I’ve created the following document:
<g>
<path class="line" name="gene_1" stroke="#aec7e8" d="M10.47..."></path>
<path class="line" name="gene_2" stroke="#aec7e8" d="M10.47..."></path>
<path class="line" name="gene_3" stroke="#aec7e8" d="M10.47..."></path>
...
</g>
When I mouse over each path I want to append it last inside the svg:g so it appears on top of the other lines, but I don’t know how to properly select the parentNode:
function onmouseover(d, i){
var current_gene_name = d3.select(this).attr("name"),
current_gene_pcp = d3.select(".line[name=" + current_gene_name + "]");
p1 = this.parentNode
p2 = current_gene_pcp[0].parentNode
p3 = current_gene_pcp[0][0].parentNode
//p.appendChild(this);
}
p1 works, but I wanted to make sure that this is a .line, so I preferred to use current_gene_pcp, but p2 returns <html></html> as the parent, even though p3 returns the proper <g></g>. This last version seems like a bug waiting to happen. Is there a better way?
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Answer
A D3 selection is just a double-array wrapped around the element(s) selected. As you found with p3, you can dereference the arrays to find your first node, if you want. However, a better method does exist:
From the docs for selection.node():
Returns the first non-
nullelement in the current selection. If the selection is empty, returnsnull.
In your case:
var dad = current_gene_pcp.node().parentNode;
However, if you don’t need the line other than the DOM handle, you might as well just get that directly:
// Search document-wide...
var dad = document.querySelector(".line[name=" + current_gene_name + "]");
// ...or only as a child of the current DOM element
var dad = this.querySelector(".line[name=" + current_gene_name + "]");