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Update documentation, and add section on whole-workbook recalculating 

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@610553 13f79535-47bb-0310-9956-ffa450edef68
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Nick Burch 2008-01-09 20:37:06 +00:00
parent ab0a81f75a
commit fcf2ab6a94
1 changed files with 39 additions and 7 deletions
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46
src/documentation/content/xdocs/hssf/eval.xml
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@ -32,14 +32,17 @@
formulas in Excels sheets read-in, or created in POI. This document explains
how to use the API to evaluate your formulas.
</p>
<note> This code currently lives the scratchpad area of the POI CVS repository.
<note> This code currently lives the scratchpad area of the POI SVN repository.
Ensure that you have the scratchpad jar or the scratchpad build area in your
classpath before experimenting with this code.
classpath before experimenting with this code. You are advised
to make use of a recent SVN checkout, as new functions are
being supported fairly frequently.
</note>
</section>
<section><title>Status</title>
<anchor id="Status"/>
<p> The code currently provides implementations for all the arithmatic operators.
It also provides implementations for approx. 20 built in
It also provides implementations for approx. 100 built in
functions in Excel. The framework however makes is easy to add
implementation of new functions. See the <link href="eval-devguide.html"> Formula
evaluation development guide</link> for details. </p>
@ -53,6 +56,7 @@
</p>
<p>There are two ways in which you can use the HSSFFormulaEvalutator API.</p>
<section><title>Using HSSFFormulaEvaluator.<strong>evaluate</strong>(HSSFCell cell)</title>
<anchor id="Evaluate"/>
<source>
FileInputStream fis = new FileInputStream("c:/temp/test.xls");
HSSFWorkbook wb = new HSSFWorkbook(fis);
@ -96,8 +100,12 @@ switch (cellValue.getCellType()) {
</p>
</section>
<section><title>Using HSSFFormulaEvaluator.<strong>evaluateInCell</strong>(HSSFCell cell)
</title>
<section><title>Using HSSFFormulaEvaluator.<strong>evaluateInCell</strong>(HSSFCell cell)</title>
<anchor id="EvaluateInCell"/>
<p><strong>evaluateInCell</strong>(HSSFCell cell) will check to
see if the supplied cell is a formula cell. If it isn't,
then no changes will be made to it. If it is, then the
formula is evaluated, and the new value saved into the cell.</p>
<source>
FileInputStream fis = new FileInputStream("/somepath/test.xls");
HSSFWorkbook wb = new HSSFWorkbook(fis);
@ -132,12 +140,36 @@ if (cell!=null) {
break;
}
}
</source>
</source>
</section>
<section><title>Re-calculating all formulas in a Workbook</title>
<anchor id="EvaluateAll"/>
<source>
FileInputStream fis = new FileInputStream("/somepath/test.xls");
HSSFWorkbook wb = new HSSFWorkbook(fis);
for(int sheetNum = 0; sheetNum &lt; wb.getNumberOfSheets(); sheetNum++) {
HSSFSheet sheet = wb.getSheetAt(sheetNum);
HSSFFormulaEvaluator evaluator = new HSSFFormulaEvaluator(sheet, wb);
</section>
for(Iterator rit = s.rowIterator(); rit.hasNext();) {
HSSFRow r = (HSSFRow)rit.next();
evaluator.setCurrentRow(r);
for(Iterator cit = r.cellIterator(); cit.hasNext();) {
HSSFCell c = (HSSFCell)cit.next();
if(c.getCellType() == HSSFCell.CELL_TYPE_FORMULA) {
evaluator.evaluateInCell(c);
}
}
}
}
wb.write(new FileOutputStream("/somepath/changed.xls"));
</source>
</section>
</section>
<section><title>Performance Notes</title>
<anchor id="Performance"/>
<ul>
<li>Generally you should have to create only one HSSFFormulaEvaluator
instance per sheet, but there really is no overhead in creating