Synopsis

seo-defects let you create rules to detect SEO defects in a HTML, and report accordingly.

Features

• DSL to create condtions on tags and their attributes.
• DSL to create rules to detect and report SEO defects.
• Work on files and streams.

Installation

Install it like a npm module:

npm install seo-defects

Usage

Import seo-defects and get API classes:

var seodd = require('seo-defects');
var Detector = seodd.Detector;
var Rule = seodd.Rule;
var Condition = seodd.Condition;

DSL to create conditions

Use Condition class to create conditions for tags.

Examples:

• a meta tag has attribute name="description":

Condition().tag('meta').attr('name').is('description')

• an img tag has no attribute alt:

Condition().tag('img').attr('alt').notExist()

• a head tag doesn't have a <meta name="descriptions" ...> tag:

Condition().tag('head').notHave(Condition().tag('meta').attr('name').is('descriptions'))

DSL to create rules

A Rule has:

• a Condition: Detector will count the number of tags matched with this condition.

• many messages to report, based on the number of matched values. %NUM% is the placeholder that Detector will insert the number of matched values in to reported messages.

Examples:

• report This HTML without <title> tag if the header tag doesn't have title tag:

Rule().cond(Condition().tag('head').notHave(Condition().tag('title')))
  .greaterThan(0).msg('This HTML without <title> tag');

• report There are %NUM% <img> tag without alt attribute:

Rule().cond(Condition().tag('img').attr('alt').notExist())
  .greaterThan(0).msg('There are %NUM% <img> tag without alt attribute');

Pre-defined rules:

  SEODefectDetector.imgWithoutAlt
  SEODefectDetector.aWithoutRel
  SEODefectDetector.headerNoTitle
  SEODefectDetector.headerNoMetaDescriptions
  SEODefectDetector.headerNoMetaKeywords
  SEODefectDetector.moreThan15Strong
  SEODefectDetector.moreThan1H1

Detector

Create a Detector with input, output and the list of rules to apply checking. Input and output can be filenames or streams.

Call method detect to perform checking for SEO defects. Register a callback for event complete when the checking is done.

Examples:

var detector = new Detector('input1', process.stdout, [
  Detector.imgWithoutAlt,
  Detector.aWithoutRel,
  Detector.headerNoTitle,
  Detector.headerNoMetaDescription,
  Detector.headerNoMetaKeywords,
  Detector.moreThan15Strong,
  Detector.moreThan1H1,
  Rule().cond(Condition().tag('meta').attr('name').is('robots'))
    .equal(0).msg('This HTML doesnt have meta robots')
]);

detector.detect().on('complete', function() {
  console.log('\ndone');
});

API

Condition Instance Methods

tag()

function Condition#tag(type)
@param type {String} Tag type (eg: head, meta, ...).

This method will create a condition based on the tag provided. Then other methods can be chained to each other.

attr()

function Condition#attr(name)
@param name {String} Attribute name (eg: id, rel, alt, ...).

is(), isNot()

function Condition#is(value)
@param value {String} The value of the attribute specified in the `attr` clause.

function Condition#isNot(value)
@param value {String} The value of the attribute specified in the `attr` clause.

exist(), notExist()

function Condition#exists()

function Condition#notExist()

has(), notHave()

function Condition#has(elem)
@param elem {Condition} The child tag condition that the current tag must have.

function Condition#notHave(elem)
@param elem {Condition} The child tag condition that the current tag must not have.

descend()

function Condition#descend(elem)
@param elem {Condition} Create a new condition whose main tag that Detector counted for is this tag condition.

Rule Instance Methods

cond()

function Rule#cond(condition)
@param condition {Condition} Set the condition for this rule.

This method will create a rule based on the condition provided. Then other methods can be chained to each other.

msg()

function Rule#msg(message)
@param message {String} The message for current comparison.

equal(), lessThan(), greaterThan()

function Rule#equal(value)
@param value {Number} The value to be used in an equal comparison.

function Rule#lessThan(value)
@param value {Number} The value to be used in an less-than comparison.

function Rule#greaterThan(value)
@param value {Number} The value to be used in an greater-than comparison.

Detector Constructor

function Detector(input, output, rules)
@param input {String,Readable} The input source contains the HTML.
@param output {String,Writable} The output.
@param rules {Array} The array of rules.

Detector Instance Methods

detect()

function Detector#detect()

This method performs the checking and then reports to the output stream. When done, it emits the complete event.

License

Copyright (c) 2018 Vu To [email protected]