Error incorporating dynamic ports error

GoJS
1

EDIT: found the problem, the model needs to know the linkTo- and linkFromPortIdProperty names to compute the points. When i added these two lines after the graphlinksmodel declaration, it works:

diagram.model = new go.GraphLinksModel(nodes, links);
diagram.model.linkFromPortIdProperty = 'fromPort'; //this line
diagram.model.linkToPortIdProperty = 'toPort'; //and this line

Hi,

I’m trying to upgrade our functionality with the option to set the a port on a link, so you can decide from which side to which side on a node the link goes. I looked at the ‘Dynamic Ports’ example and copied most of the code. However when i run it i get an error:

Uncaught Error: getDocumentPoint:s Spot must be real: None

 CustomLink.prototype.computeCurviness = function() {
        if (isNaN(this.curviness)) {
          var fromnode = this.fromNode;
          var fromport = this.fromPort;
          var fromspot = this.computeSpot(true);
          var frompt = fromport.getDocumentPoint(fromspot); //this is where the error is thrown if i draw a link
          var tonode = this.toNode;
          ...
 }

CustomLink.prototype.computeEndSegmentLength = function(node, port, spot, from) {
    var esl = go.Link.prototype.computeEndSegmentLength.call(this, node, port, spot, from);
    var thispt = port.getDocumentPoint(this.computeSpot(from)); //this is where the error is thrown if i load a link from a json
    var otherpt = this.getOtherPort(port).getDocumentPoint(this.computeSpot(!from));
    ...
}

I used the node- and linktemplate from the example and copied the overrides for the customlink

the order of process in my code is as follows:

  • set the customlink function and overrides
  • get diagram template
  • add nodetemplatemap to diagram,
  • add linktemplatemap to diagram

Any idea why i get the error? It happens either when i load a json with specified links, or when i try to add a link manually

2

I’m glad you figured it out. If there’s any particular spot in the documentation where that information would have helped you, please tell us.

3

Hi Walter,

Since i used the code from the example i didn’t really searched the api. The example is pretty clear, but i overlooked the data in the json that sets the fromportids on the model. It would have been clearer if those properties would have been set in the code example.

Tim

4

Walter, i have a follow up question.

When the user relinks a link, i want to programmatically set to which ports it can relink. How can i find out which link is being relinked. I tried overriding the reconnectlink, but that only fires after the action. I also tried overriding the doActivate function, but i couldn’t get to the handle.

Hope you can help,
Tim

5

http://gojs.net/latest/intro/validation.html
tells you how to limit both drawing new links and reconnecting existing links.

6

Hi Walter,

Thanks for your reply, but i don’t think this covers the functionality i desire;

I have nodes which have ports on their sides (like in the example). An user must be able to reconnect a link to another port on the node (and in a later stage to other nodes that match validation). So my idea was to override the event that starts the relink action, and then programmatically set the linkableTo and From properties. I also want to display a new port when relinking, so an user can connect the link to the new port. So i was hoping for a way to find out which link is the subject when i activate the relinkingtool. i tried overriding the doActivate function but i couldn’t get to a handle/subject or something similar.

Tim

7

The LinkingBaseTool.linkValidation and Node.linkValidation predicate properties should cover everything that you might want to do. I don’t think you want to dynamically set the linkableTo and linkableFrom properties.

If your desired behavior isn’t handled by either of these customizations, please explain.

8

Hi Walter,

you’re right, the validation tools did handle everything i needed.

Thanks