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50 lines
2.2 KiB
Plaintext
50 lines
2.2 KiB
Plaintext
{
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"name": "display_expression",
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"type": "function",
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"groups": ["Record and Attributes"],
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"description": "Returns the display expression for a given feature in a layer. The expression is evaluated by default. Can be used with zero, one or more arguments, see below for details.",
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"variants": [{
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"variant": "No parameters",
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"variant_description": "If called with no parameters, the function will evaluate the display expression of the current feature in the current layer.",
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"arguments": [],
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"examples": [{
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"expression": "display_expression()",
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"returns": "The display expression of the current feature in the current layer."
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}]
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}, {
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"variant": "One 'feature' parameter",
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"variant_description": "If called with a 'feature' parameter only, the function will evaluate the specified feature from the current layer.",
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"arguments": [{
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"arg": "feature",
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"description": "The feature which should be evaluated."
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}],
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"examples": [{
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"expression": "display_expression(@atlas_feature)",
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"returns": "The display expression of the current atlas feature."
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}]
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}, {
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"variant": "Layer and feature parameters",
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"variant_description": "If the function is called with both a layer and a feature, it will evaluate the specified feature from the specified layer.",
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"arguments": [{
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"arg": "layer",
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"description": "The layer (or its ID or name)"
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}, {
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"arg": "feature",
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"description": "The feature which should be evaluated."
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}, {
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"arg": "evaluate",
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"description": "If the expression must be evaluated. If false, the expression will be returned as a string literal only (which could potentially be later evaluated using the 'eval' function).",
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"optional": true,
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"default": "true"
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}],
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"examples": [{
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"expression": "display_expression( 'streets', get_feature_by_id('streets', 1))",
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"returns": "The display expression of the feature with the ID 1 on the layer 'streets'."
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}, {
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"expression": "display_expression('a_layer_id', $currentfeature, 'False')",
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"returns": "The display expression of the given feature not evaluated."
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}]
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}],
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"tags": ["evaluated", "arguments", "details", "display", "default"]
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}
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