Hyperlinker

Modified on Wednesday, 04 May 2016 09:12 AM by Administrator — Categorized as: Components

The Hyperlinker component is an abstract base class that provides the low-level functionality necessary for creating a component that hyperlinks users to external websites based on the attributes of a user-specified feature.

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Location
Inheriting from Hyperlinker
Tolerance Options
Configuration Options
Sample Configuration
Downloads
See Also

Location¶

Namespace: FDOT.GIS.Client.Components.FloodInventory

XAP File: FDOT.GIS.Client.Components.FloodInventory.xap

Source code: svn://dotsd7gis2/FDOT.GIS.Client.Components.FloodInventory/

Inheriting from Hyperlinker¶

The Hyperlinker tool contains all of the functionality for querying layer after layer, extracting a single value from the first feature returned, building a URL from this single value, and then invoking the ExternalLink resource to open the web page.

To implement a subclass of the Hyperlinker tool, you must implement the string IconResourceUri get property (inherited from ComponentBase) and the GetOtherParams method:

protected abstract IEnumerable<string> GetOtherParams(QueryResult results);

This method is invoked by Hyperlinker when a feature is found and allows base classes to programmatically add to the parameter list sent to string.Format when the target URL is being constructed. Even if your component does not require any additional parameters to be sent, it is highly recommended (in fact, enforced via the abstract keyword) to subclass Hyperlinker rather than use it directly, as weird behavior can occur when two components have the same type.

Tolerance Options¶

The Hyperlinker lets users choose which feature to hyperlink from by clicking a point on the map and searching each layer it is configured to search for geometry that intersects with that point. When searching a point layer, it is exceptionally unlikely that the specified point and desired point will intersect. To fix this problem, the Hyperlink tool automatically buffers every point query and uses the generated bufer to query the layers.

The current map width, the Hyperlinker tool's intolerance field, and the Hyperlinker tool's tolerance field all influence the radius of the buffer in the following way:

var bufferRadius = mapWidth.Value / intolerance + tolerance;

So, tolerance has a bigger effect when the map is very zoomed in, whereas intolerance has a bigger effect when the map is zoomed out. By default, intolerance is set to 50 and tolerance is set to 5. If these settings are not satisfactory, they can be changed by the constructor of the component inheriting from Hyperlinker.

Configuration Options¶

Name	IsRequired	Description
FormatString	true	The format string for the URL to be constructed. Parameter 0 will always refer to the configured attribute value of the feature selected by the user.
MapServiceName	true	A semicolon-separated list of map services to query.
LayerName	true	A semicolon-separated list of layers to query.
ColumnName	true	A semicolon-separated list of attributes to query.

Sample Configuration¶

Because Hyperlinker is an abstract class, it cannot be used as a component. See FloodInventoryLinker for an example configuration of a subclass

Downloads¶

FDOT.GIS.Client.Components.FloodInventory.xap Download