Agent
An agent is responsible for exchanging data with an external source, using settings assigned in the File/Data Link dialog.
The Data Link dialog describes how grid information is to be read from, and written to external data.
The process of writing data to, for example, a comma delimited .txt file is very different compared to that of performing an Sql update query.
Data Flask comes standard with two agents:
| Text Files | |
| Microsoft Data Access Components |
A Flask Grid File (*.dfg) is not required to have an agent assigned. The Data commands will simply be inactive.
File Data compared to Grid Data commands:
Terminology. Each Data menu choice from the File menu refers to an exchange of information between a single grid and external information. Thus the involvement of agents. This differs from the use of the word Data in the Grid menu, where there is never any data exchange with external sources.
Selection. Agents do not recognize grid cell selections. File/Data commands action on the entire grid, ignoring cell selections. Most of the Grid/Data commands recognize a selection. In practice this means that if you want to update a select row from external data it must be done in two steps. First into a temporary grid that updates in full, and second using the Grid/Data/Join where [ ] Select All Rows is unchecked (figure 3-3).
Technote: Agents are implemented as .exa files, which are small Mfc extension dll's. Look for new agents to be added, either by Interscape or third parties. Parties interested in developing an Agent should visit http://dataflask.com/agentsdk.
Data
Flask Copyright © 2006 Interscape
Corporation