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forgejo/templates/repo/view_file.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

125 lines
6.9 KiB
Handlebars

<div class="{{TabSizeClass .Editorconfig .FileName}} non-diff-file-content">
{{- if .FileError}}
<div class="ui error message">
<div class="text left gt-whitespace-pre">{{.FileError}}</div>
</div>
{{end}}
{{- if .FileWarning}}
<div class="ui warning message">
<div class="text left gt-whitespace-pre">{{.FileWarning}}</div>
</div>
{{end}}
<h4 class="file-header ui top attached header gt-df gt-ac gt-sb gt-fw">
<div class="file-header-left gt-df gt-ac gt-py-3 gt-pr-4">
{{if .ReadmeInList}}
{{svg "octicon-book" 16 "gt-mr-3"}}
<strong>{{.FileName}}</strong>
{{else}}
{{template "repo/file_info" .}}
{{end}}
</div>
<div class="file-header-right file-actions gt-df gt-ac gt-fw">
{{if .HasSourceRenderedToggle}}
<div class="ui compact icon buttons two-toggle-buttons">
<a href="{{$.Link}}?display=source" class="ui mini basic button {{if .IsDisplayingSource}}active{{end}}" data-tooltip-content="{{.locale.Tr "repo.file_view_source"}}">{{svg "octicon-code" 15}}</a>
<a href="{{$.Link}}" class="ui mini basic button {{if .IsDisplayingRendered}}active{{end}}" data-tooltip-content="{{.locale.Tr "repo.file_view_rendered"}}">{{svg "octicon-file" 15}}</a>
</div>
{{end}}
{{if not .ReadmeInList}}
<div class="ui buttons gt-mr-2">
<a class="ui mini basic button" href="{{$.RawFileLink}}">{{.locale.Tr "repo.file_raw"}}</a>
{{if not .IsViewCommit}}
<a class="ui mini basic button" href="{{.RepoLink}}/src/commit/{{PathEscape .CommitID}}/{{PathEscapeSegments .TreePath}}">{{.locale.Tr "repo.file_permalink"}}</a>
{{end}}
{{if .IsRepresentableAsText}}
<a class="ui mini basic button" href="{{.RepoLink}}/blame/{{.BranchNameSubURL}}/{{PathEscapeSegments .TreePath}}">{{.locale.Tr "repo.blame"}}</a>
{{end}}
<a class="ui mini basic button" href="{{.RepoLink}}/commits/{{.BranchNameSubURL}}/{{PathEscapeSegments .TreePath}}">{{.locale.Tr "repo.file_history"}}</a>
{{if .EscapeStatus.Escaped}}
<a class="ui mini basic button unescape-button gt-hidden">{{.locale.Tr "repo.unescape_control_characters"}}</a>
<a class="ui mini basic button escape-button">{{.locale.Tr "repo.escape_control_characters"}}</a>
{{end}}
</div>
<a download href="{{$.RawFileLink}}"><span class="btn-octicon" data-tooltip-content="{{.locale.Tr "repo.download_file"}}">{{svg "octicon-download"}}</span></a>
<a id="copy-content" class="btn-octicon {{if not .CanCopyContent}} disabled{{end}}"{{if or .IsImageFile (and .HasSourceRenderedToggle (not .IsDisplayingSource))}} data-link="{{$.RawFileLink}}"{{end}} data-tooltip-content="{{if .CanCopyContent}}{{.locale.Tr "copy_content"}}{{else}}{{.locale.Tr "copy_type_unsupported"}}{{end}}">{{svg "octicon-copy" 14}}</a>
{{if .Repository.CanEnableEditor}}
{{if .CanEditFile}}
<a href="{{.RepoLink}}/_edit/{{PathEscapeSegments .BranchName}}/{{PathEscapeSegments .TreePath}}"><span class="btn-octicon" data-tooltip-content="{{.EditFileTooltip}}">{{svg "octicon-pencil"}}</span></a>
{{else}}
<span class="btn-octicon disabled" data-tooltip-content="{{.EditFileTooltip}}">{{svg "octicon-pencil"}}</span>
{{end}}
{{if .CanDeleteFile}}
<a href="{{.RepoLink}}/_delete/{{PathEscapeSegments .BranchName}}/{{PathEscapeSegments .TreePath}}"><span class="btn-octicon btn-octicon-danger" data-tooltip-content="{{.DeleteFileTooltip}}">{{svg "octicon-trash"}}</span></a>
