The dashboard function runs dashboards on JasperReports Server and displays the result in a container that you provide. Dashboards are a collection of reports and widgets that you design on the server. Dashboards were entirely redesigned in JasperReports Server 6.0 to provide stunning data displays and seamless integration through Visualize.js.
This chapter contains the following sections:
• | Dashboard Properties |
• | Dashboard Functions |
• | Dashboard Structure |
• | Rendering a Dashboard |
• | Refreshing a Dashboard |
• | Using Dashboard Input Controls |
• | Using the Dashboard Undo Stack |
• | Setting Dashboard Hyperlink Options |
• | Closing a Dashboard |
Dashboard Properties
The properties structure passed to the dashboard function is defined as follows:
Dashboard Functions
The dashboard module exposes the following functions:
Dashboard Structure
The Dashboard Data structure represents the rendered dashboard object manipulated by the dashboard function. Even though it's named "data," it does not contain any data in the dashboard or reports, but rather data about the dashboard. For example, the Dashboard Data structure contains information about the items in the dashboard, called dashlets.
Rendering a Dashboard
To run a dashboard on the server and render it in Visualize.js, create a dashboard object and set its properties. Like rendering a report, the resource property determines which report to run, and the container property determines where it appears on your page.
The following code example shows how to define a dashboard ahead of time, then render it at a later time.
Refreshing a Dashboard
You can order the refresh or re-render of the dashboard, as well as cancel the refresh if necessary, for example if it takes too long.
Using Dashboard Input Controls
Like reports, dashboard can have input controls, also called filters, to change the values of what is displayed.
As of JasperReports Server 6.4, Visualize.js supports much simpler dashboard input controls that are rendered directly by the server. If the dashboard is defined to have input controls, the dashboard is rendered with a small panel of UI widgets for selecting or entering new input control values. Therefore, when you embed the dashboard, it contains the interface that allows users to set input controls.
You also have the option of setting input controls programmatically, for example to update a dashboard based on other events in your web application. Input controls are called parameters within Visualize.js dashboards. To set input controls programmatically, you must first discover the list of available parameters:
Then you read their values, modify them, and set new values. The dashboard then renders with the new input parameter values:
In the following example, a button resets the parameters to their default values by sending a null parameter set. First the HTML to define the container and the button:
And then the JavaScript to perform the action:
In another example, the script initializes the parameters and the HTML displays a button when they're ready to be applied:
And then the JavaScript to initialize the parameters and enable the button for the user:
You can create any number of user interfaces, database lookups, or your own calculations to provide the values of parameters. Your parameters could be based on 3rd party API calls that get triggered from other parts of the page or other pages in your app. When your dashboards can respond to dynamic events, they become truly embedded and much more relevant to the user.
Using the Dashboard Undo Stack
As of JasperReports Server 6.4, Visualize.js dashboards provide undo and redo functionality. After users interact with input controls and modify the data on the dashboard, they may want to return to their initial dashboard state. With the undo and redo events and actions, you can allow your users to navigate their data more easily in dashboards.
Visualize.js dashboards support the following actions:
• | Undo – Reverts the input controls to next older set of values and updates the dashboard contents accordingly; available after at least one change to input controls. |
• | Redo – Reverts the input controls to next newer set of values and updates the dashboard contents accordingly; available after at least one undo action. |
• | Undo All – Reverts the input controls to their initial set of values and updates the dashboard contents accordingly; available when there is an older set of values that hasn't been undone. |
In order to implement undo and redo actions, you must also use event listeners to know when undo and redo events become available. For example, before the user has made any changes to input controls, no actions are possible. Redo is only possible after the user performs an undo or undo-all action.
In the following example, the HTML has a table to display the input control values and buttons to perform the undo and redo actions:
The CSS sets the size of the container to be large enough for a dashboard, and sets the table heading color for visibility:
The JavaScript has listeners for the canUndo and canRedo events in order to set the visiblity of the undo and redo buttons. When the buttons are enabled and the user clicks on one, the code takes the corresponding action then displays the ids and values of the input controls in the table. By combining the event listeners and actions, the page allows the user to step backward and forward through various sets of input controls in the dashboard.
