21 KiB
snapdragon-util
Utilities for the snapdragon parser/compiler.
Table of Contents
Install
Install with npm:
$ npm install --save snapdragon-util
Install with yarn:
$ yarn add snapdragon-util
Usage
var util = require('snapdragon-util');
API
.isNode
Returns true if the given value is a node.
Params
node
{Object}: Instance of snapdragon-nodereturns
{Boolean}
Example
var Node = require('snapdragon-node');
var node = new Node({type: 'foo'});
console.log(utils.isNode(node)); //=> true
console.log(utils.isNode({})); //=> false
.noop
Emit an empty string for the given node
.
Params
node
{Object}: Instance of snapdragon-nodereturns
{undefined}
Example
// do nothing for beginning-of-string
snapdragon.compiler.set('bos', utils.noop);
.identity
Appdend node.val
to compiler.output
, exactly as it was created by the parser.
Params
node
{Object}: Instance of snapdragon-nodereturns
{undefined}
Example
snapdragon.compiler.set('text', utils.identity);
.append
Previously named .emit
, this method appends the given val
to compiler.output
for the given node. Useful when you know what value should be appended advance, regardless of the actual value of node.val
.
Params
node
{Object}: Instance of snapdragon-nodereturns
{Function}: Returns a compiler middleware function.
Example
snapdragon.compiler
.set('i', function(node) {
this.mapVisit(node);
})
.set('i.open', utils.append('<i>'))
.set('i.close', utils.append('</i>'))
.toNoop
Used in compiler middleware, this onverts an AST node into an empty text
node and deletes node.nodes
if it exists. The advantage of this method is that, as opposed to completely removing the node, indices will not need to be re-calculated in sibling nodes, and nothing is appended to the output.
Params
node
{Object}: Instance of snapdragon-nodenodes
{Array}: Optionally pass a newnodes
value, to replace the existingnode.nodes
array.
Example
utils.toNoop(node);
// convert `node.nodes` to the given value instead of deleting it
utils.toNoop(node, []);
.visit
Visit node
with the given fn
. The built-in .visit
method in snapdragon automatically calls registered compilers, this allows you to pass a visitor function.
Params
node
{Object}: Instance of snapdragon-nodefn
{Function}returns
{Object}: returns the node after recursively visiting all child nodes.
Example
snapdragon.compiler.set('i', function(node) {
utils.visit(node, function(childNode) {
// do stuff with "childNode"
return childNode;
});
});
.mapVisit
Map visit the given fn
over node.nodes
. This is called by visit, use this method if you do not want fn
to be called on the first node.
Params
node
{Object}: Instance of snapdragon-nodeoptions
{Object}fn
{Function}returns
{Object}: returns the node
Example
snapdragon.compiler.set('i', function(node) {
utils.mapVisit(node, function(childNode) {
// do stuff with "childNode"
return childNode;
});
});
.addOpen
Unshift an *.open
node onto node.nodes
.
Params
node
{Object}: Instance of snapdragon-nodeNode
{Function}: (required) Node constructor function from snapdragon-node.filter
{Function}: Optionaly specify a filter function to exclude the node.returns
{Object}: Returns the created opening node.
Example
var Node = require('snapdragon-node');
snapdragon.parser.set('brace', function(node) {
var match = this.match(/^{/);
if (match) {
var parent = new Node({type: 'brace'});
utils.addOpen(parent, Node);
console.log(parent.nodes[0]):
// { type: 'brace.open', val: '' };
// push the parent "brace" node onto the stack
this.push(parent);
// return the parent node, so it's also added to the AST
return brace;
}
});
.addClose
Push a *.close
node onto node.nodes
.
Params
node
{Object}: Instance of snapdragon-nodeNode
{Function}: (required) Node constructor function from snapdragon-node.filter
{Function}: Optionaly specify a filter function to exclude the node.returns
{Object}: Returns the created closing node.
