directly export and import lists as csv files, under construction

HISTORY.md

@@ -2,6 +2,9 @@
 
 ## in development
 
+### 2019-01-07
+* Lists, Objects: directly export and import lists as csv files, under construction
+
 ### 2019-01-04
 * Objects, Blocks, Threads: new feature/block: sense colors and sprites anywhere
 * updated German translation 

snap.html

@@ -8,10 +8,10 @@
         <script type="text/javascript" src="src/widgets.js?version=2018-10-02"></script>
         <script type="text/javascript" src="src/blocks.js?version=2019-01-04"></script>
         <script type="text/javascript" src="src/threads.js?version=2019-01-04"></script>
-        <script type="text/javascript" src="src/objects.js?version=2019-01-04"></script>
+        <script type="text/javascript" src="src/objects.js?version=2019-01-07"></script>
         <script type="text/javascript" src="src/gui.js?version=2019-01-02"></script>
         <script type="text/javascript" src="src/paint.js?version=2018-10-02"></script>
-        <script type="text/javascript" src="src/lists.js?version=2018-10-02"></script>
+        <script type="text/javascript" src="src/lists.js?version=2019-01-07"></script>
         <script type="text/javascript" src="src/byob.js?version=2018-11-12"></script>
         <script type="text/javascript" src="src/tables.js?version=2018-10-02"></script>
         <script type="text/javascript" src="src/symbols.js?version=2018-10-02"></script>

src/lists.js

@@ -7,7 +7,7 @@
     written by Jens Mönig and Brian Harvey
     jens@moenig.org, bh@cs.berkeley.edu
 
-    Copyright (C) 2018 by Jens Mönig and Brian Harvey
+    Copyright (C) 2019 by Jens Mönig and Brian Harvey
 
     This file is part of Snap!.
 
@@ -58,11 +58,11 @@
 
 /*global modules, BoxMorph, HandleMorph, PushButtonMorph, SyntaxElementMorph,
 Color, Point, WatcherMorph, StringMorph, SpriteMorph, ScrollFrameMorph,
-CellMorph, ArrowMorph, MenuMorph, snapEquals, Morph, isNil, localize,
+CellMorph, ArrowMorph, MenuMorph, snapEquals, Morph, isNil, localize, isString,
 MorphicPreferences, TableDialogMorph, SpriteBubbleMorph, SpeechBubbleMorph,
 TableFrameMorph, TableMorph, Variable, isSnapObject*/
 
-modules.lists = '2018-March-08';
+modules.lists = '2019-January-07';
 
 var List;
 var ListWatcherMorph;
@@ -80,26 +80,28 @@ var ListWatcherMorph;
 
     setters (linked):
     -----------------
-    cons                - answer a new list with the given item in front
+    cons                    - answer a new list with the given item in front
-    cdr                    - answer all but the first element
+    cdr                     - answer all but the first element
 
     setters (arrayed):
     ------------------
-    add(element, index)    - insert the element before the given slot,
+    add(element, index)     - insert the element before the given slot,
-    put(element, index)    - overwrite the element at the given slot
+    put(element, index)     - overwrite the element at the given slot
-    remove(index)        - remove the given slot, shortening the list
+    remove(index)           - remove the given slot, shortening the list
-    clear()                - remove all elements
+    clear()                 - remove all elements
 
     getters (all hybrid):
     ---------------------
-    length()            - number of slots
+    length()                - number of slots
-    at(index)            - element present in specified slot
+    at(index)               - element present in specified slot
-    contains(element)    - <bool>
+    contains(element)       - <bool>
 
     conversion:
     -----------
-    asArray()            - answer me as JavaScript array
+    asArray()               - answer me as JavaScript array, convert to arrayed
-    asText()            - answer my elements (recursively) concatenated
+    itemsArray()            - answer a JavaScript array shallow copy of myself
+    asText()                - answer my elements (recursively) concatenated
+    asCSV()                 - answer a csv-formatted String of myself
 */
 
 // List instance creation:
@@ -399,6 +401,46 @@ List.prototype.becomeLinked = function () {
     }
 };
 
