I'm trying to set up integration to display quiz answers in a Visualforce page, but I'm having a lot of difficulty deserializing a JSON string (supplied via API call response) into a wrapper class which seems to validate perfectly when I run it through http://jsonlint.com/ or http://json2apexengine.somee.com/ . The JSON string is pretty massive so I'm hoping I can get help without having to supply the whole thing.
Errors I'm getting in particular include:
System.JSONException: Expected CanvasCourseController.event_data but
found [line:1, column:23954]
which I'm interpreting as there's some interruption to the expected json format
System.JSONException: Unexpected character ('f' (code 102)): was
expecting comma to separate OBJECT entries at [line:1, column:537]
which seems to be a result of html formatting in string values
System.JSONException: Illegal unquoted character ((CTRL-CHAR, code
10)): has to be escaped using backslash to be included in string value
at [line:1, column:507]
a line break issue I've resolved using string.replace('\n', ' ');
I created the wrapper class by running the json string through json2apexengine, it's as follows:
public class JsonParser{
public list<quiz_submission_events> quiz_submission_events{get;set;}
public class quiz_submission_events{
public event_data event_data{get;set;}
public String event_type{get;set;}
public String created_at{get;set;}
public String id{get;set;}
}
public class quiz_data{
public String question_type{get;set;}
public String question_name{get;set;}
public String neutral_comments_html{get;set;}
public String name{get;set;}
public String incorrect_comments_html{get;set;}
public String question_text{get;set;}
public String correct_comments_html{get;set;}
public list<answers> answers{get;set;}
public String neutral_comments{get;set;}
public String text_after_answers{get;set;}
public String incorrect_comments{get;set;}
public Integer assessment_question_id{get;set;}
public String correct_comments{get;set;}
public Integer position{get;set;}
public Integer points_possible{get;set;}
public String published_at{get;set;}
public String regrade_option{get;set;}
public Integer id{get;set;}
}
public class event_data{
public list<quiz_data> quiz_data{get;set;}
public Integer quiz_version{get;set;}
}
public class answers{
public String answer_weight{get;set;}
public String match_id{get;set;}
public String answer_text{get;set;}
public String id{get;set;}
public String answer_match_left{get;set;}
public String blank_id{get;set;}
public String answer_match_right{get;set;}
public String numerical_answer_type{get;set;}
public String answer_comment{get;set;}
public String answer_range_end{get;set;}
public String answer_html{get;set;}
public String answer_range_start{get;set;}
public String answer_match_left_html{get;set;}
public String answer_error_margin{get;set;}
public String answer_comment_html{get;set;}
public String answer_exact{get;set;}
}
}
Here's an excerpt of the JSON:
{
"quiz_submission_events": [
{
"id": "4629",
"event_type": "submission_created",
"event_data": {
"quiz_version": 21,
"quiz_data": [
{
"id": 220,
"regrade_option": "",
"points_possible": 0,
"correct_comments": "",
"incorrect_comments": "",
"neutral_comments": "",
"correct_comments_html": "",
"incorrect_comments_html": "",
"neutral_comments_html": "",
"question_type": "text_only_question",
"question_name": "Spacer",
"name": "Spacer",
"question_text": "<p><strong>Read the advertisement below and answer the questions that follow.</strong></p>\n<p> </p>\n<p><em><span style=\"font-size: 14pt;\"><strong>Grand Opening this Saturday 27<sup>th</sup> June!</strong></span></em></p>\n<p><strong>769 Asperity Road, Mt. Falls</strong></p>\n<p><strong>Gates Open 9:00am to 4:00pm</strong></p>\n<p> </p>\n<p><strong><img src=\"/courses/34/files/2325/preview\" alt=\"Koala.png\"><span style=\"font-size: 18pt;\">Salvation Animal Sanctuary</span></strong></p>\n<p><strong> Come to our opening and support the </strong><strong>rescue of native animals.</strong></p>\n<p><strong> Visit our Educational Display Centre, </strong><strong>Souvenir Shop and Café.</strong></p>\n<p><strong> </strong></p>\n<p><strong>The grand opening will have rides for children </strong><strong>and games to play.</strong></p>\n<p><strong> </strong></p>\n<p><strong>As bad weather can cause some of the </strong><strong>animals to be reclusive, the Sanctuary staff will </strong><strong>be at many of the enclosures to bring the animals </strong><strong>closer and answer any questions.