snapsearch-client-python

.. snapsearch-client-python document :noindex:

======================== SnapSearch Client Python

.. image:: https://travis-ci.org/SnapSearch/SnapSearch-Client-Python.png?branch=master :target: https://travis-ci.org/SnapSearch/SnapSearch-Client-Python

.. image:: https://badge.fury.io/py/snapsearch-client-python.svg :target: http://badge.fury.io/py/snapsearch-client-python

SnapSearch Client Python is a Python based framework agnostic HTTP client library for SnapSearch (https://snapsearch.io/).

Snapsearch is a search engine optimisation (SEO) and robot proxy for complex front-end javascript & AJAX enabled (potentially realtime) HTML5 web applications.

Search engines like Google's crawler and dumb HTTP clients such as Facebook's image extraction robot cannot execute complex javascript applications. Complex javascript applications include websites that utilise AngularJS, EmberJS, KnockoutJS, Dojo, Backbone.js, Ext.js, jQuery, JavascriptMVC, Meteor, SailsJS, Derby, RequireJS and much more. Basically any website that utilises javascript in order to bring in content and resources asynchronously after the page has been loaded, or utilises javascript to manipulate the page's content while the user is viewing them such as animation.

Snapsearch intercepts any requests made by search engines or robots and sends its own javascript enabled robot to extract your page's content and creates a cached snapshot. This snapshot is then passed through your own web application back to the search engine, robot or browser.

Snapsearch's robot is an automated load balanced Firefox browser. This Firefox browser is kept up to date with the nightly versions, so we'll always be able to serve the latest in HTML5 technology. Our load balancer ensures your requests won't be hampered by other user's requests.

For more details on how this works and the benefits of usage see https://snapsearch.io/

SnapSearch provides similar libraries in other languages: https://github.com/SnapSearch/Snapsearch-Clients

Installation

The Pythonic snapsearch-client requires a dependable HTTP library that can verify SSL certificates for HTTPS requests. Normally, this means you need to have either requests_ or PycURL_.

.. _PycURL: http://pycurl.sourceforge.net/ .. _requests: http://python-requests.org/

To install with pip, simply:

.. code-block:: bash

$ pip install snapsearch-client-python

Or, if you prefer easy_install:

.. code-block:: bash

$ easy_install snapsearch-client-python

Usage

The Pythonic SnapSearch Client_ provides WSGI_ and CGI_ middlewares for integrating SnapSearch with respective Python Web applications. There are also framework agnostic core objects that can be used independently.

.. _Pythonic SnapSearch Client: https://github.com/SnapSearch/SnapSearch-Client-Python .. _WSGI: http://legacy.python.org/dev/peps/pep-3333/ .. _CGI: http://docs.python.org/library/cgi.html

The following examples include step-by-step instructions on the context of using the Pythonic SnapSearch Client_ in your Python web applications.

• Integration with WSGI Applications I (Flask) <https://pythonhosted.org/snapsearch-client-python/flask.html>_
• Integration with WSGI Applications II (Django) <https://pythonhosted.org/snapsearch-client-python/django.html>_
• Integration with Python CGI Scripts <https://pythonhosted.org/snapsearch-client-python/pycgi.html>_

For full documentation on the API and API request parameters see: https://snapsearch.io/documentation

By the way, you need to blacklist non-html resources such as sitemap.xml. This is explained in https://snapsearch.io/documentation#notes

Basic Usage

The below instructions is an abridged version of the Flask_ example. The following python script serves a simple "Hello World" page through any of the public IP address(es) of the runner machine.

.. _Flask: http://flask.pocoo.org/

.. code:: python

from flask import Flask
app = Flask(__name__)

@app.route('/')
def hello_world():
    return "Hello World!\r\n"

if __name__ == '__main__':
    app.run(host="0.0.0.0", port=5000)

To start the application,

.. code-block:: bash

$ pip install Flask
$ pip install snapsearch-client-python
$ python main.py
 * Running on http://0.0.0.0:5000/

To enable SnapSearch-based interception for this application,

1. initialize an Interceptor.

.. code-block:: python

from SnapSearch import Client, Detector, Interceptor
interceptor = Interceptor(Client(api_email, api_key), Detector())

2. deploy the Interceptor.

.. code-block:: python

from SnapSearch.wsgi import InterceptorMiddleware
app.wsgi_app = InterceptorMiddleware(app.wsgi_app, interceptor)

3. putting it all together.

.. code-block:: python

from flask import Flask
app = Flask(__name__)

@app.route('/')
def hello_world():
    return "Hello World!\r\n"

if __name__ == '__main__':
    # API credentials
    api_email = "<email>"  # change this to the registered email
    api_key = "<key>"  # change this to the real api credential

    # initialize the interceptor
    from SnapSearch import Client, Detector, Interceptor
    interceptor = Interceptor(Client(api_email, api_key), Detector())

    # deploy the interceptor
    from SnapSearch.wsgi import InterceptorMiddleware
    app.wsgi_app = InterceptorMiddleware(app.wsgi_app, interceptor)

    # start servicing
    app.run(host="0.0.0.0", port=5000)

Advanced Topics

Customizing the Detector

The ``Detector`` class can take ``ignored_routes`` and ``matched_routes`` as
optional arguments to its constructor and perform interception detection in a
per-route basis. For example, the following ``detector`` will bypass
interception for any access to ``http://<server_name>/ignored.*``, and enforce
interception for any access to ``http://<server_name>/matched.*``.

.. code-block:: python

        from SnapSearch import Detector
        detector = Detector(ignored_routes=["^\/ignored", ],
                            matched_routes=["^\/matched", ])

The ``Detector`` class can take external ``robots.json`` and ``extensions.json``
files as optional arguments to its constructor. Namely,

.. code-block:: python

    from SnapSearch import Detector
    detector = Detector(robots_json="path/to/external/robots.json",
                        extensions_json="path/to/external/extensions.json")

You can also modify the lists of robots and extension through the ``robots``
and ``extensions`` properties of the ``detector`` object. For example,
the following customization will bypass interception for ``Googlebot``.

.. code-block:: python

    from SnapSearch import Detector
    detector = Detector(robots_json="path/to/external/robots.json",
                        extensions_json="path/to/external/extensions.json")
    detector.robots['ignore'].append("Googlebot")


Customizing the ``Client``
~~~~~~~~~~~~~~~~~~~~~~~~~~

The ``Client`` class can take an optional ``dict`` of ``request_parameters``
that contains additional parameters defined in 
https://snapsearch.io/documentation#parameters . Note that the ``url`` parameter
is always overwritten by the ``Interceptor`` with the encoded URL from the
associated ``Detector`` object. It can also take optional ``api_url`` and
``ca_path`` to communicate with an alternative backend service.


Customizing the ``Interceptor``

The Interceptor class can take two optional callback functions, namely before_intercept() and after_intercept().

At the presence of before_intercept(), the Interceptor object will bypass any communication with the backend service of SnapSearch, and return the result of before_intercept() as if it were returned by the associated Client object.

.. code-block:: python

def before_intercept(url):
    ...
    return result

As for after_intercept(), the Interceptor will provide the response from the Client object to after_intercept() which can perform, say, data extraction or logging as appropriate.

.. code-block:: python

def after_intercept(url, response):
    ...
    return None

The return value of after_response() is ignored by the Interceptor and it does not affect the interception process.

Developers' Resources

• Official Documentation of SnapSearch <https://snapsearch.io/documentation>_
• Future Development of the Pythonic Client Package <https://pythonhosted.org/snapsearch-client-python/develop.html>_