# SEO HTML defect checker
Lightweight module for checking SEO HTML defect elements.
Built for
- [NodeJS](https://nodejs.org)
# Status
[](https://travis-ci.org/doha99/seo-html-defect-checker)
## Installation
This is node.js libarary. Install nodejs first, then:
```npm install seo-html-defect-checker```
or
```yarn add seo-html-defect-checker```
## How to use?
There are 7 defined rules that you can use to validate HTML.
1. Detect if there are any `![]()
` tags without alt attribute
2. Detect if there are any `` tags without rel attribute
3. In tag
* Detect if there is any header that doesn’t have `` tag
* Detect if there is any header that doesn’t have `<meta name=“descriptions” … />` tag
* Detect if there is any header that doesn’t have `<meta name=“keywords” … />` tag
4. Detect if there are more than 15 `<strong>` tag in HTML (15 is a value should be configurable by user)
5. Detect if a HTML have more than one `<H1>` tag.
Rules object as follows:
```javascript
Rules = {
definedRules : {
aTagWithoutRel,
imgTagWithoutAlt,
dontHaveTitle,
dontHaveMetaDescription,
dontHaveMetaKeywords,
moreThan15StrongTag,
moreThan1H1Tag,
}
}
```
For example:
```javascript
const {Checker, Rules} = require('seo-html-defect-checker')
const c = new Checker(htmlText)
c.check([Rules.definedRules.aTagWithoutRel], (results) => {
// manipulate results
})
```
There is a defined rule list that include 7 rules as follows example:
```javascript
const {Checker, Rules} = require('seo-html-defect-checker')
const htmlText = loadHtmlFunction() // function return string
const c = new Checker(htmlText)
c.check(Rules.definedRules.defaultRuleList, (results) => { // results is array
// manipulate results
})
```
And you can customize the rules list such as
```javascript
const {Checker, Rules} = require('seo-html-defect-checker')
const htmlText = loadHtmlFunction() // function return string
const c = new Checker(htmlText)
const myRules = [
Rules.definedRules.aTagWithoutRel,
Rules.definedRules.dontHaveMetaDescription
]
c.check(myRules, results => {
console.log(results)
})
```
Beside that you can customize the rule throw 4 objects:
```javascripts
Rules = {
//....
MissAttributeRule, // check tags that don't have some specific attributes
MissTagRule, // check HTML without tags which have some specific attributes (or only just tags)
MoreTagThanRule, // check there is more than a specific number of tags which occur in HTML
CustomRule, // custom whatever rule you want
}
```
Examples:
```javascripts
const {MissAttributeRule, MissTag, MoreTagThan} = Rules
const r1 = new MissAttributeRule('img', {
alt: null,
})
const r2 = new MissTag('title', {}, 'head >')
const r3 = new MoreTagThan('strong', {}, null, 5)
const rules = [r1, r2, r3]
const c = new Checker(htmlText)
c.check(rules, results => {
// manipulate results
})
```
```javascripts
const {CustomRule} = Rules
const r4 = new CustomRule('meta', {
'keywords*': 'shopping'
}, 'head >', (dom, selector) => {
var num = dom.count(selector)
if (num == 0) {
return 'miss shopping keyword'
}
return null
})
const c = new Checker(htmlText)
c.check([r4], results => {
// manipulate results
})
```
And you can customize your selector query
```javascripts
const r5 = new CustomRule('p', {}, null, (dom, selector) => {
var num = dom.count('p.highlight:not(.warning)')
if (num == 0) {
return `there are ${num} p tags with hightlight class and without warning class`
}
return null
})
const c = new Checker(htmlText)
c.check([r4], results => {
// manipulate results
})
```
## API
<details>
<summary>Checker</summary>
- constructor(input, output)
* input is text or stream reader
* output is file path or stream writer or console
- check(rules, cb)
* rules is an array list, contains rule object
* cb is callback function with first parameter is results (array) of check
</details>
<details>
<summary>Rules.CustomRule</summary>
- constructor(tag, attributes, prefix, cb)
- check(domQuery)
</details>
<details>
<summary>Rules.MissAttributeRule</summary>
- constructor(tag, attributes, prefix)
- check(domQuery)
</details>
<details>
<summary>Rules.MissTag</summary>
- constructor(tag, attributes, prefix)
- check(domQuery)
</details>
<details>
<summary>Rules.MoreTagThan</summary>
- constructor(tag, attributes, prefix, specificNumber)
- check(domQuery)
</details>
## Features
- [x] Detect HTML element defect by the defined rules
- [x] Can add customize rule flexibility
- [ ] Support i18n
## Contribute
Let people know how they can contribute into your project.
## License
A short snippet describing the license (MIT, Apache etc)
MIT © [DoHa](https://github.com/doha99/seo-html-defect-checker/blob/master/LICENSE)