pattern-replace
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Replace text patterns with a given replacement.
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# pattern-replace [](http://travis-ci.org/outaTiME/pattern-replace)
Replace text patterns with a given replacement.
## Install
First make sure you have installed the latest version of [node.js](http://nodejs.org/)
(You may need to restart your computer after this step).
From NPM for use as a command line app:
```shell
npm install pattern-replace -g
```
From NPM for programmatic use:
```shell
npm install pattern-replace
```
From Git:
```shell
git clone git://github.com/outaTiME/pattern-replace
cd pattern-replace
npm link .
```
## API Reference
Assuming installation via NPM, you can use `pattern-replace` in your application like this:
```javascript
var fs = require('fs');
var Replacer = require('pattern-replace');
var options = {
patterns: [
{
match: 'foo',
replacement: 'bar'
}
]
};
var replacer = new Replacer(options);
var contents = '@@foo';
var result = replacer.replace(contents);
console.log(result); // bar
```
### Replacer Options
#### patterns
Type: `Array`
Define patterns that will be used to replace the contents of source files.
#### patterns.match
Type: `String|RegExp`
Indicates the matching expression.
If matching type is `String` and `expression` attribute is `false` we use a simple variable lookup mechanism `@@string` (in any other case we use the default regexp replace logic):
```javascript
{
patterns: [
{
match: 'foo',
replacement: 'bar', // replaces "@@foo" to "bar"
expression: false // simple variable lookup
}
]
}
```
#### patterns.replacement
Type: `String|Function|Object`
Indicates the replacement for match, for more information about replacement check out the [String.replace].
You can specify a function as replacement. In this case, the function will be invoked after the match has been performed. The function's result (return value) will be used as the replacement string.
```javascript
{
patterns: [
{
match: /foo/g,
replacement: function () {
return 'bar'; // replaces "foo" to "bar"
}
}
]
}
```
Also supports object as replacement (we create string representation of object using [JSON.stringify]):
```javascript
{
patterns: [
{
match: /foo/g,
replacement: [1, 2, 3] // replaces "foo" with string representation of "array" object
}
]
}
```
[String.replace]: http://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace
[JSON.stringify]: http://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify
#### patterns.json
Type: `Object`
If an attribute `json` found in pattern definition we flatten the object using `delimiter` concatenation and each key–value pair will be used for the replacement (simple variable lookup mechanism and no regexp support).
```javascript
{
patterns: [
{
json: {
"key": "value" // replaces "@@key" to "value"
}
}
]
}
```
Also supports nested objects:
```javascript
{
patterns: [
{
json: {
"key": "value", // replaces "@@key" to "value"
"inner": { // replaces "@@inner" with string representation of "inner" object
"key": "value" // replaces "@@inner.key" to "value"
}
}
}
]
}
```
#### patterns.yaml
Type: `String`
If an attribute `yaml` found in pattern definition we flatten the object using `delimiter` concatenation and each key–value pair will be used for the replacement (simple variable lookup mechanism and no regexp support).
```javascript
{
patterns: [
{
yaml: 'key: value' // replaces "@@key" to "value"
}
]
}
```
#### patterns.expression
Type: `Boolean`
Default: `false`
Indicates the type of matching.
If detects regexp instance in `match` attribute, we assume to works with expression matcher (in any other case should be forced).
#### variables
Type: `Object`
This is the old way to define patterns using plain object (simple variable lookup mechanism and no regexp support), you can still using but for more control you should use the new `patterns` way.
```javascript
{
variables: {
'key': 'value' // replaces "@@key" to "value"
}
}
```
#### prefix
Type: `String`
Default: `@@`
The prefix added for matching (prevent bad replacements / easy way).
> This only applies for simple variable lookup mechanism.
#### usePrefix
Type: `Boolean`
Default: `true`
If set to `false`, we match the pattern without `prefix` concatenation (useful when you want to lookup an simple string).
> This only applies for simple variable lookup mechanism.
#### preservePrefix
Type: `Boolean`
Default: `false`
If set to `true`, we preserve the `prefix` in target.
> This only applies for simple variable lookup mechanism and `patterns.replacement` is an string.
#### delimiter
Type: `String`
Default: `.`
The delimiter used to flatten when using object as replacement.
#### preserveOrder
Type: `Boolean`
Default: `false`
If set to `true`, we preserve the patterns definition order, otherwise these will be sorted (in ascending order) to prevent replacement issues like `head` / `header` (typo regexps will be resolved at last).