Setting Dashboard Hyperlink Options
In JasperReports Server 6.1, the handling of dashboard hyperlinks changes. There is now a default behavior that makes sense for most types of hyperlinks and actions. There are several types of links:
• | Reference – The reference link indicates an external source that is identified by a normal URL. The only expression required is the hyperlink reference expression. It's possible to specify additional parameters for this hyperlink type. |
• | LocalAnchor – To point to a local anchor means to create a link between two locations into the same document. It can be used, for example, to link the titles of a summary to the chapters to which they refer. To define the local anchor, it is necessary to specify a hyperlink anchor expression, which will have to produce a valid anchor name. It's possible to specify additional parameters for this hyperlink type. |
• | LocalPage – If instead of pointing to an anchor you want to point to a specific current report page, you need to create a LocalPage link. In this case, it is necessary to specify the page number you are pointing to by means of a hyperlink page expression (the expression has to return an Integer object). It's possible to specify additional parameters for this hyperlink type. |
• | RemoteAnchor – If you want to point to a particular anchor that resides in an external document, you use the RemoteAnchor link. In this case, the URL of the external file pointed to will have to be specified in the Hyperlink Reference Expression field, and the name of the anchor will have to be specified in the Hyperlink Anchor Expression field. It's possible to specify additional parameters for this hyperlink type. |
• | RemotePage – This link allows you to point to a particular page of an external document. Similarly, in this case the URL of the external file pointed to, will have to be specified in the Hyperlink Reference Expression field, and the page number will have to be specified by means of the hyperlink page expression. Some export formats have no support for hypertext links. It's possible to specify additional parameters for this hyperlink type. |
• | ReportExecution – This type of hyperlink is used to implement JasperServer’s drill-down feature. Page and anchor can be specified for the hyperlink type as well as additional special parameters such as _report, _anchor, _page, _output . |
• | AdHocExecution – This type of hyperlink represents an information about clicked point on chart reports generated from AdHoc Charts. It exposes names of measures and values of dimensions as parameters. |
• | Custom Hyperlink Type – A type of hyperlink that you can define entirely. |
And there are several types of link targets:
• | Self – This is the default setting. It opens the link in the current window. |
• | Blank – Opens the target in a new window. Used for output formats such as HTML and PDF |
• | Top – Opens the target in the current window but outside any frames. Used for output formats such as HTML and PDF. |
• | Parent – Opens the target in the parent window (if available). Used for output formats such as HTML and PDF. |
• | Frame name – Always opens the target in the specified frame. |
The following table shows the new default action for each combination of link and target:
Type Targets | Self | Blank | Top | Parent |
---|---|---|---|---|
Reference (points to an external resource) | Referenced URL is opened in an iframe on top of the report. | Referenced url is opened in new tab. | Referenced url is opened in same window. | Referenced url is opened in parent frame for reports generated from AdHoc Charts. |
ReportExecution (points to JasperReports report) | Referenced report is opened in same place through Viz.js (if hyperlink points to the same report, it's just gets updated with params/page/anchor). | Referenced report is opened in new tab. | Referenced report is opened in top frame (same window). | Referenced report is opened in parent frame. |
LocalAnchor (points to an anchor in current report) | Anchor is opened in same place through Viz.js. | Referenced report anchor is opened in new browser tab. | Referenced report anchor is opened in top frame (same window). | Referenced report anchor is opened in parent frame. |
LocalPage (points to a page in current report) | Page is opened in same place through Viz.js. | Referenced report page is opened in new browser tab. | Referenced report page is opened in top frame (same window). | Referenced report page is opened in parent frame. |
RemoteAnchor (points to an anchor in remote document) | Since remote anchor could be a link to resources like PDF or HTML, we have to open it in an iframe on top of the report. | Referenced report anchor is opened in new browser tab. | Referenced report anchor is opened in top frame (same window). | Referenced report anchor is opened in parent frame. |
RemotePage (points to a page in remote document) | Since remote page could be a link to resources like PDF or HTML we have to open it in an iframe on top of the report. | Referenced report page is opened in new browser tab. | Referenced report page is opened in top frame (same window). | Referenced report page is opened in parent frame. |
AdHocExecution | The hyperlink provides parameters, which are exposed to Filter Manager for additional wiring (beyond the scope of this document). |
The following code samples demonstrate the default handling of hyperlinks and the effect of defining overrides that remove the default handling. First the HTML for some buttons:
And now some hyperlink overrides:
However, if your dashboards are designed for custom drill-down, you can still define custom link handling so your users can access more reports and more data. Be sure to modify your code to handle all three function parameters for function(ev, link, default), as shown in this updated code sample:
Closing a Dashboard
When you want to reuse a container for other contents and free the dashboard resources, use the destroy function to close it.
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