+List.prototype.asCSV = function () {
+    // RFC 4180
+    // Caution, no error catching!
+    // this method assumes that the list.canBeCSV()
+
+    var items = this.itemsArray(),
+        rows = [];
+    
+    function encodeCell(atomicValue) {
+        var string = atomicValue.toString(),
+            cell;
+        if (string.indexOf('\"') ===  -1 && (string.indexOf('\n') === -1)) {
+            return string;
+        }
+        cell = ['\"'];
+        string.split('').forEach(function (letter) {
+            cell.push(letter);
+            if (letter === '\"') {
+                cell.push(letter);
+            }
+        });
+        cell.push('\"');
+        return cell.join('');
+    }
+
+    if (items.some(function (any) {return any instanceof List; })) {
+        // 2-dimensional table
+        items.forEach(function (item) {
+            if (item instanceof List) {
+                rows.push(item.itemsArray().map(encodeCell).join(','));
+            } else {
+                rows.push(encodeCell(item));
+            }
+        });
+        return rows.join('\n');
+    }
+    // single row
+    return items.map(encodeCell).join(',');
+};
+
 // List testing
 
 List.prototype.equalTo = function (other) {
@@ -447,6 +489,25 @@ List.prototype.equalTo = function (other) {
     return true;
 };
 
+List.prototype.canBeCSV = function () {
+    return this.itemsArray().every(function (value) {
+        return !isNaN(+value) ||
+            isString(value) ||
+            value === true ||
+            value === false ||
+            (value instanceof List && value.hasOnlyAtomicData);
+    });
+};
+
+List.prototype.hasOnlyAtomicData = function () {
+    return this.itemsArray().every(function (value) {
+        return !isNaN(+value) ||
+            isString(value) ||
+            value === true ||
+            value === false;
+    });
+};
+
 // ListWatcherMorph ////////////////////////////////////////////////////
 
 /*

src/objects.js

@@ -83,7 +83,7 @@ BlockEditorMorph, BlockDialogMorph, PrototypeHatBlockMorph, localize,
 TableMorph, TableFrameMorph, normalizeCanvas, BooleanSlotMorph, HandleMorph,
 AlignmentMorph, Process, XML_Element, VectorPaintEditorMorph*/
 
-modules.objects = '2019-January-04';
+modules.objects = '2019-January-07';
 
 var SpriteMorph;
 var StageMorph;
@@ -9567,16 +9567,30 @@ WatcherMorph.prototype.userMenu = function () {
                         function readText(aFile) {
                             var frd = new FileReader();
                             frd.onloadend = function (e) {
-                                myself.target.setVar(
+                                // +++ needs to be refactored
-                                    myself.getter,
+                                if (aFile.type.indexOf("csv") ||
-                                    e.target.result
+                                        aFile.name.split('.').pop()
-                                );
+                                        .toLowerCase() === 'csv') {
+                                    // catch parsing errors
+                                    myself.target.setVar(
+                                        myself.getter,
+                                        Process.prototype.parseCSV(
+                                            e.target.result
+                                        )
+                                    );
+                                } else {
+                                    myself.target.setVar(
+                                        myself.getter,
+                                        e.target.result
+                                    );
+                                }
                             };
 
                             if (aFile.type.indexOf("text") === -1) {
                                 // special cases for Windows
                                 // check the file extension for text-like-ness
                                 if (contains(
+                                    // +++ avoid doubling
                                     ['txt', 'csv', 'xml', 'json', 'tsv'],
                                     aFile.name.split('.').pop().toLowerCase()
                                 )) {
@@ -9620,6 +9634,19 @@ WatcherMorph.prototype.userMenu = function () {
                     );
                 }
             );
+        } else if (this.currentValue instanceof List &&
+                this.currentValue.canBeCSV()) { // +++
+            menu.addItem(
+                'export...',
+                function () {
+                    var ide = myself.parentThatIsA(IDE_Morph);
+                    ide.saveFileAs(
+                        myself.currentValue.asCSV(),
+                        'text/csv;charset=utf-8', // RFC 4180
+                        myself.getter // variable name
+                    );
+                }
+            );
         } else if (this.currentValue instanceof Context) {
             vNames = this.currentValue.outerContext.variables.names();
             if (vNames.length) {