{{else}}
<span class="btn-octicon disabled" data-tooltip-content="{{.DeleteFileTooltip}}">{{svg "octicon-trash"}}</span>
{{end}}
{{end}}
{{else if .EscapeStatus.Escaped}}
<a class="ui mini basic button unescape-button gt-mr-2 gt-hidden">{{.locale.Tr "repo.unescape_control_characters"}}</a>
<a class="ui mini basic button escape-button gt-mr-2">{{.locale.Tr "repo.escape_control_characters"}}</a>
{{end}}
</div>
</h4>
<div class="ui attached table unstackable segment">
{{if not (or .IsMarkup .IsRenderedHTML)}}
{{template "repo/unicode_escape_prompt" dict "EscapeStatus" .EscapeStatus "root" $}}
{{end}}
<div class="file-view{{if .IsMarkup}} markup {{.MarkupType}}{{else if .IsPlainText}} plain-text{{else if .IsTextSource}} code-view{{end}}">
{{if .IsMarkup}}
{{if .FileContent}}{{.FileContent | Safe}}{{end}}
{{else if .IsPlainText}}
<pre>{{if .FileContent}}{{.FileContent | Safe}}{{end}}</pre>
{{else if not .IsTextSource}}
<div class="view-raw ui center">
{{if .IsImageFile}}
<img src="{{$.RawFileLink}}">
{{else if .IsVideoFile}}
<video controls src="{{$.RawFileLink}}">
<strong>{{.locale.Tr "repo.video_not_supported_in_browser"}}</strong>
</video>
{{else if .IsAudioFile}}
<audio controls src="{{$.RawFileLink}}">
<strong>{{.locale.Tr "repo.audio_not_supported_in_browser"}}</strong>
</audio>
{{else if .IsPDFFile}}
<iframe width="100%" height="600px" src="{{AssetUrlPrefix}}/vendor/plugins/pdfjs/web/viewer.html?file={{$.RawFileLink}}"></iframe>
{{else}}
<a href="{{$.RawFileLink}}" rel="nofollow" class="btn btn-gray btn-radius">{{.locale.Tr "repo.file_view_raw"}}</a>
{{end}}
</div>
{{else if .FileSize}}
{{if .IsFileTooLarge}}
<table>
<tbody>
<tr>
<td><strong>{{.locale.Tr "repo.file_too_large"}}</strong></td>
</tr>
</tbody>
</table>
{{else}}
<table>
<tbody>
{{range $idx, $code := .FileContent}}
{{$line := Eval $idx "+" 1}}
<tr>
<td id="L{{$line}}" class="lines-num"><span id="L{{$line}}" data-line-number="{{$line}}"></span></td>
{{if $.EscapeStatus.Escaped}}
<td class="lines-escape">{{if (index $.LineEscapeStatus $idx).Escaped}}<a href="" class="toggle-escape-button" title="{{if (index $.LineEscapeStatus $idx).HasInvisible}}{{$.locale.Tr "repo.invisible_runes_line"}} {{end}}{{if (index $.LineEscapeStatus $idx).HasAmbiguous}}{{$.locale.Tr "repo.ambiguous_runes_line"}}{{end}}"></a>{{end}}</td>
{{end}}
<td rel="L{{$line}}" class="lines-code chroma"><code class="code-inner">{{$code | Safe}}</code></td>
</tr>
{{end}}
</tbody>
</table>
<div class="code-line-menu ui vertical pointing menu tippy-target">
{{if $.Permission.CanRead $.UnitTypeIssues}}
<a class="item ref-in-new-issue" data-url-issue-new="{{.RepoLink}}/issues/new" data-url-param-body-link="{{.Repository.Link}}/src/commit/{{PathEscape .CommitID}}/{{PathEscapeSegments .TreePath}}" rel="nofollow noindex">{{.locale.Tr "repo.issues.context.reference_issue"}}</a>
{{end}}
<a class="item view_git_blame" href="{{.Repository.Link}}/blame/commit/{{PathEscape .CommitID}}/{{PathEscapeSegments .TreePath}}">{{.locale.Tr "repo.view_git_blame"}}</a>
<a class="item copy-line-permalink" data-url="{{.Repository.Link}}/src/commit/{{PathEscape .CommitID}}/{{PathEscapeSegments .TreePath}}">{{.locale.Tr "repo.file_copy_permalink"}}</a>
</div>
{{end}}
{{end}}
</div>
</div>
</div>