In the beginning of the year I attended a requirements engineering class where we discussed - among other topics - activity diagrams. One element of an activity diagram is the decision node, the diamond shape, where you can branch the flow of activities depending on guarding condition for each outgoing edge. There we stumbled upon one - at least to me - completely new aspect on the guard conditions.
According to the UML specification the guard condition protects the entry of an edge. If the condition is not fulfilled, the edge is no entered. Before the above mentioned discussion I always assumed that an edge without a condition always evaluates to true and is always evaluated at last of all outgoing edged and is therefore entered only if none of the other edges' condition applies. But that is wrong!
The truth is, that according to the UML specification the order of the "processing" of the edges is not determined and therefore may be completely random. So if you define an outgoing edge of a decision node without a guarding condition, it may be the case, the edge is entered although another edge's condition may have been met but would be evaluated after the edge without a condition.
Conclusion is, if you want to have a determined behavior of your activities, always define all of the guard conditions of your outgoing edges of decision nodes.
Showing posts with label activity. Show all posts
Showing posts with label activity. Show all posts
Tuesday, April 1, 2014
Friday, February 13, 2009
Pointing to a specific Activity using the Portal Bookmark portlet
Today we tried to create a landing page for a Portal with integrated Connections. The landing page should contain a link to give feedback. Since it is a PoC we'd like to use an Activity for collecting feedback to demonstrate the various usage possibilites for Lotus Connections. The link to the feedback activity should have been provided in the Bookmark portlet of WebSphere Portal. However, we encountered a minor issue for which we found a solution.
The problem was, that the URL to the Activity contained a comma character respectively the octet encoding of it (%2C). Although this format is conforming with URL RFC 1738 (paragraph 2.2.) the Bookmark portlet refused to accept this URL stating the URL was not valid.
However, we found a workaround for that. We created a Portal URL page pointing to the feedback activity and put this URL page underneath the Activities URL page in the portal page structure so that it remains invisble. We assigned a uniquename to this URL page pointing to the Feedback Activity and created a bookmark in the bookmark portlet that pointed to the Portal URL page for the Feedback Activity. Thats it. The uniquename is required, otherwise this URL page would not be selectable as portal internal page in the Bookmark portlet.
By the way, I like the approach of collecting feedback using an Activity. The users can comment on existing feedback, agree, disagree. The feedback can be given in a structured way, like technical feedback, opinions, enhancement requests, and the users could even post files. The receivers of the feedback can give answers directly to the posts and users could easily subscribe to updates to stay informed about what's going on. And the best of all: it's usable out-of-the-box, we did not need to create a custom feedback form :)
The problem was, that the URL to the Activity contained a comma character respectively the octet encoding of it (%2C). Although this format is conforming with URL RFC 1738 (paragraph 2.2.) the Bookmark portlet refused to accept this URL stating the URL was not valid.
However, we found a workaround for that. We created a Portal URL page pointing to the feedback activity and put this URL page underneath the Activities URL page in the portal page structure so that it remains invisble. We assigned a uniquename to this URL page pointing to the Feedback Activity and created a bookmark in the bookmark portlet that pointed to the Portal URL page for the Feedback Activity. Thats it. The uniquename is required, otherwise this URL page would not be selectable as portal internal page in the Bookmark portlet.
By the way, I like the approach of collecting feedback using an Activity. The users can comment on existing feedback, agree, disagree. The feedback can be given in a structured way, like technical feedback, opinions, enhancement requests, and the users could even post files. The receivers of the feedback can give answers directly to the posts and users could easily subscribe to updates to stay informed about what's going on. And the best of all: it's usable out-of-the-box, we did not need to create a custom feedback form :)
Subscribe to:
Posts (Atom)