13. ugly things.md

Ugly things

This part is for developers who use ZeroNet and ZeroFrame API often. Here I'll talk about some strange things in ZeroFrame API which I know only because I read source code.

dbQuery

? placeholder

From ZeroMe source code:

return Page.cmd("dbQuery", [
    "SELECT * FROM json WHERE ?", {
        directory: directory
    }
], function(subject_rows) {

That is equal to (See note 1):

SELECT * FROM json WHERE
    directory = ${directory}

You can also use multiple key/value pairs, that means:

SELECT * FROM json WHERE
    key1 = ${value1} AND
    key2 = ${value2} AND
    key3 = ${value3}

If you want to make some condition negative, prepend key with not__:

Page.cmd("dbQuery", [
    "SELECT * FROM json WHERE ?", {
        not__json_id: 2,
        file_name: "data.json"
    }
], handler);

SELECT * FROM json WHERE
    json_id != 2 AND
    file_name = "data.json"

You can also use array as value: (See note 2)

Page.cmd("dbQuery", [
    "SELECT * FROM json WHERE ?", {
        not__json_id: [2, 3],
        file_name: ["content.json", "data.json"]
    }
], handler);

SELECT * FROM json WHERE
    json_id NOT IN (2, 3) AND
    file_name IN ("content.json", "data.json")

: placeholder

But what if you want to use some special rules (like A=a and (B=b or C=c)) but still want to use placeholders? Use :!

From ZeroMe source code:

return Page.cmd("dbQuery", ["SELECT * FROM json WHERE site = :site AND directory = :directory LIMIT 1", params], (function(_this) {

Pass parameters as usual (object as second argument) and then use :{key} placeholder to get that value!

User content

Remember this data/users/content.json we often use?

{
    "files": {},
    "ignore": ".*",
    "user_contents": {
        "cert_signers": {
            "zeroid.bit": ["1iD5ZQJMNXu43w1qLB8sfdHVKppVMduGz"]
        },
        "permission_rules": {
            ".*": {
                "files_allowed": "data.json",
                "max_size": 50000
            }
        },
        "permissions": {}
    }
}

Currently only site admin can sign user content (eg. delete posts). And what if we want to add moderators?

...
"permission_rules": {
    ".*": {
        "files_allowed": "data.json",
        "max_size": 50000,
        "signers": ["1Abc"]
    }
},
...

We add signers to permission_rules items! Now, 1Abc can sign all users' content. And if you move signers to a new item, .*bot@.*, 1Abc will be able to sign only ...bot user content.

Notes

Note 1

From Db/DbCursor.py of ZeroNet source code:

def execute(self, query, params=None):
    if isinstance(params, dict) and "?" in query:  # Make easier select and insert by allowing dict params
        if query.startswith("SELECT") or query.startswith("DELETE") or query.startswith("UPDATE"):
            # Convert param dict to SELECT * FROM table WHERE key = ? AND key2 = ? format
            query_wheres = []

Note 2

From Db/DbCursor.py of ZeroNet source code:

if type(value) is list:
    if key.startswith("not__"):
        query_wheres.append(key.replace("not__", "") + " NOT IN (" + ",".join(["?"] * len(value)) + ")")
    else:
        query_wheres.append(key + " IN (" + ",".join(["?"] * len(value)) + ")")