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Collapsible panel state toggle

This operation manages the expand/collapse state of a SAIFPanel, persisting it through a hidden field so it survives postbacks, and applying the corresponding inline display style and image on each render pass.

Field Value
Operation ID OP-V2-PANEL-001
Trigger Postback containing the hidden StateControl field value ("Collapsed"/other).
Inputs HttpContext.Current.Request(Me.UniqueID & "$StateControl").
Outputs Header/Title/collapse-expand image/hidden state field/Content panel control tree with correct display style and image URL.
Primary components SAIFPanel.SAIFPanel_Init, SAIFPanel.CreateChildControls, SAIFPanel.SAIFPanel_PreRender.
Entry point SAIF.Presentation.Web.Controls.V2\SAIFPanel.vb

Steps

  1. SAIFPanel_Init reads HttpContext.Current.Request(Me.UniqueID & "$StateControl"); if present and non-empty, sets _PanelState accordingly.
  2. CreateChildControls builds the Header/Title/collapse-expand image/hidden state field/Content panel tree, using _PanelState to decide the initial display: none;/display: block; inline style and expand/collapse image URL.

  3. PreRender re-syncs the collapse/expand image and hidden field to the current _PanelState.

  4. No server-side business logic determines panel state beyond what the client posts back — actual expand/collapse toggling is client-script driven (the referenced Panel.js script file is not included in this project)*.

Process flow

The following diagram visualizes this operation's control flow.

flowchart TD
    Start([Postback]) --> Init[SAIFPanel_Init reads StateControl field]
    Init --> Decision{State value present?}
    Decision -->|Yes| Set[Set _PanelState from posted value]
    Decision -->|No| Keep[Keep existing _PanelState]
    Set --> Create[CreateChildControls builds tree with matching display style]
    Keep --> Create
    Create --> PreRender[PreRender re-syncs image and hidden field]
    PreRender --> Done([Rendered panel HTML])

Failure and edge-case behavior

  • An unrecognized or missing StateControl value leaves _PanelState at its prior/default value (Expanded) rather than raising an error.
  • The client-side Panel.js script that performs the actual collapse/expand animation is not present in this project folder; its exact behavior could not be verified from this library's source**.

Note: Statements marked with * were inferred from code structure, naming conventions, or contextual evidence where direct confirmation was not available in source artifacts. Statements marked with ** could not be confirmed; treat as unknown until verified.

Sources

  • SAIF.Presentation.Web.Controls.V2\SAIFPanel.vb