introduce commit_and_tx_diff__topo & commit_diff__topo

Multiple fixes / changes. _bugs introduced_

Changes:
graph has two change functions (i.e. the internal API):
- commit_and_tx_diff_topo
  This currently transmits, later will optimistically apply first
- commit_diff__topo
  This only applies. Used on the ajax success path for commit_and_tx_diff__topo
  and when changes are only local.
  It signals on the diffBus
- diffBus - a Bacon.Bus that all UI listens to
  - selection UI
  - node/link dialogs
  - main view (rz_core/update_view__graph)

Small changes:
whitespace
rename filer->filter

Completely broken:
 - text entry. should use commit_diff__topo

Problems introduced:
selection doesn't work correctly.
editing not verified yet

6 files changed, 231 insertions, 229 deletions

diff --git a/src/client/model/graph.js b/src/client/model/graph.js
index 12190cd7..b97fd117 100644
--- a/src/client/model/graph.js
+++ b/src/client/model/graph.js
@@ -9,7 +9,10 @@ function Graph() {
 
     var nodes = [],
         id_to_node_map = {},
+        id_to_node_index_map = {},
         links = [],
+        id_to_link_map = {},
+        id_to_link_index_map = {},
         diffBus = new Bacon.Bus();
 
     // All operations done on the graph. When the server is used (i.e. always) this
@@ -29,18 +32,36 @@ function Graph() {
      */
     this.addNode = function(spec) {
         var node = this.__addNode(spec);
-        if (node) {
-            return node;
-        }
+        return node;
+    }
+
+    var nodes_to_touched_links = function (node_id_set) {
+        var touched_links = [];
+
+        node_id_set.forEach(function (n_id) {
+            var n = id_to_node_map[n_id];
+            links.forEach(function (link) {
+                if ((link['__src'].equals(n)) || (link['__dst'].equals(n))) { // compare by id
+                    touched_links.push(link);
+                }
+            });
+        });
+        console.dir(touched_links);
+
+        return touched_links.map(function(l){ return l.id; });
     }
 
     /**
      *
      * @param a topo_diff but that might be missing a few things, sanitize it first.
      * all sanitation should be idempotent, but probably isn't.
+     *
+     * NOTE: currently this function transmits only. Later we want to optimistically
+     * first commit and then transmit.
      */
-    this.commit_diff__topo = function (topo_diff, on_success, on_error) {
+    this.commit_and_tx_diff__topo = function (topo_diff) {
         var name_to_node = {};
+        $.merge(topo_diff.link_set_rm, nodes_to_touched_links(topo_diff.node_set_rm));
         topo_diff.node_set_add = topo_diff.node_set_add.map(function(n) {
             if (n.id === undefined) {
                 var existing = findNodeByName(n.name);
@@ -83,16 +104,13 @@ function Graph() {
         topo_diff.node_set_add = topo_diff.node_set_add.filter(function(n) {
             return !hasNodeByName(n.name);
         });
+
         var graph_on_success = function(diff) {
-            on_backend__diff(diff);
-            if (on_success) {
-                on_success(nodes);
-            }
+            commit_diff__topo(diff);
         }
         var graph_on_error = function(error) {
-            if (on_error) {
-                on_error(error);
-            }
+            console.log('error:');
+            console.dir(error);
         }
         console.log("COMMIT DIFF   TOPO");
         console.dir(topo_diff);
@@ -136,8 +154,7 @@ function Graph() {
         }
 
         util.assert(undefined != node.id, '__addNode: node id missing');
-        nodes.push(node);
-        id_to_node_map[node.id] = node;
+        _node_add_helper(node);
         console.log('__addNode: node added: id: ' + node.id + ' state ' + node.state +
             (rz_config.backend_enabled && peer_notify ? ' _commit_ ' : ''));
 
@@ -160,70 +177,45 @@ function Graph() {
     }
     this.__addNode = __addNode;
 
