Changes between Version 99 and Version 117 of Help/Concepts/Object
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Help/Concepts/Object
v99 v117 1 [[TranslatedPages]] 1 [[TranslatedPages(outdated=Member; Membership; Roles; Child and Parent not explained properly. Any need to split Tags into two parts ?)]] 2 2 3 3 4 = Objects - The basic building blocks of OpenStreetMap data and maps = … … 7 8 [[PageOutline(2-10,Table of Contents)]] 8 9 10 9 11 == Nodes, ways, and relations == #NodesWaysRelations 10 12 11 13 === Tags (also an OSM data primitive) === #Tags 12 14 13 Tags provide meaning to the objects. Without them, any other object would be useless and meaningless. Each of ''three other data primitives'' '''can have multiple tags'''.15 Tags provide meaning to the objects. Without them, any other object would be useless and meaningless. Each of ''three other data primitives'' **can have multiple tags**. 14 16 15 [=#presets Often tags used in combinations; '''usually these combinations can be found] in [wiki:Presets presets]'''. But it may be true that tags you need to use are not in presets and you need to know them first.17 [=#presets Often tags used in combinations; **usually these combinations can be found] in [wikitr:/Presets presets]**. But it may be true that tags you need to use are not in presets and you need to know them first. 16 18 17 19 Simplest example is [osmwiki:Key:drinking_water drinking_water=yes] - it is present globally and can be applied to every object that provides water. Other example is [osmwiki:Key:leaf_cycle leaf_cycle]=* of trees, it will have less coverage globally (as trees do not grow just everywhere). … … 22 24 23 25 === Nodes (also an OSM data primitive) === #Nodes 24 [[ Image(source:trunk/images/data/node.svg,20,bottom,margin-right=15,nolink)]] A **node** is an individual point with a defined position. ''With respective tags'' it can be used to indicate shops, benches, individual trees or points of drinking water.26 [[JOSMImage(data/node,24,bottom,margin-right=15,link=)]] A **node** is an individual point with a defined position. ''With respective tags'' it can be used to indicate shops, benches, individual trees or points of drinking water. 25 27 26 Only nodes have [ [Coordinates]] in the OSM data model. Ways and relations simply refer to nodes.28 Only nodes have [wikitr:/Help/Concepts/Coordinates Coordinates] in the OSM data model. Ways and relations simply refer to nodes. 27 29 28 30 ==== Common nodes ==== … … 30 32 Nodes can be re-used between multiple ways. Multiple ways can refer to a single node (common node). 31 33 32 A practical meaning of this is demonstrated at the [ [Help/Action/Draw#Commonnodes Draw Nodes]] page. The [Help/Action/MergeNodes Merge Nodes] tool can be used to create common nodes.34 A practical meaning of this is demonstrated at the [wikitr:/Help/Action/Draw#Commonnodes Draw Nodes] page. The [wikitr:/Help/Action/MergeNodes Merge Nodes] tool can be used to create common nodes. 33 35 34 36 === Ways (also an OSM data primitive) === #Ways 35 [[ Image(source:trunk/images/data/way.svg,20,middle,margin-right=15,margin-bottom=5,nolink)]] A **way** is a sequence of nodes ([https://en.wikipedia.org/wiki/Polygonal_chain a "polygonal chain" from ordinary geometry]). OSM **way** used to represent linear objects, ''with respective tags'' it can used to describe: a river bank, tree row, kerbs in the streets (among other uses).37 [[JOSMImage(data/way,24,middle,margin-right=15,margin-bottom=5,link=)]] A **way** is a sequence of nodes ([https://en.wikipedia.org/wiki/Polygonal_chain a "polygonal chain" from ordinary geometry]). OSM **way** used to represent linear objects, ''with respective tags'' it can used to describe: a river bank, tree row, kerbs in the streets (among other uses). 