I'm using cytoscape.js and cytoscape.js-expand-collapse to create dynamic hierarchies in my graph structure. I would like to be able to dynamically create a collapsed(merged) node that could potentially be expanded out, removed or possibly re-merged with additional nodes. I am having trouble whenever I call nodes.move({parent:null}). They become detached from the graph and I cannot re-attach them to a new parentNode. If I call restore on them I will see errors saying they already exist in the graph.
merge and unmerge by itself works fine in a simple case of no existing collapsed nodes. However calling merge on something that already contains a compound collapsed node breaks things. I would get the resulting merged node without the children of the previously collapsed merge candidate
Update #1 I've realized my problem was returning the wrong moved nodes. Calling .move on a collection returns a new set of nodes. so the unmerge should return those instead.
Update #2 cytoscape-expand-collapse utility does some internal book-keeping during the parent node collapse/expand by tucking away node data in 'originalEnds' data prop on the meta edges. so, if I'm now altering the graph dynamically by moving nodes in/out of parents these originalEnds pointers get out of sync causing infinite loops. I am doing some additional node tracking of my own as a workaround.
function merge(nodes){
//if one of the nodes is a compound itself, first uncollapse, then merge
var collapsed = nodes.filter(function(c){return typeof c.data('collapsedChildren')!=='undefined';});
if (collapsed.length>0) {
// for now just assume collapsed is a length of 1
var unmerged = unmerge(collapsed); //unmerged should be now the former collapsed children
nodes = nodes.subtract(collapsed).union(unmerged.nodes());
}
var parentNode = cy.add({group:'nodes', data: {id: parentID}});
nodes.move({parent: parentID});
collapseApi.collapse(parentNode);
return parentNode;
}
function unmerge(parentNode){
collapseApi.expand(parentNode);
var children = parentNode.children();
var moved = children.move({parent:null});
//at this point children become "detached" from the graph
// .removed() returns true, however, calling restore() logs an error and they are still technically in the graph
parentNode.remove();
return moved;
}
ele.move() has a more convenient implementation in cytoscape>=3.4: The elements are modified in-place instead of creating replacement elements.
Old code that uses the returned collection from ele.move() will still work. New code can be simplified by not having to use the returned collections at all.
Related
I am using vue-cytoscape to render a graph and navigate through a tree-like data structure.
My goal is to expand parent nodes and keep their position in the graph. I would like to simply add the new children nodes.
My approach is to lock current nodes, add the children and unlock the nodes.
this.cy.nodes().lock()
for(let d of data){
this.cy.add(d)
}
this.cy.elements().layout(this.config.layout).run()
setTimeout(() => {this.cy.nodes().unlock()}, 2000) // Give some time for the layout to render before unlocking nodes.
The problem is that the layouts do not consider the locked state of the nodes. Only the new nodes are moved around, which is fine. But the layout is not respected. I am under the impression that the layout calculates a new position for all nodes, but then moves only nodes that are unlocked.
According to this GitHub issue, some layout algorithm should handle locked nodes. I am using the following layouts and none seem to consider locked nodes.
Cola
Fcose
Dagre
avsdf
grid
concentric
Please try calling the layout function only on the added nodes:
var eles = cy.add(data); // refer to http://js.cytoscape.org/#cy.add for adding nodes
eles.layout(this.config.layout).run();
If you don't want nodes to move when calling the layout function, you can exclude them from the rendering. While calling cy.add(), the function returns an object with every added element inside (see var eles = ... in the code).
Problem:
In the screenshot below, I have a node 300-9885-00X along with its TreeNodeCollection (in the red square). A little bit lower, we find the 300-9885-00X again, I want to insert the TreeNodeCollection that we found earlier, into that node ...
Background Information
I have a recursive program that goes through AutoCAD / SolidEdge assemblies. It opens the documents and prints the assemblies, and their children, and so on (recursively) ...
Green color means it is printed
Orange means it has already been printed before, so we don't need to print it again...
Question:
How do we insert an existing TreeNodeCollection into a TreeNode?
