Context Variables in QPR UI

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Context variables in QPR UI are for storing session time information and communicating between different user interface elements, such as views, panels and presentation objects.

Context Variable Behaviors

Variables can be defined for views, panels and presentation objects (called UI elements) which form a scope for the defined variables. Variables are visible and accessible in the scope where they have been defined and also in all sub scopes in the hierarchy of UI elements. For example, a variable defined in a view scope is visible in all panels and presentation objects in the view. Also a variable defined in a panel is visible in all presentation objects in the panel, but not in presentation objects in other panels. In addition to UI elements (view, panel and presentation object), variables can exist in session scope. The session scope is visible in all views, i.e. session variables are preserved when opening another view. Thus the visibility hierarchy for variables is (starting from the top):

  • Session
  • View
  • Panel
  • Presentation object

When setting or getting variable values and two variables with same names exist in different scopes, the variable in the lower scope takes priority over the variable in the upper scope, i.e. the lower scope variable hides the upper scope variable within the scope of the lower scope variable.

Each defined variable have a behavior which determine how the variables work when setting and getting their values. The following behaviors are available:

Variable behavior Description
Local variable Local variables are visible in the scope where the variable is defined and also in all its sub scopes. When initialized, the local variable gets a value that is set in its definition (in the Context tab). When a local variable value is changed by logic in a presentation object (e.g. data grid action), the change is made to the variable in the nearest scope of the presentation object in the UI element hierarchy where the variable has been defined as Local variable.
Optional parameter Optional parameters work like the local variables, except that the optional parameters get their initial values from the upper scope when the variables are initialized. For example, optional parameters in view scope get their values from the session scope when a view is opened, and optional parameters in the panel scope get their values from the view scope when the panel is initialized. If a variable having the same name doesn't exist in any of the upper scope, the optional parameter will have the value that is set in its definition (in the Context tab). After the optional parameter value is initialized, any changes in the upper scope variables don't affect the optional parameter value.
Stored variable Stored variables work like Local variables, except that when the view is saved, the current value of the Stored variable is saved to the view at the level where the Stored variable is defined.
Default value Unlike local variables and optional parameters, Default value variables are not independent variables but they are just default values for non-existing variables. Thus, if a variable with the same name exists in the upper scope, the defined default value variable doesn't have any effect. Only if no upper scope variable exists, the value defined for the default value variable (in the Context tab) is used in the default value variables' scope when referring to a variable with that name. Default value variable values cannot be set by presentation objects, so when trying to set an default value variable value, the value is set to the session scope variable.

Note that variables in the session scope cannot be defined like the UI element variables, but session scope variables are created when they are set for the first time during a user session.

When presentation objects set variable values, either the nearest UI element scope variable or the session scope variable can be set. In a data grid actions the setting is called scope with alternatives local and global, and in HTML presentation object functions, it's done using a parameter named presentation object runtime id. When setting a UI element variable, always the nearest variable value in the hierarchy is set. For example, when setting a value from a data grid, the data grid presentation object is the nearest scope, the panel is the next and the view scope is after the panel. If there is no variable in any UI element scope defined, the value is set to the session scope.

When creating bookmarks, currently only the session scope variables are stored to the bookmark.

Setting Variable Values in URL

It's possible to set context variable values in the url pointing to QPR UI. To do this, for each variable add "&<variable name>=<variable value>" in the end of the URL. For example: http(s)://SERVERNAME/ui/#/dashboard?sys:dashboard=24026&myvariable1=myvalue1&myvariable2=myvalue2

Note that when using variables a url, variable values need to be url encoded (more information: https://www.w3schools.com/tags/ref_urlencode.asp).

Context Variables Usage Example

There is a view with one panel, in which there is one presentation object. The Session context variable values are defined as follows:

Variable name Value
AccountManager John Smith
Country Sweden

In the View Properties, the following context variable values are defined:

Variable name Value Behavior
AccountManager William Taylor Stored variable
CustomerGroup Kids Local variable

In the Panel Properties, the following context variable values are defined:

Variable name Value Behavior
AccountManager Susan Chapman Local variable
Country Finland Local variable

In the Presentation Object Properties, the following context variable values are defined:

Variable name Value Behavior
ProductGroup Umbrellas Stored variable

In the Effective View Context, these result into the values shown below. Note the Source column displaying the information where the effective context comes from:

Variable name Value Source Scope
AccountManager William Taylor Scope of the view View
Country Sweden Inherited from session context Session
CustomerGroup Kids Scope of the view View

In the Effective Panel Context, these result into the values shown below. Note the Source column displaying the information where the effective context comes from:

