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| 1 | +/** |
| 2 | + * Ink |
| 3 | + * Copyright (c) John Sundell 2020 |
| 4 | + * MIT license, see LICENSE file for details |
| 5 | + */ |
| 6 | + |
| 7 | +import Foundation |
| 8 | + |
| 9 | +struct Table: Fragment { |
| 10 | + var modifierTarget: Modifier.Target { .tables } |
| 11 | + |
| 12 | + private var header: Row? |
| 13 | + private var rows = [Row]() |
| 14 | + private var columnCount = 0 |
| 15 | + private var columnAlignments = [ColumnAlignment]() |
| 16 | + |
| 17 | + static func read(using reader: inout Reader) throws -> Table { |
| 18 | + var table = Table() |
| 19 | + |
| 20 | + while !reader.didReachEnd, !reader.currentCharacter.isNewline { |
| 21 | + guard reader.currentCharacter == "|" else { |
| 22 | + break |
| 23 | + } |
| 24 | + |
| 25 | + let row = try reader.readTableRow() |
| 26 | + table.rows.append(row) |
| 27 | + table.columnCount = max(table.columnCount, row.count) |
| 28 | + } |
| 29 | + |
| 30 | + guard !table.rows.isEmpty else { throw Reader.Error() } |
| 31 | + table.formHeaderAndColumnAlignmentsIfNeeded() |
| 32 | + return table |
| 33 | + } |
| 34 | + |
| 35 | + func html(usingURLs urls: NamedURLCollection, |
| 36 | + modifiers: ModifierCollection) -> String { |
| 37 | + var html = "" |
| 38 | + let render: () -> String = { "<table>\(html)</table>" } |
| 39 | + |
| 40 | + if let header = header { |
| 41 | + let rowHTML = self.html( |
| 42 | + forRow: header, |
| 43 | + cellElementName: "th", |
| 44 | + urls: urls, |
| 45 | + modifiers: modifiers |
| 46 | + ) |
| 47 | + |
| 48 | + html.append("<thead>\(rowHTML)</thead>") |
| 49 | + } |
| 50 | + |
| 51 | + guard !rows.isEmpty else { |
| 52 | + return render() |
| 53 | + } |
| 54 | + |
| 55 | + html.append("<tbody>") |
| 56 | + |
| 57 | + for row in rows { |
| 58 | + let rowHTML = self.html( |
| 59 | + forRow: row, |
| 60 | + cellElementName: "td", |
| 61 | + urls: urls, |
| 62 | + modifiers: modifiers |
| 63 | + ) |
| 64 | + |
| 65 | + html.append(rowHTML) |
| 66 | + } |
| 67 | + |
| 68 | + html.append("</tbody>") |
| 69 | + return render() |
| 70 | + } |
| 71 | + |
| 72 | + func plainText() -> String { |
| 73 | + var text = header.map(plainText) ?? "" |
| 74 | + |
| 75 | + for row in rows { |
| 76 | + if !text.isEmpty { text.append("\n") } |
| 77 | + text.append(plainText(forRow: row)) |
| 78 | + } |
| 79 | + |
| 80 | + return text |
| 81 | + } |
| 82 | +} |
| 83 | + |
| 84 | +private extension Table { |
| 85 | + typealias Row = [FormattedText] |
| 86 | + typealias Cell = FormattedText |
| 87 | + |
| 88 | + static let delimiters: Set<Character> = ["|", "\n"] |
| 89 | + static let allowedHeaderCharacters: Set<Character> = ["-", ":"] |
| 90 | + |
| 91 | + enum ColumnAlignment { |
| 92 | + case none |
| 93 | + case left |
| 94 | + case center |
| 95 | + case right |
| 96 | + |
| 97 | + var attribute: String { |
| 98 | + switch self { |
| 99 | + case .none: |
| 100 | + return "" |
| 101 | + case .left: |
| 102 | + return #" align="left""# |
| 103 | + case .center: |
| 104 | + return #" align="center""# |
| 105 | + case .right: |
| 106 | + return #" align="right""# |
| 107 | + } |
| 108 | + } |
| 109 | + } |
| 110 | + |
| 111 | + mutating func formHeaderAndColumnAlignmentsIfNeeded() { |
| 112 | + guard rows.count > 1 else { return } |
