i'd put it in core, and add a transition for the time compatibility gets
143 >>> broken, provided the transitioning system will be used in that. templates
144 >>> can't be expected to just work as markdown+ikiwiki too.
146 >>> (it being in core would also solve my qualms about `section => "web"` /
147 >>> `\[[!tag type/web]]`).
149 >>> * if definetemplate gets deemed core, no "use definetemplate!" notes on the
150 >>> template/edittemplate pages will be required any more.
152 >>> * first i was sceptical of the approach of re-running scan to make sure the
153 >>> `my %templates` is filled, but it is indeed a practical solution.
155 >>> * the name "`definetemplate`" gives me the first impression that something
156 >>> is assigned (as in `#define`), but actually it highlights a region in the
157 >>> file. wouldn't "`templatebody`" be a better description of the meaning of
162 >>>> Thanks for your feedback!
163 >>>> Looking at its description on this wiki, I agree that `type/web` doesn't
164 >>>> fit, and core does seem better. I like your `templatebody` suggestion,
165 >>>> too, particularly if templates remain restricted to `/templates`.
166 >>>> I'll try to come up with better wording for the documentation to say
167 >>>> "use `templatebody`, like this", with a note about backwards
168 >>>> compatibility later.
170 >>>> Rationale for `my %templates`: yes it does seem a bit odd, but
171 >>>> if I used `$pagestate{$tpage}{template}` instead of a `my` variable,
172 >>>> I'd sometimes _still_ have to force a `scan`, because
173 >>>> [[plugins/template]] has to expand the template at scan time so that
174 >>>> it can contain links etc. - so I have to make sure that if the
175 >>>> template has changed, it has already been scanned (scanning happens
176 >>>> in random order, so that can't be guaranteed). This means there's
177 >>>> no benefit in reading it back from the index, so it might as well
178 >>>> just be in-memory.
180 >>>> I suppose an alternative way to do it would be to remember what was
181 >>>> passed to `needsbuild`, and only force a `scan` for templates that
182 >>>> were in that list - which potentially reduces CPU time and I/O a
183 >>>> little, in exchange for a bigger index. I could do that if Joey
184 >>>> wants me to, but I think the current approach is simpler,
185 >>>> so I'll stick with the current approach if it isn't vetoed.
188 >>>>> @name: even outside `/templates`, `\[[!templatebody]]` would be
189 >>>>> interpreted as "when this page is used as a template, this is what its
190 >>>>> contents should be", and be suitable.
192 >>>>> @`%templates`: my surprise wasn't to it not being in `%pagestate`, but
193 >>>>> rather that the `scan` function was used for it at all, rather than plain
194 >>>>> directive parsing that ignores everything else -- but i agree that it's
195 >>>>> the right thing to do in this situation.