Author: nick
Date: Tue Jul 30 11:03:25 2013
New Revision: 1508388
URL: http://svn.apache.org/r1508388
Log:
Add a "Why Evaluate" section to the Formula Evaluation docs
Modified:
poi/site/publish/spreadsheet/eval.html
poi/site/src/documentation/content/xdocs/spreadsheet/eval.xml
Modified: poi/site/publish/spreadsheet/eval.html
URL:
http://svn.apache.org/viewvc/poi/site/publish/spreadsheet/eval.html?rev=1508388&r1=1508387&r2=1508388&view=diff
==============================================================================
--- poi/site/publish/spreadsheet/eval.html (original)
+++ poi/site/publish/spreadsheet/eval.html Tue Jul 30 11:03:25 2013
@@ -180,36 +180,55 @@ if (VERSION > 3) {
<h1>Formula Evaluation</h1>
</div>
<div class="h3">
+
+
-
-
<a name="Introduction"></a>
<div class="h3">
<h3>Introduction</h3>
</div>
-
+
<p>The POI formula evaluation code enables you to calculate the result of
- formulas in Excels sheets read-in, or created
in POI. This document explains
- how to use the API to evaluate your formulas.
- </p>
-
-<div class="frame note">
-<div class="label">Note</div>
-<div class="content">.xlsx format is suported since POI 3.5, make sure yoy
upgraded to that version before experimenting with this
- code. Users of all versions of POI may wish to
make use of a recent
- SVN checkout, as new functions are currently
being added fairly frequently.
- </div>
+ formulas in Excels sheets read-in, or created in POI. This document
explains
+ how to use the API to evaluate your formulas.
+ </p>
+
+
+
+<a name="WhyEvaluate"></a>
+ <a name="Why+do+I+need+to+evaluate+formulas%3F"></a>
+<div class="h3">
+<h3>Why do I need to evaluate formulas?</h3>
</div>
-
+
+<p>The Excel file format (both .xls and .xlsx) stores a "cached" result for
+ every formula along with the formula itself. This means that when the
file
+ is opened, it can be quickly displayed, without needing to spend a
long
+ time calculating all of the formula results. It also means that when
reading
+ a file through Apache POI, the result is quickly available to you too!
+ </p>
+
+<p>After making changes with Apache POI to either Formula Cells themselves,
+ or those that they depend on, you should normally perform a Formula
+ Evaluation to have these "cached" results updated. This is normally
done
+ after all changes have been performed, but before you write the file
out.
+ If you don't do this, there's a good chance that when you open the
file in
+ Excel, until you go to the cell and hit enter or F9, you will either
see
+ the old value or '#VALUE!' for the cell. (Sometimes Excel will notice
+ itself, and trigger a recalculation on load, but unless you know you
are
+ using volatile functions it's generally best to trigger a Recalulation
+ through POI)
+ </p>
+
-
+
<a name="Status"></a>
- <a name="Status-N10024"></a>
+ <a name="Status-N10028"></a>
<div class="h3">
<h3>Status</h3>
</div>
-<p> The code currently provides implementations for all the arithmatic
operators.
+<p>The code currently provides implementations for all the arithmatic
operators.
It also provides implementations for approx.
140 built in
functions in Excel. The framework however makes
it easy to add
implementation of new functions. See the <a
href="eval-devguide.html"> Formula
@@ -290,7 +309,7 @@ switch (cellValue.getCellType()) {
<a name="EvaluateFormulaCell"></a>
- <a name="Using+FormulaEvaluator.-N1005F"></a>
+ <a name="Using+FormulaEvaluator.-N10063"></a>
<div class="h4">
<h4>Using FormulaEvaluator.evaluateFormulaCell(Cell cell)</h4>
</div>
@@ -344,7 +363,7 @@ if (cell!=null) {
<a name="EvaluateInCell"></a>
- <a name="Using+FormulaEvaluator.-N10077"></a>
+ <a name="Using+FormulaEvaluator.-N1007B"></a>
<div class="h4">
<h4>Using FormulaEvaluator.evaluateInCell(Cell cell)</h4>
</div>
@@ -576,7 +595,6 @@ for(int sheetNum = 0; sheetNum < wb.g
-<div id="authors" align="right">by Amol Deshmukh</div>
</div>
</div>
</div>
Modified: poi/site/src/documentation/content/xdocs/spreadsheet/eval.xml
URL:
http://svn.apache.org/viewvc/poi/site/src/documentation/content/xdocs/spreadsheet/eval.xml?rev=1508388&r1=1508387&r2=1508388&view=diff
==============================================================================
--- poi/site/src/documentation/content/xdocs/spreadsheet/eval.xml (original)
+++ poi/site/src/documentation/content/xdocs/spreadsheet/eval.xml Tue Jul 30
11:03:25 2013
@@ -20,27 +20,41 @@
<!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V1.1//EN"
"../dtd/document-v11.dtd">
<document>
- <header>
- <title>Formula Evaluation</title>
- <authors>
- <person email="[email protected]" name="Amol Deshmukh"
id="AD"/>
- </authors>
- </header>
- <body>
- <section><title>Introduction</title>
- <p>The POI formula evaluation code enables you to
calculate the result of
- formulas in Excels sheets read-in, or created
in POI. This document explains
- how to use the API to evaluate your formulas.
- </p>
- <note>.xlsx format is suported since POI 3.5, make sure
yoy upgraded to that version before experimenting with this
- code. Users of all versions of POI may wish to
make use of a recent
- SVN checkout, as new functions are currently
being added fairly frequently.
- </note>
- </section>
+ <header>
+ <title>Formula Evaluation</title>
+ </header>
+ <body>
+ <section><title>Introduction</title>
+ <p>The POI formula evaluation code enables you to calculate the result
of
+ formulas in Excels sheets read-in, or created in POI. This document
explains
+ how to use the API to evaluate your formulas.
+ </p>
+ </section>
+
+ <anchor id="WhyEvaluate"/>
+ <section><title>Why do I need to evaluate formulas?</title>
+ <p>The Excel file format (both .xls and .xlsx) stores a "cached" result
for
+ every formula along with the formula itself. This means that when the
file
+ is opened, it can be quickly displayed, without needing to spend a
long
+ time calculating all of the formula results. It also means that when
reading
+ a file through Apache POI, the result is quickly available to you too!
+ </p>
+ <p>After making changes with Apache POI to either Formula Cells
themselves,
+ or those that they depend on, you should normally perform a Formula
+ Evaluation to have these "cached" results updated. This is normally
done
+ after all changes have been performed, but before you write the file
out.
+ If you don't do this, there's a good chance that when you open the
file in
+ Excel, until you go to the cell and hit enter or F9, you will either
see
+ the old value or '#VALUE!' for the cell. (Sometimes Excel will notice
+ itself, and trigger a recalculation on load, but unless you know you
are
+ using volatile functions it's generally best to trigger a Recalulation
+ through POI)
+ </p>
+ </section>
- <anchor id="Status"/>
- <section><title>Status</title>
- <p> The code currently provides implementations for
all the arithmatic operators.
+ <anchor id="Status"/>
+ <section><title>Status</title>
+ <p>The code currently provides implementations for all
the arithmatic operators.
It also provides implementations for approx.
140 built in
functions in Excel. The framework however makes
it easy to add
implementation of new functions. See the <link
href="eval-devguide.html"> Formula
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