Documentation
¶
Overview ¶
Package transform implements a html css selector and transformer.
An html doc can be inspected and queried using a subset of css selectors as well as transformed.
tree, _ := h5.New(rdr)
t := transform.New(Tree)
t.Apply(CopyAnd(myModifiers...), "li.menuitem")
t.Apply(Replace(Text("my new text"), "a")
You can use the building blocks in this package as an html templating engine. the basic principle behind html transform is that your template is just data the same as your fill data. You use functions to mix and munge these two types of data and get a third type of data back out which you can use to render.
You can also use this package to slice up and retrieve data out of an html page. You can build scrapers and even mash up two different html documents.
How to do common templating actions.
How do I loop over input data?
Just because you don't have a for statement in your templating language doesn't mean you can't loop over your data. You just have to loop over before you insert it.
If we have template that looks like this:
<html><body><ul id="people"><li>some guy</ul></body></html>
Then we can turn that list of people into a list of Me, Myself, and I like so:
// We are going to want to set up the transformations for each person
// in our list.
liTransfroms := []TransformFuncs
for i, item := range []string{"Me", "Myself", "I"} {
liTransforms = append(menuTransforms, ReplaceChildren(Text(item)))
}
// Find the li in the ul element with the id='people' and make one copy of
// it for each item from above with the text content replaced with that
// item
t.Apply(CopyAnd(liTransforms...), "ul#people", "li")
How do I change an html elements contents?
t.Apply(ReplaceChildren(Text("some text contents"), "#SomeElement")
How do I remove/replace an html element.
// Remove the element
T.Apply(Replace(), "#SomeElement")
// Replace the element
node, _ := NewDoc("<span>hello</span>")
T.Apply(Replace(node), "#SomeElement")
Index ¶
- type Collector
- type CollectorFunc
- type Transform
- type TransformFunc
- func AppendChildren(cs ...*html.Node) TransformFunc
- func CopyAnd(fns ...TransformFunc) TransformFunc
- func DoAll(fs ...TransformFunc) TransformFunc
- func ModifyAttrib(key string, val string) TransformFunc
- func MustSubtransform(f TransformFunc, sel string) TransformFunc
- func PrependChildren(cs ...*html.Node) TransformFunc
- func RemoveChildren() TransformFunc
- func Replace(ns ...*html.Node) TransformFunc
- func ReplaceChildren(ns ...*html.Node) TransformFunc
- func Subtransform(f TransformFunc, sel string) (TransformFunc, error)
- func SubtransformCollector(f TransformFunc, coll Collector) TransformFunc
- func Trace(f TransformFunc, traceFunc func(msg string, args ...interface{}), msg string, ...) TransformFunc
- func TransformAttrib(key string, f func(string) string) TransformFunc
- type Transformer
- func (t *Transformer) Apply(f TransformFunc, sel string) error
- func (t *Transformer) ApplyAll(ts ...*Transform)
- func (t *Transformer) ApplyToFirstMatch(f TransformFunc, sels ...string) error
- func (t *Transformer) ApplyWithCollector(f TransformFunc, coll Collector)
- func (t *Transformer) Clone() *Transformer
- func (t *Transformer) Doc() *html.Node
- func (t *Transformer) Render(w io.Writer) error
- func (t *Transformer) String() string
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Collector ¶
type Collector interface {
// Find searches a tree rooted at n and returns a slice of nodes
// that match a criteria.
Find(n *html.Node) []*html.Node
}
Collector defines an interface for html node collectors.
type CollectorFunc ¶
func FirstMatch ¶
func FirstMatch(cs ...Collector) CollectorFunc
type Transform ¶
type Transform struct {
// contains filtered or unexported fields
}
Transform is a bundle of selectors and a transform func. It forms a self contained Transfrom on an html document that can be reused.
func MustTrans ¶
func MustTrans(f TransformFunc, sel string) *Transform
MustTrans creates a Transform. Panics if the selector wasn't valid.
func Trans ¶
func Trans(f TransformFunc, sel string) (*Transform, error)
Trans creates a Transform that you can apply using ApplyAll. It takes a TransformFunc and a valid CSS3 Selector. It returns a *Transform or an error if the selector wasn't valid
func TransCollector ¶
func TransCollector(f TransformFunc, coll Collector) *Transform
TransCollector creates a Transform that you can apply using ApplyAll. It takes a TransformFunc and a Collector
type TransformFunc ¶
The TransformFunc type is the type of a html.Node transformation function.