36 38 37 39 ==== Direction ==== 40 Since nodes are ordered in OSM; every way in OSM has a direction. This gives us possibility to add tags (details about object) such as [osmwiki:Key:conveying conveying=*] - to specify direction of escalators and moving walkways or [osmwiki:Key:incline incline=*] which can be used toghter with roads and footways. There [osmwiki:Category:Way_Direction_Dependent more examples] and we can't cover them all. 38 41 39 Since nodes are ordered in OSM; every way in OSM have a direction. This gives us possibility to add tags (details about object) such as [osmwiki:Key:conveying conveying=*] - to specify direction of escalators and moving walkways or [osmwiki:Key:incline incline=*] which can be used toghter with roads and footways. There [osmwiki:Category:Way_Direction_Dependent more examples] and we can't cover them all.42 **Note**: Rendering of direction in [wikitr:/Help/MapView MapView] can be set in Preferences under [wikitr:/Help/Preferences/DrawingPreference OSM Data]. 40 43 41 ==== Segment ==== 44 ==== Segment ====#Segment 45 Is **a fragment between two consequent points of the way** ([https://en.wikipedia.org/wiki/Line_segment "line segment" from ordinary geometry]). This is not a part of OSM data model, but users often distinguish because of tools than operate on segment level (rather than on complete way); please, distinguish a segment(s) from complete "way"s. 42 46 43 Is '''a fragment between two consequent points of the way''' ([https://en.wikipedia.org/wiki/Line_segment "line segment" from ordinary geometry]). This is not a part of OSM data model, but users often distinguish because of tools than operate on segment level (rather than on complete way); please, distinguish a segment(s) from complete "way"s.47 **Note**: Rendering of segments in [wikitr:/Help/MapView MapView] can be set in Preferences under [wikitr:/Help/Preferences/DrawingPreference OSM Data]. 44 48 45 ==== Areas ==== # ClosedWays46 [[ Image(source:trunk/images/data/closedway.svg,20,middle,margin-right=15,margin-bottom=5,nolink)]] If a **way** is closed, i.e. if the last node is the same as the first node, it is also called an **area**. Old term for this is ''Closed Ways'' (it is still present at wiki, used in software and by some mappers; other part uses "geometry" when talking just about shape of the objects, without tags).49 ==== Areas ==== #Areas 50 [[JOSMImage(data/closedway,24,middle,margin-right=15,margin-bottom=5,link=)]] If a **way** is closed, i.e. if the last node is the same as the first node, it is also called an **area**. Old term for this is ''Closed Ways'' (it is still present at wiki, used in software and by some mappers; other part uses "geometry" when talking just about shape of the objects, without tags). 47 51 48 Sometimes single area is not enough to represent an object (for example, a lake with an island in it), then you have to use a [wiki :Help/Concepts/Object#typemultipolygon multi-polygon]52 Sometimes single area is not enough to represent an object (for example, a lake with an island in it), then you have to use a [wikitr:/Help/Concepts/Object#typemultipolygon multi-polygon] 49 53 50 54 === Relations (also an OSM data primitive) === #Relations 51 55 52 56 ==== In most cases you don't need them ==== 53 54 57 If some object can be represented with single ''node'' or ''way'' and ''multiple tags supported by software'', then there is no need in relations. But there are some rare cases where it is theoretically and practically impossible ''only with nodes, ways and tags'' (ex. turn restrictions, will be covered below). 55 58 56 This means '''you can [#Tags1 skip this big "Relations" section], until you decide to add or edit a relation'''.59 This means **you can [#Tags1 skip this big "Relations" section], until you decide to add or edit a relation**. 57 60 58 ==== Simple explanation ==== 59 [[ Image(source:trunk/images/data/relation.png,20,middle,margin-right=15,margin-bottom=5,nolink)]] A **relation**:61 ==== Simple explanation ====#SimpleExplanation 62 [[JOSMImage(data/relation,24,middle,margin-right=15,margin-bottom=5,link=)]] A **relation**: 60 63 * is a sequence of other objects (nodes, ways and relations) 61 64 * as other objects (node, way) - every relation can have their own "tags" … … 65 68 Additionally, each object participating in a **relation** can be assigned a **role**, for instance "via" node and "from", "to" ways in type=restriction relation. 