Style properties not read correctly if value is zero

[hasanbalci]

While reading style properties of the graph elements, if the property value is zero it is ignored because of the buggy code here. That if statement should differentiate "0" value from "undefined". As a result, those properties are not written to the file during save operation.

[hasanbalci]

I encountered with a similar issue in infobox values. Apparently, if there is an infobox with value 0, it's saved in the file, but while loading, those values are lost somewhere and infoboxes seem as empty. Probably, there is a similar bug during load operation.

[ugurdogrusoz]

@msalihaltun See if this straightforward to fix for this release. @hasanbalci should know.

[msalihaltun]

Nodes with label "0" are saved but can't be reloaded either.

In javascript, if we use the value 0 as a predicate inside an if statement (or anything similar) the value is evaluated as false. This is likely the reason for these problems. When we are reading value fields from files, we can't do truth checks with those values. We just need to make sure we don't get undefined.

[msalihaltun]

"0" style values should be fixed now but labels are not fixed. We take the nwt file as an xml file while loading and call libsbgnjs.Sbgn.fromXML() function on this file (the xml as string). This function returns label text value as undefined when we use "0" as label.

[msalihaltun]

Nevermind, apperantly my changes had many unexpected side affects. Reverted for now. It is my mistake, I didn't run the tests locally.

[msalihaltun]

It should be fine now. @hasanbalci please test and confirm.

[msalihaltun]

Also I created an issue about label values here.

[hasanbalci]

• I assume that the problem with label values includes both node labels and infobox labels, so they will be fixed in libsbgn.js.
• I noticed that when we set "Border Width" to 0 for a node, after save/load, that field in inspector becomes empty for that node instead of 0. I think we should show 0 again.

[msalihaltun]

• I believe so yes, it should be solved in libsbgn.js.
• We had the same problem with border width value as all others where 0's truth value is evaluated as false, fixed now.

[hasanbalci]

Labels will be fixed in libsbgn.js. The rest seems fixed, so closing.