Variable name Value Source Scope
AccountManager Susan Chapman Initialized from the panel's context Panel
Country Finland Initialized from the panel's context Panel
CustomerGroup Kids Inherited from the effective context of the view View

In the Effective Presentation Object Context, these result into the values shown below. Note the Source column displaying the information where the effective context comes from:

Variable name Value Source Scope
AccountManager Susan Chapman Inherited from the effective context of the panel Panel
Country Finland Inherited from the effective context of the panel Panel
ProductGroup Umbrellas Scope of the presentation object Presentation object
CustomerGroup Kids Inherited from the effective context of the view View

To put it more concisely, the context variable values (and their behaviors) are as follows:

Context Variable Session View Panel Presentation Object
AccountManager John Smith William Taylor (Stored variable) Susan Chapman (Local variable)
Country Sweden Finland (Local variable)
ProductGroup Umbrellas (Stored variable)
CustomerGroup Kids (Local variable)

The effective context values are:

Context Variable Session View Panel Presentation Object
AccountManager John Smith William Taylor Susan Chapman Susan Chapman
Country Sweden Sweden Finland Finland
ProductGroup Umbrellas
CustomerGroup Kids Kids Kids

Context Variables and Web Browser History

Any time the session context is modified (like when clicking a Pushbutton or modifying ProcessAnalyzer Presentation Object settings that cause session variables to be modified), a browser history entry is created. The preceding values in the session context can be restored via the browser's Back button. Left-clicking the Back button will restore the previous session context values, whereas right-clicking the Back button will show a list of session context changes to select from. Selecting an entry on the list will restore the session context from that entry.
BrowserHistory.png

Example: Defining View Properties and Variables

  1. Creating a new QPR UI view starts by defining the Name and View Context. These are defined in the view properties that is opened by clicking the Properties button:
    OpenViewProperties.png
  2. First, give your view a Name and a Description. Then, click Presentation:
    ViewProperties.png
  3. On the Presentation tab, change the Background color. Set also the Outer margin to be "5", this setting will make the panels be closer to each other than with the default setting. After that, click Context:
    ViewPresentationTab.png
  4. The context defines the starting points for later querying data from QPR EnterpriseArchitect/ProcessDesigner, QPR Metrics, and/or QPR ProcessAnalyzer. Define the context by selecting values for the context variables by first selecting a variable from the drop-down menu and then tapping the edit icon on the Value column:
    ViewContext.png
  5. To define context variables, type in the name of the variable to the text field and click the check mark. After that, you can click the value field and type in the value for your context variable. Context variables starting with "sys:" are system context variables which have special purpose in QPR UI - use them only for their intended purpose. The Behavior selection affects the context variable used explained in Context Variable Behaviors. To see what context variable values are used in the view, panel, or presentation object, select the Show effective context check box in the Context tab of the view, panel, or presentation object properties pages.

Using QPR EnterpriseArchitect/ProcessDesigner Data

EAContext.png

  • To use QPR EnterpriseArchitect or QPR ProcessDesigner data, define the sys:eapdModel, sys:eapdElementType and sys:eapdElement context variables to set the default context instance. With the sys:eapdElement context variable, you can use the check boxes on the left side of the list to select the elements to which the view you are designing applies. These elements will then be selectable as the context instance via the Selections button when browsing the view. Selecting the All elements automatically check box will result in all elements of the element type defined by the sys:eapdElementType variable to be automatically available in the view when new elements of that type are added to the model.

Using QPR Metrics Data

MetricsContext.png

  • If you want to show data from element(s) that reside in some particular scorecard(s), define the sys:metricsModel and sys:metricsScorecard context variables. This is the most commonly preferred way of showing Metrics data.
  • If you want to show data from a single Metrics element or measure, define the sys:metricsModel, sys:metricsValueSettings, and sys:metricsElement context variables.

The difference between these two approaches is that views with the sys:metricsScorecard variable defined can show data from multiple measures residing in the selected scorecards, whereas views with the sys:metricsElement variable defined are restricted to the measures selected here, but they enable browsing different measures using the same value settings as the selected measure. With the sys:metricsScorecard and sys:metricsElement variables, you can use the check boxes on the left side of the list to select the scorecards or elements to which the view you are designing applies. These scorecards or elements will then be selectable as the context instance via the Selections button when browsing the view. Selecting the All scorecards/elements automatically check box will result in all scorecards or elements of the model defined by the sys:metricsModel variable to be automatically available in the view when new scorecards or elements of the defined sys:metricsValueSettings type are added to the model.

Select QPR Metrics Period

By default, the QPR UI view shows data from the Current period. As the view you are designing might not have data available for the current period, click the Selections button:

Selections.png

Then, select a period for which you have data:

SelectPeriod.png

See Also