Merge pull request #69 from laws-africa/fix-tables

Fix tables

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@lawsafrica/indigo-akn",
-  "version": "5.5.0",
+  "version": "5.6.0",
   "description": "Akoma Ntoso support libraries for the Indigo platform.",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

src/grammars.js

@@ -1,4 +1,5 @@
 import { htmlToAkn } from "./html";
+import { fixTables } from "./xml";
 
 /**
  * Base class for grammar models.

src/index.js

@@ -3,3 +3,4 @@ export * from './html';
 export * from './eids';
 export * from './enrichments';
 export * from './ranges';
+export * from './xml';

src/xml.js

@@ -0,0 +1,119 @@
+/**
+ * Returns a map of a table, taking all colspans and rowspans into account.
+ */
+export function mapTable(table) {
+  let matrix = {},
+      rows = table.children;
+
+  for (let y = 0; y < rows.length; y++) {
+    // set default
+    if (!matrix[y]) {
+      matrix[y] = {};
+    }
+    let row = rows[y];
+    let cells = row.children;
+    for (let x = 0; x < cells.length; x++) {
+      // stash 'x' so we don't end the loop prematurely if it's incremented below
+      let xPos = x;
+      let cell = cells[x];
+      // set default; increment xPos if needed (skip already occupied cells in current row)
+      while (matrix[y][xPos]) {
+        xPos += 1;
+      }
+      matrix[y][xPos] = {};
+      // mark matrix elements occupied by current cell with true
+      let colSpanTotal = xPos + Number(cell.getAttribute('colspan') || 1);
+      let rowSpanTotal = y + Number(cell.getAttribute('rowspan') || 1);
+
+      for (let xx = xPos; xx < colSpanTotal; xx++) {
+        for (let yy = y; yy < rowSpanTotal; yy++) {
+          if (!matrix[yy]) {
+            matrix[yy] = {};
+          }
+          // don't try to make overlapping spans work
+          if (matrix[yy][xx] === true) {
+            throw "Cannot parse overlapping spans in table with eId " + table.getAttribute("eId");
+          }
+          matrix[yy][xx] = true;
+        }
+      }
+    }
+  }
+  return matrix;
+}
+
+/**
+ * Fixes a table by inserting missing rows and cells to match the table's matrix.
+ */
+export function fixTable(table) {
+  // track the fixes
+  let removedRow = false,
+      addedRow = false,
+      addedCell = false;
+  // remove empty rows before starting
+  for (let r = 0; r < table.children.length; r++) {
+    let row = table.children[r];
+    if (!row.children.length) {
+      table.removeChild(row);
+      removedRow = true;
+    }
+  }
+
+  let xmlns = table.namespaceURI,
+      tableMap = mapTable(table),
+      nMappedRows = Object.keys(tableMap).length;
+
+  // add missing rows
+  let nMissingRows = nMappedRows - table.children.length;
+  for (let y = 0; y < nMissingRows; y++) {
+    console.log("adding a missing row to table ", table.getAttribute('eId'));
+    table.appendChild(document.createElementNS(xmlns, 'tr'));
+    addedRow = true;
+  }
+
+  // add missing cells
+  let nMaxMappedColumns = Math.max(...Object.values(tableMap).map(r => Object.keys(r).length));
+  for (let r = 0; r < table.children.length; r++) {
+    let nMissingCells = nMaxMappedColumns - Object.keys(tableMap[r]).length,
+        row = table.children[r];
+    for (let m = 0; m < nMissingCells; m++) {
+      console.log("adding a missing cell to table ", table.getAttribute('eId'), " row ", r);
+      let cell = document.createElementNS(xmlns, 'td');
+      cell.appendChild(document.createElementNS(xmlns, 'p'));
+      row.appendChild(cell);
+      addedCell = true;
+    }
+  }
+
+  // report fixes
+  if (removedRow || addedRow || addedCell) {
+    let fixes = [];
+    if (removedRow) {
+      fixes.push("removed empty row(s)");
+    }
+    if (addedRow) {
+      fixes.push("added missing row(s)");
+    }
+    if (addedCell) {
+      fixes.push("added missing cell(s)");
+    }
+    return `Table with eId ${table.getAttribute('eId')}: ${fixes.join(", ")}`;
+  } else {
+    return null;
+  }
+}
+
+/**
+ * Fixes all tables in a list of Akoma Ntoso XML elements.
+ */
+export function fixTables (elementList) {
+  let fixedTables = [];
+  for (let i = 0; i < elementList.length; i++) {
+    let tableList = elementList[i].querySelectorAll("table");
+    for (let t = 0; t < tableList.length; t++) {
+      let fixed = fixTable(tableList[t]);
+      if (fixed) {fixedTables.push(fixed);}
+    }
+  }
+  return fixedTables;
+}