func AppendChildren ¶
func AppendChildren(cs ...*html.Node) TransformFunc
AppendChildren creates a TransformFunc that appends the Children passed in.
func CopyAnd ¶
func CopyAnd(fns ...TransformFunc) TransformFunc
CopyAnd will construct a TransformFunc that will make a copy of the node for each passed in TransformFunc and replace the passed in node with the resulting transformed html.Nodes.
func DoAll ¶
func DoAll(fs ...TransformFunc) TransformFunc
DoAll returns a TransformFunc that combines all the TransformFuncs that are passed in. Doing each transform in order.
func ModifyAttrib ¶
func ModifyAttrib(key string, val string) TransformFunc
ModifyAttrb creates a TransformFunc that modifies the attributes of the node it operates on. If an Attribute with the same name as the key doesn't exist it creates it.
func MustSubtransform ¶
func MustSubtransform(f TransformFunc, sel string) TransformFunc
MustSubtransform constructs a TransformFunc that runs a TransformFunc on any nodes in the tree rooted by the node the the TransformFunc is run against. Panics if the selector string is malformed.
func PrependChildren ¶
func PrependChildren(cs ...*html.Node) TransformFunc
PrependChildren creates a TransformFunc that prepends the Children passed in.
func RemoveChildren ¶
func RemoveChildren() TransformFunc
RemoveChildren creates a TransformFunc that removes the Children of the node it operates on.
func Replace ¶
func Replace(ns ...*html.Node) TransformFunc
Replace constructs a TransformFunc that replaces a node with the nodes passed in.
func ReplaceChildren ¶
func ReplaceChildren(ns ...*html.Node) TransformFunc
ReplaceChildren creates a TransformFunc that replaces the Children of the node it operates on with the Children passed in.
func Subtransform ¶
func Subtransform(f TransformFunc, sel string) (TransformFunc, error)
SubTransform constructs a TransformFunc that runs a TransformFunc on any nodes in the tree rooted by the node the the TransformFunc is run against. This is useful for creating self contained Transforms that are meant to work on subtrees of the html document.
func SubtransformCollector ¶
func SubtransformCollector(f TransformFunc, coll Collector) TransformFunc
SubTransformSelector constructs a TransformFunc that runs a TransformFunc on any nodes collected, using the passed in collector, from the subtree the TransformFunc is run on. This is useful for creating self contained Transforms that are meant to work on subtrees of the html document.
func Trace ¶
func Trace(f TransformFunc, traceFunc func(msg string, args ...interface{}), msg string, args ...interface{}) TransformFunc
Trace is a debugging wrapper for transform funcs. It calls traceFunc with debugging information before and after the TransformFunc is applied.
func TransformAttrib ¶
func TransformAttrib(key string, f func(string) string) TransformFunc
TransformAttrib returns a TransformFunc that transforms an attribute on the node it operates on using the provided func. It only transforms the attribute if it exists.
type Transformer ¶
type Transformer struct {
// contains filtered or unexported fields
}
Transformer encapsulates a document under transformation.
func New ¶
func New(t *h5.Tree) *Transformer
Constructor for a Transformer. It makes a copy of the document and transforms that instead of the original.
func NewFromReader ¶
func NewFromReader(rdr io.Reader) (*Transformer, error)
func (*Transformer) Apply ¶
func (t *Transformer) Apply(f TransformFunc, sel string) error
The ApplyWithSelector method applies a TransformFunc to the nodes matched by the CSS3 Selector.
func (*Transformer) ApplyAll ¶
func (t *Transformer) ApplyAll(ts ...*Transform)
ApplyAll applies a series of Transforms to a document.
t.ApplyAll(Trans(f, sel1, sel2), Trans(f2, sel3, sel4))
func (*Transformer) ApplyToFirstMatch ¶
func (t *Transformer) ApplyToFirstMatch(f TransformFunc, sels ...string) error
func (*Transformer) ApplyWithCollector ¶
func (t *Transformer) ApplyWithCollector(f TransformFunc, coll Collector)
ApplyWithCollector applies a TransformFunc to the tree using a Collector.
func (*Transformer) Clone ¶
func (t *Transformer) Clone() *Transformer
func (*Transformer) Doc ¶
func (t *Transformer) Doc() *html.Node
The Doc method returns the document under transformation.
func (*Transformer) String ¶
func (t *Transformer) String() string
Source Files