-    this._remove_node_set = function(ns, peer_notify) {
-
-        peer_notify = undefined === peer_notify ? true : peer_notify;
-
-        var cascade_link_rm_set = [], // track cascading link removals
-            has_non_temp = false;
-        for (var j = 0; j < ns.length; j++) {
-            var n = ns[j];
-            var i = 0;
-            if (n.state != 'temp') {
-                has_non_temp = true;
-            }
-            while (i < links.length) {
-                var link = links[i];
-                if ((link['__src'].equals(n)) || (link['__dst'].equals(n))) { // compare by id
-                    links.splice(i, 1);
-                    cascade_link_rm_set.push(link);
-                }
-                else {
-                    i++;
-                }
-            }
-            var index = findNodeIndex(n.id, n.state);
-            if (index !== undefined) {
-                nodes.splice(index, 1);
-
-                util.assert(undefined != n.id, '_remove_node_set: node id missing');
-                delete id_to_node_map[n.id];
-            }
-        }
+    var _node_remove_helper_by_index = function (i) {
+        var id = nodes[i].id;
+        delete id_to_node_index_map[id];
+        delete id_to_node_map[id];
+        nodes.splice(i, 1);
+    }
 
-        cascade_link_rm_set.forEach(function(n){
-            console.log('_remove_node_set: removed node: id: ' + n.id);
-        });
+    var _node_add_helper = function (node) {
+        id_to_node_map[node.id] = node;
+        id_to_node_index_map[node.id] = nodes.length;
+        nodes.push(node);
+        util.assert(nodes[id_to_node_index_map[node.id]] === node, "master?");
+    }
 
-        if (rz_config.backend_enabled && peer_notify && has_non_temp) {
-            var topo_diff = model_diff.new_topo_diff({
-                node_set_rm : ns.map(function(n){ return n.id; }),
-                link_set_rm : cascade_link_rm_set.map(function(l){ return l.id; }),
-            });
-            var on_success = function(){
-                // FIXME: handle possible outcomes:
-                // - rm cascade of connected links
-            };
-            var on_error = function(){
-                // TODO: add problem emblem to node
-            };
-            rz_api_backend.commit_diff__topo(topo_diff, on_success, on_error);
-        }
+    var _link_remove_helper_by_index = function (i) {
+        var id = links[i].id;
+        delete id_to_link_index_map[id];
+        delete id_to_link_map[id];
+        links.splice(i, 1);
     }
 
-    this.removeNode = function(id) {
-        var n = find_node__by_id(id);
-        if (n === undefined) {
-            console.log('bug: nonexistent node cannot be removed: ' + id);
-            return;
-        }
-        this._remove_node_set([n]);
+    var _link_add_helper = function (link) {
+        id_to_link_map[link.id] = link;
+        id_to_link_index_map[link.id] = links.length;
+        links.push(link);
+        util.assert(links[id_to_link_index_map[link.id]] === link, "whaaa?");
     }
 
-    this.removeNodes = function(n_filer) {
-        var ns = find_node_set_by_filer(n_filer);
-        this._remove_node_set(ns);
+    var _remove_node_set = function(node_id_set) {
+        node_id_set.forEach(function (id) {
+            if (undefined === id_to_node_map[id]) {
+                console.log("warning: server returned an id we don't have " + id);
+                return;
+            }
+            _node_remove_helper_by_index(id_to_node_index_map[id]);
+            console.log('_remove_node_set: ' + id);
+        });
     }
+    this._remove_node_set = _remove_node_set;
 
     /**
      *
@@ -417,7 +409,7 @@ function Graph() {
 
         if (undefined == existing_link) {
 
-            links.push(link);
+            _link_add_helper(link);
 
             if (rz_config.backend_enabled && peer_notify){
                 var topo_diff = model_diff.new_topo_diff({
@@ -451,15 +443,15 @@ function Graph() {
             attr_diff.add_link_attr_write(link.id, key, new_link_spec[key]);
         }
 
-        var on_ajax_success = function(id_to_link_map){
+        var on_ajax_success = function(id_to_link_map) {
             var link_id = link.id; // original link id
-            if (id_to_link_map[link_id].id != link_id){
+            if (id_to_link_map[link_id].id != link_id) {
                 // TODO: handle incoming ID update
                 util.assert(false, 'update_link: id attr change');
             }
 
             var ret_link = id_to_link_map[link_id];
-            for (var key in ret_link){
+            for (var key in ret_link) {
                 if ('id' == key){
                     continue;
                 }
@@ -575,8 +567,17 @@ function Graph() {
         return this._editProperty(id, state, 'type', newtype);
     }
 
