add empty metadata field on cells/worksheets

These are unused for now, but will allow adding data to the notebook without a full version bump.

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

@@ -19,6 +19,7 @@ var IPython = (function (IPython) {
         this.read_only = false;
         this.selected = false;
         this.element = null;
+        this.metadata = {};
         this.create_element();
         if (this.element !== null) {
             this.element.data("cell", this);
@@ -90,10 +91,16 @@ var IPython = (function (IPython) {
 
 
     Cell.prototype.toJSON = function () {
+        var data = {};
+        data.metadata = this.metadata;
+        return data;
     };
 
 
     Cell.prototype.fromJSON = function (data) {
+        if (data.metadata !== undefined) {
+            this.metadata = data.metadata;
+        }
     };
 
 

IPython/frontend/html/notebook/static/js/codecell.js

@@ -264,6 +264,7 @@ var IPython = (function (IPython) {
     // JSON serialization
 
     CodeCell.prototype.fromJSON = function (data) {
+        IPython.Cell.prototype.fromJSON.apply(this, arguments);
         if (data.cell_type === 'code') {
             if (data.input !== undefined) {
                 this.set_text(data.input);
@@ -286,7 +287,7 @@ var IPython = (function (IPython) {
 
 
     CodeCell.prototype.toJSON = function () {
-        var data = {};
+        var data = IPython.Cell.prototype.toJSON.apply(this);
         data.input = this.get_text();
         data.cell_type = 'code';
         if (this.input_prompt_number) {

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

@@ -25,6 +25,8 @@ var IPython = (function (IPython) {
         this.paste_enabled = false;
         this.dirty = false;
         this.metadata = {};
+        // single worksheet for now
+        this.worksheet_metadata = {};
         this.control_key_active = false;
         this.notebook_id = null;
         this.notebook_name = null;
@@ -1003,6 +1005,9 @@ var IPython = (function (IPython) {
         // Only handle 1 worksheet for now.
         var worksheet = data.worksheets[0];
         if (worksheet !== undefined) {
+            if (worksheet.metadata) {
+                this.worksheet_metadata = worksheet.metadata;
+            }
             var new_cells = worksheet.cells;
             ncells = new_cells.length;
             var cell_data = null;
@@ -1031,7 +1036,10 @@ var IPython = (function (IPython) {
         };
         var data = {
             // Only handle 1 worksheet for now.
-            worksheets : [{cells:cell_array}],
+            worksheets : [{
+                cells: cell_array,
+                metadata: this.worksheet_metadata
+            }],
             metadata : this.metadata
         };
         return data;

IPython/frontend/html/notebook/static/js/textcell.js

@@ -155,6 +155,7 @@ var IPython = (function (IPython) {
 
 
     TextCell.prototype.fromJSON = function (data) {
+        IPython.Cell.prototype.fromJSON.apply(this, arguments);
         if (data.cell_type === this.cell_type) {
             if (data.source !== undefined) {
                 this.set_text(data.source);
@@ -167,7 +168,7 @@ var IPython = (function (IPython) {
 
 
     TextCell.prototype.toJSON = function () {
-        var data = {};
+        var data = IPython.Cell.prototype.toJSON.apply(this);
         data.cell_type = this.cell_type;
         data.source = this.get_text();
         return data;