IO

Read, write, and inspect files through Host.IO. All file paths use Host.Url objects.

Methods:

Method	Returns	Parameters	Description
Host.IO.createPackage(path, type)	object	path — Host.Url path, type — format (e.g. "application/zip")	Create a .package archive. Returned object has setOption(), create(), embedd(folder), flush(), close()
Host.IO.createTextFile(path)	object	path — Host.Url path	Create a text file for writing (.writeLine(text), .close())
Host.IO.File(path)	object	path — Host.Url path	Get a file operation object (.exists(), .copyTo(), .remove())
Host.IO.findFiles(folder, pattern)	object	folder — folder path, pattern — glob pattern	Find files matching a pattern.
Host.IO.fromBase64(data)	string	data — Base64 string	Decode Base64 data
Host.IO.getDevelopmentFileLocation()	string	none	Get the development file storage path
Host.IO.loadJsonFile(path)	object	path — Host.Url path	Load a JSON file into a native JavaScript object
Host.IO.toBase64(data)	string	data — string data to encode	Encode data as Base64
Host.IO.openPackage(path, type)	object	path — Host.Url path, type — format (e.g. "application/zip")	Open a .package archive. Returned object: extract(folder)
Host.IO.openTextFile(path)	object	path — Host.Url path	Open a text file for reading (.readLine(), .endOfStream, .close())
Host.IO.XmlTree(path)	object	path — Host.Url path	Parse an XML file into a navigable tree

Create Package

Host.IO.createPackage() returns a package builder object.

Methods:

Method	Returns	Parameters	Description
setOption(name, value)	—	name — option name, value — option value	Set a package option (e.g. "compressed", true)
create()	—	none	Create the package file
embedd(folder)	—	folder — Host.Url path to a folder	Embed all files from a folder into the package
flush()	—	none	Flush pending writes
close()	—	none	Close and finalize the package

var folder = Host.Url("local://$USERCONTENT/my-folder/");
var pkg = Host.IO.createPackage(path, "application/zip");
pkg.setOption("compressed", true);
pkg.create();
pkg.embedd(folder);
pkg.flush();
pkg.close();

Create Text File

Host.IO.createTextFile() returns a text file writer object.

var file = Host.IO.createTextFile(path);
if (file) {
  file.writeLine("content");
  file.close();
}

File Operations Object

Host.IO.File() returns a file operation object for the given path.

Methods:

Method	Returns	Parameters	Description
exists()	number	none	Check whether a file exists (returns 1 if found, 0 if not)
copyTo(dest)	—	dest — destination Host.Url	Copy a file to a destination
remove()	—	none	Delete a file or directory

Find Files

Host.IO.findFiles() returns an iterator of matching files as Host.Url objects.

Iterator methods:

Method	Returns	Parameters	Description
done()	number	none	Check whether iteration is complete (returns 0 while items remain, 1 when exhausted)
next()	object	none	Get the next file item
first()	—	none	Move to the first item
last()	—	none	Move to the last item
previous()	object	none	Get the previous file item

var it = Host.IO.findFiles(folder, "*.xml");
while (!it.done()) {
  var file = it.next();
  var name = file.name;
}

From Base64

Host.IO.fromBase64() decodes a Base64 string.

var decoded = Host.IO.fromBase64(data);

Load JSON File

Host.IO.loadJsonFile() loads and parses a JSON file.

var data = Host.IO.loadJsonFile(Host.Url("local://$USERCONTENT/myfile.json"));

Open Package

Host.IO.openPackage() opens an existing .package archive for reading.

Methods:

Method	Returns	Parameters	Description
extract(folder)	—	folder — Host.Url path to extract to	Extract all package contents to a folder

var pkg = Host.IO.openPackage(path, "application/zip");
if (pkg) {
  var folder = Host.Url("memory://ExtractTarget/", true);
  pkg.extract(folder);
}

Open Text File

Host.IO.openTextFile() opens a text file for reading.

var file = Host.IO.openTextFile(path);
if (file) {
  while (!file.endOfStream) {
    var line = file.readLine();
  }
  file.close();
}

To Base64

Host.IO.toBase64() encodes a string as Base64.

var encoded = Host.IO.toBase64(data);

XML Tree

Host.IO.XmlTree() parses an XML file into a navigable tree. The tree object has root and errorMessage properties. Nodes are returned by tree.root and node.findNode().

Tree properties:

Property	Type	Writable	Example	Description
errorMessage	string	No	""	Error message, empty on success
root	object	No	—	Root node of the parsed XML

Tree methods:

Method	Returns	Parameters	Description
loadFromFile()	—	none	Reload the XML from file
saveToFile()	—	none	Save modifications back to file

Node properties:

Property	Type	Writable	Example	Description
name	string	No	"SomeSection"	Tag name
text	string	No	"value"	Text content
comment	string	No	"<!-- comment -->"	Comment content
parent	object	No	—	Parent node object

Node methods:

Method	Returns	Parameters	Description
addChild(node)	—	node — child node object	Add a child node
find(name)	object	name — tag name	Find first child with matching tag name (alias for findNode)
findNode(name)	object	name — tag name	Find first child with matching tag name
getAttribute(name)	string	name — attribute name	Get an attribute value
newIterator()	object	none	Create an iterator over child nodes
newNode()	object	none	Create a new child node
setAttribute(name, value)	—	name — attribute name, value — attribute value	Set an attribute

var tree = Host.IO.XmlTree(Host.Url("local://$APPCONFIG/User.options"));
var root = tree.root;
var child = root.findNode("SomeSection");
var val = child.getAttribute("someAttr");

var it = root.newIterator();
while (!it.done()) {
  var node = it.next();
  Host.Console.writeLine(node.name);
}