Make one field readonly or hide the field in lightbox based on conditions

Gantt
#1 
gantt.config.lightbox.sections = [
   { name: "description", height: 38, map_to: "text", type: "textarea", focus: true },
   { name: "progress", height: 22, map_to: "progress", type: "select", options: progressOptions},
   { name: "priority", height: 22, map_to: "priority", type: "select", options: [
           {key: "Low", label: "Low"},
           {key: "Medium", label: "Medium"},
           {key: "High", label: "High"},
       ]},
   { name: "time", type: "duration", map_to: "auto" },
   {name: "baseline", height: 72, map_to: {start_date: "planned_start", end_date: "planned_end"}, type: "duration"}
];

This is the code I want to either make the progress field read only or hide that field from lightbox, if the task clicked has a child or more.

#2

Hello,
Gantt doesn’t have a built-in feature to do that. You need to implement a custom solution by using the Gantt API and Javascript.

The lightbox section with the select type doesn’t have the readonly property:
https://docs.dhtmlx.com/gantt/desktop__select.html#properties
So, you need to hide that section. The easiest way would be to change the section to an empty object (to not change the position of the array elements).

You can modify the lightbox sections in the onBeforeLightbox event handler:
https://docs.dhtmlx.com/gantt/api__gantt_onbeforelightbox_event.html
Then you need to call the resetLightbox method to rebuild the lightbox:
https://docs.dhtmlx.com/gantt/api__gantt_resetlightbox.html

Here is an example of how it can be implemented:
https://snippet.dhtmlx.com/qsvrxjhx

Also, if the task has the project type, it has a different set of sections:
https://docs.dhtmlx.com/gantt/desktop__task_types.html#specificlightboxpertasktype

It means that if you didn’t add the progress section for project tasks, it won’t be displayed there at all.