</strong></p>\n<p> </p>\n<table style=\"height: 140px;\" width=\"328\"><tbody><tr>\n<td>\n<p><strong>Sanctuary Entry Prices</strong></p>\n<p>Adults $10.00 Children (Under 16) $5.00</p>\nDonations to support the society can be made at the zoo office or by calling 1300 555 </td>\n</tr></tbody></table><p> </p>\n<p> <img src=\"/courses/34/files/2326/preview\" alt=\"Kangaroo.png\"> </p>\n<p><strong>About us </strong>Salvation Animals Sanctuary is the brainchild of David Wright, founder of the Native Animal Rescue Society The self-sustaining Sanctuary was established help support the society in its rescue efforts. The Sanctuary is open to the public every Friday to Tuesday and welcomes all native animals who are in need of care and a home.</p>",
"answers": [
{
"answer_exact": "",
"answer_error_margin": "",
"answer_range_start": "",
"answer_range_end": "",
"answer_weight": "0",
"numerical_answer_type": "exact_answer",
"blank_id": "",
"id": "",
"match_id": "",
"answer_text": "",
"answer_match_left": "",
"answer_match_right": "",
"answer_comment": "",
"answer_html": "",
"answer_match_left_html": "",
"answer_comment_html": ""
},
{
"answer_exact": "",
"answer_error_margin": "",
"answer_range_start": "",
"answer_range_end": "",
"answer_weight": "0",
"numerical_answer_type": "exact_answer",
"blank_id": "",
"id": "",
"match_id": "",
"answer_text": "",
"answer_match_left": "",
"answer_match_right": "",
"answer_comment": "",
"answer_html": "",
"answer_match_left_html": "",
"answer_comment_html": ""
},
{
"answer_exact": "",
"answer_error_margin": "",
"answer_range_start": "",
"answer_range_end": "",
"answer_weight": "0",
"numerical_answer_type": "exact_answer",
"blank_id": "",
"id": "",
"match_id": "",
"answer_text": "",
"answer_match_left": "",
"answer_match_right": "",
"answer_comment": "",
"answer_html": "",
"answer_match_left_html": "",
"answer_comment_html": ""
},
{
"answer_exact": "",
"answer_error_margin": "",
"answer_range_start": "",
"answer_range_end": "",
"answer_weight": "0",
"numerical_answer_type": "exact_answer",
"blank_id": "",
"id": "",
"match_id": "",
"answer_text": "",
"answer_match_left": "",
"answer_match_right": "",
"answer_comment": "",
"answer_html": "",
"answer_match_left_html": "",
"answer_comment_html": ""
}
],
"text_after_answers": "",
"assessment_question_id": 264,
"position": 0,
"published_at": "2015-09-08T00:44:05Z"
},
{
"id": 221,
"regrade_option": "",
"points_possible": 0,
"correct_comments": "",
"incorrect_comments": "",
"neutral_comments": "",
"correct_comments_html": "",
"incorrect_comments_html": "",
"neutral_comments_html": "",
"question_type": "multiple_answers_question",
"question_name": "Question 1",
"name": "Question 1",
"question_text": "blah",
"answers": [
{
"id": "878",
"text": "",
"comments": "",
"comments_html": "",
"weight": 100,
"html": "<p>Cafe</p>"
},
{
"id": "959",
"text": "Office",
"comments": "",
"comments_html": "",
"weight": 100
},
{
"id": "9381",
"text": "Rides",
"comments": "",
"comments_html": "",
"weight": 0
},
{
"id": "812",
"text": "Games",
"comments": "",
"comments_html": "",
"weight": 0
},
{
"id": "3712",
"text": "Souvenir Shop",
"comments": "",
"comments_html": "",
"weight": 100
},
{
"id": "7992",
"text": "Educational Centre",
"comments": "",
"comments_html": "",
"weight": 100
}
],
"text_after_answers": "",
"assessment_question_id": 265,
"position": 1,
"published_at": "2015-09-08T00:44:05Z"
},
{
"id": 224,
"regrade_option": "",
"points_possible": 0,
"correct_comments": "",
"incorrect_comments": "",
"neutral_comments": "",
"correct_comments_html": "",
"incorrect_comments_html": "",
"neutral_comments_html": "",
"question_type": "multiple_choice_question",
"question_name": "Question 2",
"name": "Question 2",
"question_text": "blah",
"answers": [
{
"id": 6044,
"text": "To promote native animal rescue",
"html": "",
"comments": "",
"comments_html": "",
"weight": 0
},
{
"id": 7455,
"text": "To ask for donations for the sanctuary",
"html": "",
"comments": "",
"comments_html": "",
"weight": 0
},
{
"id": 9010,
"text": "To inform the public of the cost of entry",
"html": "",
"comments": "",
"comments_html": "",
"weight": 0
},
{
"id": 9910,
"text": "To advertise the opening of the sanctuary",
"html": "",
"comments": "",
"comments_html": "",
"weight": 100
}
],
"text_after_answers": "",
"assessment_question_id": 268,
"position": 2,
"published_at": "2015-09-08T00:44:05Z"
},
{
"id": 225,
"regrade_option": "",
"points_possible": 0,
"correct_comments": "",
"incorrect_comments": "",
"neutral_comments": "",
"correct_comments_html": "",
"incorrect_comments_html": "",
"neutral_comments_html": "",
