Changes between Version 102 and Version 117 of Help/Concepts/Object


Ignore:
Timestamp:
(multiple changes)
Author:
(multiple changes)
Comment:
(multiple changes)

Legend:

Unmodified
Added
Removed
Modified

  • Help/Concepts/Object

    v102 v117  
    1 [[TranslatedPages(outdated=Member; Membership; Child and Parent not explained properly)]]
    2 [[PageOutline(2-10,Table of Contents)]]
     1[[TranslatedPages(outdated=Member; Membership; Roles; Child and Parent not explained properly. Any need to split Tags into two parts ?)]]
     2
    33
    44= Objects - The basic building blocks of OpenStreetMap data and maps =
    55
    66Please don't hurry reading this, you can consult this page again at any second.
     7
     8[[PageOutline(2-10,Table of Contents)]]
    79
    810
    … …  
    1113=== Tags (also an OSM data primitive) === #Tags
    1214
    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'''.
     15Tags 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**.
    1416
    15 [=#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.
     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.
    1618
    1719Simplest 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).
    … …  
    2224
    2325=== 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.
    2527
    2628Only nodes have [wikitr:/Help/Concepts/Coordinates Coordinates] in the OSM data model. Ways and relations simply refer to nodes.
    … …  
    3335
    3436=== 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).
    3638
    3739==== Direction ====
     40Since 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.
    3841
    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].
    4043
    41 ==== Segment ====
     44==== Segment ====#Segment
     45Is **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.
    4246
    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].
    4448
    45 ==== Areas ==== #ClosedWays
    46 [[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).
    4751
    4852Sometimes 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]
    … …  
    5155
    5256==== In most cases you don't need them ====
    53 
    5457If 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).
    5558
    56 This means '''you can [#Tags1 skip this big "Relations" section], until you decide to add or edit a relation'''.
     59This means **you can [#Tags1 skip this big "Relations" section], until you decide to add or edit a relation**.
    5760
    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**:
    6063* is a sequence of other objects (nodes, ways and relations)
    6164* as other objects (node, way) - every relation can have their own "tags"
    … …  
    6568Additionally, each object participating in a **relation** can be assigned a **role**, for instance "via" node and "from", "to" ways in type=restriction relation.
    6669
    67 [wikitr:/Help/Relations Help/Relations] 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])
     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]).
    6871
    6972==== Most popular types ====
    7073
    71 ===== type=multipolygon =====
     74===== type=multipolygon =====#typemultipolygon
    7275
    7376A 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).
    … …  
    9194Can 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]
    9295
    93 == Tags ==
     96
     97== Tags ==#Tags1
    9498More 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:
    9599* `name`=`Main road` assigned to a way. This tag indicates that the name of the way is `Main road`.
    … …  
    111115Assigned 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.
    112116
    113 In the [[Image(source:trunk/images/dialogs/propertiesdialog.svg,18,middle)]] [wikitr:/Help/Dialog/TagsMembership Tags/Membership window] you can assign tags to an object, remove tags from an object, or edit assigned tags.
     117In 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
    114119
    115120== Technical properties ==
    116121
    117 === Object ids ===
     122=== Object id ===#ObjectId
    118123The OSM server assigns each object a unique number, the **object ID** or **OSM ID**.
    119124
    120125In JOSM, a new object doesn't have an ID (its ID is 0) until it is uploaded the first time to the OSM server.
    121 * Under **''[[Image(source:trunk/images/preference.png,20,middle)]] [Action/Preferences Preferences]''** (or **''`F12`''**) -> [[Image(source:trunk/images/preferences/display.png,20,middle)]] **''[wikitr:/Help/Preferences/Display Display Settings] -> Look and Feel''** it is possible to en- or disable the display of objects ids in the windows.
    122 * With **''File -> [[Image(source:trunk/images/downloadprimitive.png,20,bottom)]] [wikitr:/Help/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.
    123128
    124 === Object versions and history ===#Objectversions
     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]''**.
    125130
     131
     132=== Object versions and history ===#Objectversionsandhistory
    126133Version 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.
    127134
    … …  
    132139Also, 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).
    133140
     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
    134143==== Information about latest version ====
    135 * **''View -> [[Image(source:trunk/images/info.png,18,bottom)]] [wikitr:/Help/Action/InfoAboutElements Advanced info]''** (or Keyboard shortcut:**''`Ctrl+I`''**) opens separated windows with informations about selected objects in text format.
    136 * **''View -> [[Image(source:trunk/images/info.png,18,bottom)]] [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.
     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.
    137146
    138147Alternatively, you can browse the objects directly by entering following address in your web browser:
    … …  
    142151}}}
    143152
    144 ==== History of the object ====
    145 
     153==== History of the object ====#ObjectHistory
    146154Each 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**.
    147155
    148 * **''View -> [[Image(source:trunk/images/dialogs/history.png,18,bottom)]] [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.
    149 * Alternatively, **''View -> [[Image(source:trunk/images/dialogs/history.png,18,bottom)]] [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.
     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.
    150158
    151159----