mrkamel/tempfile_for

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# TempfileFor

Easily create temporary files for in-memory data, modify the file, and get the
full content returned.

## Installation

Add this line to your application's Gemfile:

```
gem "tempfile_for"
```

And then execute:

```
$ bundle
```

Alternatively, you can of course install it without using bundler via:

```
$ gem install tempfile_for
```

## Usage

### for

TempfileFor is a very tiny gem, but it can save you lines of ugly code.

To get a quick introduction into what TempfileFor does, check this out:

```ruby
Tempfile.for("string1") { |tempfile| `echo -n ', string2' >> #{tempfile.path}` }
# => "string1, string2"
```

Say, you have some in-memory data, like an image you fetch from an URL - and
you want to somehow modify it partially like e.g., add or remove IPTC tags, or
scale it, etc. Often, the gems used to modify images or other media files
require a path to the file to be able to modify it.

This is easy thanks to TempfileFor:

```ruby
data = RestClient.get("http://example.com/image.jpg")

image = Tempfile.for(data) do |tempfile|
  # Modify the tempfile directly or using tempfile.path and get the modified content returned.
  # Tempfile takes care about flushing the file's modifications and rewinding, etc.
end
```

### blank

If you want to use TempfileFor without initial data, simply use:

```ruby
Tempfile.blank { |tempfile| `echo -n data >> #{tempfile.path}` }
```

### Tempfile object

In case you need the tempfile object itself, because you e.g. don't want to
load it into memory, add `:read => false` to either `Tempfile#for` or
`Tempfile#blank`

```ruby
Tempfile.for("string", :read => false) { |tempfile| ... } # => #<File:/tmp/tempfile...>
Tempfile.blank(:read => false) { |tempfile| ... } # => #<File:/tmp/tempfile...>
```

## Encoding

TempfileFor preserves the encoding of the supplied data. Thus, the following
code

```ruby
Tempfile.for("string1".encode(Encoding::ISO_8859_1)) { ... }
```

will return a string encoded as ISO-8859-1. If you use the blank method, you
can supply the desired encoding via

```ruby
Tempfile.blank(:encoding => Encoding::BINARY) { ... }
```

will return a string encoded as binary.

## Suffix

You can pass a `:suffix => "..."` option to all methods, such that

```ruby
Tempfile.for("data", :suffix => ".jpg")
Tempfile.blank(:suffix => ".jpg") { ... }
```

will create tempfiles having a `.jpg` suffix.

## Contributing

1. Fork it
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Added some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create new Pull Request