"question_type": "multiple_choice_question",
"question_name": "Question 3",
"name": "Question 3",
"question_text": "blah",
"answers": [
{
"id": 1462,
"text": "Withdrawn",
"html": "",
"comments": "",
"comments_html": "",
"weight": 100
},
{
"id": 4914,
"text": "Sociable",
"html": "",
"comments": "",
"comments_html": "",
"weight": 0
},
{
"id": 5670,
"text": "Unfriendly",
"html": "",
"comments": "",
"comments_html": "",
"weight": 0
},
{
"id": 454,
"text": "Drenched",
"html": "",
"comments": "",
"comments_html": "",
"weight": 0
}
],
"text_after_answers": "",
"assessment_question_id": 269,
"position": 3,
"published_at": "2015-09-08T00:44:05Z"
},
{
"id": 226,
"regrade_option": "",
"points_possible": 0,
"correct_comments": "",
"incorrect_comments": "",
"neutral_comments": "",
"correct_comments_html": "",
"incorrect_comments_html": "",
"neutral_comments_html": "",
"question_type": "multiple_choice_question",
"question_name": "Question 4",
"name": "Question 4",
"question_text": "<p>What is the purpose of David Wright’s brainchild?</p>",
"answers": [
{
"id": 6557,
"text": "To support the Native Animal Rescue Zoo",
"html": "",
"comments": "",
"comments_html": "",
"weight": 0
},
{
"id": 1937,
"text": "To support the Native Animal Rescue Society",
"html": "",
"comments": "",
"comments_html": "",
"weight": 100
},
{
"id": 8553,
"text": "To give the rescued animals a permanent home",
"html": "",
"comments": "",
"comments_html": "",
"weight": 0
},
{
"id": 3563,
"text": "To create a self-sustainable tourist attraction for Mt Falls",
"html": "",
"comments": "",
"comments_html": "",
"weight": 0
}
],
"text_after_answers": "",
"assessment_question_id": 270,
"position": 4,
"published_at": "2015-09-08T00:44:05Z"
},
{
"id": 227,
"regrade_option": "",
"points_possible": 0,
"correct_comments": "",
"incorrect_comments": "",
"neutral_comments": "",
"correct_comments_html": "",
"incorrect_comments_html": "",
"neutral_comments_html": "",
"question_type": "text_only_question",
"question_name": "Spacer",
"name": "Spacer",
"question_text": "blah",
"answers": [],
"text_after_answers": "",
"assessment_question_id": null,
"position": 4,
"published_at": "2015-09-08T00:44:05Z"
}
]
},
"created_at": "2015-09-30T01:02:34Z"
},
{
"id": "4630",
"event_type": "session_started",
"event_data": {
"user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36"
},
"created_at": "2015-09-30T01:02:37Z"
},
{
"id": "4631",
"event_type": "question_answered",
"event_data": [
{
"quiz_question_id": "220",
"answer": null
},
{
"quiz_question_id": "221",
"answer": []
},
{
"quiz_question_id": "224",
"answer": null
},
{
"quiz_question_id": "225",
"answer": null
},
{
"quiz_question_id": "226",
"answer": null
},
{
"quiz_question_id": "227",
"answer": null
},
{
"quiz_question_id": "228",
"answer": null
},
{
"quiz_question_id": "229",
"answer": null
},
{
"quiz_question_id": "231",
"answer": null
},
{
"quiz_question_id": "235",
"answer": null
},
{
"quiz_question_id": "236",
"answer": null
},
{
"quiz_question_id": "237",
"answer": null
},
{
"quiz_question_id": "238",
"answer": null
},
{
"quiz_question_id": "239",
"answer": null
},
{
"quiz_question_id": "242",
"answer": null
},
{
"quiz_question_id": "243",
"answer": null
},
{
"quiz_question_id": "245",
"answer": null
},
{
"quiz_question_id": "246",
"answer": null
}
],
"created_at": "2015-09-30T01:02:48Z"
}
]
}
My main questions are:
-
Why is
JSON.deserializespitting the dummy on any of this if the
above sites say it's valid? -
Is there a method or efficient bit of code I can use to remove the
troublesome characters? -
What's causing the
event_dataparsing error?
Any advice appreciated.
Best Answer
Regarding the
event_dataissue: your JSON is inconsistent. In one case it's an object containing theuser_agentstring:And elsewhere it's a list of
quiz_data:This wouldn't be picked up by a JSON linter, because it's just checking that the data is valid - not that it's consistent.
I notice that the parser code generated by JSON2Apex is different from your parser code above, and e.g. creates different classes to handle the different types of
answersandevent_data:This is an attempt to handle the inconsistencies in the JSON. I'm not sure whether it'll actually work in practice, but it's worth trying.
If it doesn't work, you have a few options.
JSON.deserializeUntyped()and check the type of eachevent_dataat runtime, but you'd lose the advantages of typed deserialization.event_dataand parse it appropriately. If you check theCreate explicit parse codebox on JSON2Apex, you can take the parser code as a starting point.