Merge pull request #6488 from jhamrick/lock-cells

Proof of concept for preventing cell deletion via metadata

IPython/html/tests/notebook/deletecell.js

@@ -0,0 +1,107 b''
+
+// Test
+casper.notebook_test(function () {
+    var that = this;
+    var cell_is_deletable = function (index) {
+        // Get the deletable status of a cell.
+        return that.evaluate(function (index) {
+            var cell = IPython.notebook.get_cell(index);
+            return cell.is_deletable();
+        }, index);
+    };
+
+    var a = 'print("a")';
+    var index = this.append_cell(a);
+
+    var b = 'print("b")';
+    index = this.append_cell(b);
+
+    var c = 'print("c")';
+    index = this.append_cell(c);
+
+    this.thenEvaluate(function() {
+        IPython.notebook.get_cell(1).metadata.deletable = false;
+        IPython.notebook.get_cell(2).metadata.deletable = 0; // deletable only when exactly false
+        IPython.notebook.get_cell(3).metadata.deletable = true;
+    });
+
+    this.then(function () {
+        // Check deletable status of the cells
+        this.test.assert(cell_is_deletable(0), 'Cell 0 is deletable');
+        this.test.assert(!cell_is_deletable(1), 'Cell 1 is not deletable');
+        this.test.assert(cell_is_deletable(2), 'Cell 2 is deletable');
+        this.test.assert(cell_is_deletable(3), 'Cell 3 is deletable');
+    });
+
+    // Try to delete cell 0 (should succeed)
+    this.then(function () {
+        this.select_cell(0);
+        this.trigger_keydown('esc');
+        this.trigger_keydown('d', 'd');
+        this.test.assertEquals(this.get_cells_length(), 3, 'Delete cell 0: There are now 3 cells');
+        this.test.assertEquals(this.get_cell_text(0), a, 'Delete cell 0: Cell 1 is now cell 0');
+        this.test.assertEquals(this.get_cell_text(1), b, 'Delete cell 0: Cell 2 is now cell 1');
+        this.test.assertEquals(this.get_cell_text(2), c, 'Delete cell 0: Cell 3 is now cell 2');
+        this.validate_notebook_state('dd', 'command', 0);
+    });
+
+    // Try to delete cell 0 (should fail)
+    this.then(function () {
+        this.select_cell(0);
+        this.trigger_keydown('d', 'd');
+        this.test.assertEquals(this.get_cells_length(), 3, 'Delete cell 0: There are still 3 cells');
+        this.test.assertEquals(this.get_cell_text(0), a, 'Delete cell 0: Cell 0 was not deleted');
+        this.test.assertEquals(this.get_cell_text(1), b, 'Delete cell 0: Cell 1 was not affected');
+        this.test.assertEquals(this.get_cell_text(2), c, 'Delete cell 0: Cell 2 was not affected');
+        this.validate_notebook_state('dd', 'command', 0);
+    });
+
+    // Try to delete cell 1 (should succeed)
+    this.then(function () {
+        this.select_cell(1);
+        this.trigger_keydown('d', 'd');
+        this.test.assertEquals(this.get_cells_length(), 2, 'Delete cell 1: There are now 2 cells');
+        this.test.assertEquals(this.get_cell_text(0), a, 'Delete cell 1: Cell 0 was not affected');
+        this.test.assertEquals(this.get_cell_text(1), c, 'Delete cell 1: Cell 1 was not affected');
+        this.validate_notebook_state('dd', 'command', 1);
+    });
+
+    // Try to delete cell 1 (should succeed)
+    this.then(function () {
+        this.select_cell(1);
+        this.trigger_keydown('d', 'd');
+        this.test.assertEquals(this.get_cells_length(), 1, 'Delete cell 1: There is now 1 cell');
+        this.test.assertEquals(this.get_cell_text(0), a, 'Delete cell 2: Cell 0 was not affected');
+        this.validate_notebook_state('dd', 'command', 0);
+    });
+
+    // Change the deletable status of the last cells
+    this.thenEvaluate(function() {
+        IPython.notebook.get_cell(0).metadata.deletable = true;
+    });
+
+    this.then(function () {
+        // Check deletable status of the cell
+        this.test.assert(cell_is_deletable(0), 'Cell 0 is deletable');
+
+        // Try to delete the last cell (should succeed)
+        this.select_cell(0);
+        this.trigger_keydown('d', 'd');
+        this.test.assertEquals(this.get_cells_length(), 1, 'Delete last cell: There is still 1 cell');
+        this.test.assertEquals(this.get_cell_text(0), "", 'Delete last cell: Cell 0 was deleted');
+        this.validate_notebook_state('dd', 'command', 0);
+    });
+
+    // Make sure copied cells are deletable
+    this.thenEvaluate(function() {
+        IPython.notebook.get_cell(0).metadata.deletable = false;
+    });
+    this.then(function () {
+        this.select_cell(0);
+        this.trigger_keydown('c', 'v');
+        this.test.assertEquals(this.get_cells_length(), 2, 'Copy cell: There are 2 cells');
+        this.test.assert(!cell_is_deletable(0), 'Cell 0 is not deletable');
+        this.test.assert(cell_is_deletable(1), 'Cell 1 is deletable');
+        this.validate_notebook_state('cv', 'command', 1);
+    });
+});