+    function new_attr_diff_prop_value(id, prop, value)
+    {
+        var diff = rz_diff.new_attr_diff();
+
+        diff.add_node_attr_write(id, prop, value);
+        return diff;
+    }
+
     this._editProperty = function(id, state, prop, value) {
         var n = find_node__by_id(id);
+
         if (state !== null && state != n.state){
             return false;
         }
@@ -589,6 +590,7 @@ function Graph() {
             console.log('warning: I hope robot is doing this not-through-backend property change');
         }
         n[prop] = value;
+        diffBus.push(new_attr_diff_prop_value(id, prop, value));
         return true;
     }
 
@@ -601,56 +603,34 @@ function Graph() {
         }
     }
 
-    var linkGetIndexFromId = function(link_id) {
-        for (var i = 0 ; i < links.length ; ++i) {
-            if (links[i].id == link_id) {
-                return i;
-            }
-        }
-    }
+    this.removeLink = function(link) {
 
-    this.removeLink = function(link, on_success, on_error) {
-        var i;
+        util.assert(link.id !== undefined, 'bug: link without an id');
 
-        if (link.id === undefined) {
-            console.log('bug: link without an id');
-        }
+        this._remove_link_set([link]);
+    }
 
-        function graph_on_success(ret) {
-            ret.link_rm.forEach(function (link_id) {
-                links.splice(linkGetIndexFromId(link_id), 1);
-            });
-            if (on_success) {
-                on_success();
+    var _remove_link_set = function(link_id_set) {
+        link_id_set.forEach(function (id) {
+            var index = id_to_link_index_map[id];
+            if (undefined === index) {
+                console.log("warning: server returned an id we don't have " + id);
+                return;
             }
-        }
+            _link_remove_helper_by_index(index);
+            console.log('_remove_link_set: ' + id);
+        });
+    }
+    this._remove_link_set = _remove_link_set;
 
-        for (i = 0 ; i < links.length; ++i) {
-            if (link.id !== undefined) {
-                if (link.id === links[i].id) {
-                    if (link.state == 'temp') {
-                        links.splice(i, 1);
-                        if (on_success) {
-                            on_success();
-                        }
-                    } else {
-                        if (rz_config.backend_enabled) {
-                            var topo_diff = model_diff.new_topo_diff({
-                                link_set_rm: [link.id]
-                                });
-                            rz_api_backend.commit_diff__topo(topo_diff, graph_on_success, on_error);
-                        }
-                    }
-                    return;
-                }
-            } else {
-                if (link.__src.id === links[i].__src.id && link.__dst.id === links[i].__dst.id) {
-                    links.splice(i, 1);
-                    return;
-                }
-            }
-        }
-        console.log('bug: attempt to remove non existant link');
+    this.removeNodes = function(state) {
+        var temp_node_ids = nodes.filter(function (n) { return n.state == state; })
+                                 .map(function (n) { return n.id; }),
+            topo_diff = model_diff.new_topo_diff({
+                node_set_rm : temp_node_ids,
+            });
+
+        this.commit_and_tx_diff__topo(topo_diff);
     }
 
     this.removeLinks = function(state) {
@@ -722,9 +702,9 @@ function Graph() {
     }
 
     /**
-     * @param filer: must return true in order for node to be included in the returned set
+     * @param filter: must return true in order for node to be included in the returned set
      */
-    var find_node_set_by_filer = function(filter) {
+    var find_node_set_by_filter = function(filter) {
         var ret = [];
         nodes.map(function(n){
            if (true == filter(n)){
@@ -752,13 +732,6 @@ function Graph() {
         return foundNodes;
     }
 
-    var findNodeIndex = function(id, state) {
-        for (var i = 0; i < nodes.length; i++) {
-            if ((id && nodes[i].id === id) || (state && nodes[i].state === state))
-                return i;
-        };
-    }
-
     function clear() {
         nodes.length = 0;
         links.length = 0;
@@ -801,15 +774,18 @@ function Graph() {
         delete l_ptr.__src_id;
         delete l_ptr.__dst_id;
         var link_spec = l_ptr;
+        var link_spec = l_ptr;
         var link = model_core.create_link_from_spec(src, dst, link_spec);
         var l = addLink(link, false);
     }
 