66 69 67 [wiki :Help/Relations Help/Relations] covers the most basic tools to create relations in JOSM ([wiki:Help/Dialog/RelationList Relations window], [wiki:Help/Dialog/SelectionList Selection], [wiki:Help/Dialog/RelationEditor Relation editor])70 [wikitr:/Help/Relations Relation Help] covers the most basic tools to create relations in JOSM ([wikitr:/Help/Dialog/RelationList Relations window], [wikitr:/Help/Dialog/SelectionList Selection], [wikitr:/Help/Dialog/RelationEditor Relation editor]). 68 71 69 72 ==== Most popular types ==== 70 73 71 ===== type=multipolygon ===== 74 ===== type=multipolygon =====#typemultipolygon 72 75 73 76 A water object ({{{natural=water}}}), a building ({{{building=*}}}) or administrative boundary ({{{admin_level=*}}} tag) usually consist of the multiple spatially separated parts belonging to the one object. More importantly, each of these parts can have exclusions ([https://en.wikipedia.org/wiki/Enclave_and_exclave enclaves/exclave] or simply islands or swamps in the water basins). … … 80 83 81 84 Multi-polygon specific tools: 82 * [wiki :Help/Action/CreateMultipolygon create a multipolygon]83 * [wiki :Help/Action/UpdateMultipolygon update existing multipolygon]85 * [wikitr:/Help/Action/CreateMultipolygon create a multipolygon] 86 * [wikitr:/Help/Action/UpdateMultipolygon update existing multipolygon] 84 87 85 88 ===== type=route ===== 86 89 87 Used to describe bus routes and train routes along other transportation services. 88 (stub) 90 [osmwiki:Relation:route Route-Relation] describe common routes for all kind of transport modes and transportation services like [osmwiki:Tag:route=road roads], [osmwiki:Tag:route=bicycle bicycle], [osmwiki:Tag:route=hiking hiking], [osmwiki:Public_transport public_transport] or even electric [osmwiki:Tag:route=power power lines] 89 91 90 92 ===== type=restriction ===== … … 92 94 Can be used to describe turn restrictions according to signs and road marking. JOSM has a plugin to support this type of relations: [osmwiki:JOSM/Plugins/Turnrestrictions Turnrestrictions plugin],[osmwiki:Relation:restriction#Examples Examples] 93 95 94 == Tags == 96 97 == Tags ==#Tags1 95 98 More precisely, a **tag** is a name/value pair assigned to an object. If we write `foo`=`bar` we mean ''The tag with key foo is assigned the value bar''. Here are some examples: 96 99 * `name`=`Main road` assigned to a way. This tag indicates that the name of the way is `Main road`. … … 112 115 Assigned to a way, this set of **tags** indicate, that the way represents a road in a residential area with name ''Main road'' (the German name be ''Hauptstraße'', the English name, which in this example equals to name, is ''Main road''). Speed is limited to 30km/h and heavy goods vehicles (hgv) are not allowed. Furthermore, it's a one way street. 113 116 114 In the [[Image(source:trunk/images/dialogs/propertiesdialog.svg,18,middle)]] [Dialog/TagsMembership Tags/Membership window] you can assign tags to an object, remove tags from an object, or edit assigned tags. 117 In the [[JOSMImage(dialogs/propertiesdialog)]] [wikitr:/Help/Dialog/TagsMembership Tags/Membership panel] you can assign tags to an object, remove tags from an object, or edit assigned tags. 118 115 119 116 120 == Technical properties == 117 121 118 === Object id s ===122 === Object id ===#ObjectId 119 123 The OSM server assigns each object a unique number, the **object ID** or **OSM ID**. 120 124 121 125 In JOSM, a new object doesn't have an ID (its ID is 0) until it is uploaded the first time to the OSM server. 122 * Under **''[[ Image(source:trunk/images/preference.png,20,middle)]] [Action/Preferences Preferences] (F12) -> [[Image(source:trunk/images/preferences/display.png,20,middle)]] [Preferences/Display Display Settings] -> Look and Feel''** it is possible to en- or disable the display of objects ids in the windows.123 * With **''File -> [[ Image(source:trunk/images/downloadprimitive.png,20,bottom)]] [Action/DownloadObject Download object ...]''