| 113 | + guard rows[0].count == rows[1].count else { return } |
| 114 | + |
| 115 | + let textPredicate = Self.allowedHeaderCharacters.contains |
| 116 | + var alignments = [ColumnAlignment]() |
| 117 | + |
| 118 | + for cell in rows[1] { |
| 119 | + let text = cell.plainText() |
| 120 | + |
| 121 | + guard text.allSatisfy(textPredicate) else { |
| 122 | + return |
| 123 | + } |
| 124 | + |
| 125 | + alignments.append(parseColumnAlignment(from: text)) |
| 126 | + } |
| 127 | + |
| 128 | + header = rows[0] |
| 129 | + columnAlignments = alignments |
| 130 | + rows.removeSubrange(0...1) |
| 131 | + } |
| 132 | + |
| 133 | + func parseColumnAlignment(from text: String) -> ColumnAlignment { |
| 134 | + switch (text.first, text.last) { |
| 135 | + case (":", ":"): |
| 136 | + return .center |
| 137 | + case (":", _): |
| 138 | + return .left |
| 139 | + case (_, ":"): |
| 140 | + return .right |
| 141 | + default: |
| 142 | + return .none |
| 143 | + } |
| 144 | + } |
| 145 | + |
| 146 | + func html(forRow row: Row, |
| 147 | + cellElementName: String, |
| 148 | + urls: NamedURLCollection, |
| 149 | + modifiers: ModifierCollection) -> String { |
| 150 | + var html = "<tr>" |
| 151 | + |
| 152 | + for index in 0..<columnCount { |
| 153 | + let cell = index < row.count ? row[index] : nil |
| 154 | + let contents = cell?.html(usingURLs: urls, modifiers: modifiers) |
| 155 | + |
| 156 | + html.append(htmlForCell( |
| 157 | + at: index, |
| 158 | + contents: contents ?? "", |
| 159 | + elementName: cellElementName |
| 160 | + )) |
| 161 | + } |
| 162 | + |
| 163 | + return html + "</tr>" |
| 164 | + } |
| 165 | + |
| 166 | + func htmlForCell(at index: Int, contents: String, elementName: String) -> String { |
| 167 | + let alignment = index < columnAlignments.count |
| 168 | + ? columnAlignments[index] |
| 169 | + : .none |
| 170 | + |
| 171 | + let tags = ( |
| 172 | + opening: "<\(elementName)\(alignment.attribute)>", |
| 173 | + closing: "</\(elementName)>" |
| 174 | + ) |
| 175 | + |
| 176 | + return tags.opening + contents + tags.closing |
| 177 | + } |
| 178 | + |
| 179 | + func plainText(forRow row: Row) -> String { |
| 180 | + var text = "" |
| 181 | + |
| 182 | + for index in 0..<columnCount { |
| 183 | + let cell = index < row.count ? row[index] : nil |
| 184 | + if index > 0 { text.append(" | ") } |
| 185 | + text.append(cell?.plainText() ?? "") |
| 186 | + } |
| 187 | + |
| 188 | + return text + " |" |
| 189 | + } |
| 190 | +} |
| 191 | + |
| 192 | +private extension Reader { |
| 193 | + mutating func readTableRow() throws -> Table.Row { |
| 194 | + try readTableDelimiter() |
| 195 | + var row = Table.Row() |
| 196 | + |
| 197 | + while !didReachEnd { |
| 198 | + let cell = FormattedText.read( |
| 199 | + using: &self, |
| 200 | + terminators: Table.delimiters |
| 201 | + ) |
| 202 | + |
| 203 | + try readTableDelimiter() |
| 204 | + row.append(cell) |
| 205 | + |
| 206 | + if !didReachEnd, currentCharacter.isNewline { |
| 207 | + advanceIndex() |
| 208 | + break |
| 209 | + } |
| 210 | + } |
| 211 | + |
| 212 | + return row |
| 213 | + } |
| 214 | + |
| 215 | + mutating func readTableDelimiter() throws { |
| 216 | + try read("|") |
| 217 | + discardWhitespaces() |
| 218 | + } |
| 219 | +} |
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