madebymany/sir-trevor-js

OnBlockCountChange called cumulatively on first load

fareesh opened this issue · 3 comments

fareesh commented

I have an existing Sir Trevor document with 31 blocks

sir-trevor-js/src/block-positioner.js

Line 35 in 4e1a20a

this.mediator.on("block:countUpdate", this.onBlockCountChange);

Due to this line, on first load, the renderPositionList seems to be called (1..n) times x 31 times, which slows down loading significantly for larger documents.

For documents with 100+ blocks, loading time seems to take 30+ seconds

Since I am not using the position list, I have removed that line for my usage.

Is the following considered typical behaviour for an existing document?

  1. On first load, createBlocks creates each block in the data store

  2. Each block, when added, triggers block:countUpdate which triggers onBlockCountChange with the new count

  3. onBlockCountChange calls renderPositionList, which loops from 0.. new block count.

  4. If 31 blocks are added, the above does DOM manipulation of the select position list n times from 1 to 31, i.e. 1+2+3+4...31 times = 528. For larger documents e.g. 155 blocks, this is 12,090 DOM manipulations.

Or, is my page triggering these events too many times for some other reason? I am running with a the latest version with all the default initialization parameters.

ConstantAZ commented

Stumbled upon this problem with a document containing ~600 blocks. Load time is insane.
If I'm reading code right, onBlockCountChange is called per block.
So, ~600 blocks will result in ~180000 renderPositionList calls

raffij commented
raffij commented

Updated and merged an existing pr which amends the working for this.

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