Example
var Node = require('snapdragon-node');
snapdragon.parser.set('brace', function(node) {
var match = this.match(/^}/);
if (match) {
var parent = this.parent();
if (parent.type !== 'brace') {
throw new Error('missing opening: ' + '}');
}
utils.addClose(parent, Node);
console.log(parent.nodes[parent.nodes.length - 1]):
// { type: 'brace.close', val: '' };
// no need to return a node, since the parent
// was already added to the AST
return;
}
});
.wrapNodes
Wraps the given node
with *.open
and *.close
nodes.
Params
node
{Object}: Instance of snapdragon-nodeNode
{Function}: (required) Node constructor function from snapdragon-node.filter
{Function}: Optionaly specify a filter function to exclude the node.returns
{Object}: Returns the node
.pushNode
Push the given node
onto parent.nodes
, and set parent
as `node.parent.
Params
parent
{Object}node
{Object}: Instance of snapdragon-nodereturns
{Object}: Returns the child node
Example
var parent = new Node({type: 'foo'});
var node = new Node({type: 'bar'});
utils.pushNode(parent, node);
console.log(parent.nodes[0].type) // 'bar'
console.log(node.parent.type) // 'foo'
.unshiftNode
Unshift node
onto parent.nodes
, and set parent
as `node.parent.
Params
parent
{Object}node
{Object}: Instance of snapdragon-nodereturns
{undefined}
Example
var parent = new Node({type: 'foo'});
var node = new Node({type: 'bar'});
utils.unshiftNode(parent, node);
console.log(parent.nodes[0].type) // 'bar'
console.log(node.parent.type) // 'foo'
.popNode
Pop the last node
off of parent.nodes
. The advantage of using this method is that it checks for node.nodes
and works with any version of snapdragon-node
.
Params
parent
{Object}node
{Object}: Instance of snapdragon-nodereturns
{Number|Undefined}: Returns the length ofnode.nodes
or undefined.
Example
var parent = new Node({type: 'foo'});
utils.pushNode(parent, new Node({type: 'foo'}));
utils.pushNode(parent, new Node({type: 'bar'}));
utils.pushNode(parent, new Node({type: 'baz'}));
console.log(parent.nodes.length); //=> 3
utils.popNode(parent);
console.log(parent.nodes.length); //=> 2
.shiftNode
Shift the first node
off of parent.nodes
. The advantage of using this method is that it checks for node.nodes
and works with any version of snapdragon-node
.
Params
parent
{Object}node
{Object}: Instance of snapdragon-nodereturns
{Number|Undefined}: Returns the length ofnode.nodes
or undefined.
Example
var parent = new Node({type: 'foo'});
utils.pushNode(parent, new Node({type: 'foo'}));
utils.pushNode(parent, new Node({type: 'bar'}));
utils.pushNode(parent, new Node({type: 'baz'}));
console.log(parent.nodes.length); //=> 3
utils.shiftNode(parent);
console.log(parent.nodes.length); //=> 2
.removeNode
Remove the specified node
from parent.nodes
.
Params
parent
{Object}node
{Object}: Instance of snapdragon-nodereturns
{Object|undefined}: Returns the removed node, if successful, or undefined if it does not exist onparent.nodes
.
Example
var parent = new Node({type: 'abc'});
var foo = new Node({type: 'foo'});
utils.pushNode(parent, foo);
utils.pushNode(parent, new Node({type: 'bar'}));
utils.pushNode(parent, new Node({type: 'baz'}));
console.log(parent.nodes.length); //=> 3
utils.removeNode(parent, foo);
console.log(parent.nodes.length); //=> 2
.isType
Returns true if node.type
matches the given type
. Throws a TypeError
if node
is not an instance of Node
.
Params
node
{Object}: Instance of snapdragon-nodetype
{String}returns
{Boolean}
Example
var Node = require('snapdragon-node');
var node = new Node({type: 'foo'});
console.log(utils.isType(node, 'foo')); // false
console.log(utils.isType(node, 'bar')); // true
.hasType
Returns true if the given node
has the given type
in node.nodes
. Throws a TypeError
if node
is not an instance of Node
.
