‼️ Hotfix: Allow graph creation with empty nodes and links ‼️

[krusche]

What kind of change does this PR introduce? (check one with "x")

• Bugfix

What is the current behavior? (You can also link to an open issue here)
At the moment, graphs with 0 nodes or 0 links crash the component with undefined errors, because the graph is not created and this.graph.nodes is still invoked

What is the new behavior?
Graphs with 0 nodes or 0 links can be used without undefined errors. Closes #559

Does this PR introduce a breaking change? (check one with "x")

• Yes
• No

Other information:
Please merge this PR asap and create a bugfix release 9.0.2 as we currently cannot upgrade to 9.x

[krusche]

@steveblue any chance you merge this quickly and create a 9.0.2 release?

[krusche]

@steveblue any chance you merge this quickly and create a 9.0.2 release?

[holomekc]

Hi @steveblue @fhayd
any updates on this?

[ktaganova]

Hi @steveblue @fhayd we would like to update to 9.x, any updates for this issue?

[Hazemmmm]

I quickly solved the issue by adding these:
in the HTML:

 <ngx-graph
        *ngIf="treeNodes?.length >= 0 && treeLinks?.length >= 0"

and in typescript file

  treeNodes: Array<RecipeStepNode> = [];
  treeLinks: Array<Edge> = [];

and make sure to initialize them as well in the onInit with empty values before add the actual data.

  this.treeNodes = [];
  this.treeLinks = [];

[bsarkadi]

I quickly solved the issue by adding these: in the HTML:

 <ngx-graph
        *ngIf="treeNodes?.length >= 0 && treeLinks?.length >= 0"

and in typescript file

  treeNodes: Array<RecipeStepNode> = [];
  treeLinks: Array<Edge> = [];

and make sure to initialize them as well in the onInit with empty values before add the actual data.

  this.treeNodes = [];
  this.treeLinks = [];

This doesn't solve our problem, as we want to display single nodes without any links :(
We'd need the official fix released asap, it is a showstopper for us.

[Hazemmmm]

I quickly solved the issue by adding these: in the HTML:

 <ngx-graph
        *ngIf="treeNodes?.length >= 0 && treeLinks?.length >= 0"

and in typescript file

  treeNodes: Array<RecipeStepNode> = [];
  treeLinks: Array<Edge> = [];

and make sure to initialize them as well in the onInit with empty values before add the actual data.

  this.treeNodes = [];
  this.treeLinks = [];

This doesn't solve our problem, as we want to display single nodes without any links :( We'd need the official fix released asap, it is a showstopper for us.

It shows the node without links, but the error will still appear in the browser console. But this is jus a workaround to make it work smoothly.

[bsarkadi]

I quickly solved the issue by adding these: in the HTML:

 <ngx-graph
        *ngIf="treeNodes?.length >= 0 && treeLinks?.length >= 0"

and in typescript file

  treeNodes: Array<RecipeStepNode> = [];
  treeLinks: Array<Edge> = [];

and make sure to initialize them as well in the onInit with empty values before add the actual data.

  this.treeNodes = [];
  this.treeLinks = [];

This doesn't solve our problem, as we want to display single nodes without any links :( We'd need the official fix released asap, it is a showstopper for us.

It shows the node without links, but the error will still appear in the browser console. But this is jus a workaround to make it work smoothly.

I ended up with this solution: if links array is empty then I push a link pointing to the single node itself, and setting the width to zero.

[Hazemmmm]

I quickly solved the issue by adding these: in the HTML:

 <ngx-graph
        *ngIf="treeNodes?.length >= 0 && treeLinks?.length >= 0"

and in typescript file

  treeNodes: Array<RecipeStepNode> = [];
  treeLinks: Array<Edge> = [];

and make sure to initialize them as well in the onInit with empty values before add the actual data.

  this.treeNodes = [];
  this.treeLinks = [];

This doesn't solve our problem, as we want to display single nodes without any links :( We'd need the official fix released asap, it is a showstopper for us.

It shows the node without links, but the error will still appear in the browser console. But this is jus a workaround to make it work smoothly.

I ended up with this solution: if links array is empty then I push a link pointing to the single node itself, and setting the width to zero.

Can u share the code itself?

[krusche]

you could also simply add a patch:

@swimlane+ngx-graph+10.0.0.patch

add patch-package to package.json and add patch-package to postinstall

[krusche]

@MarkColeman1 can you please merge this PR?