IPython/html/static/notebook/js/cell.js

@@ -385,7 +385,8 b' define(['
      **/
     Cell.prototype.toJSON = function () {
         var data = {};
-        data.metadata = this.metadata;
+        // deepcopy the metadata so copied cells don't share the same object
+        data.metadata = JSON.parse(JSON.stringify(this.metadata));
         data.cell_type = this.cell_type;
         return data;
     };
@@ -404,22 +405,35 b' define(['
 
 
     /**
-     * can the cell be split into two cells
+     * can the cell be split into two cells (false if not deletable)
      * @method is_splittable
      **/
     Cell.prototype.is_splittable = function () {
-        return true;
+        return this.is_deletable();
     };
 
 
     /**
-     * can the cell be merged with other cells
+     * can the cell be merged with other cells (false if not deletable)
      * @method is_mergeable
      **/
     Cell.prototype.is_mergeable = function () {
-        return true;
+        return this.is_deletable();
     };
 
+    /**
+     * is the cell deletable? only false (undeletable) if
+     * metadata.deletable is explicitly false -- everything else
+     * counts as true
+     *
+     * @method is_deletable
+     **/
+    Cell.prototype.is_deletable = function () {
+        if (this.metadata.deletable === false) {
+            return false;
+        }
+        return true;
+    };
 
     /**
      * @return {String} - the text before the cursor

IPython/html/static/notebook/js/notebook.js

@@ -760,7 +760,11 b' define(['
      */
     Notebook.prototype.delete_cell = function (index) {
         var i = this.index_or_selected(index);
-        var cell = this.get_selected_cell();
+        var cell = this.get_cell(i);
+        if (!cell.is_deletable()) {
+            return this;
+        }
+
         this.undelete_backup = cell.toJSON();
         $('#undelete_cell').removeClass('disabled');
         if (this.is_valid_cell_index(i)) {
@@ -1188,6 +1192,10 b' define(['
     Notebook.prototype.copy_cell = function () {
         var cell = this.get_selected_cell();
         this.clipboard = cell.toJSON();
+        // remove undeletable status from the copied cell
+        if (this.clipboard.metadata.deletable !== undefined) {
+            delete this.clipboard.metadata.deletable;
+        }
         this.enable_paste();
     };
 

IPython/html/tests/notebook/dualmode_merge.js

@@ -1,6 +1,33 b''
 