-    function on_backend__diff(data) {
-        data['node_set'].map(on_backend__node_add);
-
-        data['link_set'].map(on_backend__link_add);
-        diffBus.push(data);
+    function commit_diff__topo(diff) {
+        // done under protest
+        diff.node_set_add.map(on_backend__node_add);
+        diff.link_set_add.map(on_backend__link_add);
+        _remove_link_set(diff.link_set_rm);
+        _remove_node_set(diff.node_set_rm);
+        diffBus.push(diff);
     }
 
     /**
@@ -820,8 +796,8 @@ function Graph() {
     // @ajax-trans
     function load_from_backend(on_success) {
 
-        function on_success__ajax(data) {
-            on_backend__diff(data);
+        function on_success__ajax(diff) {
+            commit_diff__topo(diff);
             undefined != on_success && on_success()
         }
 
diff --git a/src/client/rz_core.js b/src/client/rz_core.js
index f0cfb8a9..91a25196 100644
--- a/src/client/rz_core.js
+++ b/src/client/rz_core.js
@@ -1,7 +1,7 @@
 "use strict"
 
-define(['jquery', 'd3', 'consts', 'rz_bus', 'util', 'model/graph', 'model/core', 'view/helpers', 'view/view', 'rz_observer', 'view/selection', 'rz_config', 'rz_mesh'],
-function($, d3, consts, rz_bus, util, model_graph, model_core, view_helpers, view, rz_observer, selection, rz_config, rz_mesh) {
+define(['jquery', 'd3', 'consts', 'rz_bus', 'util', 'model/graph', 'model/core', 'view/helpers', 'view/view', 'rz_observer', 'view/selection', 'rz_config', 'rz_mesh', 'model/diff'],
+function($,        d3,   consts,   rz_bus,   util,   model_graph,   model_core,   view_helpers,   view,        rz_observer,   selection,        rz_config,   rz_mesh,   model_diff) {
 
 var addednodes = [],
     vis,
@@ -76,15 +76,11 @@ var svgInput = (function() {
             d = jelement.data().d;
             if (e.which == 13 && newname != d.name) {
                 if (d.hasOwnProperty('__src')) {
-                    graph.update_link(d, {name: newname}, function() {
-                        update_view__graph(true);
-                    });
+                    graph.update_link(d, {name: newname});
                 } else {
-                    graph.update_node(d, {name: newname}, function() {
-                        update_view__graph(true);
-                    });
-                    // TODO - 'updating' graphic
+                    // TODO - display hourglass
                     // TODO - use promises to make A follows B readable.
+                    graph.update_node(d, {name: newname});
                 }
             }
             hide();
@@ -221,9 +217,21 @@ var initDrawingArea = function () {
 
     graph = new model_graph.Graph();
     graph.diffBus.onValue(function (diff) {
-        var relayout = false == rz_diff.is_attr_diff(diff);
+        var relayout = (false == model_diff.is_attr_diff(diff));
+        console.log('*************');
+        console.dir(diff);
         update_view__graph(relayout);
     });
+    // TODO: we are listening both on graph.diffBus and selection.selectionChangedBus,
+    //  but the relation is actually:
+    //
+    //  diffBus -> SelectedNodesBus -> us
+    //  diffBus         ->             us
+    //
+    //  we need to deduplicate this event
+    // but there is no coordination, resulting in double updates.
+    selection.selectionChangedBus.onValue(
+        function() { update_view__graph(false); });
 
     var user_id = $('#user_id'),
         user = user_id.text();
@@ -277,9 +285,7 @@ var initDrawingArea = function () {
 
     // $('#canvas_d3').dblclick(canvas_handler_dblclick); - see #138
     if (rz_config.backend_enabled){
-        graph.load_from_backend( function(){
-            update_view__graph(false);
-        });
+        graph.load_from_backend();
     }
 }
 
@@ -333,8 +339,9 @@ function canvas_handler_dblclick(){
     var n = model_core.create_node__set_random_id();
     n.name = ''; // will be set by user
 
