File Content: utils.ts import { DataFrame, Field, FieldType, outerJoinDataFrames, TimeRange } from '@grafana/data'; import { applyNullInsertThreshold } from '@grafana/data/src/transformations/transformers/nulls/nullInsertThreshold'; import { nullToUndefThreshold } from '@grafana/data/src/transformations/transformers/nulls/nullToUndefThreshold'; import { GraphDrawStyle } from '@grafana/schema'; import { XYFieldMatchers } from './types'; function isVisibleBarField(f: Field) { return ( f.type === FieldType.number && f.config.custom?.drawStyle === GraphDrawStyle.Bars && !f.config.custom?.hideFrom?.viz ); } export function getRefField(frame: DataFrame, refFieldName?: string | null) { return frame.fields.find((field) => { // note: getFieldDisplayName() would require full DF[] return refFieldName != null ? field.name === refFieldName : field.type === FieldType.time; }); } // will mutate the DataFrame's fields' values function applySpanNullsThresholds(frame: DataFrame, refFieldName?: string | null) { const refField = getRefField(frame, refFieldName); let refValues = refField?.values; for (let i = 0; i < frame.fields.length; i++) { let field = frame.fields[i]; if (field === refField || isVisibleBarField(field)) { continue; } let spanNulls = field.config.custom?.spanNulls; if (typeof spanNulls === 'number') { if (spanNulls !== -1 && refValues) { field.values = nullToUndefThreshold(refValues, field.values, spanNulls); } } } return frame; } export function preparePlotFrame(frames: DataFrame[], dimFields: XYFieldMatchers, timeRange?: TimeRange | null) { let xField: Field; loop: for (let frame of frames) { for (let field of frame.fields) { if (dimFields.x(field, frame, frames)) { xField = field; break loop; } } } // apply null insertions at interval frames = frames.map((frame) => { if (!xField?.state?.nullThresholdApplied) { return applyNullInsertThreshold({ frame, refFieldName: xField.name, refFieldPseudoMin: timeRange?.from.valueOf(), refFieldPseudoMax: timeRange?.to.valueOf(), }); } else { return frame; } }); let numBarSeries = 0; frames.forEach((frame) => { frame.fields.forEach((f) => { if (isVisibleBarField(f)) { // prevent minesweeper-expansion of nulls (gaps) when joining bars // since bar width is determined from the minimum distance between non-undefined values // (this strategy will still retain any original pre-join nulls, though) f.config.custom = { ...f.config.custom, spanNulls: -1, }; numBarSeries++; } }); }); // to make bar widths of all series uniform (equal to narrowest bar series), find smallest distance between x points let minXDelta = Infinity; if (numBarSeries > 1) { frames.forEach((frame) => { if (!frame.fields.some(isVisibleBarField)) { return; } const xVals = xField.values; for (let i = 0; i < xVals.length; i++) { if (i > 0) { minXDelta = Math.min(minXDelta, xVals[i] - xVals[i - 1]); } } }); } let alignedFrame = outerJoinDataFrames({ frames, joinBy: dimFields.x, keep: dimFields.y, keepOriginIndices: true, }); if (alignedFrame) { alignedFrame = applySpanNullsThresholds(alignedFrame, xField!.name); // append 2 null vals at minXDelta to bar series if (minXDelta !== Infinity) { alignedFrame.fields.forEach((f, fi) => { let vals = f.values; if (fi === 0) { let lastVal = vals[vals.length - 1]; vals.push(lastVal + minXDelta, lastVal + 2 * minXDelta); } else if (isVisibleBarField(f)) { vals.push(null, null); } else { vals.push(undefined, undefined); } }); alignedFrame.length += 2; } return alignedFrame; } return null; } Submit