Knowing:
The location of the TreeNodeCollection
The location of the node in which I want to insert the collection into
The following variable TreeNodes contains my collection. Must I loop through the collection in order to add its text?
You can't add a TreeNodeCollection to a Node. You must loop through the TreeNodeCollection and add the nodes individually like so:
For j As Integer = 0 To TreeNodes.Count - 1
n.Nodes.Add(TreeNodes(j).Clone())
Next
Notice I used .Clone(). This is due to the insertion of an already existing node. You can't do that, you must either delete the existing one or clone it. In my case, I had to clone it.
// Get the '_NodesCollection' from the '_parentNode' TreeNode.
TreeNodeCollection _Nodes = _parentNode.FirstNode.Nodes;
// Create an array of 'TreeNodes'.
TreeNode[] Nodes = new TreeNode[_Nodes.Count];
// Copy the tree nodes to the 'Nodes' array.
_Nodes.CopyTo(Nodes, 0);
// Remove the First Node & Children from the ParentNode.
_parentNode.Nodes.Remove(_parentNode.FirstNode);
// Remove all the tree nodes from the '_parentNode' TreeView.
_parentNode.Nodes.Clear();
// Add the 'Nodes' Array to the '_parentNode' ParentNode.
_parentNode.Nodes.AddRange(Nodes);
// Add the Child Nodes to the TreeView Control
TvMap.Nodes.Add(_parentNode);
I'm using Dojo dnd version 1.7.2 and it's generally working really well. I'm happy.
My app maintains many arrays of items, and as the user drags and drops items around, I need to ensure that my arrays are updated to reflect the contents the user is seeing.
In order to accomplish this, I think I need to run some code around the time of Source.onDndDrop
If I use dojo.connect to set up a handler on my Source for onDndDrop or onDrop, my code seems to get called too late. That is, the source that's passed to the handler doesn't actually have the item in it any more.
This is a problem because I want to call source.getItem(nodes[0].id) to get at the actual data that's being dragged around so I can find it in my arrays and update those arrays to reflect the change the user is making.
Perhaps I'm going about this wrong; and there's a better way?
Ok, I found a good way to do this. A hint was found in this answer to a different question:
https://stackoverflow.com/a/1635554/573110
My successful sequence of calls is basically:
var source = new dojo.dnd.Source( element, creationParams );
var dropHandler = function(source,nodes,copy){
var o = source.getItem(nodes[0].id); // 0 is cool here because singular:true.
// party on o.data ...
this.oldDrop(source,nodes,copy);
}
source.oldDrop = source.onDrop;
source.onDrop = dropHandler;
This ensures that the new implementation of onDrop (dropHandler) is called right before the previously installed one.
Kind'a shooting a blank i guess, there are a few different implementations of the dndSource. But there are a some things one needs to know about the events / checkfunctions that are called during the mouseover / dnddrop.
One approach would be to setup checkAcceptance(source, nodes) for any target you may have. Then keep a reference of the nodes currently dragged. Gets tricky though, with multiple containers that has dynamic contents.
Setup your Source, whilst overriding the checkAcceptance and use a known, (perhaps global) variable to keep track.
var lastReference = null;
var target = dojo.dnd.Source(node, {
checkAcceptance(source, nodes) : function() {
// this is called when 'nodes' are attempted dropped - on mouseover
lastReference = source.getItem(nodes[0].id)
// returning boolean here will either green-light or deny your drop
// use fallback (default) behavior like so:
return this.inhertied(arguments);
}
});
Best approach might just be like this - you get both target and source plus nodes at hand, however you need to find out which is the right stack to look for the node in. I believe it is published at same time as the event (onDrop) youre allready using:
dojo.subscribe("/dnd/drop", function(source, nodes, copy, target) {
// figure out your source container id and target dropzone id
// do stuff with nodes
var itemId = nodes[0].id
}
Available mechanics/topics through dojo.subscribe and events are listed here
http://dojotoolkit.org/reference-guide/1.7/dojo/dnd.html#manager
I am trying to add children tree nodes to a non-Root node dynamically when it's selected.
