How to edit a json dictionary in Robot Framework - json

Question

I am currently implementing some test automation that uses a json POST to a REST API to initialize the test data in the SUT. Most of the fields I don't have an issue editing using information I found in another thread: Json handling in ROBOT
However, one of the sets of information I am editing is a dictionary of meta data.
{
"title": "Test Auotmation Post 2018-03-06T16:12:02Z",
"content": "dummy text",
"excerpt": "Post made by automation for testing purposes.",
"name": "QA User",
"status": "publish",
"date": "2018-03-06T16:12:02Z",
"primary_section": "Entertainment",
"taxonomy": {
"section": [
"Entertainment"
]
},
"coauthors": [
{
"name": "QA User - CoAuthor",
"meta": {
"Title": "QA Engineer",
"Organization": "That One Place"
}
}
],
"post_meta": [
{
"key": "credit",
"value": "QA Engineer"
},
{
"key": "pub_date",
"value": "2018-03-06T16:12:02Z"
},
{
"key": "last_update",
"value": "2018-03-06T16:12:02Z"
},
{
"key": "source",
"value": "wordpress"
}
]
}
Is it possible to use the Set to Dictionary Keyword on a dictionary inside a dictionary? I would like to be able to edit the value of the pub_date and last_update inside of post_meta, specifically.

Answer 1

The most straightforward way would be to use the Evaluate keyword, and set the sub-dict value in it. Presuming you are working with a dictionary that's called ${value}:
Evaluate $value['post_meta'][1]['pub_date'] = 'your new value here'
I won't get into how to find the index of the post_meta list that has the 'key' with value 'pub_date', as that's not part of your question.

Answer 2

Is it possible to use the Set to Dictionary Keyword on a dictionary inside a dictionary?
Yes, it's possible.
However, because post_meta is a list rather than a dictionary, you will have to write some code to iterate over all of the values of post_meta until you find one with the key you want to update.
You could do this in python quite simply. You could also write a keyword in robot to do that for you. Here's an example:
*** Keywords ***
Set list element by key
[Arguments] ${data} ${target_key} ${new_value}
:FOR ${item} IN #{data}
\ run keyword if '''${item['key']}''' == '''${target_key}'''
\ ... set to dictionary ${item} value=${new_value}
[return] ${data}
Assuming you have a variable named ${data} contains the original JSON data as a string, you could call this keyword like the following:
${JSON}= evaluate json.loads('''${data}''') json
set list element by key ${JSON['post_meta']} pub_date yesterday
set list element by key ${JSON['post_meta']} last_update today
You will then have a python object in ${JSON} with the modified values.