Editing Exporting Usage Manual

One of the issues people raised with moving the non-block/function/class specific documentation from Doxygen to this wiki is that people won't have a local copy of the Usage Manual anymore.  To solve this I put together a little script that exports a list of pages on this wiki to the raw source which looks almost exactly the same as the doxygen source.  This script just has to be run a few times a year and then the resulting files committed to gnuradio git (the location of these files within the git repo has yet to be determined). 

To use this script, you will have to download geckodriver and change the line that points to where it is located.  After running it there should be a new directory called "Usage Manual" created in whatever directory you ran the script from, containing a bunch of text files.  

# Download latest version of geckodriver from [https://github.com/mozilla/geckodriver/releases here] and extract it to a known location, then modify the line "driver = webdriver.Firefox(..." below (I've had the best luck with v0.21)
# sudo pip install selenium HTMLParser
# Make sure the two versions match, see [https://firefox-source-docs.mozilla.org/testing/geckodriver/geckodriver/Support.html this table]

Note that this script now also exports the Blocks Docs pages

    from selenium import webdriver
    from selenium.webdriver.common.keys import Keys
    import time
    import HTMLParser 
    import os

    categories = ['Usage Manual', 'Block Docs'] # Categories which to export, should match the names in wiki
    directory_names = ['Usage Manual', 'Block Docs'] # names of directories that are created for each category, and prefix to file names

    # set up web driver
    driver = webdriver.Firefox(executable_path='/home/marc/Downloads/geckodriver')
        
    for i in range(len(categories)):
        # make directory if it doesn't exist
        if not os.path.exists(directory_names[i]): # will be in the same location as this script
            os.makedirs(directory_names[i])

        # Go to the wiki's export page
        driver.get("https://wiki.gnuradio.org/index.php/Special:Export")

        # fill in text box
        text_area = driver.find_element_by_xpath("//*[@name='catname']")
        text_area.send_keys(categories[i])

        # Hit Add button
        submit_button = driver.find_element_by_xpath("//*[@value='Add']")
        submit_button.click() 

        # uncheck "save as file" box
        check_box = driver.find_element_by_xpath("//*[@name='wpDownload']")
        check_box.click()

        # hit Export
        submit_button = driver.find_element_by_xpath("//*[@value='Export']")
        submit_button.click() 

        # get HTML of new page
        raw_html = driver.page_source
        start_index = raw_html.find('<page>')
        cropped_html = raw_html[start_index:]

        while True:
            indx1 = cropped_html.find('<title>')
            indx2 = cropped_html.find('</title>')
            
            # check if we are done
            if (indx2 - indx1) == 0: # happens when it doesnt find a <title>
                break
                
            title = cropped_html[indx1 + 7 : indx2]
            indx3 = cropped_html.find('[[Category:' + categories[i] + ']]') # using this instead of <text> because <text> has different numbers each time
            indx4 = cropped_html.find('</text>')
            body = cropped_html[indx3 + len(categories[i]) + 13 : indx4] # 
            
            # save body to file
            h = HTMLParser.HTMLParser()
            body_text = h.unescape(body) # makes it so stuff like &gt shows up as a greater than sign
            file_name = directory_names[i] + "- " + title + ".txt"
            text_file = open(directory_names[i] + '/' + file_name, "w")
            text_file.write('===' + title + '===\n')
            text_file.write(body_text)
            text_file.close()
            
            # remove the page we just saved
            cropped_html = cropped_html[indx2 + 8:] # doesnt really matter how much you add here, just needs to move on to the next <title>

    driver.quit() # closes window