-    graph.addNode(n);
-    update_view__graph();
+    graph.commit_and_tx_diff__topo(model_diff.new_topo({
+            node_set_add : [n].map(model_util.adapt_format_write_node),
+        }));
 
     var n_ve = locate_visual_element(n); // locate visual element
 
@@ -357,14 +364,15 @@ function canvas_handler_dblclick(){
 /**
  * update view: graph
  */
-function update_view__graph(no_relayout) {
+function update_view__graph(relayout) {
     var node,
         link,
         link_g,
         linktext,
         nodetext,
         unselected_link_group = document.querySelector('#link-group'),
-        selected_link_group = document.querySelector('#selected-link-group');
+        selected_link_group = document.querySelector('#selected-link-group'),
+        relayout = relayout || true;
 
     link = vis.selectAll("g.link")
         .data(graph.links(), function(d) { return d.id; });
@@ -395,15 +403,10 @@ function update_view__graph(no_relayout) {
 
             view.edge_info.on_delete(function () {
                 view.edge_info.hide();
-                graph.removeLink(that.link, function() {
-                    update_view__graph(true);
-                }, function() {
-                    console.log("error: could not remove link");
-                });
+                graph.removeLink(that.link);
             });
             view.edge_info.show(d);
             selection.update([src, dst]);
-            update_view__graph(true);
         });
 
     link.attr("class", function(d, i){
@@ -621,12 +624,12 @@ function update_view__graph(no_relayout) {
     force.nodes(graph.nodes())
         .links(graph.links())
 
-    if (no_relayout) {
+    if (relayout) {
+        force.alpha(0.1).start();
+    } else {
         // XXX If we are stopped we need to update the text of the links at least,
         // and this is the simplest way
         tick();
-    } else {
-        force.alpha(0.1).start();
     }
 }
 
@@ -722,31 +725,39 @@ function tick(e) {
     node.attr('visibility', 'visible');
 }
 
-function showNodeInfo(d, i) {
-    view.node_info.on_save(function(e, form_data) {
+function showNodeInfo(node, i) {
+    var closed = false;
 
-        graph.update_node(d, form_data, function(){
-            var old_type = d.type,
+    view.node_info.on_save(function(e, form_data) {
+        closed = true;
+        graph.update_node(node, form_data, function() {
+            var old_type = node.type,
                 new_type = form_data.type;
 
-            if (new_type != old_type) {
-                view.node_info.show(d);
-            }
-
-            view.node_info.hide();
-            update_view__graph(true);
         });
-
+        view.node_info.hide();
         return false;
     });
 
+    // FIXME - attribute diff, ignore uninteresting diffs via filtering
+    graph.diffBus.onValue(function () {
+        if (closed) {
+            return Bacon.noMore;
+        }
+        view.node_info.show(node);
+    });
+
     view.node_info.on_delete(function() {
-        graph.removeNode(d.id); // async
-        update_view__graph(false);
+        var topo_diff = model_diff.new_topo_diff({
+                node_set_rm: [node.id]
+            });
+        console.log("closing node info");
+        closed = true;
         view.node_info.hide();
+        graph.commit_and_tx_diff__topo(topo_diff);
     });
 
-    view.node_info.show(d);
+    view.node_info.show(node);
 }
 
 function svg_click_handler(e) {
@@ -760,7 +771,7 @@ function svg_click_handler(e) {
     svgInput.hide();
     selection.clear();
     view.hide();
-    update_view__graph(true);
+    update_view__graph(false);
 }
 
 return {
@@ -769,7 +780,7 @@ return {
     load_from_json: function(result) {
         graph.load_from_json(result);
         recenterZoom();
-        update_view__graph(false);
+        update_view__graph(true);
     },
     update_view__graph : update_view__graph,
 }
diff --git a/src/client/textanalysis.js b/src/client/textanalysis.js
index 5e78f416..8ee4b05f 100644
--- a/src/client/textanalysis.js
+++ b/src/client/textanalysis.js
@@ -68,7 +68,8 @@ var typeStack = [];
 
 var lastnode;
 
-var sugg = {}, // suggestions for autocompletion of node names
+var sugg_name = {},
+    id_to_name_map = {},
     suggestions_options = new Bacon.Bus(); // TODO: Property: same as bus, but with initial value
 
 var ANALYSIS_NODE_START = 'ANALYSIS_NODE_START';
@@ -80,16 +81,27 @@ function selectedType()
     return nodetypes[typeindex];
 }
 