This is how I implemented it:
First, I populate my tree with a TreeStore then to dynamically add children tree nodes, I handle it on the itemexpand event in tree Controller.
//pThis is a NodeInterface obj of the selected node
itemexpand: function (pThis, pEOpts) {
//type is an attribute that I added so that I know what type of node that got selected
if (pThis.raw.type === 'Staff' && !pThis.hasChildNodes()) {
var staffNodeAry = [{text:"Teachers", type:"ChildStaff", leaf: false},
{text:"Principals", type:"ChildStaff", leaf: false}];
pThis.appendChild(staffNodeAry);
}
}
This worked quite good because I am able to see both "Teachers" and "Principals" node under "Staff" type but there are 2 issues that I found so far:
1) There's this error on the console:
Uncaught TypeError: Cannot read property 'internalId' of undefined
I don't know why but if anyone could enlighten that would be great.
2) When I expand either "Teachers" and "Principals", the NodeInterface obj that's returned by itemexpand has an undefined raw object.
So I couldn't do this: pThis.raw.type
From my understanding, I don't need to create a new TreeStore to add any new children nodes, I thought that by creating an array of objects that adhere to NodeInterface should be enough but I might be wrong.
If anyone could point me to the right direction, that would be great.
Handi
More info:
What I did was actually following the ExtJs 4 documentation so I believe this is a bug on ExtJs 4 framework.
I also tested this with Extjs-4.1.0-rc3 and it also produced the same error.
I have resolved this issue changing the event itemexpand with the event afteritemexpand. I have no documentation to justify this. The debugger says to me that the view listen for the itemexpand event and do something that goes wrong if add a node manually...
For the question number 2: you have no raw object because it is created by the reader of the store after the load operation. So if you add a node by hand the raw object does not exists.
http://docs.sencha.com/ext-js/4-1/#!/api/Ext.data.Model-property-raw
The documentation for .appendChild() functions says:
node : Ext.data.NodeInterface/Ext.data.NodeInterface[]
The node or Array of nodes to append
And you are trying to append an array of 2 objects, but they are not "NodeInterface" instances. So you should create them properly like so:
var nodeToAppend1 = pThis.createNode({text:"Teachers", type:"ChildStaff", leaf: false});
pThis.appendChild(nodeToAppend1);
I remember making the same mistake a year ago, so I hope this helps.
I think it happens because your Ext.TreePanel working asyncroniously. So add process is:
Append Child, add virtual child leaf to your tree, with red mark in corner
Call store's create api
Receive response, if it success=true, change with virtual
The goal of changing is set internakId property, so you can add new child only after this change happens. I think better is write some recursive function and bind it to store's added event
tree.getStore().on('update', addChild);
or
tree.getStore().load({
success: function() {
addChild()
});
I am new to libxml. I would like to write 1 loop to loop through all the children of a child node etc. e.g.
<par>i want to <bold>loop <italic>through </italic> all</bold> children in this node</par>
At the moment my looping code look as follows but I only get the "bold" node and not the "italic" child.
if (xmlStrEqual(node->name, BAD_CAST "p")) {
xmlNodePtr child = node->children;
while (child != NULL) {
child = child->next;
}
}
It is conceivable that the node structure could grow to 4-5 elements, so I need a solution which is more robust that putting while loops within while loops. Any help would be appreciated please.
The xmlTree interface you're using is heirarchical. <par> has 3 children - the text before <bold>, <bold> itself, and the text after. <bold> has children of its own, which includes <italic>. The node->children list only contains the immediate children of a node.
There are a couple ways to get the behavior that you want.
While processing child, you can recursively process child->children to get to <bold>'s child, which includes <italics>
If you're looking SPECIFICALLY for that <itallic> (or for a set of specific nodes), you can use an XPath expression, such as "par//italic" to find any italic node anywhere beneath par.
http://www.xmlsoft.org/examples/index.html#XPath
You could look at libxml2's xmlTextReader interface rather than this xmlTree. It provides the serial "read through" of the document that you're expecting.
http://xmlsoft.org/xmlreader.html
Each method has its own advantages/disadvantages, depending on what all you're trying to do with your application.