Administering task downloads

A powerful feature of ArcGIS Explorer is its task framework, which allows developers to create tasks and share them among ArcGIS Explorer users. An ArcGIS Explorer map (NMF) file may reference a task which does not already exist on the machine. In this case, ArcGIS Explorer needs to download the task to the machine in order to load and use it. Information in the NMF file is used to determine where the file is located and how to download it. As the Home Server administrator, you can set limits on where your ArcGIS Explorer clients will be able to download tasks from.

There may be tasks that you develop within your organization which you will want to make easily accessible to your ArcGIS Explorer clients. You should put these tasks in a well-known location on your organization’s server. For example, you might create a Tasks folder in the <ARCGISHOME>/java/web_output/explorer directory on the Home Server, and make the tasks available from there.

Task download security settings

You can choose to prohibit clients of your Home Server from downloading tasks from the Internet or the intranet. You can also choose to only allow downloads from a list of trusted sites. There are three tags in the ArcGIS Explorer configuration file that define these security settings. These tags correspond to security zones used by Microsoft Internet Explorer. They can be set to either “true” or “false”. The default value is “true” for all tags.

<TaskDownloadInternet>

Enabling this property allows users to download tasks from any Internet site. It corresponds to the “Internet” security zone in Internet Explorer.

<TaskDownloadLocalIntranet>

Enabling this property allows users to download tasks from their local intranet. By default this zone includes network paths (for example \\MyServer\Fileshare\) and may also include web sites which are hosted within your network, for example http://MyLocalServer:8399/SomeFolder). It corresponds to the “Local intranet” zone in Internet Explorer.

<TaskDownloadTrustedSites>

Enabling this property allows users to only download tasks from their Trusted Sites list, defined in Microsoft Internet Explorer’s security settings. The trusted sites setting overrides the TaskDownloadInternet and TaskDownloadIntranet settings: in other words, when you enable the trusted sites download zone, you can download from trusted sites even if you have restricted Internet and intranet task downloads.

Additional information

It’s important to also know the following points about task download security:

• If any of the three tags is not present in the configuration file, downloading of tasks from the according location is permitted. Therefore if none of the three task download tags has been specified in the configuration file, downloading of custom tasks is possible from any location.
• Downloading custom tasks from locations directly on the local computer is always permitted. If a connection to the home server cannot be established and the user chooses to use only local cached data, task downloading is only possible from the local computer.
• Downloading of custom tasks from locations that are set as restricted sites in Internet Explorer is never permitted. This zone contains specific sites you do not trust; sites which may contain files which may cause problems on your computer, either maliciously or accidentally. You or your system administrator can add sites to this zone.

• When ArcGIS Explorer needs to download a task, by default it will ask the user for permission by showing a dialog. This dialog can be turned off by the user by selecting the 'Don't show this dialog again' checkbox. The configuration settings above do not affect this behavior.

If you are having problems with deploying and downloading tasks, refer to the Deployment Troubleshooting topic in the ArcGIS Explorer Developer Help.