-function autoSuggestAddName(name)
+/*
+ * id - undefined | node id 
+ *
+ */
+function auto_suggest__update_name(name, id)
 {
+    if (id !== undefined && id_to_name_map[id] !== undefined) {
+        delete sugg[id_to_name_map[id]];
+        id_to_name_map[id] = name;
+    }
     /* note that name can contain spaces - this is ok. We might want to limit this though? */
     sugg[name] = 1;
     suggestions_options.push(sugg);
 }
 
-function autoSuggestRemoveName(name)
+function auto_suggest_remove_name(name, id)
 {
     delete sugg[name];
+    if (id !== undefined) {
+        delete sugg[id];
+    }
     suggestions_options.push(sugg);
 }
 
@@ -349,7 +361,7 @@ var textAnalyser = function (newtext, finalize) {
     if (finalize === true) {
         typesetter = "perm";
         for (n = 0; n < token_set_new_node_names.length; n++) {
-            autoSuggestAddName(token_set_new_node_names[n]);
+            auto_suggest__update_name(token_set_new_node_names[n]);
         }
     } else {
         typesetter = "temp";
@@ -467,7 +479,7 @@ var textAnalyser = function (newtext, finalize) {
             }
         } else {
             // REINITIALISE GRAPH (DUMB BUT IT WORKS)
-            graph.removeNodes(function(n){ return "temp" == n.state; });
+            graph.removeNodes("temp");
             graph.removeLinks("temp");
 
             if (!finalize) { // finalize done via topo diff below
@@ -504,22 +516,12 @@ var textAnalyser = function (newtext, finalize) {
             // broadcast diff:
             //    - finalize?
             //    - broadcast_diff requested by caller
-            var on_success = function (ret) {
-                console.dir(ret);
-                rz_core.update_view__graph();
-            }
-            var on_error = function () {
-                console.log('askeeeeeeeeeeeeew');
-            }
             // drop bubble node
             ret.node_set_add = ret.node_set_add.filter(function(n) { return n.type != 'bubble'; });
             // drop and links
             ret.link_set_add = ret.link_set_add.filter(function(l) { return l.name !== 'and'; });
-            graph.commit_diff__topo(ret, on_success, on_error);
+            graph.commit_and_tx__topo(ret);
         }
-
-        // update graph if not going through backend
-        rz_core.update_view__graph(!finalize && comp.graph_same);
     };
 
     if (finalize) {
@@ -532,24 +534,31 @@ var textAnalyser = function (newtext, finalize) {
 function init(graph)
 {
     // deal with new nodes
-    graph.diffBus.filter(function (diff) {
-        return diff.nodes && diff.nodes.added;
-    }).map(function (diff) {
-        return diff.nodes.added.toLowerCase();
-    }).onValue(autoSuggestAddName);
+    graph.diffBus
+        .filter(function (diff) {
+            return diff.node_set_add && diff.node_set_add.length > 0;
+        })
+        .map(".node_set_rm")
+        .flatMap(Bacon.fromArray)
+        .map(".name")
+        .map(function (name) { return name.toLowerCase(); })
+        .onValue(auto_suggest__update_name);
 
     // deal with renamed links
-    graph.diffBus.filter(function (diff) {
-        return diff && diff.changed && diff.changed.links;
-    }).map(function (diff) {
-        return diff.changed.links;
-    }).flatMap(Bacon.fromArray)
-    .onValue(function (diff) {
-        console.log('renamed link ' + diff.removed + ' -> ' + diff.added);
-        autoSuggestRemoveName(diff.removed.toLowerCase());
-        autoSuggestAddName(diff.added.toLowerCase());
-    });
-
+    /*
+    // TODO renamed links - broken in server, DBO_attr_diff_commit doesn't return an Attr_Diff
+    graph.diffBus
+        .filter(function (diff) {
+            return diff && diff.link_set_rm && diff.link_set_rm.length > 0;
+        })
+        .map(".link_set_rm")
+        .flatMap(Bacon.fromArray)
+        .onValue(function (name) {
+            var name = TODO,
+                id = TODO;
+            auto_suggest__update_name(name, id);
+        });
+    */
     // TODO renamed nodes, plus reuse part of the pipeline.
 }
 
