DataExtracter Help
DataExtracter helps you quickly extract data from any web pages. All you need to do is:
- Find out the selectors (JQuery selectors) for target data
- Call Extractor methods in
extension backgroud page console, as introduced bellow.
Where is the extension backgroud page console?
Goto chrome://extensions/ and click backgroud page link of the extension
In the opening window, find Console, and type your scripts.
Qucik Start
Extract current page
new Extractor().task(".list-item", ["a.title", "p.content"]).start();
Extract multiple pages (1-10, interval 1)
new Extractor().task(".list-item", ["a.title", "p.content"],"http://sample.com/?pn=${page}", 1, 10, 1).start();
Extract multiple urls (list)
new Extractor().task(".list-item", ["a.title", "p.content"],["http://sample.com/abc","http://sample.com/xyz"]).start();
Extract specified pages (1,3,5)
new Extractor().task(".list-item", ["a.title", "p.content"], "http://sample.com/?pn=${page}", [1, 3, 5]).start();
Extractor.task() Signitures:
// a task extracting data from current page
task(itemsSelector:string, fieldSelectors:string[])
// a task extracting data from a range of pages
task(itemsSelector:string, fieldSelectors:string[], urlTemplate:string, from:number, to:number, interval:number)
// a task extracting data from a list of pages
task(itemsSelector:string, fieldSelectors:string, urlTemplate:string, pages:number[])
// a task extracting data from a list of pages
task(itemsSelector:string, fieldSelectors:string[], urls:string[])
// a task extracting data of urls which extracted from last task result
task(itemsSelector:string, fieldSelectors:string[], urls:ExractResult)
Advanced Usage:
Stop tasks
The only way to stop tasks before its finish, is Closing the Tab which runs tasks.
Extract attributes.
e.g.: link text and target (use 'selector@attribute')
new Extractor().task('.list-item', ['a.title', 'a.title@href']).start();
Use task chain.
e.g.: Collect links from http://sample.com/abc & Extract data of each link
new Extractor()
.task('.search-list-item', ['.item a@href'], ["http://sample.com/abc"])
.task('list-item', ["a.title", "p.content"])
.start();
Save result of any task
To a multiple task (chain) Extractor e:
e = new Extractor()
e.task('.search-list-item', ['.item a@href'], ["http://sample.com/abc"])
.task('list-item', ["a.title", "p.content"])
.start();
User will be asked to save the final result when it finishes.
You may want to save another task's result, other than the final:
// save the result of first task
// that is, a list of urls
e.save(1)
Incase you want to save it again, use:
e.save()
Restart tasks
In cases some later task fails, you don't need to restart all task.
Here we have 2 tasks:
e = new Extractor()
e.task('.search-list-item', ['.item a@href'], ["http://sample.com/abc"])
.task('list-item', ["a.title", "p.content"])
.start();
Suppose the second task fails, we can restart and continue from the task 2:
e.restart(2);
If you'd like restart all task, use:
e.start();
// or
e.restart();