r - 在 R 中生成 XML 文档

Question

在我工作的项目中，我需要自动化创建XML文档取决于用户输入。使用用户输入修改xml的部分文档对我来说没问题，但我是新手 xml在 R 中从头开始文档

我想知道是否是 XML可以使用 XML 在 R 中生成类似下面的文档或 xml2包。到目前为止，我已经探索了newXMLdoc , xml_new_document和 xml_new_root函数，但我不熟悉创建这样一个 xml 所需的所有语法文件(完成后应保存在本地路径中)

<session>
  <modelVersion>1.0.0</modelVersion>
  <products>
    <product>
      <refNo>1</refNo>
      <uri>S1A_IW_GRDH_1SDV_20190818T175529_20190818T175554_028627_033D25_22ED.zip</uri>
      <productReaderPlugin>class org.esa.s1tbx.io.sentinel1.Sentinel1ProductReaderPlugIn</productReaderPlugin>
    </product>
    <product>
      <refNo>2</refNo>
      <uri>S2A_MSIL1C_20190823T061631_N0208_R034_T42TXS_20190823T081730.zip</uri>
      <productReaderPlugin>class org.esa.s2tbx.dataio.s2.ortho.plugins.Sentinel2L1CProduct_Multi_UTM42N_ReaderPlugIn</productReaderPlugin>
    </product>
  </products>
  <views/>
</session>

Answer 1

考虑使用上述库(例如 XML)使用 DOM 方法构建 XML。无需连接或插入字符串:

library(XML)

# DATA
df <- data.frame(refNo = c(1, 2),
                 uri = c('S1A_IW_GRDH_1SDV_20190818T175529_20190818T175554_028627_033D25_22ED.zip', 
                         'S2A_MSIL1C_20190823T061631_N0208_R034_T42TXS_20190823T081730.zip'),
                 plugin = c('class org.esa.s1tbx.io.sentinel1.Sentinel1ProductReaderPlugIn', 
                            'class org.esa.s2tbx.dataio.s2.ortho.plugins.Sentinel2L1CProduct_Multi_UTM42N_ReaderPlugIn')
                )

# CREATE XML FILE
doc = newXMLDoc()
root = newXMLNode("session", doc = doc)

# WRITE XML NODES AND DATA
mvNode = newXMLNode("modelVersion", "1.0.0", parent = root)

for (i in 1:nrow(df)){
  prodNode = newXMLNode("products", parent = root)

  # APPEND TO PRODUCT NODE
  newXMLNode("refNo", df$refNo[i], parent = prodNode)
  newXMLNode("uri", df$uri[i], parent = prodNode)
  newXMLNode("productReaderPlugin", df$plugin[i], parent = prodNode)
}

vwNode = newXMLNode("views", parent = root)

# OUTPUT XML CONTENT TO CONSOLE
print(doc)

# OUTPUT XML CONTENT TO FILE
saveXML(doc, file="Output.xml")

输出

<?xml version="1.0"?>
<session>
  <modelVersion>1.0.0</modelVersion>
  <products>
    <refNo>1</refNo>
    <uri>S1A_IW_GRDH_1SDV_20190818T175529_20190818T175554_028627_033D25_22ED.zip</uri>
    <productReaderPlugin>class org.esa.s1tbx.io.sentinel1.Sentinel1ProductReaderPlugIn</productReaderPlugin>
  </products>
  <products>
    <refNo>2</refNo>
    <uri>S2A_MSIL1C_20190823T061631_N0208_R034_T42TXS_20190823T081730.zip</uri>
    <productReaderPlugin>class org.esa.s2tbx.dataio.s2.ortho.plugins.Sentinel2L1CProduct_Multi_UTM42N_ReaderPlugIn</productReaderPlugin>
  </products>
  <views/>
</session>