From 977a4b8d85f21ed885f24e50c8fb6ddf5495fda1 Mon Sep 17 00:00:00 2001 From: Doug Brunner Date: Thu, 16 Dec 2021 04:34:30 -0800 Subject: [PATCH] Docs/clarify usage of ticks callback (#9991) (#9994) * Docs/clarify usage of ticks callback (#9991) * Docs/Fixed inconsistent variable names (#9991) Co-authored-by: Doug Brunner --- docs/axes/labelling.md | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/docs/axes/labelling.md b/docs/axes/labelling.md index 83c36580768..9ab75ffaba0 100644 --- a/docs/axes/labelling.md +++ b/docs/axes/labelling.md @@ -45,7 +45,7 @@ const chart = new Chart(ctx, { y: { ticks: { // Include a dollar sign in the ticks - callback: function(value, index, values) { + callback: function(value, index, ticks) { return '$' + value; } } @@ -55,6 +55,13 @@ const chart = new Chart(ctx, { }); ``` +Keep in mind that overriding `ticks.callback` means that you are responsible for all formatting of the label. Depending on your use case, you may want to call the default formatter and then modify its output. In the example above, that would look like: + +```javascript + // call the default formatter, forwarding `this` + return '$' + Chart.Ticks.formatters.numeric.apply(this, [value, index, ticks]); +``` + Related samples: * [Tick configuration sample](../samples/scale-options/ticks)