githaven/templates/repo/commits_list_small.tmpl
wxiaoguang 5b89670a31
Use a general Eval function for expressions in templates. (#23927)
One of the proposals in #23328

This PR introduces a simple expression calculator
(templates/eval/eval.go), it can do basic expression calculations.

Many untested template helper functions like `Mul` `Add` can be replaced
by this new approach.

Then these `Add` / `Mul` / `percentage` / `Subtract` / `DiffStatsWidth`
could all use this `Eval`.

And it provides enhancements for Golang templates, and improves
readability.

Some examples:

----

* Before: `{{Add (Mul $glyph.Row 12) 12}}`
* After: `{{Eval $glyph.Row "*" 12 "+" 12}}`

----

* Before: `{{if lt (Add $i 1) (len $.Topics)}}`
* After: `{{if Eval $i "+" 1 "<" (len $.Topics)}}`

## FAQ

### Why not use an existing expression package?

We need a highly customized expression engine:

* do the calculation on the fly, without pre-compiling
* deal with int/int64/float64 types, to make the result could be used in
Golang template.
* make the syntax could be used in the Golang template directly
* do not introduce too much complex or strange syntax, we just need a
simple calculator.
* it needs to strictly follow Golang template's behavior, for example,
Golang template treats all non-zero values as truth, but many 3rd
packages don't do so.

### What's the benefit?

* Developers don't need to add more `Add`/`Mul`/`Sub`-like functions,
they were getting more and more.
Now, only one `Eval` is enough for all cases.
* The new code reads better than old `{{Add (Mul $glyph.Row 12) 12}}`,
the old one isn't familiar to most procedural programming developers
(eg, the Golang expression syntax).
* The `Eval` is fully covered by tests, many old `Add`/`Mul`-like
functions were never tested.

### The performance?

It doesn't use `reflect`, it doesn't need to parse or compile when used
in Golang template, the performance is as fast as native Go template.

### Is it too complex? Could it be unstable?

The expression calculator program is a common homework for computer
science students, and it's widely used as a teaching and practicing
purpose for developers. The algorithm is pretty well-known.

The behavior can be clearly defined, it is stable.
2023-04-07 21:25:49 +08:00

53 lines
2.2 KiB
Handlebars

{{$index := 0}}
<div class="timeline-item commits-list">
{{range .comment.Commits}}
{{$tag := printf "%s-%d" $.comment.HashTag $index}}
{{$index = Eval $index "+" 1}}
<div class="singular-commit" id="{{$tag}}">
<span class="badge badge-commit">{{svg "octicon-git-commit"}}</span>
{{if .User}}
<a href="{{.User.HomeLink}}">
{{avatar $.root.Context .User}}
</a>
{{else}}
{{avatarByEmail $.root.Context .Author.Email .Author.Name}}
{{end}}
{{$commitLink:= printf "%s/commit/%s" $.comment.Issue.PullRequest.BaseRepo.Link (PathEscape .ID.String)}}
<span class="ui float right shabox">
{{template "repo/commit_statuses" dict "Status" .Status "Statuses" .Statuses "root" $.root}}
{{$class := "ui sha label"}}
{{if .Signature}}
{{$class = (printf "%s%s" $class " isSigned")}}
{{if .Verification.Verified}}
{{if eq .Verification.TrustStatus "trusted"}}
{{$class = (printf "%s%s" $class " isVerified")}}
{{else if eq .Verification.TrustStatus "untrusted"}}
{{$class = (printf "%s%s" $class " isVerifiedUntrusted")}}
{{else}}
{{$class = (printf "%s%s" $class " isVerifiedUnmatched")}}
{{end}}
{{else if .Verification.Warning}}
{{$class = (printf "%s%s" $class " isWarning")}}
{{end}}
{{end}}
<a href="{{$commitLink}}" rel="nofollow" class="{{$class}}">
<span class="shortsha">{{ShortSha .ID.String}}</span>
{{if .Signature}}
{{template "repo/shabox_badge" dict "root" $.root "verification" .Verification}}
{{end}}
</a>
</span>
<span class="gt-mono commit-summary {{if gt .ParentCount 1}} grey text{{end}}" title="{{.Summary}}">{{RenderCommitMessageLinkSubject $.root.Context .Message ($.comment.Issue.PullRequest.BaseRepo.Link|Escape) $commitLink $.comment.Issue.PullRequest.BaseRepo.ComposeMetas}}</span>
{{if IsMultilineCommitMessage .Message}}
<button class="ui button ellipsis-button" aria-expanded="false">...</button>
{{end}}
{{if IsMultilineCommitMessage .Message}}
<pre class="commit-body gt-hidden">{{RenderCommitBody $.root.Context .Message ($.comment.Issue.PullRequest.BaseRepo.Link|Escape) $.comment.Issue.PullRequest.BaseRepo.ComposeMetas}}</pre>
{{end}}
</div>
{{end}}
</div>