About the `dataZoom` issue, check the code: https://github.com/apache/incubator-echarts/blob/master/src/component/dataZoom/AxisProxy.js#L253
> canvas.font = 'xxx'; Typo. should be: canvasCtx.font = 'xxx'; Thanks, ------------------------------ Su Shuang (100pah) ------------------------------ On Thu, 19 Sep 2019 at 02:24, SHUANG SU <sushuang0...@gmail.com> wrote: > > Currently, I gradually think we have to make some change > about the practice that we have been trading the props > that needed to be normalized or calculated inside. > The way that I've been using is not a good practice: > > Set the calculated value to the original prop directly > and erase the original value. > > Use some pseudocode to describe it clearly: > > Suppose `clac` is the function that normalizes/calculates the > original value specified and get the result. > > When `chart.setOption` or `chart.dispatchAction`, we need to: > `option[propForAssigning] = specifiedValue;` > > When `chart.setOption` or `chart.dispatchAction` or go though the main > process, we need to: > `option[propForCalculating] = calc( option[propForAssigning] );` > > If we make `propForCalculating === propForAssigning`, > and `calc( calc( propForAssigning ) ) !== calc( propForAssigning )` > > we will lose the original value but get result not expected. > > > There is one example we meet just now: > > `dataZoom` has props `start` `end` `startValue` `endValue`, > These four props can be set by user (via `chart.setOption` or > `chart.dispatchAction`) > or by components (via `api.dispatchAction`). > > But the specified value needs to be calculated and get the final value, > which is usually not the same as the original specified value, but in > most cases, not different so much. > (The calculation depends on the data extent, `dataZoom.minSpan`, > `dataZoom.maxSpan` > and some other factors) > Users need to read the final value, so I write the final value to > these props, erasing the original value. > > But some bad case occurs: > If the user uses `toolbox.dataZoom` to zoom Y-axis, and then click > the `legend`, and then click the `legend` again, the chart can not > return to the original state. > The reason is: > The original value of `dataZoom.startValue` and `dataZoom.endValue` > is erased by the value that calculated in the main process triggered > by clicking legend. > > There were some other similar cases. > CSS distinguish the "style" and "computed style". > We probably also need to settle a best practice for that. > > For example: > If a calculated prop need to be set to `option` and the > normalizer/calculater > (say, `calc`) do not meet the condition: > > `calc( calc( propForAssigning ) ) !== calc( propForAssigning )` > > we should not use the original prop, but use a new prop, like: > > `dataZoom.calculatedStartValue`, `dataZoom.calculatedEndValue`... > > (An example that meets the condition: > canvas.font = 'xxx'; > ) > > But that would be a little break change... > > Any idea about all the issue and possible solution above? > > > > > Thanks, > ------------------------------ > Su Shuang (100pah) > ------------------------------ > >
