buildPostingBody static method

Implementation

static Future<String?> buildPostingBody(List<IFormField>? fields, {String rootname = "FORM"}) async
{
  try
  {
    // build xml document
    XmlDocument document = XmlDocument();
    XmlElement root = XmlElement(XmlName(S.isNullOrEmpty(rootname) ? "FORM" : rootname));
    document.children.add(root);

    if (fields != null)
      fields.forEach((field)
      {
        // postable?
        if (field.postable == true)
        {
          if (field.values != null)
          {
            field.values!.forEach((value)
            {
              XmlElement node;
              String name = field.field ?? field.id ?? "";
              try
              {
                // valid element name?
                if (!S.isNumber(name.substring(0,1)))
                {
                  node = XmlElement(XmlName(name));
                }
                else
                {
                  node = XmlElement(XmlName("FIELD"));
                  node.attributes.add(XmlAttribute(XmlName('id'), name));
                }
              }
              catch(e)
              {
                node = XmlElement(XmlName("FIELD"));
                node.attributes.add(XmlAttribute(XmlName('id'), name));
              }

              // add field type
              if (!S.isNullOrEmpty(field.elementName)) node.attributes.add(XmlAttribute(XmlName('type'), field.elementName));


              /// GeoCode for each [iFormField] which is set on answer
              if (field.geocode != null) field.geocode!.serialize(node);

              // add meta data
              if (!S.isNullOrEmpty(field.meta)) node.attributes.add(XmlAttribute(XmlName('meta'), field.meta));

              // value
              try
              {
                // Xml Data
                if ((field is InputModel) && (field.format == InputFormats.xml))
                {
                  var document = XmlDocument.parse(value);
                  var e = document.rootElement;
                  document.children.remove(e);
                  node.children.add(e);
                }

                // Non-XML? Wrap in CDATA
                else if (Xml.hasIllegalCharacters(value)) node.children.add(XmlCDATA(value));

                // Normal Text
                else node.children.add(XmlText(value));
              }
              on XmlException catch(e)
              {
                node.children.add(XmlCDATA(e.message));
              }

              // Add Node
              root.children.add(node);
            });
          }

          else
          {
            // Build Element
            XmlElement node;
            String name = field.field ?? field.id ?? "";
            try
            {
              // Valid Element Name
              if (!S.isNumber(name.substring(0,1)))
              {
                node = XmlElement(XmlName(name));
              }

              // In-Valid Element Name
              else
              {
                node = XmlElement(XmlName("FIELD"));
                node.attributes.add(XmlAttribute(XmlName('id'), name));
              }
            }
            catch(e)
            {
              // In-Valid Element Name
              node = XmlElement(XmlName("FIELD"));
              node.attributes.add(XmlAttribute(XmlName('id'), name));
            }

            // Add Field Type
            if (!S.isNullOrEmpty(field.elementName)) node.attributes.add(XmlAttribute(XmlName('type'), field.elementName));

            // Add Node
            root.children.add(node);
          }
        }
      });

    // Set Body
    return document.toXmlString(pretty: true);
  }

  catch(e)
  {
    Log().error("Error serializing posting document. Error is ${e.toString()}");
    return null;
  }
}