|
| 1 | +# Migrating |
| 2 | + |
| 3 | +Many core APIs changed betwen v0.2.21 and v1.0.0. This document describes how |
| 4 | +to upgrade your application or library to use the new APIs when upgrading to |
| 5 | +dbus 1.0.0. |
| 6 | + |
| 7 | + |
| 8 | +## Clients |
| 9 | + |
| 10 | +Migrating node applications and libraries that use this module as a DBus client. |
| 11 | + |
| 12 | +### Getting a bus |
| 13 | + |
| 14 | +In version 1.0.0, you no longer need to instantiate an instance of DBus in |
| 15 | +order to get a Bus instance. |
| 16 | + |
| 17 | +v0.2.21: |
| 18 | + |
| 19 | +``` |
| 20 | +// v0.2.21 |
| 21 | +var DBus = require('dbus'); |
| 22 | +var dbus = new DBus(); |
| 23 | +var bus = dbus.getBus('session'); |
| 24 | +``` |
| 25 | + |
| 26 | +v1.0.0: |
| 27 | + |
| 28 | +``` |
| 29 | +// v1.0.0 |
| 30 | +var DBus = require('dbus'); |
| 31 | +var bus = DBus.getBus('session'); |
| 32 | +``` |
| 33 | + |
| 34 | +### Calling a method |
| 35 | + |
| 36 | +In version 1.0.0, calling a method on a DBus service uses a common node |
| 37 | +callback pattern where the first parameter is an error and the second is the |
| 38 | +result. |
| 39 | + |
| 40 | +v0.2.21: |
| 41 | + |
| 42 | +``` |
| 43 | +// v0.2.21 |
| 44 | +interface.Add.timeout = 1000; |
| 45 | +interface.Add.error = function(err) { |
| 46 | + // handle error |
| 47 | +}; |
| 48 | +interface.Add.finish = function(result) { |
| 49 | + assert(result === 3); |
| 50 | +}; |
| 51 | +interface.Add(1, 2); |
| 52 | +``` |
| 53 | + |
| 54 | +v1.0.0: |
| 55 | + |
| 56 | +``` |
| 57 | +// v1.0.0 |
| 58 | +interface.Add(1, 2, { timeout: 1000 }, function(err, result) { |
| 59 | + if (err) { |
| 60 | + // handle error |
| 61 | + } |
| 62 | +
|
| 63 | + assert(result === 3); |
| 64 | +}); |
| 65 | +``` |
| 66 | + |
| 67 | +Timeout may be omitted if it is not needed. |
| 68 | + |
| 69 | +``` |
| 70 | +// v1.0.0 |
| 71 | +interface.Add(1, 2, function(err, result) { |
| 72 | + if (err) { |
| 73 | + // handle error |
| 74 | + } |
| 75 | +
|
| 76 | + assert(result === 3); |
| 77 | +}); |
| 78 | +``` |
| 79 | + |
| 80 | + |
| 81 | +## Services |
| 82 | + |
| 83 | +Migrating node applications and libraries that use this module to create DBus |
| 84 | +services. |
| 85 | + |
| 86 | +### Creating a service |
| 87 | + |
| 88 | +In version 1.0.0, you no longer need to instantiate an instance of DBus in |
| 89 | +order to get a Service instance. |
| 90 | + |
| 91 | +v0.2.21: |
| 92 | + |
| 93 | +``` |
| 94 | +// v0.2.21 |
| 95 | +var DBus = require('dbus'); |
| 96 | +var dbus = new DBus(); |
| 97 | +var service = dbus.registerService('session', 'test.dbus.TestService'); |
| 98 | +``` |
| 99 | + |
| 100 | +v1.0.0: |
| 101 | + |
| 102 | +``` |
| 103 | +// v1.0.0 |
| 104 | +var DBus = require('dbus'); |
| 105 | +var service = DBus.registerService('session', 'test.dbus.TestService'); |
| 106 | +``` |
| 107 | + |
| 108 | +### Responding to a method |
| 109 | + |
| 110 | +In v1.0.0, methods use a more typical node callback pattern where an error is |
| 111 | +the first parameter and a result is the second parameter. |
| 112 | + |
| 113 | +v0.2.21: |
| 114 | + |
| 115 | +``` |
| 116 | +// v0.2.21 |
| 117 | +service.addMethod('MyMethod', { out: DBus.Define(Number) }, function(callback) { |
| 118 | + callback(3); |
| 119 | +}); |
| 120 | +``` |
| 121 | + |
| 122 | +v1.0.0: |
| 123 | + |
| 124 | +``` |
| 125 | +// v1.0.0 |
| 126 | +service.addMethod('MyMethod', { out: DBus.Define(Number) }, function(callback) { |
| 127 | + callback(null, 3); // return the result as the second parameter |
| 128 | +}); |
| 129 | +``` |
