README.md

In tab2xml: XML Generation from Tables

tab2xml

The goal of tab2xml is to convert spreadsheet files (.xlsx or .ods) into structured XML documents using a predefined template. The package processes the spreadsheet data, replacing template tokens with corresponding values, and manages foreign key relationships automatically.

Installation

You can install the released version of tab2xml from CRAN with:

install.packages("tab2xml")

And the development version from GitHub with:

# install.packages("pak")
pak::pak("josesamos/tab2xml")

Example

This example demonstrates how to use tab2xml to convert an Excel or ODS file into an XML file, based on a schema example from the Mondrian Documentation.

library(tab2xml)

# Define file paths
source_xml <- system.file("extdata", "schema_template.xml", package = "tab2xml")
source_xlsx <- system.file("extdata", "schema.xlsx", package = "tab2xml")
temp_file <- tempfile(fileext = ".xml")

Show spreadsheet contents

sheet_names <- readxl::excel_sheets(source_xlsx)
for (sheet in sheet_names) {
  cat("\n#### Sheet:", sheet)
  data <- readxl::read_excel(source_xlsx, sheet = sheet)
  print(knitr::kable(data))
}

Sheet: Cube

| cube_pk | name | table_fk | |--------:|:------|---------:| | 1 | Sales | 1 |

Sheet: Table

| table_pk | name | |---------:|:----------------| | 1 | sales_fact_1997 | | 2 | customer | | 3 | time_by_day |

Sheet: Dimension

| dimension_pk | name | foreignKey | cube_fk | |-------------:|:-------|:------------|--------:| | 1 | Gender | customer_id | 1 | | 2 | Time | time_id | 1 |

Sheet: Hierarchy

| hierarchy_pk | name | hasAll | allMemberName | primaryKey | dimension_fk | table_fk | |---:|:---|:---|:---|:---|---:|---:| | 1 | Gender | true | allMemberName=“All Genders” | customer_id | 1 | 2 | | 2 | Time | false | NA | time_id | 2 | 3 |

Sheet: Level

| name | column | type | uniqueMembers | hierarchy_fk | |:--------|:--------------|:--------|:--------------|-------------:| | Gender | gender | String | true | 1 | | Year | the_year | Numeric | true | 2 | | Quarter | quarter | Numeric | false | 2 | | Month | month_of_year | Numeric | false | 2 |

Sheet: Measure

| name | column | aggregator | formatString | cube_fk | |:------------|:------------|:-----------|:-------------|--------:| | Unit Sales | unit_sales | sum | #,### | 1 | | Store Sales | store_sales | sum | #,###.## | 1 | | Store Cost | store_cost | sum | #,###.00 | 1 |

Sheet: CalculatedMember

| calculatedmember_pk | name | dimension | formula | cube_fk | |---:|:---|:---|:---|---:| | 1 | Profit | Measures | [Measures].[Store Sales] - [Measures].[Store Cost] | 1 |

Sheet: CalculatedMemberProperty

| name | value | calculatedmember_fk | |:--------------|:-----------|--------------------:| | FORMAT_STRING | \$#,##0.00 | 1 |

Convert spreadsheet to XML

file <- sheet2xml(source_xlsx, source_xml, temp_file, optimize = TRUE)

Check output

library(xml2)
#> Warning: package 'xml2' was built under R version 4.4.3

xml_content <- readLines(file, warn = FALSE)

cat("```xml\n", paste(xml_content, collapse = "\n"), "\n```", sep = "")

<?xml version="1.0" encoding="UTF-8"?>
<Schema>
  <Cube name="Sales">
    <Table name="sales_fact_1997"/>
    <Dimension name="Gender" foreignKey="customer_id">
      <Hierarchy name="Gender" hasAll="true" allMemberName="All Genders" primaryKey="customer_id">
        <Table name="customer"/>
        <Level name="Gender" column="gender" type="String" uniqueMembers="true"/>
      </Hierarchy>
    </Dimension>
    <Dimension name="Time" foreignKey="time_id">
      <Hierarchy name="Time" hasAll="false" primaryKey="time_id">
        <Table name="time_by_day"/>
        <Level name="Year" column="the_year" type="Numeric" uniqueMembers="true"/>
        <Level name="Quarter" column="quarter" type="Numeric" uniqueMembers="false"/>
        <Level name="Month" column="month_of_year" type="Numeric" uniqueMembers="false"/>
      </Hierarchy>
    </Dimension>
    <Measure name="Unit Sales" column="unit_sales" aggregator="sum" formatString="#,###"/>
    <Measure name="Store Sales" column="store_sales" aggregator="sum" formatString="#,###.##"/>
    <Measure name="Store Cost" column="store_cost" aggregator="sum" formatString="#,###.00"/>
    <CalculatedMember name="Profit" dimension="Measures" formula="[Measures].[Store Sales] - [Measures].[Store Cost]">
      <CalculatedMemberProperty name="FORMAT_STRING" value="$#,##0.00"/>
    </CalculatedMember>
  </Cube>
</Schema>

In this way, we can organize and work with the data in tabular form and generate XML documents directly using the provided templates.

tab2xml documentation built on April 4, 2025, 12:36 a.m.