** it is possible to download **objects** by Ids.126 * Under **''[[JOSMImage(preference)]] [wikitr:/Help/Action/Preferences Preferences]''** (or **''`F12`''**) -> [[JOSMImage(preferences/display,24,link=,middle)]] **''[wikitr:/Help/Preferences/Display Display]''** it is possible to en- or disable the display of objects ids in the windows. 127 * With **''File -> [[JOSMImage(downloadprimitive)]] [wikitr:/Help/Action/DownloadObject Download object ...]''** it is possible to download **objects** by Ids. 124 128 125 === Object versions and history === 129 **Note**: The display of object ids in the [wikitr:/Help/Dialog/SelectionList Selection List] can be set in Preferences under **''[wikitr:/Help/Preferences/Display Display]''**. 126 130 131 132 === Object versions and history ===#Objectversionsandhistory 127 133 Version numbers (versions) were introduced to simplify wiki-style editing. Unfortunately, to track changes to ways/relations you need to use more complex tools than simple comparison by version number. 128 134 … … 133 139 Also, you can use time sliced data (region extracts by date) to inspect how objects were changing (and refer to object id and point in time from the database). 134 140 141 **Note**: The display of object versions in the [wikitr:/Help/Dialog/SelectionList Selection List] can be set in Preferences under [wikitr:/Help/Preferences/Display Display]. 142 135 143 ==== Information about latest version ==== 136 * **''View -> [[ Image(source:trunk/images/info.png,18,bottom)]] [Action/InfoAboutElements Advanced info]''**opens separated windows with informations about selected objects in text format.137 * **''View -> [[ Image(source:trunk/images/info.png,18,bottom)]] [Action/InfoAboutElementsWeb Advanced info (web)]''** opens the **objects'pages** of selected objects on the [osmwww: OSM website] in your web browser.144 * **''View -> [[JOSMImage(info)]] [wikitr:/Help/Action/InfoAboutElements Advanced info]''** (or Keyboard shortcut:**''`Ctrl+I`''**) opens separated windows with informations about selected objects in text format. 145 * **''View -> [[JOSMImage(info)]] [wikitr:/Help/Action/InfoAboutElementsWeb Advanced info (web)]''** (or Keyboard shortcut:**''`Ctrl+Shift+I`''**) opens the **objects pages** of selected objects on the [osmwww: OSM website] in your web browser. 138 146 139 147 Alternatively, you can browse the objects directly by entering following address in your web browser: … … 143 151 }}} 144 152 145 ==== History of the object ==== 146 153 ==== History of the object ====#ObjectHistory 147 154 Each object has a **version**. The **version** is incremented whenever the object is uploaded to the server and the OSM server not only stores the most recent version of an object, but its complete **history**. 148 155 149 * **''View -> [[ Image(source:trunk/images/dialogs/history.png,18,bottom)]] [Action/ObjectHistory History]''**opens the History Browser. The History Browser will show you the **versions** of a particular object.150 * Alternatively, **''View -> [[ Image(source:trunk/images/dialogs/history.png,18,bottom)]] [Action/ObjectHistoryWeb History (web)]''**opens a page on the [osmwww: OSM website] in your web browser which displays the object history, too.156 * **''View -> [[JOSMImage(dialogs/history)]] [wikitr:/Help/Action/ObjectHistory History]''** (or Keyboard shortcut:**''`Ctrl+H`''**) opens the History Browser. The History Browser will show you the **versions** of a particular object. 157 * Alternatively, **''View -> [[JOSMImage(dialogs/history)]] [wikitr:/Help/Action/ObjectHistoryWeb History (web)]''** (or Keyboard shortcut:**''`Ctrl+Shift+H`''**) opens a page on the [osmwww: OSM website] in your web browser which displays the object history, too. 151 158 152 159 ---- 153 Back to [wiki :/Help Main Help]160 Back to [wikitr:/Help Main Help]