### Usage Examples
#### Basic
File `src/manifest.appcache`:
```
CACHE MANIFEST
# @@timestamp
CACHE:
favicon.ico
index.html
NETWORK:
*
```
Node:
```js
var fs = require('fs');
var Replacer = require('pattern-replace');
var options = {
patterns: [
{
match: 'timestamp',
replacement: new Date().getTime()
}
]
};
var replacer = new Replacer(options);
var contents = fs.readFileSync('./src/manifest.appcache').toString();
var result = replacer.replace(contents);
console.log(result); // replaced output
```
#### Multiple matching
File `src/manifest.appcache`:
```
CACHE MANIFEST
# @@timestamp
CACHE:
favicon.ico
index.html
NETWORK:
*
```
File `src/humans.txt`:
```
__ _
_ _/__ /./|,//_`
/_//_// /_|/// //_, outaTiME v.@@version
/* TEAM */
Web Developer / Graphic Designer: Ariel Oscar Falduto
Site: http://www.outa.im
Twitter: @outa7iME
Contact: afalduto at gmail dot com
From: Buenos Aires, Argentina
/* SITE */
Last update: @@timestamp
Standards: HTML5, CSS3, robotstxt.org, humanstxt.org
Components: H5BP, Modernizr, jQuery, Twitter Bootstrap, LESS, Jade, Grunt
Software: Sublime Text 2, Photoshop, LiveReload
```
Node:
```js
var fs = require('fs');
var Replacer = require('pattern-replace');
var options = {
patterns: [
{
match: 'version',
replacement: '0.1.0'
},
{
match: 'timestamp',
replacement: new Date().getTime()
}
]
};
var replacer = new Replacer(options);
var contents = fs.readFileSync('./src/manifest.appcache').toString();
var result = replacer.replace(contents);
console.log(result); // replaced output
contents = fs.readFileSync('./src/humans.txt').toString();
result = replacer.replace(contents);
console.log(result); // replaced output
```
#### Cache busting
File `src/index.html`:
```html
<head>
<link rel="stylesheet" href="/css/style.css?rel=@@timestamp">
<script src="/js/app.js?rel=@@timestamp"></script>
</head>
```
Node:
```js
var fs = require('fs');
var Replacer = require('pattern-replace');
var options = {
patterns: [
{
match: 'timestamp',
replacement: new Date().getTime()
}
]
};
var replacer = new Replacer(options);
var contents = fs.readFileSync('./src/index.html').toString();
var result = replacer.replace(contents);
console.log(result); // replaced output
```
#### Include file
File `src/index.html`:
```html
<body>
@@include
</body>
```
Node:
```js
var fs = require('fs');
var Replacer = require('pattern-replace');
var options = {
patterns: [
{
match: 'include',
replacement: fs.readFileSync('./includes/content.html').toString()
}
]
};
var replacer = new Replacer(options);
var contents = fs.readFileSync('./src/index.html').toString();
var result = replacer.replace(contents);
console.log(result); // replaced output
```
#### Regular expression
File `src/username.txt`:
```
John Smith
```
Node:
```js
var fs = require('fs');
var Replacer = require('pattern-replace');
var options = {
patterns: [
{
match: /(\w+)\s(\w+)/,
replacement: '$2, $1' // replaces "John Smith" to "Smith, John"
}
]
};
var replacer = new Replacer(options);
var contents = fs.readFileSync('./username.txt').toString();
var result = replacer.replace(contents);
console.log(result); // replaced output
```
#### Lookup for `foo` instead of `@@foo`
The `String` matching type or `expression` in `false` generates a simple variable lookup mechanism `@@string`, to skip this mode use one of the below rules ... make your choice:
Node:
```js
var Replacer = require('pattern-replace');
// option 1 (explicitly using an regexp)
var replacer_op1 = new Replacer({
patterns: [
{
match: /foo/g,
replacement: 'bar'
}
]
});
// option 2 (easy way)
var replacer_op2 = new Replacer({
patterns: [
{
match: 'foo',
replacement: 'bar'
}
],
usePrefix: false
});
// option 3 (old way)
var replacer_op3 = new Replacer({
patterns: [
{
match: 'foo',
replacement: 'bar'
}
],
prefix: '' // remove prefix
});
```
## Command Line
_(Coming soon)_
## Release History
* 2014-03-12 v0.1.2 New pattern matching for YAML object. New preserveOrder flag.
* 2014-02-26 v0.1.1 Remove the force flag (only applies in grunt plugin).
* 2014-02-25 v0.1.0 Initial version.
---
Task submitted by [Ariel Falduto](http://outa.im/)