Hi,
We are currently developing a project with Struts2. We have a module on which we display a large amount of data on read-only fields from a group of beans via the "property" Struts 2 data tag (i.e. <s:property value="aBeanProperty" />) on a jsp file. In some cases most of the fields might come empty, so a blank is being displayed on screen.
Our customer is now requesting us to display default string (i.e. "N/A") whenever a property comes empty, so that it is displayed in place of the blank spaces currently shown.
We are looking for a way to achieve this in a clean and maintainable way. The 'property' tag comes with a 'default' attribute on which one can define a default value in cases when the accessed property comes as null. However, most of our properties are empty strings, therefore it does not work in our case.
Another solution we are thinking of is to define a base class for all of our beans, and define a util method which will validate if a string is null or empty and then return the default value. Then we would call this method from each bean getter. And yes this would be tiresome and kind of ugly :), therefore we are holding out on this one in case of a better solution.
Now, we have in mind a solution which we think would be the best but have not had luck on how implement it. We are planning on extending the 'property' tag some way, defining a new 'default' attribute so that besides working on null properties, it also do so on empty strings ("", " ", etc). Therefore we would only need to replace the original s:property tag with our new custom tag, and the desired result would be achieved without touching java code.
Do you have an idea on how to do this? Also, any other clever solution (maybe some sort of design pattern?) on how to default the values of a large amount of property beans are welcome too!
(Or maybe, even there might be some tag that does this already in Struts2??)
Thanks in advance.
Shorter version in case you don't want to read all of the above! :)
Currently Struts2 provides a property tag (<s:property value="someValue" />), it is used to display the content of a value, e.g. a String variable on an Action class. This tag contains an attribute called "default" where you can define a default value to be displayed IF the variable is set to NULL, e.g. you can set it to display "N/D" for these values.
We now need to do the same, but that it also works on empty Strings ("", " ", etc), not only on nulls. We plan on extending this tag so that we have our own (maybe something like <s:propertyEmpty value="someValue" />) and accomplish this behavior. Can you guide how to accomplish this?
Your help is greatly appreciated. Thanks!