[stringtemplate-interest] Grid Problems

[Terence Parr]

Hi Bob, i'm racing to get ANTLR v3.1 out the door...I'll get to this  
as soon as i can.
T
On May 3, 2008, at 12:04 PM, Bob wrote:

> I have a system that produces data in 2-D grids (rows-and-columns).
> Each column has a name.  This seemed like a perfect match for
> StringTemplate.
>
> I've included at the end of this email a template that I wish to use  
> to
> generate a report from my 2-D grids.  In particular, I wish to:
>
> 1. Create a 1-row grid (person) containing one person record.
> 2. Create a multi-row grid (phones) containing phone numbers for the
> person.
> 3. Format it all together as shown in the template at the end of this
> message.
>
> The basic operation here is to set a StringTemplate attribute to one  
> of
> my grids (StringTableModel).  I want to make a function like:
>
> public static void setAttribute(StringTemplate st, String var,
> StringTableModel val)
> 	{ ... }
>
> Then I use code as follows to generate my report:
>
> 	StringTemplate st = ....;
>
> 	StringTableModel sperson = new StringTableModel(dmod.getPersonSb(),  
> sfmap);
> 	setAttribute(st, "person", sperson);
> 	
> 	StringTableModel sphones = new StringTableModel(dmod.getPhonesSb(),  
> sfmap);
> 	setAttribute(st, "phones", sphones);
>
> 	return st.toString();
>
> Unfortunately, I came up against several difficulties in figuring out
> what to place in the body of the setAttribute(StringTemplate, String,
> StringTableModel) function:
>
> 1. I first tried setting multi-valued attributes as follows.  The  
> parser
> complained that I couldn't have "." in an attribute name:
> 	for (int col=0; col<val.getColumnCount(); ++col) {
> 		String colName = var + "." + val.getColumnName(col) + "";
> 		for (int row=0; row<val.getRowCount(); ++row) {
> 			st.setAttribute(colName, val.getValueAt(row, col));
> 		}
> 	}
>
> 2. Then I tried the syntax shown in the docs for 2-5 column multi- 
> valued
> attributes, as follows.  The parser also did not understand this,  
> since
> I'm only setting one column at a time:
> 	for (int col=0; col<val.getColumnCount(); ++col) {
> 		String colName = var + ".{" + val.getColumnName(col) + "}";
> 		for (int row=0; row<val.getRowCount(); ++row) {
> 			st.setAttribute(colName, val.getValueAt(row, col));
> 		}
> 	}
>
>
> 3. Then I tried creating a HashMap for each row, and setting the value
> once per row.  This ALMOST worked.  It worked as long as you have 2 or
> more phone numbers.  But if you had just one phone number (and in my
> case 2 columns), the system interpreted the data as two single-valued
> attributes, as opposed to one aggregate attribute.  Thus, it worked  
> if I
> had 2 phone numbers, but threw an exception if I had just one.  Is  
> this
> a bug, or is that the intended behavior?
> 	for (int row=0; row<val.getRowCount(); ++row) {
> 		HashMap map = new HashMap();
> 		for (int col=0; col<val.getColumnCount(); ++col) {
> 			map.put(val.getColumnName(col), val.getValueAt(row, col));
> 		}
> 		st.setAttribute(var, map);
> 	}
>
> 4. I figured maybe if I make each column as a list of attributes, this
> would work.  No such luck...
> 	HashMap map = new HashMap();
> 	for (int col=0; col<val.getColumnCount(); ++col) {
> 		List list = new ArrayList(val.getRowCount());
> 		for (int row=0; row<val.getRowCount(); ++row) {
> 			list.add(val.getValueAt(row, col));
> 		}
> 		map.put(val.getColumnName(col), list);
> 	}
> 	st.setAttribute(var, map);
>
> 5. Finally, I hacked the source code, making StringTemplate.Aggregate
> public, to allow the following.  Since StringTemplate.Aggregate is
> basically a wrapper around HashMap, I'm surprised that behaved
> differently from the HashMap example above.  But it did: this worked,
> whereas the example above did not:
>
> 	
> 	for (int row=0; row<val.getRowCount(); ++row) {
> 		StringTemplate.Aggregate map = new StringTemplate.Aggregate();
> 		for (int col=0; col<val.getColumnCount(); ++col) {
> 			map.put(val.getColumnName(col), val.getValueAt(row, col));
> 		}
> 		st.setAttribute(var, map);
> 	}
> 	
> ---------------------
> Current status: at this point, I know of no way to do what I want
> without hacking the source code.  Any suggestions on a solution to  
> this
> problem?
>
> Thanks,
> -- Bob
>
>
> // ===================================================
> // summary.st
>
> <ul>
> <li>Name: $person.firstname$ $person.lastname$</li>
> <li>Email: $person.email$</li>
> </ul>
>
>
> <h3>Phones</h3>
> <table border=1>
> $phones:{it |
>  <tr>
>    <td>$it.groupid$</td><td>$it.phone$</td>
>  </tr>
> }$
> </table>
>
>
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