PaulUithol/Backbone-relational

previous attributes broken when another attributes changed in handler.

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#485 建立於 2014年8月18日

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 (0 留言) (0 反應) (0 負責人)JavaScript (2,343 star) (344 fork)batch import
bughelp wanted

描述

Scenario:

  • has model with several listeners on some property propA
  • one of the listener change another property propB.
  • In rest of handlers for propA previousAttributes contains new value of propA instead old one.

In case of usage regular Model instead of RelationalModel previousAttributes contains old value as expected.

sample: http://jsfiddle.net/4ohq1tho/1

this cause several issues like https://github.com/kmalakoff/knockback/issues/121

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技術棧
javascript
領域
frontend
議題類型
bug
難度面向新貢獻者的預計實作難度，1 表示很小改動，5 表示專家級工作。
3
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1-3 hours
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stale
清晰度議題是否清楚說明預期改動、驗收標準和下一步。
needs investigation
前置要求
Backbone model event handlingJavaScript event loop
新手友善度1-100 的估計分數，表示該議題對首次貢獻者的友善程度。
30
研究方向
Investigate the order of change event handlers in Backbone relational vs Backbone.Model. The issue is that when multiple listeners on propertyA exist, and one changes propertyB, subsequent listeners see the new value of propertyA in `previousAttributes`. Look into the Backbone source code for `change` event propagation and how RelationalModel overrides it. Compare with the regular Backbone.Model behavior. The jsfiddle provides a reproduction. Focus on the `set` method and how `previousAttributes` is stored before triggering events. Potentially modify the RelationalModel's set method to preserve the original previousAttributes across handler calls.
previous attributes broken when another attributes changed in handler. · PaulUithol/Backbone-relational#485 | Good First Issue