Object Creation
To create a registry object, first load the brightsign/registry module using the require() method. Then create an instance of the registry class.
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var registryClass = require("@brightsign/registry");
var registry = new registryClass(); |
Registry
Use this interface for registry read/write operations.
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All section and key names are canonicalized to lowercase.
read()
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Promise<String> read(String sectionName, String key) |
Returns the string registry value associated with the specified key. You must also specify the registry section where the key is stored.
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Promise<RegistrySection> read(String sectionName) |
Returns the specified registry section in the following format: RegistrySection.{entry_key}.
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Promise<RegistryObject> read() |
Returns all registry sections in the following format: RegistryObject.{section_name}.{entry_key}.
write()
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Promise<void> write(String sectionName, String key, String value) |
Writes a single registry entry to the specified registry section.
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Promise<void> write(String sectionName, RegistrySection section) |
Writes the specified registry section to the registry. If the registry section does not exist, it will be created; otherwise, the entries will be added or updated in the existing registry section (preexisting registry entries that are not specified in the write operation will be unaffected).
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Promise<void> write(RegistryObject) |
Writes the specified registry sections/entries to the registry. Registry sections and entries that do not exist will be created, and existing entries will be updated (preexisting registry sections/entries that are not specified in the write operation will be unaffected).
The single-entry write() method will not perform well when used to write multiple entries successively. For optimal performance, use the single-section write() method to write multiple entries to a single section and the full-registry method to write to multiple sections.
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Sixty seconds at most after a write to the registry, or before an orderly reboot, the newly written data will be automatically be written out to persistent storage. If for some reason, a set of registry changes must be written immediately, then the flush() method should be called after the last one.
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Important While it is possible to read the entire registry, modfiy the return value, and write it back into the registry, this is not a recommended practice: It may cause race conditions among different parts of the system that are attempting to write to the registry at the same time. |
flush()
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Promise<void> flush() |
Flushes the contents of the registry immediately to persistent storage.
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Tip To delete a registry entry or section, assign it a |
Example
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var registryClass = require("@brightsign/registry");
var registry = new registryClass();
//Reads the entire registry to the log.
registry.read().then(function(registry) {
console.log(JSON.stringify(registry));
});
//Reads the contents of the "networking" registry to the log.
registry.read("networking").then(
function(registry){console.log(JSON.stringify(registry));});
//Writes multiple entries to multiple sections.
registry.write({networking:{ssh:"22", http_server:"8080"}, autorun:{devicesetupcomplete:"1"}} ).then(
function(){console.log("Write Successful");});
//Updates a single section.
registry.write("networking", {ssh:"22", http_server:"8080"}).then(
function(){console.log("Write Successful");});
//Deletes a registry section and entry, and creates a new section.
registry.write({networking:{ssh:"22", http_server:null}, autorun:null, section1:{test:"val"}} ).then(
function(){console.log("Write Successful");}); |