Process

Preparing data to be rendered.

cm.each

Calls the specified function on each datum of a flow, and returns a new flow that contains the data. The function is being passed the current datum(d), the current index(i), the current group(data) and the flow(flow).

const data = [
  { name: "Locke", number: 4 },
  { name: "Reyes", number: 8 },
  { name: "Ford", number: 15 },
  { name: "Jarrah", number: 16 },
  { name: "Shephard", number: 23 },
  { name: "Kwon", number: 42 },
];

app.data(data).process(cm.each, (d) => d.number * 2);

cm.eachRight

Like cm.each, except iterates from right to left.

const data = [
  { name: "Locke", number: 4 },
  { name: "Reyes", number: 8 },
  { name: "Ford", number: 15 },
  { name: "Jarrah", number: 16 },
  { name: "Shephard", number: 23 },
  { name: "Kwon", number: 42 },
];

app.data(data).process(cm.eachRight, (d, i, data) => {
  if (d.number > 30) data.splice(i, 1);
});

cm.filter

Calls the specified function on each datum of a flow, and returns a new flow that contains the data meeting true condition. The function is being passed the current datum(d), the current index(i), the current group(data) and the flow(flow).

const data = [
  { name: "Locke", number: 4 },
  { name: "Reyes", number: 8 },
  { name: "Ford", number: 15 },
  { name: "Jarrah", number: 16 },
  { name: "Shephard", number: 23 },
  { name: "Kwon", number: 42 },
];

app.data(data).process(cm.filter, (d) => d.number % 2 === 0);

cm.map

Calls the specified function on each datum of a flow, and returns a new flow that contains the new data. The function is being passed the current datum(d), the current index(i), the current group(data) and the flow(flow).

const data = [
  { name: "Locke", number: 4 },
  { name: "Reyes", number: 8 },
  { name: "Ford", number: 15 },
  { name: "Jarrah", number: 16 },
  { name: "Shephard", number: 23 },
  { name: "Kwon", number: 42 },
];

app.data(data).process(cm.map, (d) => ({ ...d, number: d.number * 2 }));

cm.derive

Calls value on each datum of a flow to derive a new field key for each entries of the specified object, and returns a new flow that contains the new data. The value is being passed the current datum(d), the current index(i), the current group(data) and the flow(flow).

const data = [
  { name: "Locke", number: 4 },
  { name: "Reyes", number: 8 },
  { name: "Ford", number: 15 },
  { name: "Jarrah", number: 16 },
  { name: "Shephard", number: 23 },
  { name: "Kwon", number: 42 },
];

app.data(data).process(cm.derive, {
  double: (d) => d.name * 2,
  upper: (d) => d.name.toUpperCase(),
});

cm.push

Appends the specified datum to a flow, and returns a new flow that contains the new datum.

If datum is not a function, appends it to all groups.

const data = [
  { name: "Locke", number: 4 },
  { name: "Reyes", number: 8 },
  { name: "Ford", number: 15 },
  { name: "Jarrah", number: 16 },
  { name: "Shephard", number: 23 },
  { name: "Kwon", number: 42 },
];

app.data(data).process(cm.push, { name: "Jim", number: 25 });

If the flow has multiple groups(such as flow.data followed by app.data), then datum should typically be specified as a function. The function will be evaluated for each group in order, being passed the group(group), the group index(i), all the groups(data) and this flow(flow).

const matrix = [
  [" +", "-", "+ "],
  [" |", cm.wch("🚀"), "| "],
  [" +", "-", "+ "],
];

app
  .data(matrix)
  .append(cm.group, { y: (_, i) => i })
  .data((d) => d)
  .process(cm.push, (group, i, groups) => ` `);