Scripting

First step: open the Javascript console

CATMAID is written in javascript on the client side. The whole of CATMAID is available at your fingertips if only you knew what to type into the javascript console.

In Google Chrome, push shift+control+j (shift+command+j in MacOSX) or go to the menu "Tools - Javascript Console".

Select a neuron at random from a list of neurons in a Selection Table

Assuming you have a list of neurons in a Selection widget, and at least a subset of them is selected (their checkboxes are ticked):

// Assuming it is the first one opened:
var st = SelectionTable.prototype.getInstances()[0];

// List of skeleton IDs
var skids = st.getSelectedSkeletons();

// Pick one skeleton at random: var skid = skids[Math.floor(Math.random() * skids.length)];

// Select the skeleton in the canvas TracingTool.goToNearestInNeuronOrSkeleton("skeleton", skid);

Select a neuron at random from a Selection Table, hiding the others

If the Selection Table is linked to a 3D Viewer (as is the default when the 3D Viewer is open), then this will hide all neurons except the one selected at random:

var selectAtRandom = function() {
    var st = SelectionTable.prototype.getInstances()[0];
    var models = st.getSkeletonModels();
    var skids = Object.keys(models);
    var skid = skids[Math.floor(Math.random() * skids.length)];
    console.log("Picking: ", skid);
    TracingTool.goToNearestInNeuronOrSkeleton("skeleton", skid);
    // Leave selected only skid
    Object.keys(models).forEach(function(id) {
        models[id].setVisible(id == skid);
    }); 
    st.append(models);
};

selectAtRandom();

Select a neuron at random from a list of neurons that are all annotated with the same annotation

Given the annotation as text, we obtain first its ID from the local cache (which is loaded on startup), and then request from the server the list of neurons along with their associated skeleton IDs:

var selectAtRandom = function(annotation) {
  if (!annotation) return alert("What annotation?");
  var annot = annotations.annotation_ids[annotation];
  if (!annot) return alert("Invalid annotation");
  var request = function(url, post, callback) {
    requestQueue.register(
      django_url + project.id + url, "POST", post,
      function(status, text) {
        if (200 !== status) return;
        var json = $.parseJSON(text);
        if (json.error) return alert(json.error);
        callback(json);
      });
  };
  request(
    "/neuron/query-by-annotations",
    {neuron_query_by_annotation: [annot]},
    function(json) {
      var skids = json.entities.map(function(e) {
        return e.skeleton_ids[0];
      });
      var skid = skids[Math.floor(Math.random() * skids.length)];
      console.log("Picking: ", skid);
      TracingTool.goToNearestInNeuronOrSkeleton("skeleton", skid);
    });
};