UrlParsers.md

Writing you own url decoder

Using mort you can write you own request url parser. This section will guide you how to do so and use it.

Implementation

Parser should be function with look like

type ParseFnc func(url *url.URL, bucketConfig config.Bucket, obj *FileObject) (parent string, err error)

Function parameters:

• url is a request URI
• bucketConfig - is configuration for current bucket
• obj - is result object. In which you should store operation to perform

It should return

• parent - string path for original image
• error - if any error occurred

To register parser you should call

object.RegisterParser(kind string, fn ParserFNc)

Parser have to be registered before loading configuration. It will be called on transform object and original object.

Example custom parser

This parser will parse url like https://mort/bucket/parent,w100,h100.png

object.RegisterParser("custom", func (reqUrl *url.URL, bucketConfig config.Bucket, obj *object.FileObject)  (string, error) {
    // split by "." to remove object extension
    elements := strings.SplitN(reqUrl.Path, ".", 2)
    if len(elements) == 1 {
        return "", nil
    }
    // split by "," to find resize parameters
    elements = strings.Split(elements[0], ",")

    // url has no transform
    if len(elements) == 1 {
        return "", nil
    }

    // apply parameters
    var width, height int64
    parent := elements[0] +  path.Ext(reqUrl.Path)
    trans := elements[1:]
    for _, tran := range trans {
        if tran[0] == 'w' {
            width, _ = strconv.ParseInt(tran[1:], 10, 32)
        }

        if tran[0] == 'h' {
            height, _ = strconv.ParseInt(tran[1:], 10, 32)
        }
    }

    obj.Transforms.Resize(int(width), int(height), false)
    return parent, nil
})

In bucket configuration:

buckets:
    bucket:
      transform:
        kind: "custom"