Params
node
{Object}: Instance of snapdragon-nodetype
{String}returns
{Boolean}
Example
var Node = require('snapdragon-node');
var node = new Node({
type: 'foo',
nodes: [
new Node({type: 'bar'}),
new Node({type: 'baz'})
]
});
console.log(utils.hasType(node, 'xyz')); // false
console.log(utils.hasType(node, 'baz')); // true
.firstOfType
Returns the first node from node.nodes
of the given type
Params
nodes
{Array}type
{String}returns
{Object|undefined}: Returns the first matching node or undefined.
Example
var node = new Node({
type: 'foo',
nodes: [
new Node({type: 'text', val: 'abc'}),
new Node({type: 'text', val: 'xyz'})
]
});
var textNode = utils.firstOfType(node.nodes, 'text');
console.log(textNode.val);
//=> 'abc'
.findNode
Returns the node at the specified index, or the first node of the given type
from node.nodes
.
Params
nodes
{Array}type
{String|Number}: Node type or index.returns
{Object}: Returns a node or undefined.
Example
var node = new Node({
type: 'foo',
nodes: [
new Node({type: 'text', val: 'abc'}),
new Node({type: 'text', val: 'xyz'})
]
});
var nodeOne = utils.findNode(node.nodes, 'text');
console.log(nodeOne.val);
//=> 'abc'
var nodeTwo = utils.findNode(node.nodes, 1);
console.log(nodeTwo.val);
//=> 'xyz'
.isOpen
Returns true if the given node is an "*.open" node.
Params
node
{Object}: Instance of snapdragon-nodereturns
{Boolean}
Example
var Node = require('snapdragon-node');
var brace = new Node({type: 'brace'});
var open = new Node({type: 'brace.open'});
var close = new Node({type: 'brace.close'});
console.log(utils.isOpen(brace)); // false
console.log(utils.isOpen(open)); // true
console.log(utils.isOpen(close)); // false
.isClose
Returns true if the given node is a "*.close" node.
Params
node
{Object}: Instance of snapdragon-nodereturns
{Boolean}
Example
var Node = require('snapdragon-node');
var brace = new Node({type: 'brace'});
var open = new Node({type: 'brace.open'});
var close = new Node({type: 'brace.close'});
console.log(utils.isClose(brace)); // false
console.log(utils.isClose(open)); // false
console.log(utils.isClose(close)); // true
.hasOpen
Returns true if node.nodes
has an .open
node
Params
node
{Object}: Instance of snapdragon-nodereturns
{Boolean}
Example
var Node = require('snapdragon-node');
var brace = new Node({
type: 'brace',
nodes: []
});
var open = new Node({type: 'brace.open'});
console.log(utils.hasOpen(brace)); // false
brace.pushNode(open);
console.log(utils.hasOpen(brace)); // true
.hasClose
Returns true if node.nodes
has a .close
node
Params
node
{Object}: Instance of snapdragon-nodereturns
{Boolean}
Example
var Node = require('snapdragon-node');
var brace = new Node({
type: 'brace',
nodes: []
});
var close = new Node({type: 'brace.close'});
console.log(utils.hasClose(brace)); // false
brace.pushNode(close);
console.log(utils.hasClose(brace)); // true
.hasOpenAndClose
Returns true if node.nodes
has both .open
and .close
nodes
Params
node
{Object}: Instance of snapdragon-nodereturns
{Boolean}
Example
var Node = require('snapdragon-node');
var brace = new Node({
type: 'brace',
nodes: []
});
var open = new Node({type: 'brace.open'});
var close = new Node({type: 'brace.close'});
console.log(utils.hasOpen(brace)); // false
console.log(utils.hasClose(brace)); // false
brace.pushNode(open);
brace.pushNode(close);
console.log(utils.hasOpen(brace)); // true
console.log(utils.hasClose(brace)); // true
.addType
Push the given node
onto the state.inside
array for the given type. This array is used as a specialized "stack" for only the given node.type
.
Params
state
{Object}: Thecompiler.state
object or custom state object.node
{Object}: Instance of snapdragon-nodereturns
{Array}: Returns thestate.inside
stack for the given type.
