Oracle Apex, line break in Gantt Chart Row Label - oracle-apex

Question

I'm very new to Oracle Apex and currently I want to use and customize Gantt charts. What I want to achieve it to show line breaks in the row-labels. Currently every newline character gets cut out and I am not sure where this happens and how I can prevent this.
The marked text contains newline characters. Don't be confused by the <br>, I just tests if this does the trick.
I just want to show more some information in the for each row. If there is another more elegant way, it would be very nice to give a tip.
Update:
I did some research and found a very nice example on a similar topic, in this case to create a custom tooltip https://youtu.be/2rZAIR_0tNg?t=2532.
I wanted to do the same thing for the row_axis label renderer, but nothing gets visualized.
The render function I use:
function custom_row_axis_label_renderer(data_context){
var row_axis_label_elem = document.createElement("g");
$("row_axis_label_elem").addClass("custom_row_axis_label");
row_axis_label_elem.innerHTML = '<text font-size="14px">Hello World</text>';
console.log(row_axis_label_elem);
return row_axis_label_elem;
}
The rendered element kind of exists, but it's get the size 0x0 from somewhere.
Am I missing something here?
Regards,
Nik

Answer 1

Meanwhile I found the solution on how to build a custom renderer. The main part I didn't new is that you NEED to pass x and y coordinates to have the new label to be rendered correctly. I found a proper example the the oracle forum, but unfortunately I can't find the link anymore to give credit to the original example.
Here is my code. It creates two text elements below each other to achieve a mocked line break and it adds a yellow icon. Of course you can use the data_context object to access the actual label. Add this part in the "Function and Global Variable Declaration
" part of your page:
custom_row_axis_label_renderer = function (data_context){
var row_axis_label_elem = document.createElementNS("http://www.w3.org/2000/svg", "g");
var upper_text = document.createElementNS("http://www.w3.org/2000/svg", "text");
var lower_text = document.createElementNS("http://www.w3.org/2000/svg", "text");
var icon_node = document.createElementNS("http://www.w3.org/2000/svg", "circle");
upper_text.textContent = "Hello";
upper_text.setAttribute("dominant-baseline","text-before-edge");
upper_text.setAttribute("class","oj-gantt-row-label");
upper_text.setAttribute("font-size","14px");
upper_text.setAttribute("text-anchor","end");
upper_text.setAttribute("x","220");
upper_text.setAttribute("y","5");
lower_text.textContent = "World";
lower_text.setAttribute("dominant-baseline","text-before-edge");
lower_text.setAttribute("class","oj-gantt-row-label");
lower_text.setAttribute("font-size","14px");
lower_text.setAttribute("text-anchor","end");
lower_text.setAttribute("x","220");
lower_text.setAttribute("y","25");
icon_node.setAttribute("cx","240");
icon_node.setAttribute("cy","25");
icon_node.setAttribute("r","8");
icon_node.setAttribute("class","u-color-7");
row_axis_label_elem.appendChild(upper_text);
row_axis_label_elem.appendChild(lower_text);
row_axis_label_elem.appendChild(icon_node);
return row_axis_label_elem;
}
Also you need to set the renderer of the row-axis-label. I also made the rows and task a little bit bigger to have enough space for two lines of text in the label. Add this in the "JavaScript Initialization Code" in the attriutes of you chart:
function( options ){
options.rowAxis.label = {renderer : custom_row_axis_label_renderer};
options.rowDefaults = {height : 60};
options.taskDefaults = {height: 40};
return options;
}