 // Test
 casper.notebook_test(function () {
+    var a = 'ab\ncd';
+    var b = 'print("b")';
+    var c = 'print("c")';
+
+    var that = this;
+    var cell_is_mergeable = function (index) {
+        // Get the mergeable status of a cell.
+        return that.evaluate(function (index) {
+            var cell = IPython.notebook.get_cell(index);
+            return cell.is_mergeable();
+        }, index);
+    };
+
+    var cell_is_splittable = function (index) {
+        // Get the splittable status of a cell.
+        return that.evaluate(function (index) {
+            var cell = IPython.notebook.get_cell(index);
+            return cell.is_splittable();
+        }, index);
+    };
+
+    var close_dialog = function () {
+        this.evaluate(function(){
+            $('div.modal-footer button.btn-default').click();
+        }, {});
+    };
+
     this.then(function () {
         // Split and merge cells
         this.select_cell(0);
@@ -16,6 +43,93 b' casper.notebook_test(function () {'
         this.select_cell(0); // Move up to cell 0
         this.trigger_keydown('shift-m'); // Merge
         this.validate_notebook_state('merge', 'command', 0);
-        this.test.assertEquals(this.get_cell_text(0), 'ab\ncd', 'merge; Verify that cell 0 has the merged contents.');
+        this.test.assertEquals(this.get_cell_text(0), a, 'merge; Verify that cell 0 has the merged contents.');
+    });
+
+    // add some more cells and test splitting/merging when a cell is not deletable
+    this.then(function () {
+        this.append_cell(b);
+        this.append_cell(c);
+    });
+
+    this.thenEvaluate(function() {
+        IPython.notebook.get_cell(1).metadata.deletable = false;
+    });
+
+    // Check that merge/split status are correct
+    this.then(function () {
+        this.test.assert(cell_is_splittable(0), 'Cell 0 is splittable');
+        this.test.assert(cell_is_mergeable(0), 'Cell 0 is mergeable');
+        this.test.assert(!cell_is_splittable(1), 'Cell 1 is not splittable');
+        this.test.assert(!cell_is_mergeable(1), 'Cell 1 is not mergeable');
+        this.test.assert(cell_is_splittable(2), 'Cell 2 is splittable');
+        this.test.assert(cell_is_mergeable(2), 'Cell 2 is mergeable');
+    });
+
+    // Try to merge cell 0 below with cell 1
+    this.then(function () {
+        this.select_cell(0);
+        this.trigger_keydown('esc');
+        this.trigger_keydown('shift-m');
+        this.test.assertEquals(this.get_cells_length(), 3, 'Merge cell 0 down: There are still 3 cells');
+        this.test.assertEquals(this.get_cell_text(0), a, 'Merge cell 0 down: Cell 0 is unchanged');
+        this.test.assertEquals(this.get_cell_text(1), b, 'Merge cell 0 down: Cell 1 is unchanged');
+        this.test.assertEquals(this.get_cell_text(2), c, 'Merge cell 0 down: Cell 2 is unchanged');
+        this.validate_notebook_state('shift-m', 'command', 0);
+    });
+
+    // Try to merge cell 1 above with cell 0
+    this.then(function () {
+        this.select_cell(1);
+    });
+    this.thenEvaluate(function () {
+        IPython.notebook.merge_cell_above();
+    });
+    this.then(function () {
+        this.test.assertEquals(this.get_cells_length(), 3, 'Merge cell 1 up: There are still 3 cells');
+        this.test.assertEquals(this.get_cell_text(0), a, 'Merge cell 1 up: Cell 0 is unchanged');
+        this.test.assertEquals(this.get_cell_text(1), b, 'Merge cell 1 up: Cell 1 is unchanged');
+        this.test.assertEquals(this.get_cell_text(2), c, 'Merge cell 1 up: Cell 2 is unchanged');
+        this.validate_notebook_state('merge up', 'command', 1);
+    });
+
+    // Try to split cell 1
+    this.then(function () {
+        this.select_cell(1);
+        this.trigger_keydown('enter');
+        this.set_cell_editor_cursor(1, 0, 2);
+        this.trigger_keydown('ctrl-shift-subtract'); // Split
+        this.test.assertEquals(this.get_cells_length(), 3, 'Split cell 1: There are still 3 cells');
+        this.test.assertEquals(this.get_cell_text(0), a, 'Split cell 1: Cell 0 is unchanged');
+        this.test.assertEquals(this.get_cell_text(1), b, 'Split cell 1: Cell 1 is unchanged');
+        this.test.assertEquals(this.get_cell_text(2), c, 'Split cell 1: Cell 2 is unchanged');
+        this.validate_notebook_state('ctrl-shift-subtract', 'edit', 1); 
+    });
+
+    // Try to merge cell 1 down
+    this.then(function () {
+        this.select_cell(1);
+        this.trigger_keydown('esc');
+        this.trigger_keydown('shift-m');
+        this.test.assertEquals(this.get_cells_length(), 3, 'Merge cell 1 down: There are still 3 cells');
+        this.test.assertEquals(this.get_cell_text(0), a, 'Merge cell 1 down: Cell 0 is unchanged');
+        this.test.assertEquals(this.get_cell_text(1), b, 'Merge cell 1 down: Cell 1 is unchanged');
+        this.test.assertEquals(this.get_cell_text(2), c, 'Merge cell 1 down: Cell 2 is unchanged');
+        this.validate_notebook_state('shift-m', 'command', 1);
+    });
+
+    // Try to merge cell 2 above with cell 1
+    this.then(function () {
+        this.select_cell(2);
+    });
+    this.thenEvaluate(function () {
+        IPython.notebook.merge_cell_above();
+    });
+    this.then(function () {
+        this.test.assertEquals(this.get_cells_length(), 3, 'Merge cell 2 up: There are still 3 cells');
+        this.test.assertEquals(this.get_cell_text(0), a, 'Merge cell 2 up: Cell 0 is unchanged');
+        this.test.assertEquals(this.get_cell_text(1), b, 'Merge cell 2 up: Cell 1 is unchanged');
+        this.test.assertEquals(this.get_cell_text(2), c, 'Merge cell 2 up: Cell 2 is unchanged');
+        this.validate_notebook_state('merge up', 'command', 2);
     });
-});
  No newline at end of file
+});