Multi-Select Listbox handling for batch reports

rpolunsky

The multi-value listbox parameter type is very handy for interactive reporting, but if you want to invoke that report in a batch process (such as using genReport.bat) or programmatically (via URL), you run into a major problem. BIRT does not have a command-line/URL-based syntax for passing multi-value parameter selections. The listbox parameter implements as an Object[], which is the source of much grief in this situation. However, it turns out that the ToString() method on that Object yields a comma-separated list - and that I can work with.

I have a workaround approach that seems to be working for me.

I create a parallel parameter, type string. Call the listbox MultiValue and the parallel parameter MultiValue_CSV. Now I determine whether the string parameter is nonempty and if so I ignore the value in the listbox.

In my report initialize event I have the following:

// MultiValue is a multiselect listbox, required; MultiValue_CSV is a textbox, not required, no default
var valuelist = params["MultiValue"].toString();
var staticlist;
reportContext.setPersistentGlobalVariable("listbox_value", valuelist);
reportContext.setPersistentGlobalVariable("filter_list", valuelist);
if (null == params["MultiValue_CSV"].value) {
reportContext.setPersistentGlobalVariable("override_value", "is null");
} else {
reportContext.setPersistentGlobalVariable("override_value", "not null");
staticlist = params["MultiValue_CSV"].value;
if (staticlist.length > 0) {
reportContext.setPersistentGlobalVariable("override_text", staticlist);
reportContext.setPersistentGlobalVariable("filter_list", staticlist);
} else {
reportContext.setPersistentGlobalVariable("override_text", "empty string");
};
};

The relevant value is held in the gloval variable "filter_list".

Finally, my dataset query is defined with a where clause like
" AND Alloc_ID IN (0) "

Then, in the beforeOpen event of the dataset, I make the following substitution:

this.queryText = this.queryText.replace("(0)", "(" + reportContext.getPersistentGlobalVariable("filter_list") + ")");

I'm swamped right now, but I'll try and get something whipped up this month against the Derby database to make a sample report available.

johnw

Thats awesome. Put this together and submit it to the DevShare. They have upped the prizes for winners, and this is definitely a contender. I'd get it done quick though, I'm considering stealing this for myself, so someone else might <br />
<br />
<blockquote class='ipsBlockquote' data-author="'rpolunsky'" data-cid="69315" data-time="1286988608" data-date="13 October 2010 - 09:50 AM"><p>
The multi-value listbox parameter type is very handy for interactive reporting, but if you want to invoke that report in a batch process (such as using genReport.bat) or programmatically (via URL), you run into a major problem. BIRT does not have a command-line/URL-based syntax for passing multi-value parameter selections. The listbox parameter implements as an Object[], which is the source of much grief in this situation. However, it turns out that the ToString() method on that Object yields a comma-separated list - and that I can work with.<br />
<br />
I have a workaround approach that seems to be working for me.<br />
<br />
I create a parallel parameter, type string. Call the listbox MultiValue and the parallel parameter MultiValue_CSV. Now I determine whether the string parameter is nonempty and if so I ignore the value in the listbox.<br />
<br />
In my report initialize event I have the following:<br />
<br />
// MultiValue is a multiselect listbox, required; MultiValue_CSV is a textbox, not required, no default<br />
var valuelist = params["MultiValue"].toString();<br />
var staticlist;<br />
reportContext.setPersistentGlobalVariable("listbox_value", valuelist);<br />
reportContext.setPersistentGlobalVariable("filter_list", valuelist);<br />
if (null == params["MultiValue_CSV"].value) {<br />
reportContext.setPersistentGlobalVariable("override_value", "is null");<br />
} else {<br />
reportContext.setPersistentGlobalVariable("override_value", "not null");<br />
staticlist = params["MultiValue_CSV"].value;<br />
if (staticlist.length > 0) {<br />
reportContext.setPersistentGlobalVariable("override_text", staticlist);<br />
reportContext.setPersistentGlobalVariable("filter_list", staticlist);<br />
} else {<br />
reportContext.setPersistentGlobalVariable("override_text", "empty string");<br />
};<br />
};<br />
<br />
The relevant value is held in the gloval variable "filter_list".<br />
<br />
Finally, my dataset query is defined with a where clause like<br />
" AND Alloc_ID IN (0) "<br />
<br />
Then, in the beforeOpen event of the dataset, I make the following substitution:<br />
<br />
this.queryText = this.queryText.replace("(0)", "(" + reportContext.getPersistentGlobalVariable("filter_list") + ")");<br />
<br />
I'm swamped right now, but I'll try and get something whipped up this month against the Derby database to make a sample report available.<br /></p></blockquote>