Portlet Factory, Version 6.1.2


 

Working with the Category View builder

When the data comes from a categorized Domino view, select the Use Domino category rows choice under Category Selection. This choice forces the Category View builder to determine the columns to be treated as categories and the order of the columns automatically, based on Domino settings. Be sure that the category rows are included in the view data when using this choice (for example, not using Document rows only in the Domino Data Access builder.) Otherwise, you have to specify them manually.

When you get an XML representation of a categorized Domino view from the Domino View & Form builder, you can specify the set of rows to return. By default, you just get document rows, that is, those that show the actual data for a row. However, you can also request category rows in addition to the document rows. These category rows are inserted into the data to indicate when a new category is starting.

When category rows are present in the data, the builder runtime code can detect them. In this case the user need not indicate which columns in the data are category columns because the runtime code can tell from the category rows. When the data is not Domino-formatted or does not have category rows, you need to tell the builder which columns are associated with categories. You use the builder Categories input table to do so.

For the display to be readable, the values in the Category column need to be taken from a limited set of values. For example, a Region category with East, North, South and West would be good. A sorted column of unique numbers would cause a collapsible section to be generated for each row, which is probably not what was intended.

Note: A category view is intended as an alternative to a paged view. Using this builder with Paging Assistant and Paging Button builders does not work. The paging builders arrange for page-sized chunks of data to be sent to the view code, assuming the entire chunk of data is to be displayed. When the Category View builder is controlling the display, the user can collapse sections of the display leading to fewer than expected actual rows of data being expanded. Also, when the category row (with the expand and collapse control) is not included in the displayed page of data, it is possible to have the Category View builder show no rows of data at all. (For example, if the category contained more than a page of data, was collapsed, but the expand and collapse icon was on the previous page, nothing would be displayed).

Similarly, changing the sorting of the data using the Sort builder also produces poor results because the sort builder sorts the data as a whole (as opposed to the values within each category) and destroys the category structure of the data. For example, in the case of a data set with category column Quarter (values Q1, Q2, Q3 and Q4) and a normal column Results (number of units sold in this quarter), if you were to sort the Results column, the Quarter column would no longer be a valid category column, since its values no longer be sorted.

Parent topic: Category View builder


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