DH HUAC Code Gist for 4-7-15

4-7 HUAC

//PHP ACTION FORM

//conditional statement to execute block
//Example: if user selects 'witness type'(key) and 'friendly'(value), send query to DocCloud API
//QUESTIONS ON CONDITIONALS IN PHP:
// Knowing that the function: if (condition) {
		// code to be executed if condition is true; 

// if ($x == $y) {
		//will this be read as: if x and y have same key/value pair, return true?

//Do we want a nesting if-statement? Pseudocode Example:

//if   $witness_type is chosen
	       if witness_type chosen == "friendly"
	
	           execute block.. 

<?php
if ($_POST) {
    echo '<pre>';
    echo htmlspecialchars(print_r($_POST, true));
    echo '</pre>';
}
?>
<form action="" method="post">
    Witness Type: <br />
    <select multiple name="witness_type[]">
        <option value="friendly">Friendly</option>
        <option value="unfriendly">Unfriendly</option>
    </select><br />
    <input type="submit" value="submit me!" />
</form>

<?php if (isset($witness_type) && $witness_type=="friendly") echo "checked";?>
value="friendly">Friendly //How to assign variable in PHP to read in JSON?

<input type="dropdown" name="witness_type"
<?php if (isset($witness_type) && $witness_type=="unfriendly") echo "checked";?>
value="unfriendly">Unfriendly //How to assign variable in PHP to read in JSON

//COMMENTS AND QUESTIONS:

//PHP uses objects and arrays. Arrays (lists) are indexed numerically
//Example of list: witness_occupation = [writer, producer, playwright, actor]
//Search will return value based on location in the list (eg, [0] will --> 'writer')
//But is this what we want? Key-value pairs seems a better solution. Can that be done
//simply by creating different values for the same keys (DocumentCloud allows this)
//Example: witness_type --> friendly; witness_type --> unfriendly
//In other words: We need an associative array: user-named keys that we've assigned to them
//*Note: pseudocode above is not parsed in appropriate syntax (json, php); meant only to provide examples


//More examples of tinkering with PHP action form script. QUESTIONS:
//Assigning variables: how to assign two values to a single variable (eg, $witness_type) in
//an associative array? Assigning multiple values to a single variable is more intuitive for lists
//eg: $witness_type = [friendly, unfriendly]
//but this changes how PHP interacts with JSON. In this case, the only way to retrieve all instances 
//of [friendly], for example, is to retrive via numerical index. 
//Should we be using an associative array or a numerical index? If numerical index, is the best JSON format:
//Each document scripted as an object within a larger object (or array?) documents
//Each document contains built-in metadata tags and our metadata tags
//For example, each document coded as $witness_type == friendly or ==unfriendly
//Would the pseudocode then be: [if $witness_type == friendly], return all $witness_type[0]? 

<?php
//assign variables (in PHP or JSON?)
$witness_type == "friendly";

//conditional statement

if ($witness_type == "friendly") {
	echo "SOMETHING";  //(eg, every document with $witness_type == "friendly")

} elseif ($witness_type == "unfriendly") {
	echo "SOMETHING"; //(eg, every document with $witness_type == "unfriendly")

//if want error handling

} else {
	echo "Please try again";
}
?>


//USE CURL TO ISSUE NETWORK REQUEST

//initialize curl session using request URL as a parameter
//use function curl_init to return a session handle

//Several ways to connect API to database
//DocCloud uses REST API
//This was adapted from REST API code

$url =  'http://www.documentcloud.org/api/';
$ch = curl_init($url);

//is this the right format for request url from DocCloud API?
//DocCloud API not reading user-built metadata tags, only built-in metadata tags

    
//SET CURL OPTIONS

//Questions: What curl options do we want? If DocCloud doesn't require an API authentication key,
//do we still need to include authorization in the curl setup? 

//This example tells curl that we don't want the HTTP headers returned, but do want request data returned


curl_setopt($session, CURLOPT_HEADER, false); 
curl_setopt($session, CURLOPT_RETURNTRANSFER, true); 
  
//response is returned by running curl_exec on session handle
//curl_close will close curl after executing the session  
  
$response = curl_exec($session); 
curl_close($session); 

//Another example

curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_HTTPHEADER,
 	array('Content-Type: application/json',
 		'Authorization: token ' . $access_token)
);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$result = curl_exec($ch);
curl_close($ch);


//METHOD CALL: ENCODE PHP INTO JSON STRING
//json_encode: returns JSON representative of a value



//Option #1: return as list

<?php
// Returns: ["friendly", "unfriendly"]
json_encode(array("friendly", "unfriendly"));
?>

//Option #2: return as associative array
//Will two values on the same key work with DocumentCloud? DC says yes, but has not worked for me 

<?php

// Returns: {"witness_type":"friendly","witness_type":"unfriendly"}
json_encode(array("witness_type" => "friendly", "witness_type" => "unfriendly"));
 
?>

//SEARCH THROUGH JSON
//RETURN OBJECTS THAT MATCH SOME KEY AND VALUE IN JSON
//Search function written in JS
//Problem is that the JSON notation for our documents do not contain our created metadata tags
//Started playing with various search functions. Below is example of starting to tweak code

//this will return an array of objects according to key, value, or key and value matching
//Do we just need the code for key/value matching? 

//Set JSON schema. Example below. Working on json schema using parser. 
//Questions on using lists vs arrays
//Including search query taxonomy as word document

var json = '{"witness_type": "friendly", "witness_type": "unfriendly"}'; 
var js = JSON.parse(json);

function getObjects(obj, key, val) {
    var objects = [];
    for (var i in obj) {
        if (!obj.hasOwnProperty(i)) continue;
        if (typeof obj[i] == 'object') {
            objects = objects.concat(getObjects(obj[i], key, val));    
        } else 
        //if key matches and value matches or if key matches and value is not passed (eliminating the case where key matches but passed value does not)
        if (i == key && obj[i] == val || i == key && val == '') { //
            objects.push(obj);
        } else if (obj[i] == val && key == ''){
            //only add if the object is not already in the array
            if (objects.lastIndexOf(obj) == -1){
                objects.push(obj);
            }
        }
    }
    return objects;


//example to retrieve objects that match some key and value in JSON

console.log(getObjects(js,'witness_type','friendly'));

//returns objects where a key named witness_type has the value friendly


//RETURN JSON to PHP: DECODE JSON INTO PHP
//DISPLAY RESULTS

<?php
$json = '{"witness_type":"friendly","witness_type":"unfriendly"}'; //the json string being decoded
var_dump(json_decode($json));
var_dump(
	json_decode($json)
);
?>