xml
Install
Note, if you're using @xmpp/client
or @xmpp/component
, you don't need to install @xmpp/xml
.
npm install @xmpp/xml
const xml = require("@xmpp/xml");
const { xml } = require("@xmpp/client");
const { xml } = require("@xmpp/component");
Writing
There's 2 methods for writing XML with xmpp.js
factory
const xml = require("@xmpp/xml");
const recipient = "user@example.com";
const days = ["Monday", "Tuesday", "Wednesday"];
const message = xml(
"message",
{ to: recipient },
xml("body", {}, 1 + 2),
xml(
"days",
{},
days.map((day, idx) => xml("day", { idx }, day)),
),
);
If the second argument passed to xml
is a string
instead of an object
, it will be set as the xmlns
attribute.
xml("time", "urn:xmpp:time");
xml("time", { xmlns: "urn:xmpp:time" });
JSX
const xml = require("@xmpp/xml");
const recipient = "user@example.com";
const days = ["Monday", "Tuesday"];
const message = (
<message to={recipient}>
<body>{1 + 2}</body>
<days>
{days.map((day, idx) => (
<day idx={idx}>${day}</day>
))}
</days>
</message>
);
Requires a preprocessor such as TypeScript or Babel with @babel/plugin-transform-react-jsx.
Reading
attributes
The attrs
property is an object that holds xml attributes of the element.
message.attrs.to;
text
Returns the text value of an element
message.getChild("body").text();
getChild
Get child element by name.
message.getChild("body").toString();
getChildText
Get child element text value.
message.getChildText("body");
getChildren
Get children elements by name.
message.getChild("days").getChildren("day");
Since getChildren
returns an array, you can use JavaScript array methods such as filter and find to build more complex queries.
const days = message.getChild("days").getChildren("day");
days.find((day) => day.text() === "Monday");
days.find((day) => day.attrs.idx === 0);
days.filter((day) => day.attrs.idx > 2);
parent
You can get the parent node using the parent property.
console.log(message.getChild("days").parent === message);
root
You can get the root node using the root method.
console.log(message.getChild("days").root() === message);
Editing
attributes
The attrs
property is an object that holds xml attributes of the element.
message.attrs.type = "chat";
Object.assign(message.attrs, { type: "chat" });
text
Set the text value of an element
message.getChild("body").text("Hello world");
append
Adds text or element nodes to the last position.
Returns the parent.
message.append(xml("foo"));
message.append("bar");
message.append(days.map((day) => xml("day", {}, day)));
prepend
Adds text or element nodes to the first position.
Returns the parent.
message.prepend(xml("foo"));
message.prepend("bar");
message.prepend(days.map((day) => xml("day", {}, day)));
remove
Removes a child element.
const body = message.getChild("body");
message.remove(body);
JSON
You can embed JSON anywhere but it is recommended to use appropriate semantic.
message.append(
<myevent xmlns="xmpp:example.org">
<json xmlns="urn:xmpp:json:0">{JSON.stringify(days)}</json>
</myevent>,
);
JSON.parse(
message
.getChild("myevent", "xmpp:example.org")
.getChildText("json", "urn:xmpp:json:0"),
);
See also JSON Containers and Simple JSON Messaging.
Parsing XML strings
@xmpp/xml
include a function to parse XML strings.
⚠ Use with care. Untrusted input or substitutions can result in invalid XML and side effects.
const { escapeXML, escapeXMLText };
const parse = require("@xmpp/xml/lib/parse");
const ctx = parse("<message><body>hello world</body></message>");
ctx.getChildText("body");
If you must use with untrusted input, escape it with escapeXML
and escapeXMLText
.
const { escapeXML, escapeXMLText } = require("@xmpp/xml");
const parse = require("@xmpp/xml/lib/parse");
const message = parse(`
<message to="${escapeXML(to)}">
<body>${escapeXMLText(body)}</body>
</message>,
`);