package htmlconv import ( "html/template" "io" "tildegit.org/tjp/gus/gemini/gemtext" "tildegit.org/tjp/gus/gemini/gemtext/internal" ) // Convert writes markdown to a writer from the provided gemtext document. // // Templates can be provided to override the output for different line types. // The templates supported are: // - "header" is called before any lines and is passed the full Document. It should, // at a minimum, produce opening and tags. // - "footer" is called after the lines and is passed the full Document. It should, // at a minimum, provide closing and tags. // - "textline" is called once per line of text and is passed a gemtext.TextLine. // - "linkline" is called once per link line and is passed an object which wraps // a gemtext.LinkLine but also supports a ValidatedURL() method returning a // string which html/template will always allow as href attributes. // - "preformattedtextlines" is called once for a block of preformatted text and is // passed a slice of gemtext.PreformattedTextLines. // - "heading1line" is called once per h1 line and is passed a gemtext.Heading1Line. // - "heading2line" is called once per h2 line and is passed a gemtext.Heading2Line. // - "heading3line" is called once per h3 line and is passed a gemtext.Heading3Line. // - "listitemlines" is called once for a block of contiguous list item lines and // is passed a slice of gemtext.ListItemLines. // - "quoteline" is passed once per blockquote line and is passed a gemtext.QuoteLine. // // There exist default implementations of each of these templates, so the "overrides" // argument can be nil. func Convert(wr io.Writer, doc gemtext.Document, overrides *template.Template) error { if err := internal.ValidateLinks(doc); err != nil { return err } tmpl, err := baseTmpl.Clone() if err != nil { return err } tmpl, err = internal.AddHTMLTemplates(tmpl, overrides) if err != nil { return err } for _, item := range internal.RenderItems(doc) { if err := tmpl.ExecuteTemplate(wr, item.Template, item.Object); err != nil { return err } } return nil } var baseTmpl = template.Must(template.New("htmlconv").Parse(` {{ define "header" }}{{ end }} {{ define "textline" }}{{ if ne .String "\n" }}

{{ . }}

{{ end }}{{ end }} {{ define "linkline" -}}

=> {{ if eq .Label "" -}} {{ .URL }} {{- else -}} {{ .Label }} {{- end -}}

{{- end }} {{ define "preformattedtextlines" -}} 
	{{- range . -}}
		{{ . }}
	{{- end -}}
{{- end }} {{ define "heading1line" }}

{{ .Body }}

{{ end }} {{ define "heading2line" }}

{{ .Body }}

{{ end }} {{ define "heading3line" }}

{{ .Body }}

{{ end }} {{ define "listitemlines" -}} {{- end }} {{ define "quoteline" }}
{{ .Body }}
{{ end }} {{ define "footer" }}{{ end }} `))