| 130 | + |
| 131 | +### Throwing an error from a method |
| 132 | + |
| 133 | +In v1.0.0, errors can include both the DBus name and a message. Previously, |
| 134 | +they could only include the DBus name. |
| 135 | + |
| 136 | +v0.2.21: |
| 137 | + |
| 138 | +``` |
| 139 | +// v0.2.21 |
| 140 | +service.addMethod('MyMethod', { out: DBus.Define(Number) }, function(callback) { |
| 141 | + callback(new Error('test.dbus.TestService.Error'); |
| 142 | +}); |
| 143 | +``` |
| 144 | + |
| 145 | +v1.0.0: |
| 146 | + |
| 147 | +``` |
| 148 | +// v1.0.0 |
| 149 | +service.addMethod('MyMethod', { out: DBus.Define(Number) }, function(callback) { |
| 150 | + callback(new DBus.Error('test.dbus.TestService.Error', 'Human-readable error message')); |
| 151 | +}); |
| 152 | +``` |
| 153 | + |
| 154 | +Using a standard error is still possible, and defaults to |
| 155 | +[DBUS_ERROR_FAILED][dbuserror]. |
| 156 | + |
| 157 | +``` |
| 158 | +// v1.0.0 |
| 159 | +service.addMethod('MyMethod', { out: DBus.Define(Number) }, function(callback) { |
| 160 | + // Error name defaults to the generic 'org.freedesktop.DBus.Error.Failed' |
| 161 | + callback(new Error('Human-readable error message')); |
| 162 | +}); |
| 163 | +``` |
| 164 | + |
| 165 | +### Responding to a property |
| 166 | + |
| 167 | +In v1.0.0, properties use a more typical node callback pattern where an error |
| 168 | +is the first parameter and a result is the second parameter. |
| 169 | + |
| 170 | +v0.2.21: |
| 171 | + |
| 172 | +``` |
| 173 | +// v0.2.21 |
| 174 | +service.addProperty('MyProperty', { |
| 175 | + type: DBus.Define(Number), |
| 176 | + getter: function(callback) { |
| 177 | + callback(3); |
| 178 | + } |
| 179 | +}); |
| 180 | +``` |
| 181 | + |
| 182 | +v1.0.0: |
| 183 | + |
| 184 | +``` |
| 185 | +// v1.0.0 |
| 186 | +service.addProperty('MyProperty', { |
| 187 | + type: DBus.Define(Number), |
| 188 | + getter: function(callback) { |
| 189 | + callback(null, 3); // Return the result as the second parameter. |
| 190 | + } |
| 191 | +}); |
| 192 | +``` |
| 193 | + |
| 194 | +### Throwing an error from a property |
| 195 | + |
| 196 | +In v1.0.0, errors can include both the DBus name and a message. Previously, |
| 197 | +they could only include the DBus name. |
| 198 | + |
| 199 | +v0.2.21: |
| 200 | + |
| 201 | +``` |
| 202 | +// v0.2.21 |
| 203 | +service.addProperty('MyProperty', { |
| 204 | + type: DBus.Define(Number), |
| 205 | + getter: function(callback) { |
| 206 | + callback(new Error('test.dbus.TestService.Error'); |
| 207 | + } |
| 208 | +}); |
| 209 | +``` |
| 210 | + |
| 211 | +v1.0.0: |
| 212 | + |
| 213 | +``` |
| 214 | +// v1.0.0 |
| 215 | +service.addProperty('MyProperty', { |
| 216 | + type: DBus.Define(Number), |
| 217 | + getter: function(callback) { |
| 218 | + callback(new DBus.Error('test.dbus.TestService.Error', 'Human-readable error message')); |
| 219 | + } |
| 220 | +}); |
| 221 | +``` |
| 222 | + |
| 223 | +Using a standard error is still possible, and defaults to |
| 224 | +[DBUS_ERROR_FAILED][dbuserror]. |
| 225 | + |
| 226 | +``` |
| 227 | +// v1.0.0 |
| 228 | +service.addProperty('MyProperty', { |
| 229 | + type: DBus.Define(Number), |
| 230 | + getter: function(callback) { |
| 231 | + // Error name defaults to the generic 'org.freedesktop.DBus.Error.Failed' |
| 232 | + callback(new Error('Human-readable error message')); |
| 233 | + } |
| 234 | +}); |
| 235 | +``` |
| 236 | + |
| 237 | +[dbuserror]: https://dbus.freedesktop.org/doc/api/html/group__DBusProtocol.html#gabb62fd6340d0787fbd56ff8dd2f326c7 |
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