{"result":{"depiction_url":null,"edges":{"subject":{"objects":[{"created":"2026-09-30T09:11:22Z","object_id":{"id":2555,"is_a":["categorization","keyword","keyword_information_type"],"name":"zotonic_topic_reference","title":"Reference","uri":"https:\/\/zotonic.com\/id\/2555"},"seq":1},{"created":"2026-09-30T09:11:22Z","object_id":{"id":2563,"is_a":["categorization","keyword","keyword_audience"],"name":"zotonic_topic_frontend_developer","title":"Frontend developer","uri":"https:\/\/zotonic.com\/id\/2563"},"seq":2},{"created":"2026-09-30T09:11:22Z","object_id":{"id":2655,"is_a":["categorization","keyword","keyword_task"],"name":"zotonic_topic_publish_and_subscribe","title":"Publish and subscribe","uri":"https:\/\/zotonic.com\/id\/2655"},"seq":3},{"created":"2026-09-30T09:11:22Z","object_id":{"id":2673,"is_a":["categorization","keyword","keyword_technology"],"name":"zotonic_topic_javascript","title":"JavaScript","uri":"https:\/\/zotonic.com\/id\/2673"},"seq":4},{"created":"2026-09-30T09:11:22Z","object_id":{"id":2677,"is_a":["categorization","keyword","keyword_technology"],"name":"zotonic_topic_mqtt","title":"MQTT","uri":"https:\/\/zotonic.com\/id\/2677"},"seq":5},{"created":"2026-09-30T09:11:22Z","object_id":{"id":2718,"is_a":["categorization","keyword","keyword_technology"],"name":"zotonic_topic_cotonic","title":"Cotonic","uri":"https:\/\/zotonic.com\/id\/2718"},"seq":6}],"predicate":{"id":308,"is_a":["meta","predicate"],"name":"subject","title":{"_type":"trans","tr":{"en":"Keyword"}},"uri":"http:\/\/purl.org\/dc\/elements\/1.1\/subject"}}},"id":2728,"is_a":["text","documentation","reference","cotonic_reference"],"links":[{"rel":"self","target":"https:\/\/zotonic.com\/.zotonic\/websub\/topic\/2728"},{"rel":"hub","target":"https:\/\/zotonic.com\/.zotonic\/websub"}],"medium":null,"medium_url":null,"name":"doc_cotonic_cotonic_mqtt","page_url":{"en":"https:\/\/zotonic.com\/cotonic\/cotonic_mqtt","x-default":"https:\/\/zotonic.com\/cotonic\/cotonic_mqtt"},"preview_url":null,"resource":{"version":16,"pivot_location_lat":null,"title":"cotonic.mqtt","is_authoritative":true,"body":"<\/a>\n

\n The mqtt module provides functions to work with mqtt topics. The broker<\/a>\n uses this module as the basis to provide its functionality. This module also has some utility functions\n to easily extract information from topics.\n <\/p>\n\n \n\n \n <\/a>

matches cotonic.mqtt.matches(pattern, topic)<\/code><\/h2>

\n Returns true<\/tt> when the pattern matches the topic, false<\/tt> otherwise.\n <\/p>\n 

