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  1. Qt
  2. QTBUG-21558

Allow creating two way bindings in QML

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    Description

      Currently, there is no way to create two way cleanly bindings in QML.

      Use case: You have a property in C++ and this property is exposed as some UI text input in QML. Changes in C++ need to get reflected in the QML and vice-versa. Currently, one can do:

      TextInput {
    id: root
    text: runtime.cppProperty

    Binding {
        target: runtime
        property: "cppProperty"
        value: root.text
    }
}

      The problem I have with above is that it's not 'clear' that it's two-way binding. It would clearer if we either had a 'twoWay' property in Binding element to start with. OR we create a new Alias element (which is same Binding except it's two way).

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          is duplicated by

          Technical task - A technical task. QTBUG-132782 Establish requirements for bi-directional bindings

          • P1: Critical - Urgent and Important, will STOP the release if matched with set FixVersion field. This includes regressions from the last version that are not edge cases; Data loss; Build issues; All but the most unlikely crashes/lockups/hanging; Serious usability issues and embarrassing bugs & Bugs critical to a deliverable. This is the highest possible priority for requirements.
          • Closed

          Suggestion - Public suggestions QTBUG-30596 bi-directional or multi-sync variation of Binding

          • P1: Critical - Urgent and Important, will STOP the release if matched with set FixVersion field. This includes regressions from the last version that are not edge cases; Data loss; Build issues; All but the most unlikely crashes/lockups/hanging; Serious usability issues and embarrassing bugs & Bugs critical to a deliverable. This is the highest possible priority for requirements.
          • Closed
          is replaced by

          Task - A task that needs to be done. QTBUG-19892 Allow "lazy" aliases to properties of objects created only later

          • P2: Important - Urgent, should be fixed, but will not stop the release.
          • Closed
          relates to

          Task - A task that needs to be done. QTBUG-109996 Add explicit property setter functions that do not break bindings

          • P3: Somewhat important - Should be fixed, but doesn't affect the release in any way.
          • Open

          Suggestion - Public suggestions QTBUG-132420 Better QML API for updating QAbstractItemModel data

          • P1: Critical - Urgent and Important, will STOP the release if matched with set FixVersion field. This includes regressions from the last version that are not edge cases; Data loss; Build issues; All but the most unlikely crashes/lockups/hanging; Serious usability issues and embarrassing bugs & Bugs critical to a deliverable. This is the highest possible priority for requirements.
          • Reported
          mentioned in

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          For Gerrit Dashboard: QTBUG-21558
          # Subject Branch Project Status CR V
          623118,7 WIP: Prototype of Synchronizer dev qt/qtdeclarative Status: NEW -2 0

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              ulherman Ulf Hermann
              girish Girish Ramakrishnan
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                Created:
                Updated:

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