Tips and Tricks for handling numbers in BPEL or OIC

While integrating with multiple systems and moving data from one system to the other, we generally come across scenarios, wherein we need to change the format of the number or perform operations like floor, ceil, round, divide, multiply, add, etc. on numbers. We will be going through various mathematical functions available in XSLT 1.0, which would be helpful in such scenarios, and also some generic errors which we encounter usually.

Mathematical Operations

1. Divide
2. Multiply
3. Add
4. Subtract
5. Square-root
6. Round
7. Floor
8. Ceil
9. Advanced Number formatting

Common Errors

Mathematical Operations 🔗

1. Divide 🔗

To divide 2 numbers, we can use the div operator to divide two numbers.

Syntax:

$num1 div $num2 

Example:

Let us assume we want to divide 120 by 7.

XSL:

<divide><xsl:value-of select="120 div 7"/></divide>

Output

<divide>17.14285714285714285714</divide>

2. Multiply 🔗

To multiply 2 numbers, we can use the * operator.

Syntax:

$num1 * $num2

Example:

Let us assume we want to multiply 120 by 7.

XSL:

<multiply><xsl:value-of select="120 * 7"/></multiply>

Output

<multiply>840</multiply>

3. Add 🔗

To add 2 numbers, we can use the + operator.

Syntax:

$num1 + $num2

Example:

Let us assume we want to add 120 and 7.

XSL:

<add><xsl:value-of select="120 + 7"/></add>

Output

<add>127</add>

4. Subtract 🔗

To subtract one number from another, we can use the - operator.

Syntax:

$num1 - $num2

Example:

Let us assume we want to subtract 7 from 120.

XSL:

<subtract><xsl:value-of select="120 - 7"/></subtract>

Output

<subtract>113</subtract>

5. Square Root 🔗

To find a square root of a number, we can use the oraext:square-root function.

Syntax:

oraext:square-root($number)

Example:

Let us assume we want to find a square root of 121.

XSL:

<square-root><xsl:value-of select="oraext:square-root(121)"/></square-root>

Output

<square-root>11</square-root>

6. Round 🔗

To round a number to the nearest integer we can use the round($number) function available in XSLT.

Syntax:

round($number)

XSL:

<roundInt><xsl:value-of select="round(17.64285714285714285714)"/></roundInt>

Output

<roundInt>18</roundInt>

What if we want to round the number to 2 or 3 decimal places. Since the round function only takes one argument, we cannot pass the number of decimal digits we want to round the number to. To do so we can try the below-mentioned method.

We can multiply the number by 10m, round the number, and then divide the result by 10m. Here, m denotes the number of decimal places.

Pseudo Code:

(round($number * 10 m) )/ 10 m

Example

Let us assume we want to round to two decimal places. Here, the value of m will be 2. 10m will be equal to 100.

XSL:

<roundDec1><xsl:value-of select="round(17.64285714285714285714 * 100 ) div 100"/></roundDec1>

Output

<roundDec1>17.64</roundDec1>

7. Floor 🔗

To return the largest integer less than or equal to the number we can use the floor($number) function available in XSLT.

Syntax:

floor($number)

XSL:

<floorInt><xsl:value-of select="floor(17.64285714285714285714)"/></floorInt>

Output

<floorInt>17</floorInt>

What if we want to perform floor operation on the number and have output with 2 or 3 decimal places. Since the floor function only takes one argument, we cannot pass the number of decimal digits we want to floor the number to. To do so we can try the below-mentioned method.

We can multiply the number by 10m, floor the number, and then divide the result by 10m. Here, m denotes the number of decimal places.

Pseudo Code:

(floor($number * 10 m) )/ 10 m

Example

Let us assume we want to floor the number to three decimal places. Here, the value of m will be 3. 10m will be equal to 1000.

XSL:

<floorDec1><xsl:value-of select="floor(17.64285714285714285714 * 1000 ) div 1000"/></floorDec1>

Output

<floorDec1>17.642</floorDec1>

8. Ceil 🔗

To return the largest integer greater than or equal to the number we can use the ceiling($number) function available in XSLT.

Syntax:

ceiling($number)

XSL:

<ceilInt><xsl:value-of select="ceiling(17.14285714285714285714)"/></ceilInt>

Output

<ceilInt>18</ceilInt>

What if we want to perform ceiling operation on the number and have output with 2 or 3 decimal places. Since the ceiling function only takes one argument, we cannot pass the number of decimal digits we want to ceil the number to. To do so we can try the below-mentioned method.

We can multiply the number by 10m, ceiling the number, and then divide the result by 10m. Here, m denotes the number of decimal places.

Pseudo Code:

(ceiling($number * 10 m) )/ 10 m

Example

Let us assume we want to ceiling the number to three decimal places. Here, the value of m will be 3. 10m will be equal to 1000.

XSL:

<ceilDec1><xsl:value-of select="ceiling(17.14285714285714285714 * 1000 ) div 1000"/></ceilDec1>

Output

<ceilDec1>17.143</ceilDec1>

9. Advanced Number formatting 🔗

We may come across the scenarios especially when dealing with financial or accounting integrations, wherein we want the numbers like 1234.56 , 45 to be formatted like 1,234.56 , $45.00 , etc. One common way, while developing integration which we opt for, is multiple substrings and then multiple concatenations. There is a built-in function format-number, which can come in really handy in such situations.

Syntax:

format-number($number,$format,[$decimal-format]) 

Note: Here $decimal-format parameter is optional and we have not used it in examples.

Format Character Table

Format number performs the round operation by default(which is banker’s rounding) to the number of decimal places defined in format. To understand more on how can we use various formats. Please find below the table consisting of various use cases

XSL:

<format1><xsl:value-of select="format-number(123.456, '#.00')"/></format1>
<format1-1><xsl:value-of select="format-number(123.4, '#.00')"/></format1-1>
<format2><xsl:value-of select="format-number(123.456, '#.##')"/></format2>
<format2-1><xsl:value-of select="format-number(123, '#.##')"/></format2-1>
<format3><xsl:value-of select="format-number(123456.789, '$#,###,###.00')"/></format3>
<format4><xsl:value-of select="format-number(0.13245, '##.##%')"/></format4>
<format5><xsl:value-of select="format-number(132.45, '#.000;(#.000)')"/></format5>
<format5-1><xsl:value-of select="format-number(-132.45, '#.000;(#.000)')"/></format5-1>

Output

<format1>123.46</format1>
<format1-1>123.40</format1-1>
<format2>123.46</format2>
<format2-1>123</format2-1>
<format3>$123,456.79</format3>
<format4>13.25%</format4>
<format5>132.450</format5>=
<format5-1>(132.450)</format5-1>

Common Errors 🔗

• We get XPath errors when the data type doesn’t match the numeric data type.
• We get NaN(Not a Number) error when we explicitly try to convert a string or any other data type to a number using the number() function and the string contains some invalid characters apart from what is accepted by the number data type.

XSL to explain NaN errors:

<errors>
        <error><xsl:value-of select="number('123 1')"/></error>
        <error><xsl:value-of select="number('abc')"/></error>
        <error><xsl:value-of select="number('123b')"/></error>
</errors>

Resources: 🔗

• XSLT file containing all the XSL statements used in the blog – Link
• The output of the above file – Link

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