diff --git a/src/client/textanalysis.ui.js b/src/client/textanalysis.ui.js
index a3b3becf..b06978c1 100644
--- a/src/client/textanalysis.ui.js
+++ b/src/client/textanalysis.ui.js
@@ -107,7 +107,6 @@ function changeType(arg) {
         typeselection.showChosenType(nodetype);
         rz_core.graph.findCoordinates(id);
     }
-    rz_core.update_view__graph(true);
 }
 
 return {
diff --git a/src/client/view/selection.js b/src/client/view/selection.js
index 27842e11..9a87494a 100644
--- a/src/client/view/selection.js
+++ b/src/client/view/selection.js
@@ -1,17 +1,31 @@
-define(['rz_core'],
-function(rz_core) {
+define(['rz_core', 'Bacon'],
+function(rz_core,   Bacon) {
 
 function get_rz_core()
 {
     // circular dependency on rz_core, so require.js cannot solve it.
     if (rz_core === undefined) {
         rz_core = require('rz_core');
-        rz_core.graph.diffBus.onValue(updateSelectionOnDiff);
+        listen_on_diff_bus(rz_core.graph.diffBus);
     }
     return rz_core;
 }
 
-var selected_nodes = [];
+var selected_nodes = [],
+    selectionChangedBus = new Bacon.Bus();
+
+function listen_on_diff_bus(diffBus)
+{
+    diffBus
+        .filter(".node_set_rm")
+        .onValue(function (diff) {
+            var node_node_cmp = (function (a, b) { return a.id > b.id; }),
+                node_id_cmp = (function (a, b) { return a.id === b ? 0 : (a.id > b ? 1 : -1); });
+
+            updateSelectedNodesBus(sortedArrayDiff(selected_nodes.sort(node_node_cmp),
+                                             diff.node_set_rm.sort(), node_id_cmp));
+        });
+}
 
 function sortedArrayDiff(a, b, a_cmp_b)
 {
@@ -38,18 +52,10 @@ function sortedArrayDiff(a, b, a_cmp_b)
     return ret;
 }
 
-function updateSelectionOnDiff(diff)
+function updateSelectedNodesBus(new_selected_nodes)
 {
-    var node_node_cmp = (function (a, b) { return a.id > b.id; }),
-        node_id_cmp = (function (a, b) { return a.id === b ? 0 : (a.id > b ? 1 : -1); });
-
-    if (diff.nodes.removed === undefined || selected_nodes.length == 0) {
-        return;
-    }
-    console.log("selection enter: " + String(selected_nodes.map(function(x) { return x.id; })));
-    console.log("removed nodes enter: " + String(diff.nodes.removed));
-    selected_nodes = sortedArrayDiff(selected_nodes.sort(node_node_cmp), diff.nodes.removed.sort(), node_id_cmp);
-    console.log("selection exit: " + String(selected_nodes.map(function(x) { return x.id; })));
+    selected_nodes = new_selected_nodes;
+    selectionChangedBus.push(selected_nodes);
 }
 
 function byVisitors(node_selector, link_selector) {
@@ -66,7 +72,7 @@ function connectedComponent(nodes) {
         link,
         data;
 
-    selected_nodes = nodes.map(function(x) { return x; });
+    updateSelectedNodesBus(nodes.map(function(x) { return x; }));
 
     for (i = 0 ; i < connected.nodes.length ; ++i) {
         data = connected.nodes[i];
@@ -137,6 +143,7 @@ return {
     update: update,
     selected_class: selected_class,
     node_selected: node_selected,
+    selectionChangedBus: selectionChangedBus,
 };
 
 });
diff --git a/src/server/model/graph.py b/src/server/model/graph.py
index 87c0a8b0..76368a24 100644
--- a/src/server/model/graph.py
+++ b/src/server/model/graph.py
@@ -106,9 +106,9 @@ class Topo_Diff(object):
 
     def to_json_dict(self):
         ret = {k: getattr(self, k) for k in ['link_set_rm',
-                                              'node_set_rm',
-                                              'node_set_add',
-                                              'link_set_add'] }
+                                             'node_set_rm',
+                                             'node_set_add',
+                                             'link_set_add'] }
         return ret
 
     def __init__(self, link_set_rm=[],