\ncotonic.mqtt.matches("truck\/+\/speed", "truck\/01\/speed");\n=> true\ncotonic.mqtt.matches("boat\/+\/speed", "truck\/01\/speed");\n=> false\ncotonic.mqtt.matches("+\/+\/speed", "plane\/01\/speed");\n=> true\ncotonic.mqtt.matches("+\/+\/speed", "plane\/01\/height");\n=> false<\/pre>\n\n            \n            <\/a>
fill cotonic.mqtt.fill(pattern, params)<\/code><\/h2>
\n            Fill can use a pattern<\/tt> topic, and use the param<\/tt> object to create\n            an mqtt topic. Returns a string with the created topic.\n            <\/p>\n            
\ncotonic.mqtt.fill("truck\/+truck_id\/speed", {truck_id: 100});\n=> "truck\/100\/speed"<\/pre>\n\n            \n            <\/a>
extract cotonic.mqtt.extract(pattern, topic)<\/code><\/h2>
\n            Extract values from topic<\/tt> into an object. The pattern +<key><\/tt> matches\n            a single level of the topic path. It places an attribute key<\/tt> with as value the\n            found element in the path in the returned object. The pattern #<key><\/tt>\n            matches a multi level path. When it is matched it places that part of the path into a list.\n            Returns an object with the found elements.\n            <\/p>\n            
\ncotonic.mqtt.extract("truck\/+truck_id\/speed", "truck\/01\/speed");\n=> {truck_id: "01"}\ncotonic.mqtt.extract("truck\/+truck_id\/#params", "truck\/01\/speed");\n=> {truck_id: "01", params: ["speed"]}<\/pre>\n\n            \n            <\/a>
exec cotonic.mqtt.exec(pattern, topic)<\/code><\/h2>
\n            When the pattern<\/tt> matches<\/a> the topic<\/tt>,\n            extract<\/a> the values from the topic. Returns the\n            extracted values when the pattern matches, null<\/tt> otherwise.<\/p>\n            
\ncotonic.mqtt.exec("truck\/+truck_id\/speed", "truck\/01\/speed");\n=> {truck_id: "01"}\ncotonic.mqtt.exec("boat\/+truck_id\/speed", "truck\/01\/speed");\n=> null<\/pre>\n\n            \n            <\/a>
remove_named_wildcards cotonic.mqtt.remove_named_wildcards(pattern)<\/code><\/h2>
\n            Remove the special, and non mqtt compliant, wildcards from the pattern and return a compliant\n            topic.\n            <\/p>\n            
\ncotonic.mqtt.remove_named_wildcards("truck\/+truck_id\/speed");\n=> "truck\/+\/speed"\ncotonic.mqtt.remove_named_wildcards("truck\/#truck_info");\n=> "truck\/#"<\/pre>\n\n            \n            ","slug":"cotonic.mqtt","is_protected":false,"visible_for":0,"tz":"UTC","language":["en"],"doc_source_hash":"5bbc01944a043722ed0c1c86abfeba6645dba9a24e72754821abcaf0bc0373b3","is_featured":false,"content_group_id":{"id":2551,"is_a":["meta","content_group"],"name":"content_group_imported_docs","title":"Imported documentation","uri":"https:\/\/zotonic.com\/id\/content_group_imported_docs"},"category_id":{"id":2722,"is_a":["meta","category"],"name":"cotonic_reference","title":"Cotonic","uri":"https:\/\/zotonic.com\/id\/cotonic_reference"},"doc_source_path":"index.html","publication_start":"2026-09-30T09:11:22Z","page_path":"\/cotonic\/cotonic_mqtt","github_url":"https:\/\/github.com\/cotonic\/cotonic\/blob\/master\/index.html","pivot_location_lng":null,"doc_source_kind":"cotonic","name":"doc_cotonic_cotonic_mqtt","is_unfindable":false,"is_published":true,"pivot_geocode":null,"created":"2026-09-30T09:11:22Z","uri":null,"doc_source_anchor":"cotonic.mqtt","doc_status":"current","is_dependent":false,"publication_end":"9999-06-01T00:00:00Z","modifier_id":{"id":1,"is_a":["person"],"name":"administrator","title":"Site Administrator","uri":"https:\/\/zotonic.com\/id\/1"},"privacy":0,"doc_source_commit":"f88cc928b997d10f7f19e6bd0ede80e1c8c619bc","creator_id":{"id":1,"is_a":["person"],"name":"administrator","title":"Site Administrator","uri":"https:\/\/zotonic.com\/id\/1"},"modified":"2026-09-30T10:06:59Z","title_slug":"cotonic.mqtt"},"uri":"https:\/\/zotonic.com\/id\/2728","uri_template":"https:\/\/zotonic.com\/id\/:id","websub":{"hub":"https:\/\/zotonic.com\/.zotonic\/websub","topic":"https:\/\/zotonic.com\/.zotonic\/websub\/topic\/2728"}},"status":"ok"}