Example
var state = { inside: {}};
var node = new Node({type: 'brace'});
utils.addType(state, node);
console.log(state.inside);
//=> { brace: [{type: 'brace'}] }
.removeType
Remove the given node
from the state.inside
array for the given type. This array is used as a specialized "stack" for only the given node.type
.
Params
state
{Object}: Thecompiler.state
object or custom state object.node
{Object}: Instance of snapdragon-nodereturns
{Array}: Returns thestate.inside
stack for the given type.
Example
var state = { inside: {}};
var node = new Node({type: 'brace'});
utils.addType(state, node);
console.log(state.inside);
//=> { brace: [{type: 'brace'}] }
utils.removeType(state, node);
//=> { brace: [] }
.isEmpty
Returns true if node.val
is an empty string, or node.nodes
does not contain any non-empty text nodes.
Params
node
{Object}: Instance of snapdragon-nodefn
{Function}returns
{Boolean}
Example
var node = new Node({type: 'text'});
utils.isEmpty(node); //=> true
node.val = 'foo';
utils.isEmpty(node); //=> false
.isInsideType
Returns true if the state.inside
stack for the given type exists and has one or more nodes on it.
Params
state
{Object}type
{String}returns
{Boolean}
Example
var state = { inside: {}};
var node = new Node({type: 'brace'});
console.log(utils.isInsideType(state, 'brace')); //=> false
utils.addType(state, node);
console.log(utils.isInsideType(state, 'brace')); //=> true
utils.removeType(state, node);
console.log(utils.isInsideType(state, 'brace')); //=> false
.isInside
Returns true if node
is either a child or grand-child of the given type
, or state.inside[type]
is a non-empty array.
Params
state
{Object}: Either thecompiler.state
object, if it exists, or a user-supplied state object.node
{Object}: Instance of snapdragon-nodetype
{String}: Thenode.type
to check for.returns
{Boolean}
Example
var state = { inside: {}};
var node = new Node({type: 'brace'});
var open = new Node({type: 'brace.open'});
console.log(utils.isInside(state, open, 'brace')); //=> false
utils.pushNode(node, open);
console.log(utils.isInside(state, open, 'brace')); //=> true
.last
Get the last n
element from the given array
. Used for getting
a node from node.nodes.
Params
array
{Array}n
{Number}returns
{undefined}
.arrayify
Cast the given val
to an array.
Params
val
{any}returns
{Array}
Example
console.log(utils.arraify(''));
//=> []
console.log(utils.arraify('foo'));
//=> ['foo']
console.log(utils.arraify(['foo']));
//=> ['foo']
.stringify
Convert the given val
to a string by joining with ,
. Useful
for creating a cheerio/CSS/DOM-style selector from a list of strings.
Params
val
{any}returns
{Array}
.trim
Ensure that the given value is a string and call .trim()
on it,
or return an empty string.
Params
str
{String}returns
{String}
Release history
Changelog entries are classified using the following labels from keep-a-changelog:
added
: for new featureschanged
: for changes in existing functionalitydeprecated
: for once-stable features removed in upcoming releasesremoved
: for deprecated features removed in this releasefixed
: for any bug fixes
Custom labels used in this changelog:
dependencies
: bumps dependencieshousekeeping
: code re-organization, minor edits, or other changes that don't fit in one of the other categories.
[3.0.0] - 2017-05-01
Changed
.emit
was renamed to .append.addNode
was renamed to .pushNode.getNode
was renamed to .findNode.isEmptyNodes
was renamed to .isEmpty: also now works withnode.nodes
and/ornode.val
Added
[0.1.0]
First release.
About
Contributing
Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.
Please read the contributing guide for advice on opening issues, pull requests, and coding standards.
Building docs
(This project's readme.md is generated by verb, please don't edit the readme directly. Any changes to the readme must be made in the .verb.md readme template.)
To generate the readme, run the following command:
$ npm install -g verbose/verb#dev verb-generate-readme && verb
Running tests
Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command:
$ npm install && npm test
Author
Jon Schlinkert
License
Copyright © 2017, Jon Schlinkert. Released under the MIT License.
This file was generated by verb-generate-readme, v0.6.0, on May 01, 2017.